👤 Takafumi Sakai

Although the regenerative capacity of the mammalian brain is quite weak, internal neural stem/progenitor cells (NSPCs) in the brain can provide new neurons into the brain lesions. Leukocytes, particularly T cells, infiltrate injured brain tissue and participate in immune reactions and have a large impact on the progress of the lesion. However, the effect of T cells on the regeneration of brain tissue remains unclear. Trimethyltin (TMT) is an organotin that has selective neurotoxicity on granule neurons in the hippocampal dentate gyrus. TMT-induced hippocampal lesion is mostly regenerated because adjacent NSPCs can provide new granule neurons. In this study, using TMT-injected mice as a model of brain tissue regeneration, the influence of T cells on hippocampal tissue regeneration was investigated. When TMT was injected into nude mice lacking T cells, they exhibited shortened immobility time in the tail suspension test, indicating improved functional outcomes. Immunohistochemical analysis revealed improved granule neuron replenishment and enhanced survival and differentiation of new neurons in nude mice. Microglial reaction characterized by phagocytosis and astrocytic reaction with brain-derived neurotrophic factor (BDNF) expression were enhanced in nude mice. Hippocampal tissue regeneration was impaired when nude mice were repopulated with total lymphocytes or with CD4- or CD8-positive cells. Repopulations of T cells altered microglial reactions; however, changes in astrocytes were not reproduced. These results suggest that both helper and cytotoxic T cells inhibit hippocampal tissue regeneration by preventing neuronal replenishment. T cells also affect lesion clearance by microglia and astrocytic BDNF expression; however, their effect is stronger on microglia. These findings provide novel insights into the immune regulation of brain tissue regeneration. Show less

Diabetes is an increasingly prevalent global disease and is often accompanied by sarcopenia, particularly in older adults. While insulin resistance is a well-known contributor to muscle loss in diabetes, the role of glucose signaling in diabetic skeletal muscle atrophy, particularly under insulin-deficient conditions, remains poorly understood. This study aimed to elucidate the pathophysiological role of the carbohydrate-responsive element-binding protein (ChREBP), a glucose-sensing transcription factor encoded by the Chrebp gene in mice, in diabetic sarcopenia by generating Chrebp-deficient, insulin-deficient Ins2Akita/+ mice. We evaluated Chrebp +/+, Chrebp -/-, Ins2Akita/+ /Chrebp +/+, and Ins2Akita/+ /Chrebp -/- mice for muscle strength, endurance, survival, body composition, and muscle histology. Skeletal muscles were analyzed for gene expressions related to anabolic and catabolic pathways. We found that Ins2Akita/+ /Chrebp -/- mice exhibited significant reductions in body weight, grip strength, survival, and skeletal muscle mass - particularly in the tibialis anterior, soleus, gastrocnemius, and quadriceps - compared to Ins2Akita/+ controls, despite similar hyperglycemia. Histological analysis revealed a smaller mean muscle fiber size and reduced cross-sectional area of type 2A and 2B fibers, without changes in fiber-type composition. Furthermore, Igf-1 expression was suppressed, while the atrophy marker Fbxo32/Atrogin-1 was upregulated. These findings demonstrate that Chrebp deletion exacerbates muscle atrophy and frailty in insulin-deficient mice, underscoring a key role for ChREBP-mediated glucose signaling in maintaining muscle mass under diabetic conditions. The Ins2Akita/+ /Chrebp -/- model provides a valuable platform for exploring diabetic sarcopenia mechanisms and potential therapeutic targets. Show less

Cerebrotendinous xanthomatosis is a rare autosomal recessive lipid storage disorder involving bile acid biosynthesis. Reduced mitochondrial cytochrome P450 enzyme activity leads to abnormal lipid accumulation in various tissues, especially tendons, lenses, and the central and peripheral nervous systems. This condition manifests with systemic symptoms such as neurological disorders, atherosclerosis, tendon xanthomas, and cataracts. Cerebrotendinous xanthomatosis typically presents in individuals with homozygous or compound heterozygous mutations in the CYP27A1 gene because of its autosomal recessive inheritance pattern. However, the phenotypic expression in heterozygous carriers remains uncertain. We report a 53-year-old Japanese man who was clinically diagnosed with familial hypercholesterolemia. He presented with marked Achilles tendon xanthomas and refractory hyper-low-density-lipoprotein cholesterolemia. Initiation of intensified lipid-lowering therapy, including inclisiran, resulted in improvement of hyper-low-density-lipoprotein cholesterolemia. Genetic testing revealed heterozygous mutations in CYP27A1 (p.Arg405Gln) and apolipoprotein B (APOB) (p.Pro955Ser). He had no neurological symptoms, cataracts, or other features suggestive of cerebrotendinous xanthomatosis without Achilles tendon xanthomas. This case highlights a rare presentation of a potential CYP27A1 heterozygous mutation-related phenotype. The APOB (p.Pro955Ser) variant is associated with reduced low-density-lipoprotein receptor activity, contributing to hyper-low-density-lipoprotein cholesterolemia and Achilles tendon xanthomas. However, this patient's Achilles tendon xanthoma was thicker than those reported in previous cases with APOB (p.Pro955Ser) gene mutations, suggesting a potential contribution from the CYP27A1 mutation. Although the patient did not exhibit elevated serum cholestanol levels or other cerebrotendinous xanthomatosis features, the marked Achilles tendon thickening raises the possibility that the combination of a heterozygous CYP27A1 gene mutation and an APOB gene mutation contributed to the condition. Show less

Previously, we advocated the importance of classifying hepatocellular carcinoma (HCC) based on physiological functions. This study aims to classify HCC by focusing on liver-intrinsic metabolism and glycolytic pathway in cancer cells. Comprehensive RNA/DNA sequencing, immunohistochemistry, and radiological evaluations were performed on HCC tissues from the training cohort (n=136) and validated in 916 public samples. HCC was classified using hierarchical clustering and compared with previous molecular, histopathological, and hemodynamic classifications. Liver-specific metabolism and glycolysis are mutually exclusive and were divided into two major subclasses: The "rich metabolism" subclass (60.3%) is characterized by enhanced bile acid and fatty acid metabolism, wellto-moderate differentiation, microtrabecular or pseudoglandular pattern, and homogeneous arterial-phase hyperenhancement (APHE), corresponding to Hoshida S3 with favorable prognosis. In IL6-JAK-STAT3-high (25.0%) conditions, upregulated ALB expression, enhanced gluconeogenesis and urea cycle activity, and an inflammatorymicroenvironment are observed. Conversely, the Wnt/β-catenin-high environment (19.9%) features elevated GLUL, APOB and CYP3A4 expression, frequent CTNNB1 (D32-S37) mutations, and an immune-desert/excluded phenotype. The "glycolysis" subclass (39.7%), characterized by histopathological dedifferentiation and downregulated liver-specific metabolism, encompasses subclasses with PI3K/mTOR (20.6%) and NOTCH/TGF-β (19.1%) signaling. These often exhibit TP53 mutations, macrotrabecular massive or compact patterns, inhomogeneous/rim-APHE, and high expression of hypoxia-inducible factors and glucose transporters, corresponding to Hoshida S1/2 with poor prognosis. The loss of liver-specific metabolism correlates with morphological dedifferentiation, indicating cellular dedifferentiation may exhibit both physiological and pathological duality. Key signaling pathways involved in the maturation process from fetal to adult liver and zonation program may play a critical role in defining HCC diversity. Show less

Neuronal ceroid lipofuscinosis (NCL) is a heterogeneous group of lysosomal disorders characterized by progressive psychomotor regression, visual impairment, and intractable seizures. Genetically, NCL type 3 (CLN3) is associated with variants in the gene encoding a lysosomal transmembrane protein. To date, few Japanese patients with CLN3 have been reported. Thus, their neurodevelopmental and clinical features remain unclear. Here, we report the clinical course of a genetically confirmed Japanese patient with CLN3. A 17-year-old Japanese boy was diagnosed with retinitis pigmentosa at age 7. Visual impairment progressed over a 10-year follow-up period. Generalized tonic-clonic seizures also began at age 7. Developmental regression was recognized at age 13, with an accelerated decline in motor and communication skills following a COVID-19 infection at age 17. Tube feeding and gastrostomy were initiated for dysphagia and recurrent respiratory infections. Serial MRI revealed progressive cerebral and cerebellar atrophy. Lymphopenia (351-1467/μL) was present from age 9; peripheral blood smear revealed vacuolated lymphocytes. Exome sequencing identified a heterozygous CLN3 variant, NM₀₀₁₀₄₂₄₃₂.2:c.295-2A > C. SpliceAI suggested exon 6 skipping and/or an 80-bp deletion, leading to nonsense-mediated mRNA decay. Manual inspection using Integrated Genomic Viewer revealed a second variant (c.178₁₈₀delinsACATCCTTAGCCACAAGAG) missed initially. Trio Sanger sequencing confirmed compound heterozygosity: NM₀₀₁₀₄₂₄₃₂.2:c.[295-2A > C]; [178₁₈₀delinsACATCCTTAGCCACAAGAG] p.[?]; [His60Thrfs∗10]. A review of 430 genetically confirmed CLN3 patients (1989-2025) identified no hematologic abnormalities. This Japanese CLN3 patient developed visual impairment 7-8 years before systemic deterioration. Retinal degeneration, together with vacuolated peripheral lymphocytes, may provide early diagnostic clues for CLN3 in Japanese patients. Show less

Lipoprotein(a) [Lp(a)] is recognized as an independent risk factor for cardiovascular disease (CVD), but its characterization within the Japanese population remains unexplored. This systematic literature review synthesizes evidence on the association between Lp(a) levels and CVD in Japanese patients. To ensure comparability, the review focused on studies using the widely used LATEX-based immunoassay method. Most studies categorized patients into "high" and "low" Lp(a) groups; this review concentrates on findings from the "high" groups to evaluate the impact of elevated Lp(a). Although definitions of "high" Lp(a) varied, a consistent association between elevated Lp(a) and increased cardiovascular risk has been observed, aligning with international findings. Variability across studies was noted, likely due to differences in study design, endpoints, and follow-up durations. Although no approved therapies specifically target elevated Lp(a), several randomized controlled trials are currently ongoing. Continued research is essential to better understand the clinical implications of elevated Lp(a) among Japanese individuals. Show less

Liposarcoma and lymphoma are very rare tumors, and their combination is extremely rare. Moreover, there have been no reports of liposarcoma and lymphoma occurring in the same region. A 58-year-old man presented to Kanagawa Cancer Center with a mass in his left thigh and underwent a needle biopsy. Histological analysis showed an increase in the number of small lymphocytes and plasma cells; immunohistochemical analysis showed an increase in CD20-positive cells with Lambda light-chain restriction; therefore, the diagnosis of B-cell malignancy with plasma cell differentiation was made. A bone marrow biopsy specimen showed infiltration of atypical cells of the same phenotype and increased serum IgM-M levels; therefore, a diagnosis of Waldenström macroglobulinemia/lymphoplasmacytic lymphoma (LPL) was made. The needle biopsy specimen showed scattered CDK4-positive cells in the background of the lymphoma cells and sporadic MDM2 signal amplification on fluorescence in situ hybridization, suggesting mixed well-differentiated liposarcoma (WDL). Tumor resection was performed. The tumor contained a mixture of WDL and LPL areas. RNA sequencing revealed upregulated expression of chemokine genes, including CCL5, CCL18, and CCL19, in WDL and that of the corresponding chemokine receptor genes CCR4, CCR6, and CCR7 in the lymphoma cells. Chemokine-chemokine receptor axes may be involved in the pathogenesis of LPL cell-infiltrating WDL. This is an extremely rare case, and we have reported some considerations regarding the tumorigenesis of LPL cell-infiltrating WDL. Show less

With the aging of society, the incidence of chronic kidney disease (CKD), a common cause of death, has been increasing. Transcription factor EB (TFEB), the master transcriptional regulator of the autophagy/lysosomal pathway, is regarded as a promising candidate for preventing various age-related diseases. However, whether TFEB in the proximal tubules plays a significant role in elderly patients with CKD remains unknown. First, we found that nuclear TFEB localization in proximal tubular epithelial cells (PTECs) declined with age in both mice and humans. Next, we generated PTEC-specific Tfeb-deficient mice and bred them for up to 24 months. We found that TFEB deficiency in the proximal tubules caused metabolic disorders and occasionally led to apolipoprotein A4 (APOA4) amyloidosis. Supporting this result, we identified markedly decreased nuclear TFEB localization in the proximal tubules of elderly patients with APOA4 amyloidosis. The metabolic disturbances were accompanied by mitochondrial dysfunction due to transcriptional changes involved in fatty acid oxidation and oxidative phosphorylation pathways, as well as decreased mitochondrial clearance. This decreased clearance was reflected by the accumulation of mitochondria-lysosome-related organelles, which depended on lysosomal function. These results shed light on the presumptive mechanisms of APOA4 amyloidosis pathogenesis and provide a therapeutic strategy for CKD-related metabolic disorders and APOA4 amyloidosis. Show less

Immunotherapy is becoming a promising approach for unresectable-hepatocellular carcinoma (HCC); the anti-tumor response is affected by the tumor microenvironment (TME). Although Wnt/β-catenin mutations are reported to cause non-inflamed phenotype, their role on TME remains controversial. We aimed to clarify the heterogeneity of immunophenotype in HCC with Wnt/β-catenin mutations. This study includes 152 resected HCCs; mutations in the Forty of 152 (26.3%) HCCs carried the Wnt/β-catenin mutations. Of these, 33 were classified as non-inflamed (33/40, 82.5%) and 7 as inflamed (7/40, 17.5%). Non-inflamed class was characterized by low number of CD3+, CD4+, and CD8+ cells on immunostaining, and high mRNA expressions of Heterogeneity of tumor traits and TME was observed in HCC with Wnt/β-catenin mutation. The potential was indicated that tumor traits and TME are determined not only by the activation of the Show less

We previously reported that combined therapy with epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) osimertinib and AXL inhibitor ONO-7475 is effective in preventing the survival of drug-tolerant cells in high-AXL-expressing EGFR-mutated non-small cell lung cancer (NSCLC) cells. Nevertheless, certain residual cells are anticipated to eventually develop acquired resistance to this combination therapy. In this study, we attempted to establish a multidrug combination therapy from the first-line setting to overcome resistance to this combination therapy in high-AXL-expressing EGFR-mutated NSCLC. siRNA screening assay showed that fibroblast growth factor receptor 1 (FGFR1) knockdown induced pronounced inhibition of cell viability in the presence of the osimertinib-ONO-7475 combination, which activates FGFR1 by upregulating FGF2 via the c-Myc pathway. Cell-based assays showed that triple therapy with osimertinib, ONO-7475, and the FGFR inhibitor BGJ398 significantly increased apoptosis by increasing expression of proapoptotic factor Bim and reduced cell viability compared with that observed for the osimertinib-ONO-7475 therapy. Xenograft models showed that triple therapy considerably suppressed tumor regrowth. A novel therapeutic strategy of additional initial FGFR1 inhibition may be highly effective in suppressing the emergence of osimertinib- and ONO-7475-resistant cells. Show less

Solid-predominant lung adenocarcinoma (SPA), which is one of the high-risk subtypes with poor prognosis and unsatisfactory response to chemotherapy and targeted therapy in lung adenocarcinoma, remains molecular profile unclarified. Weighted correlation network analysis (WGCNA) was used for data mining, especially for studying biological networks based on pairwise correlations between variables. This study aimed to identify disease-related protein co-expression networks associated with early-stage SPA. We assessed cancerous cells laser-microdissected from formalin-fixed paraffin-embedded (FFPE) tissues of a SPA group ( Among the forty WGCNA network modules identified, two network modules were found to be associated significantly with the SPA subtype. Canonical enriched pathways were highly associated with cellular growth, proliferation, and immune response. Upregulated HLA class I molecules HLA-G and HLA-B implicated high mutation burden and T cell activation in the SPA subtype. Upstream analysis implicated the involvement of highly activated oncogenic regulators, MYC, MLXIPL, MYCN, the redox master regulator NFE2L2, and the highly inhibited LARP1, leading to oncogenic IRES-dependent translation, and also regulators of the adaptive immune response, including highly activated IFNG, TCRD, CD3-TCR, CD8A, CD8B, CD3, CD80/CD86, and highly inhibited LILRB2. Interestingly, the immune checkpoint molecule HLA-G, which is the counterpart of LILRB2, was highly expressed characteristically in the SPA subtype and might be associated with antitumor immunity. Our findings provide a disease molecular profile based on protein co-expression networks identified for the high-risk solid predominant adenocarcinoma, which will help develop future therapeutic strategies. Show less

Neoatherosclerosis (NA), which refers to neointimal atherosclerosis within a stent, is considered one of the underlying causes of late-phase stent failure following a newer generation drug-eluting stent (DES) placement procedure. Even contemporary guideline-directed medical therapy may be insufficient to prevent NA. This study aimed to investigate how intricately lipid markers are associated with NA formation in the early phase of treatment with well-maintained low-density lipoprotein cholesterol (LDL-C) levels. We enrolled 114 consecutive patients undergoing statin treatment and percutaneous coronary intervention (PCI) with current-generation DES for coronary artery disease. At a median 12 months after PCI, optical coherence tomography (OCT) was performed. Various lipid markers, including LDL-C, triglyceride (TG), triglyceride-rich lipoprotein cholesterol (TRL-C), non-high-density lipoprotein cholesterol (non-HDL-C), malondialdehyde-modified LDL (MDA-LDL), and several apolipoproteins, were also evaluated. NA was observed in 17 (14.9%) patients. The LDL-C level was equivalent in patients with or without NA (77.2 vs. 69.8 mg/dL; p=0.15). However, the levels of TG, apolipoprotein C3 (apoC3), TRL-C, non-HDL-C, and apolipoprotein B (apoB), and MDA-LDL were significantly higher in the patients with NA. Furthermore, multivariate logistic regression adjusting for HbA1c and stent duration revealed apoC3, TRL-C, non-HDL-C, apoB, and MDA-LDL levels as risk factors for NA. However, when apoB was included as a covariate, other factors became nonsignificant. Abnormal triglyceride-rich lipoprotein metabolism and high atherogenic apoB-containing lipoprotein particle numbers are associated with the formation of NA in patients undergoing statin treatment at a median 12 months post-PCI. Show less

As an uncommon but nonrandom translocation in acute myeloid leukemia (AML) t(5;11)(q31;q23) results in fusion between KMT2A at 11q23 and ARHGAP26 at 5q31. The 5q31 region has another KMT2A partner, AFF4, which was identified in acute lymphoblastic leukemia harboring ins(5;11)(q31;q13q23). We report here a 65-year-old woman with AML M5b. G-banding and spectral karyotyping demonstrated 46,XX,t(5;11)(q31;q23.3). Fluorescence in situ hybridization revealed not only separated 5' and 3' KMT2A signals but a faint 5' KMT2A signal. Reverse transcription polymerase chain reaction (RT-PCR), using a KMT2A sense primer and ARHGAP26 antisense primer, detected no band whereas RT-PCR with a AFF4 antisense primer revealed an amplified band. However, sequence analysis unexpectedly disclosed that KMT2A exon 6 was connected with MLLT10 exons 15 to 18. This may be due to cross-hybridization between MLLT10 exon 18 and AFF4 antisense primer derived from AFF4 exon 10 since both exons had eight identical bases (AAGCAGCT). The MLLT10 gene is located at 10p12.31; a faint 5' KMT2A signal was probably present at this locus. These findings indicate that in AML the 5' KMT2A fragment containing exons 1 to 6 may be cryptically inserted into MLLT10 intron 14 when a reciprocal translocation t(5;11)(q31;q23.3) involving KMT2A occurred. Show less

Imeglimin and metformin act in metabolic organs, including β-cells, via different mechanisms. In the present study, we investigated the impacts of imeglimin, metformin, or their combination (Imeg + Met) on β-cells, the liver, and adipose tissues in db/db mice. Imeglimin, metformin, or Imeg + Met treatment had no significant effects on glucose tolerance, insulin sensitivity, respiratory exchange ratio, or locomotor activity in db/db mice. The responsiveness of insulin secretion to glucose was recovered by Imeg + Met treatment. Furthermore, Imeg + Met treatment increased β-cell mass by enhancing β-cell proliferation and ameliorating β-cell apoptosis in db/db mice. Hepatic steatosis, the morphology of adipocytes, adiposity assessed by computed tomography, and the expression of genes related to glucose or lipid metabolism and inflammation in the liver and fat tissues showed no notable differences in db/db mice. Global gene expression analysis of isolated islets indicated that the genes related to regulation of cell population proliferation and negative regulation of cell death were enriched by Imeg + Met treatment in db/db islets. In vitro culture experiments confirmed the protective effects of Imeg + Met against β-cell apoptosis. The expression of Snai1, Tnfrsf18, Pdcd1, Mmp9, Ccr7, Egr3, and Cxcl12, some of which have been linked to apoptosis, in db/db islets was attenuated by Imeg + Met. Treatment of a β-cell line with Imeg + Met prevented apoptosis induced by hydrogen peroxide or palmitate. Thus, the combination of imeglimin and metformin is beneficial for the maintenance of β-cell mass in db/db mice, probably through direct action on β-cells, suggesting a potential strategy for protecting β-cells in the treatment of type 2 diabetes. Show less

Melanocortin 4 receptor gene-knockout (MC4R-KO) mice are known to develop obesity with a high-fat diet. Meanwhile, daisaikoto, one of Kampo medicines, is a drug that is expected to have therapeutic effects on obesity. Here, we report the efficacy of daisaikoto in MC4R-KO mice. Eight-week-old MC4R-KO male mice (n = 12) were divided into three groups as follows: the SD group, which is fed with a standard diet; the HFD group, fed a high-fat diet; and the DSK group, fed with a high-fat diet containing 10% of daisaikoto. After the four-week observation period, mice in each group were sacrificed and samples were collected. The body weights at 12 weeks were significantly higher in the HFD group than in the other groups, indicating that daisaikoto significantly reduced body weight gain and fat deposition of the liver. The metabolome analysis indicated that degradation of triglycerides and fatty acid oxidation in the liver were enhanced by daisaikoto administration. In MC4R-KO mice, the cytoplasm and uncoupling protein 1 expression of brown adipose tissue was decreased; however, it was reversed in the DSK group. In conclusion, daisaikoto has potentially improved fatty liver and obesity, making it a useful therapeutic agent for obesity and fatty liver. Show less

ONO-1301 is a novel long-lasting prostaglandin (PG) I The therapeutic effects of ONO-1301 against liver damage, fibrosis, and occurrence of liver tumors were evaluated using melanocortin 4 receptor-deficient (Mc4r-KO) NASH model mice. The effects of ONO-1301 against macrophages, hepatic stellate cells, and endothelial cells were also evaluated in vitro. ONO-1301 ameliorated liver damage and fibrosis progression, was effective regardless of NASH status, and suppressed the occurrence of liver tumors in Mc4r-KO NASH model mice. In the in vitro study, ONO-1301 suppressed LPS-induced inflammatory responses in cultured macrophages, suppressed hepatic stellate cell (HSC) activation, upregulated vascular endothelial growth factor (VEGF) expression in HSCs, and upregulated hepatocyte growth factor (HGF) and VEGF expression in endothelial cells. The results of our study highlight the potential of ONO-1301 to reverse the progression and prevent the occurrence of liver tumors in NASH using in vivo and in vitro models. ONO-1301 is a multidirectional drug that can play a key role in various pathways and can be further analyzed for use as a new drug candidate against NASH. Show less

Mitochondria are fundamentally important in cell function, and their malfunction can cause the development of cancer, cardiovascular disease, and neuronal disorders. Myosin 19 (Myo19) shows discrete localization with mitochondria and is thought to play an important role in mitochondrial dynamics and function; however, the function of Myo19 in mitochondrial dynamics at the cellular and molecular levels is poorly understood. Critical missing information is whether Myo19 is a processive motor that is suitable for transportation of mitochondria. Here, we show for the first time that single Myo19 molecules processively move on actin filaments and can transport mitochondria in cells. We demonstrate that Myo19 dimers having a leucine zipper processively moved on cellular actin tracks in demembraned cells with a velocity of 50 to 60 nm/s and a run length of ∼0.4 μm, similar to the movement of isolated mitochondria from Myo19 dimer-transfected cells on actin tracks, suggesting that the Myo19 dimer can transport mitochondria. Furthermore, we show single molecules of Myo19 dimers processively moved on single actin filaments with a large step size of ∼34 nm. Importantly, WT Myo19 single molecules without the leucine zipper processively move in filopodia in living cells similar to Myo19 dimers, whereas deletion of the tail domain abolished such active movement. These results suggest that Myo19 can processively move on actin filaments when two Myo19 monomers form a dimer, presumably as a result of tail-tail association. In conclusion, Myo19 molecules can directly transport mitochondria on actin tracks within living cells. Show less

This study investigated whether the small dense low-density lipoprotein cholesterol (sd-LDL-c) level is associated with the rapid progression (RP) of non-culprit coronary artery lesions and cardiovascular events (CE) after acute coronary syndrome (ACS). In 142 consecutive patients with ACS who underwent primary percutaneous coronary intervention for the culprit lesion, the sd-LDL-c level was measured using a direct homogeneous assay on admission for ACS and at the 10-month follow-up coronary angiography. RP was defined as a progression of any pre-existing coronary stenosis and/or stenosis development in the initially normal coronary artery. CEs were defined as cardiac death, myocardial infarction, stroke, or coronary revascularization. Patients were divided into two groups based on the presence (n=29) or absence (n=113) of RP after 10 months. The LDL-c and sd-LDL-c levels at baseline were equivalent in both the groups. However, the sd-LDL-c, triglyceride, remnant lipoprotein cholesterol (RL-c), and apoC3 levels at follow-up were significantly higher in the RP group than in the non-RP group. The optimal threshold values of sd-LDL-c, triglyceride, RL-c, and apoC3 for predicting RP according to receiver operating characteristics analysis were 20.9, 113, 5.5, and 9.7 mg/dL, respectively. Only the sd-LDL-c level (≥ 20.9 mg/dL) was significantly associated with incident CEs at 31±17 months (log-rank: 4.123, p=0.043). The sd-LDL-c level on treatment was significantly associated with RP of non-culprit lesions, resulting in CEs in ACS patients. On-treatment sd-LDL-c is a residual risk and aggressive reduction of sd-LDL-c might be needed to prevent CEs. Show less

No therapeutic targets have been identified for lung squamous cell cancer (SqCC) which is the second most prevalent lung cancer because its molecular profiles remain unclear. This study aimed to unveil disease-related protein networks by proteomic and bioinformatic assessment of laser-microdissected cancerous cells from seven SqCCs compared with eight representative lung adenocarcinomas. We identified three network modules significant to lung SqCC using weighted gene co-expression network analysis. One module was intrinsically annotated to keratinization and cell proliferation of SqCC, accompanied by hypoxia-induced aerobic glycolysis, in which key regulators were activated (HIF1A, ROCK2, EFNA1-5) and highly suppressed (KMT2D). The other two modules were significant for translational initiation, nonsense-mediated mRNA decay, inhibited cell death, and interestingly, eIF2 signaling, in which key regulators, MYC and MLXIPL, were highly activated. Another key regulator LARP1, the master regulator in cap-dependent translation, was highly suppressed although upregulations were observed for hub proteins including EIF3F and LARP1 targeted ribosomal proteins, among which PS25 is the key ribosomal protein in IRES-dependent translation. Our results suggest an underlying progression mechanism largely caused by switching to the cap-independent, IRES-dependent translation of mRNA subsets encoding oncogenic proteins. Our findings may help to develop therapeutic strategies to improve patient outcomes. Show less

Macroautophagy/autophagy plays a critical role in the pathogenesis of various human diseases including neurodegenerative disorders such as Parkinson disease (PD) and Huntington disease (HD). Chemical autophagy inducers are expected to serve as disease-modifying agents by eliminating cytotoxic/damaged proteins. Although many autophagy inducers have been identified, their precise molecular mechanisms are not fully understood because of the complicated crosstalk among signaling pathways. To address this issue, we performed several chemical genomic analyses enabling us to comprehend the dominancy among the autophagy-associated pathways followed by an aggresome-clearance assay. In a first step, more than 400 target-established small molecules were assessed for their ability to activate autophagic flux in neuronal PC12D cells, and we identified 39 compounds as autophagy inducers. We then profiled the autophagy inducers by testing their effect on the induction of autophagy by 200 well-established signal transduction modulators. Our principal component analysis (PCA) and clustering analysis using a dataset of "autophagy profiles" revealed that two Food and Drug Administration (FDA)-approved drugs, memantine and clemastine, activate endoplasmic reticulum (ER) stress responses, which could lead to autophagy induction. We also confirmed that SMK-17, a recently identified autophagy inducer, induced autophagy via the PRKC/PKC-TFEB pathway, as had been predicted from PCA. Finally, we showed that almost all of the autophagy inducers tested in this present work significantly enhanced the clearance of the protein aggregates observed in cellular models of PD and HD. These results, with the combined approach, suggested that autophagy-activating small molecules may improve proteinopathies by eliminating nonfunctional protein aggregates. Show less

Recognition of the non-self signature of invading pathogens is a crucial step for the initiation of the innate immune mechanisms of the host. The host response to viral and bacterial infection involves sets of pattern recognition receptors (PRRs), which bind evolutionarily conserved pathogen structures, known as pathogen-associated molecular patterns (PAMPs). Recent advances in the identification of different types of PRRs in teleost fish revealed a number of cytosolic sensors for recognition of viral and bacterial nucleic acids. These are DExD/H-box RNA helicases including a group of well-characterized retinoic acid inducible gene I (RIG-I)-like receptors (RLRs) and non-RLR DExD/H-box RNA helicases (e.g., DDX1, DDX3, DHX9, DDX21, DHX36 and DDX41) both involved in recognition of viral RNAs. Another group of PRRs includes cytosolic DNA sensors (CDSs), such as cGAS and LSm14A involved in recognition of viral and intracellular bacterial dsDNAs. Moreover, dsRNA-sensing protein kinase R (PKR), which has a role in antiviral immune responses in higher vertebrates, has been identified in fish. Additionally, fish possess a novel PKR-like protein kinase containing Z-DNA binding domain, known as PKZ. Here, we review the current knowledge concerning cytosolic sensors for recognition of viral and bacterial nucleic acids in teleosts. Show less

Macroautophagy/autophagy is a lysosomal degradation system which plays a protective role against kidney injury. RUBCN/Rubicon (RUN domain and cysteine-rich domain containing, Beclin 1-interacting protein) inhibits the fusion of autophagosomes and lysosomes. However, its physiological role in kidney proximal tubular epithelial cells (PTECs) remains uncertain. In the current study, we analyzed the phenotype of newly generated PTEC-specific Show less

Peritoneal fibrosis (PF) is a severe complication of peritoneal dialysis, but there are few effective therapies for it. Recent studies have revealed a new biological function of trehalose as an autophagy inducer. Thus far, there are few reports regarding the therapeutic effects of trehalose on fibrotic diseases. Therefore, we examined whether trehalose has anti-fibrotic effects on PF. PF was induced by intraperitoneal injection of chlorhexidine gluconate (CG). CG challenges induced the increase of peritoneal thickness, ColIα Show less

Non-alcoholic steatohepatitis (NASH), characterized by chronic inflammation and fibrosis, is predicted to be the leading cause of cirrhosis and hepatocellular carcinoma (HCC) in the next decade. Although recent evidence suggests the importance of fibrosis as the strongest determinant of HCC development, the molecular mechanisms underlying NASH-induced carcinogenesis still remain unclear. Here we performed RNA sequencing analysis to compare gene expression profiles of activated fibroblasts prepared from two distinct liver fibrosis models: carbon tetrachloride-induced fibrosis as a model without obesity and HCC and genetically obese melanocortin 4 receptor-deficient (MC4R-KO) mice fed Western diet, which develop steatosis, NASH, and eventually HCC. Our data showed that activated fibroblasts exhibited distinct gene expression patterns in each etiology, and that the 'pathways in cancer' were selectively upregulated in the activated fibroblasts from MC4R-KO mice. The most upregulated gene in these pathways was fibroblast growth factor 9 (FGF9), which was induced by metabolic stress such as palmitate. FGF9 exerted anti-apoptotic and pro-migratory effects in fibroblasts and hepatoma cells in vitro and accelerated tumor growth in a subcutaneous xenograft model. This study reveals upregulation of cancer-associated gene expression in activated fibroblasts in NASH, which would contribute to the progression from NASH to HCC. Show less

Numerous cytosolic DNA sensors (CDSs), which are very important for recognizing cytosolic dsDNA derived from intracellular viruses and bacteria, exist in mammals. However, teleost CDSs are poorly understood. In this study, four CDSs, including the cyclic GMP-AMP synthase (cGAS), Sm-like protein 14 homolog A (LSm14A), DEAH-box helicase (DHX) 9, and DHX36 genes were identified in Japanese medaka, Oryzias latipes, and their expression patterns were elucidated. The expression of these genes was upregulated in the intestines and kidney of CpG-ODN-stimulated medaka. The cGAS and LSm14A genes were significantly induced in the intestines, kidney, and spleen of formalin-killed Edwardsiella tarda-treated medaka; the DHX9 and DHX36 genes were not. cGAS gene expression was induced only in the intestines of live E. tarda-treated medaka. These results suggest that the transcription of four CDS genes of medaka responds to dsDNA stimulation, and cGAS is probably more important for the immune response against E. tarda infection. Show less

Roux-en-Y gastric bypass (RYGB) limits food ingestion and may alter the intestinal expression of genes involved in the endogenous synthesis of polyunsaturated fatty acids (PUFAs). These changes may decrease the systemic availability of bioactive PUFAs after RYGB. To study the impact of RYGB on the dietary ingestion and plasma concentration of PUFAs and on the intestinal expression of genes involved in their endogenous biosynthesis in severely obese women with type 2 diabetes. Before, and 3 and 12 months after RYGB, obese women (n = 20) self-reported a seven-day dietary record, answered a food frequency query and provided plasma samples for alpha-linolenic (ALA), eicosapentaenoic (EPA), docosahexaenoic (DHA) and arachidonic (ARA) acid assessment by gas chromatography. Intestinal biopsies (duodenum, jejunum and ileum) were collected through double-balloon endoscopy before and 3 months after RYGB for gene expression analysis by microarray (Human GeneChip 1.0 ST array) and RT-qPCR validation. Compared to the preoperative period, patients had decreased intakes of PUFAs, fish and soybean oil (p < 0.05) and lower plasma concentrations of ALA and EPA (p < 0.001) 3 and 12 months after RYGB. FADS1 gene expression was lower in duodenum (RT-qPCR fold change = -1.620, p < 0.05) and jejunum (RT-qPCR fold change = -1.549, p < 0.05) 3 months following RYGB, compared to before surgery. RYGB decreased PUFA ingestion, plasma ALA and EPA levels, and intestinal expression of FADS1 gene. The latter encodes a key enzyme involved in endogenous biosynthesis of PUFAs. These data suggest that supplementation of omega-3 PUFAs may be required for obese patients undergoing RYGB. Clinical Trial Registry number and website: www.clinicaltrials.gov - NCT01251016; Plataforma Brasil - 19339913.0.0000.0068. Show less

Accumulating evidence has suggested that farnesoid X receptor (FXR) agonists, such as obeticholic acid (OCA) are therapeutically useful for non-alcoholic steatohepatitis (NASH). However, it is still unclear how FXR agonists protect against NASH and which cell type is the main target of FXR agonists. In this study, we examined the effects of OCA on the development of NASH using melanocortin 4 receptor-deficient (MC4R-KO) mice that progressively developed hepatic steatosis and NASH on Western diet (WD). Treatment with OCA effectively prevented chronic inflammation and liver fibrosis in WD-fed MC4R-KO mice with only marginal effect on body weight and hepatic steatosis. Hepatic crown-like structure (hCLS) is a unique histological structure characteristic of NASH, which triggers hepatocyte death-induced interstitial fibrosis. Intriguingly, treatment with OCA markedly reduced hCLS formation even after MC4R-KO mice developed NASH, thereby inhibiting the progression of liver fibrosis. As its mechanism of action, OCA suppressed metabolic stress-induced p53 activation and cell death in hepatocytes. Our findings in this study highlight the role of FXR in hepatocytes in the pathogenesis of NASH. Collectively, this study demonstrates the anti-fibrotic effect of OCA in a murine model of NASH with obesity and insulin resistance, which suggests the clinical implication for human NASH. Show less

Subcutaneous transplantation of engineered hepatocyte/fibroblast sheets (EHFSs) is a low invasive and safe approach to construct vascularized subcutaneous human liver tissue (VSLT). However, the liver-specific structures and functionalities in the development process of VSLTs in mice remain poorly understood. Here, we describe time-dependent characteristics of the formation of the vascular network, cell-cell adhesions, liver transporters, liver-specific protein synthesis, and metabolizing activities. The EHFSs formed multilayered thick tissues by rapid neovascularization, which allows overcoming extremely difficult problems, such as the lack of oxygen supply on the formation of three-dimensional primary hepatocyte tissue under the skin. The blood vessels consisted of mouse-origin endothelial cells (ECs) (mVEGFR2) from the subcutaneous space at 1-7 days, and the following formation of the vascular network was performed by human-origin ECs (hVEGFR2). Many varieties of liver-specific gene expressions increased with the construction of the VSLTs: cell-cell adhesion molecules (CDH1, CLDN3, and CX32), transporters at basal (OATP1A1, OCT1, and NTCP) and apical membranes (MRP2, MDR1, and BSEP), blood coagulation factors (F8 and F9), urea synthesis (CPS1, OTC, and ARG1), and metabolism enzymes (CYP7A1, CYP1A2, CYP2B6, CYP3A4, and UGT1A1). Subacute hepatic failure model mice with VSLT were alive at least 7 weeks after liver damage. Thus, the ectopic liver organ offers the potential for a low invasive and safe treatment for liver diseases. Show less

Abnormal activation of the Wnt/β-catenin signaling is implicated in the osteoarthritis (OA) pathology. We searched for a pre-approved drug that suppresses abnormally activated Wnt/β-catenin signaling and has a potency to reduce joint pathology in OA. We introduced the TOPFlash reporter plasmid into HCS-2/8 human chondrosarcoma cells to estimate the Wnt/β-catenin activity in the presence of 10 μM each compound in a panel of pre-approved drugs. We found that fluoxetine, an antidepressant in the class of selective serotonin reuptake inhibitors (SSRI), down-regulated Wnt/β-catenin signaling in human chondrosarcoma cells. Fluoxetine inhibited both Wnt3A- and LiCl-induced loss of proteoglycans in chondrogenically differentiated ATDC5 cells. Fluoxetine increased expression of Sox9 (the chondrogenic master regulator), and decreased expressions of Axin2 (a marker for Wnt/β-catenin signaling) and Mmp13 (matrix metalloproteinase 13). Fluoxetine suppressed a LiCl-induced increase of total β-catenin and a LiCl-induced decrease of phosphorylated β-catenin in a dose-dependent manner. An in vitro protein-binding assay showed that fluoxetine enhanced binding of β-catenin with Axin1, which is a scaffold protein forming the degradation complex for β-catenin. Fluoxetine suppressed LiCl-induced β-catenin accumulation in human OA chondrocytes. Intraarticular injection of fluoxetine in a rat OA model ameliorated OA progression and suppressed β-catenin accumulation. Show less