👤 Masaki Kobayashi

Neural pathways related to total calorie intake have been extensively studied. However, it remains unclear how these mechanisms control food selection. Male mice were subjected to glucoprivation through the intraperitoneal (i.p.) administration of 2-deoxy-d-glucose (2DG) and were examined for food selection between a high-carbohydrate diet (HCD) and a high-fat diet (HFD) in a diet choice paradigm. This involved the chemogenetic or optogenetic modulation of the neural activity of AMP-activated protein kinase (AMPK)-regulated corticotropin-releasing hormone (CRH) neurons, melanocortin-4 receptor (MC4R) neurons in the paraventricular nucleus of the hypothalamus (PVH), and neuropeptide Y (NPY) neurons projecting to the PVH. Glucoprivation induced by 2DG administration in mice influenced two distinct neural pathways in the PVH that separately promote the intake of an HCD or an HFD. Injection of 2DG activated PVH-projecting NPY neurons in the nucleus of the solitary tract (NTS) and ventrolateral medulla (VLM), resulting in a rapid increase in HCD intake through stimulation of PVH AMPK-regulated CRH neurons and recovery from glucoprivation. In contrast, PVH-projecting NPY neurons in the NTS, VLM, and arcuate nucleus of the hypothalamus (ARC) promoted HFD intake by inhibiting MC4R neurons in the PVH, reflecting the strong innate preference for an HFD in mice. The ARC NPY neurons specifically promoted HFD selection. Our findings reveal a previously unrecognized mechanism for food selection between HCD and HFD during glucoprivation. Show less

Apolipoprotein C-III (ApoC-III) amyloidosis is an extremely rare systemic amyloidosis previously reported only in humans and white lions. This report describes the first case of ApoC-III amyloidosis in an Asiatic lion (16-year-old male) that died with clinical manifestations of renal failure. Histopathological and ultrastructural examinations identified amyloid deposits predominantly at the renal corticomedullary junction. Mass spectrometry and immunohistochemistry identified ApoC-III as an amyloid precursor protein. Sequencing of the lion's APOC3 gene found no pathogenic mutations, although lion species have a unique M30V substitution compared with other Panthera species, which may predispose them to Apo-CIII amyloidosis. This first case of a non-white lion indicates that ApoC-III amyloidosis is not restricted to white lions. Show less

In the phase 3 CLEAR study, lenvatinib plus pembrolizumab showed improved efficacy versus sunitinib for patients with clear cell renal cell carcinoma (ccRCC). Previous preclinical studies demonstrated that lenvatinib attenuated tumor-associated macrophage (TAM) infiltration into tumor tissues by inhibiting fibroblast growth factor receptor (FGFR). However, the role of the FGFR pathway in ccRCC remains underexplored. This study aims to evaluate FGFR1-4 expression in ccRCC and investigate its relationship with the tumor microenvironment, particularly TAM. We primarily analyzed FGFR1-4 expression and CD163 positive cell count as estimation of TAM infiltration in 57 ccRCC specimens from patients undergoing nephrectomy using immunohistochemistry. Transcriptomic analysis was performed to assess immune-related gene signature and gene expressions. FGFR1 expression was elevated in over 80% of ccRCC samples and was significantly associated with increased CD163-positive TAM infiltration. FGFR1 expression was also negatively correlated with the IMmotion150 Teff gene signature and the expression of interferon-γ signaling targeted genes such as IFNG, GZMB, and CD274, suggesting an immunosuppressive phenotype. In contrast, FGFR2 and FGFR4 expression were less prevalent, and FGFR3 expression was not detected. This study provides the first comprehensive evaluation of FGFR1-4 expression in ccRCC and suggests that FGFR1 expression may contribute to the immunosuppressive tumor microenvironment by recruiting TAM. These findings indicate that FGFR1 could serve as a potential biomarker for therapeutic strategies and highlight the need for further research to explore FGFR-targeted therapies in ccRCC. Show less

Large cell neuroendocrine carcinoma (LCNEC) is a neuroendocrine carcinoma (NEC) of the lung that is characterized by its heterogeneous morphology, diverse immunophenotypes, and complex genomic profiles. Among LCNECs, a subset expressing the transcription factor POU2F3 (LCNEC-P) has been suggested to share similarities with small cell lung carcinoma (SCLC)-P, a subtype of SCLC defined by POU2F3 expression. However, the specific characteristics of LCNEC-P have not been fully elucidated. Therefore, the aim of the present study is to clarify the clinicopathological, immunohistochemical, and genetic characteristics of LCNEC-P. Fifty-six LCNEC cases were analyzed, including 12 LCNEC-P and 44 LCNEC-non-P cases. Morphologically, LCNEC-P exhibited significantly lower cytomorphology scores, indicating a resemblance to SCLC. Immunohistochemically, LCNEC-P showed the lower expression of neuroendocrine markers (SYP, CHGA, and INSM1), but the higher expression of C-MYC than LCNEC-non-P. A strong mutually exclusive expression pattern was observed between POU2F3 and ASCL1/NEUROD1. Whole-genome sequencing of 20 cases revealed that LCNEC-P harbored RB1 mutations in 100 % of cases, which was significantly higher than in LCNEC-non-P (40 %). FGFR1 amplification was observed in 60 % of LCNEC-P cases, representing a higher prevalence than previously reported for LCNEC. In addition, LCNEC-P showed a distinct copy number alteration profile, including frequent 20q13 amplification, compared with LCNEC-non-P. These results demonstrate that LCNEC-P represents a distinct subgroup of LCNEC that is characterized by a specific morphological, immunohistochemical, and genetic profile, closely resembling SCLC-P. This study provides insights into the biology of LCNEC-P and supports its classification as a unique entity within LCNEC. Show less

Research indicates that impairment of instrumental activities of daily living (IADLs) leads to reduced physical activity (PA) in daily life. However, these studies often rely on subjective measures such as questionnaires and interviews to assess PA. This study examined the association between IADL frequency and objectively measured PA in stable individuals with cardiovascular disease (CVD). In this cross-sectional study, we included people with CVD who had been receiving outpatient care under stable conditions for at least 6 months. IADL frequency was assessed using the Frenchay Activities Index (FAI). PA was measured using accelerometers over 2 weeks to calculate the daily average number of steps, low-intensity PA (LPA), and moderate-to-vigorous-intensity PA (MVPA). A multivariate linear regression model analyzed the associations between the FAI scores (total and sub-items) and PA levels. This study included 1126 stable participants with CVD (median age, 74.0 years; 278 females). After adjusting for clinical confounding factors, a high FAI total score was significantly associated with higher levels of PA (number of steps per day, unstandardized coefficient [В] = 78.1, LPA per day, В = 0.7, and MVPA per day, В = 0.2). In the FAI subitems, 4 housework and 6 leisure activities were positively associated with the daily average number of steps and LPA, and 2 leisure activities were positively associated with daily MVPA. Greater IADL frequency was associated with higher objectively measured PA in stable participants with CVD. Leisure-related activities were associated with increased MVPA, suggesting that encouraging these activities may help promote meaningful PA engagement in this population. Show less

Metabolic dysfunction-associated steatotic liver disease (MASLD) can progress to steatohepatitis (MASH), which is closely associated with obesity and insulin resistance. Resmetirom, and semaglutide, have been shown to have therapeutic effects in clinical studies. We compared these mechanisms in western diet (WD)-fed melanocortin 4 receptor knockout (MC4R-KO) mice, a human MASH pathology model. Male MC4R-KO mice were fed WD for 6 weeks starting from 22 weeks of age for disease induction and were administered drugs for 7 weeks with WD feeding, for a total duration of 13 weeks. Both resmetirom and semaglutide treatments for 7 weeks substantially improved these parameters. Although resmetirome and semaglutide improved liver hydroxyproline deposition and total fat mass, semaglutide markedly suppressed total lean mass. Moreover, resmetirom enhanced oxygen consumption, whereas semaglutide reduced energy expenditure. Histopathological evaluation showed that resmetirom significantly and semaglutide tended to improve liver steatosis score. On the fibrosis score, semaglutide significantly reduced it. Resmetirom and semaglutide have different mechanisms of action against MASH. Similar to clinical evidence, semaglutide treatment, might cause muscle mass reduction due to food intake suppression. This is the first study to simultaneously compare the effects of resmetirom and semaglutide on MASH phenotypes and reveal the differences on their mechanisms of action in WD-fed MC4R-KO mice. Show less

Estrogen is synthesized throughout various tissues in the body, and its production is regulated by the rate-limiting enzyme aromatase (encoded by the Cyp19a1 gene). Notably, aromatase is also expressed in central nervous system cells, allowing for localized estrogen synthesis in regions such as the hypothalamus. Estrogens produced within these neurons are referred to as neuroestrogens. In this study, we investigated the role of neuroestrogens in the regulation of appetite through modulation of hypothalamic pathways in OVX, ArKO, and aromatase-restored mice. Estrogen suppresses appetite by influencing the expression of appetite-regulating peptides, including POMC and NPY, via MC4R. We explored the direct effects of neuroestrogens, independent from ovarian estrogen, on appetite suppression and the underlying molecular mechanisms. We monitored body weight and food intake and evaluated the expression of Cyp19a1, Mc4r, and other appetite-related genes. Our findings indicate that OVX and ArKO mice exhibited increased body weight and food consumption, which correlated with altered expression of Mc4r and Cyp19a1. Conversely, restoration of Cyp19a1 expression in a neuron specific manner significantly decreased food intake and increased Mc4r expression in the hypothalamus. Furthermore, neuroestrogens enhanced leptin responsiveness. Our results imply that neuroestrogens likely contribute to appetite regulation and may be relevant for body weight reduction. Show less

Amyloidosis is a group of protein misfolding diseases and a well-recognized disorder in avian species. However, the knowledge of wild avian amyloid proteome is scarce. We report here gross, histopathological, ultrastructural, immunohistochemical and proteomic findings of systemic amyloidosis in seven Eurasian stone-curlews (Burhinus oedicnemus) necropsied in the Canary Islands. Spleen (5/6-83.33%), liver (3/5-60%), kidney (3/5-60%), proventricle (3/5-60%) and intestine (3/6-50%) were the more severely affected organs. All cases underwent chronic inflammatory processes associated to helminth, bacteria or fungi infection. Verminous chronic ventriculitis was the most frequent associated pathology in 5/7 (71.43%) followed by bumblefoot in 2/7 (28.57%) cases. Electron microscopy revealed a predominantly amorphous substance with 10 nm diameter non-branching amyloid fibrils. AA amyloidosis was characterized by immunohistochemistry and mass spectrometry analysis. By mass spectrometry three amyloid signature proteins were also identified: vitronectin, apolipoprotein A-IV and apolipoprotein A-I in 6/7 (85.71%), 4/7 (57.14%), and 3/7 (42.86%) cases, respectively, contributing with new knowledge about the amyloid proteome of amyloidosis in wild avian species. Show less

Verubecestat, atabecestat, and elenbecestat are small-molecule BACE1 inhibitors. Based on their structures, we designed and synthesized a novel BACE1 inhibitor with a hydroxyproline-derived N-amidinopyrrolidine scaffold. The initially synthesized derivative 7a showed a weak but detectable inhibitory activity against recombinant BACE1, which suggested that this novel scaffold was a viable BACE1 inhibitor. To enhance its activity, 22 derivatives with various substituents on the terminal benzene rings of the two biphenyl groups were synthesized and evaluated. Structure-activity relationship studies showed that introducing a substituent at the meta position of the biphenyl group on the hydroxy terminal improved the activity, and we identified the highly active derivative 12f. In contrast, substituents at the para position of the biphenyl group on the carboxy terminal increased activity. Additionally, we investigated the absolute configuration of the substituted pyrrolidine ring, which showed that the (2S,4R)-derivative exhibited the highest activity. Docking simulations suggested that a bulkier substituent tended to be located in the S1 and S3 pockets and that the binding mode significantly changed depending on which biphenyl group the substituent was attached to. These results show that the new scaffold would be useful for further development of small-molecule BACE1 inhibitors. Show less

An 88-year-old man was referred with peripheral edema, pleural effusion and nephrotic syndrome that had developed 3 months prior. Based on a kidney biopsy, the majority of glomeruli exhibited capillary wall thickening and the slight area of glomeruli exhibited spike formations and bubbly appearances. Fluorescent immunostaining showed global deposition of neural epidermal growth factor-like 1 (NELL-1), immunoglobulin (Ig) G1 and complement (C) 3c within the glomerular capillary wall. Electron microscopy showed the presence of unique subepithelial electron-dense deposits distributed in a ribbon-like manner along more than 75% of glomerular capillary walls. Fluorescent immunostaining showed no positivity for other recently identified antigens associated with membranous nephropathy, including M-type phospholipase A2 receptor (PLA2R), thrombospondin type 1 domain-containing 7A (THSD7A), and exostosin 1 (EXT1). A comprehensive medical examination for malignant diseases yielded negative results, and there was no discernible change in κ/λ staining. Additionally, serum complement levels were within the normal range. The patient was therefore diagnosed with NELL-1-positive membranous nephropathy and has been refractory to the treatment with prednisolone, cyclosporine (CyA) and rituximab for 10 months. According to previous reports, segmental or incomplete IgG capillary loop staining have been observed in 93.4% of cases of NELL-1-positive membranous nephropathy. Diffuse and global ribbon-like deposits, as observed in this case, are exceedingly rare. Show less

Pancreatic ductal adenocarcinomas (PDACs) with wild-type KRAS constitute a small fraction of PDACs, and these tumors were recently shown to harbor frequent actionable oncogenic mutations and fusions. However, the clinicopathological features of KRAS wild-type PDAC have not been well studied. Additionally, precancerous lesions occurring in patients with KRAS wild-type PDACs have rarely been characterized. Here, we investigated the clinicopathological characteristics and outcomes of 75 patients with KRAS wild-type PDAC. Molecular analyses were performed in 40 patients using targeted DNA and whole-exome sequencing and targeted RNA sequencing. We demonstrated that patients with metastatic PDAC with wild-type KRAS were younger (median 59.5 years) than those with mutated KRAS (median 67 years, p < 0.000055). The wild-type KRAS status was not a significant prognostic factor for metastatic disease. Molecularly, genes in the RAS pathway are frequently mutated or rearranged (46%, 16/35), including mutations in BRAF, NRAS, HRAS, EGFR, MAP2K1, FGFR1, FGFR3 and ERBB4 and fusions of FGFR2 (FGFR2::CCDC147, FGFR2::CAT, FGFR2::TXLNA), ALK (STRN::ALK, EML4::ALK), and BRAF (TRIP11::BRAF). Mismatch repair deficiency was identified in 10% (4/39) of patients. Potentially actionable alterations were identified frequently in KRAS wild-type PDACs (30%, 12/40), in which nontubular-type carcinomas were significantly enriched with actionable alterations compared with tubular adenocarcinomas [67% (6/9) versus 16% (5/31); p = 0.007]. Finally, we investigated the precursors of PDACs in 13 pancreatectomy specimens from patients with KRAS wild-type PDAC. We identified three pancreatic intraepithelial neoplasias (PanINs) and two intraductal papillary mucinous neoplasms (IPMNs) harboring oncogenic fusions of ALK and BRAF and driver mutations in BRAF and AKT1. This study suggests that in the context of unmutated KRAS, PDAC is driven by alternative oncogenic mutations or fusions of RAS pathway genes, which may be introduced during the early phase of tumorigenesis. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. Show less

Tirabrutinib, a second-generation Bruton's tyrosine kinase inhibitor, is used to treat lymphoplasmacytic lymphoma (LPL). A hallmark complication of LPL is hyperviscosity syndrome (HVS), caused by markedly elevated serum IgM levels. Plasma exchange (PE) is a standard treatment for HVS but may also remove circulating drugs, particularly those with high protein binding, potentially reducing drug exposure and efficacy. Evaluating the impact of PE on the pharmacokinetics of drugs used to treat LPL is important for optimal treatment. We report the case of a 63-year-old man with LPL who presented with acute headache and was diagnosed with HVS. Tirabrutinib (480 mg, once daily) was initiated, and PE was performed the next day because of persistent IgM elevation. To assess the impact of PE on tirabrutinib plasma concentrations, blood samples were collected approximately 3 h prior to PE (C15), immediately before PE (C18), and immediately after PE (C20). The concentrations at C15, C18 and C20 were 33.3, 16.9, and 11.4 ng/mL, respectively. The elimination rate constant (ke) was calculated as 0.226 h⁻¹ before PE and 0.197 h⁻¹ during PE. Based on the pre-PE ke, the predicted post-PE concentration (C20) assuming no PE was approximately 10.6 ng/mL, slightly lower than the observed value. PE appeared to have minimal impact on the tirabrutinib plasma concentration, likely due to its large volume of distribution. Although further cases are needed, this case supports the feasibility of concomitant PE during tirabrutinib therapy without significant compromise of drug efficacy. Show less

The impact of Graves' hyperthyroidism treatment on lipid metabolism remains unclear. This prospective observational study aimed to clarify the changes in lipid profiles and associated metabolic pathways, including cholesterol synthesis, absorption, and low-density lipoprotein (LDL) receptor regulation, following treatment. Seventeen patients newly diagnosed with Graves' hyperthyroidism were enrolled and followed for 6 months after achieving euthyroid status. Serum lipids (total cholesterol, LDL-cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides), apolipoproteins, non-cholesterol sterols (markers of cholesterol synthesis and absorption), proprotein convertase subtilisin/kexin type 9 (PCSK9), and lipoprotein lipase (LPL) levels were measured at baseline, at euthyroid status (Eu-0M), and 6 months after euthyroid status (Eu-6M). After treatment, serum total cholesterol, LDL-C, and HDL-C levels increased rapidly compared to baseline, while triglyceride levels showed a delayed but significant increase at Eu-6M. Levels of apolipoprotein (apo) AI, AII, B, and CIII increased significantly after treatment, whereas apo B-48 increased only at Eu-6M, and apo CII and apo E remained unchanged. Markers of cholesterol synthesis (lathosterol) and absorption (sitosterol, campesterol, and cholestanol) increased significantly after treatment, indicating enhanced cholesterol metabolism. Circulating PCSK9 levels increased significantly and remained elevated, while LPL levels did not change significantly. Treatment of Graves' hyperthyroidism rapidly increases cholesterol levels through enhanced cholesterol synthesis and absorption, possibly mediated by increased circulating PCSK9. Show less

Being overweight exacerbates various metabolic diseases, necessitating the identification of target molecules for obesity control. In the current study, we investigated common physiological features related to metabolism in mice with low weight gain: (1) G protein-coupled receptor, family C, group 5, member B-knockout; (2) gastric inhibitory polypeptide receptor-knockout; and (3) Iroquois-related homeobox 3-knockout. Moreover, we explored genes involved in metabolism by analyzing differentially expressed genes (DEGs) between low-weight gain mice and the respective wild-type control mice. The common characteristics of the low-weight gain mice were low inguinal white adipose tissue (iWAT) and liver weight despite similar food intake along with lower blood leptin levels and high energy expenditure. The DEGs of iWAT, epididymal (gonadal) WAT, brown adipose tissue, muscle, liver, hypothalamus, and hippocampus common to these low-weight gain mice were designated as candidate genes associated with metabolism. One such gene tetraspanin 7 (Tspan7) from the iWAT was validated using knockout and overexpressing mouse models. Mice with low Tspan7 expression gained more weight, while those with high Tspan7 expression gained less weight, confirming the involvement of the Tspan7 gene in weight regulation. Collectively, these findings suggest that the candidate gene list generated in this study contains potential target molecules for obesity regulation. Further validation and additional data from low-weight gain mice will aid in understanding the molecular mechanisms associated with obesity. Show less

Anaplastic thyroid carcinoma (ATC) is considered a very aggressive carcinoma and has been difficult to treat with therapeutic strategies. This study examines the landscape of genomic alteration in ATC, including the BRAF V600E mutation, and its clinical implications. A retrospective observational study was conducted using collected at the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) in Japan, utilizing comprehensive genomic profiling data from 102 ATC cases. Additionally, AACR-GENIE data from 267 cases were analysed for validation. Statistical methods, including the conditional Kendall tau statistic and χ Among 102 ATCs, BRAF, RAS, and other driver mutations were found in 83 cases (81.2%). The prevalence of BRAF V600E mutations was as high as 60%. Co-mutation analysis identified different genomic profiles in the BRAF, RAS, and wild-type groups. Despite the diverse molecular backgrounds, no significant differences in clinical variables and overall survival were observed. The analysis considering left-side amputation suggested that RAS mutations had a poorer prognosis. In the BRAF/RAS wild-type group, FGFR1 and NF1 were identified as driver mutations, with an accumulation of copy number variations and less TERT promoter mutations. This molecular subgrouping was also supported by the AACR-GENIE data. Comprehensive genomic analysis of ATC in Japan revealed distinct molecular subgroups, highlighting the importance of BRAF V600E mutations, particularly V600E, as potential therapeutic targets and suggest the relevance of tailor-made therapeutic strategies based on genomic profiling. Show less

The epithelial-mesenchymal transition (EMT) is a phenomenon, in which epithelial cells acquire a mesenchymal cell phenotype. It is important during wound healing; however, chronic inflammation leads to excessive EMT and causes tissue barrier dysfunction with hyperplasia. EMT is induced by several cytokines, such as interleukin (IL)-4 and IL-13. Additionally, IL-4 and IL-13 are known to increase in atopic dermatitis (AD) characterized by intense itching and eczema. Therefore, we assumed that there was commonality between the respective EMT and AD phenotypes. Herein, we evaluated EMT marker expression in AD skin and demonstrated that EMT-maker Snai1 and Twist expression were increased in AD mice model and patients with AD. Moreover, the epithelial-marker keratin 5 and mesenchymal marker Vimentin were co-expressed in the skin epidermis of mice with AD, suggesting the existence of hybrid epithelial-mesenchymal (E/M) cells possessing both epithelial and mesenchymal characteristics. In fact, we found that ΔNp63a, a stabilizing factor for hybrid E/M cells, was upregulated in the skin epidermis of the AD model mouse. Interestingly, increased expression of EMT markers was observed even at a nonlesion site in a patient with AD without initial inflammation or scratching. Therefore, EMT-like phenomena may occur independently of wound healing in skin of patients with AD. Show less

Melanin is a pigment produced from the amino acid L-tyrosine in melanosomes. The CNC-family transcription factor Nrf3 is expressed in the basal layer of the epidermis, where melanocytes reside, but its melanogenic function is unclear. Here, we show that Nrf3 regulates macropinocytosis and autophagy to coordinate melanogenesis cascade. In response to an exogenous inducer of melanin production, forskolin, Nrf3 upregulates the core melanogenic gene circuit, which includes Mitf, Tyr, Tyrp1, Pmel, and Oca2. Furthermore, Nrf3 induces the gene expression of Cln3, an autophagosome-related factor, for melanin precursor uptake by macropinocytosis. Ulk2 and Gabarapl2 are also identified as Nrf3-target autophagosome-related genes for melanosome formation. In parallel, Nrf3 prompts autolysosomal melanosome degradation for melanocyte survival. An endogenous melanogenic inducer αMSH also activates Nrf3-mediated melanin production, whereas it is suppressed by an HIV-1 protease inhibitor, nelfinavir. These findings indicate the significant role of Nrf3 in the melanogenesis and the anti-melanogenic potential of nelfinavir. Show less

Lung adenocarcinoma is the most common type of lung cancer. Known risk variants explain only a small fraction of lung adenocarcinoma heritability. Here, we conducted a two-stage genome-wide association study of lung adenocarcinoma of East Asian ancestry (21,658 cases and 150,676 controls; 54.5% never-smokers) and identified 12 novel susceptibility variants, bringing the total number to 28 at 25 independent loci. Transcriptome-wide association analyses together with colocalization studies using a Taiwanese lung expression quantitative trait loci dataset (n = 115) identified novel candidate genes, including FADS1 at 11q12 and ELF5 at 11p13. In a multi-ancestry meta-analysis of East Asian and European studies, four loci were identified at 2p11, 4q32, 16q23, and 18q12. At the same time, most of our findings in East Asian populations showed no evidence of association in European populations. In our studies drawn from East Asian populations, a polygenic risk score based on the 25 loci had a stronger association in never-smokers vs. individuals with a history of smoking (P Show less

Histiocytic sarcoma (HS) is an incurable aggressive tumor, and no consensus has been made on the treatment due to its rare occurrence. Since dogs spontaneously develop the disease and several cell lines are available, they have been advocated as translational animal models. In the present study, therefore, we explored gene mutations and aberrant molecular pathways in canine HS by next generation sequencing to identify molecular targets for treatment. Whole exome sequencing and RNA-sequencing revealed gene mutations related to receptor tyrosine kinase pathways and activation of ERK1/2, PI3K-AKT, and STAT3 pathways. Analysis by quantitative PCR and immunohistochemistry revealed that fibroblast growth factor receptor 1 (FGFR1) is over-expressed. Moreover, activation of ERK and Akt signaling were confirmed in all HS cell lines, and FGFR1 inhibitors showed dose-dependent growth inhibitory effects in two of the twelve canine HS cell lines. The findings obtained in the present study indicated that ERK and Akt signaling were activated in canine HS and drugs targeting FGFR1 might be effective in part of the cases. The present study provides translational evidence that leads to establishment of novel therapeutic strategies targeting ERK and Akt signaling in HS patients. Show less

G protein-coupled receptor class C group 5 member B (GPRC5B) is involved in extracellular glucose sensing, glucose metabolism, and insulin resistance. Many cancers require glucose at high concentrations to survive and grow. We have investigated the association between tumour GPRC5B expression and the prognosis for patients with cancer, including head-and-neck squamous cell carcinoma (HNSCC), using data from The Human Protein Atlas. The 5-year survival rate was significantly reduced in patients with HNSCC, gastric, pancreatic, colorectal, and breast cancers if their tumours exhibited high levels of GPRC5B expression. The role of GPRC5B in glucose metabolism was assessed using six HNSCC cell lines with varying levels of GPRC5B expression. High levels of GPRC5B expression were found to favour rapid cell growth. The viability of an HNSCC cell line with normal and transfected GPRC5B expression was also assessed and no differences were observed under standard culture conditions. However, under glucose-deficient culture conditions, GPRC5B-overexpressing cells exhibited increased viability and reduced apoptosis. The results highlight the association between high GPRC5B expression and poor 5-year survival rates in patients with various cancers, including HNSCC. Furthermore, we have demonstrated that GPRC5B supports cancer cell survival under glucose-depleted conditions and could be a target molecule for cancer therapy. Show less

Adequate mass and function of adipose tissues (ATs) play essential roles in preventing metabolic perturbations. The pathological reduction of ATs in lipodystrophy leads to an array of metabolic diseases. Understanding the underlying mechanisms may benefit the development of effective therapies. Several cellular processes, including autophagy and vesicle trafficking, function collectively to maintain AT homeostasis. Here, we investigated the impact of adipocyte-specific deletion of the lipid kinase phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3) on AT homeostasis and systemic metabolism in mice. We report that PIK3C3 functions in all ATs and that its absence disturbs adipocyte autophagy and hinders adipocyte differentiation, survival, and function with differential effects on brown and white ATs. These abnormalities cause loss of white ATs, whitening followed by loss of brown ATs, and impaired "browning" of white ATs. Consequently, mice exhibit compromised thermogenic capacity and develop dyslipidemia, hepatic steatosis, insulin resistance, and type 2 diabetes. While these effects of PIK3C3 largely contrast previous findings with the autophagy-related (ATG) protein ATG7 in adipocytes, mice with a combined deficiency in both factors reveal a dominant role of the PIK3C3-deficient phenotype. We have also found that dietary lipid excess exacerbates AT pathologies caused by PIK3C3 deficiency. Surprisingly, glucose tolerance is spared in adipocyte-specific PIK3C3-deficient mice, a phenotype that is more evident during dietary lipid excess. These findings reveal a crucial yet complex role for PIK3C3 in ATs, with potential therapeutic implications. Show less

The melanin-concentrating hormone (MCH) system is involved in numerous functions, including energy homeostasis, food intake, sleep, stress, mood, aggression, reward, maternal behavior, social behavior, and cognition. In rodents, MCH acts on MCHR1, a G protein-coupled receptor, which is widely expressed in the brain and abundantly localized to neuronal primary cilia. Cilia act as cells' antennas and play crucial roles in cell signaling to detect and transduce external stimuli to regulate cell differentiation and migration. Cilia are highly dynamic in terms of their length and morphology; however, it is not known if cilia length is causally regulated by MCH system activation in vivo. In the current work, we examined the effects of activation and inactivation of MCH system on cilia lengths by using different experimental models and methodologies, including organotypic brain slice cultures from rat prefrontal cortex (PFC) and caudate-putamen (CPu), in vivo pharmacological (MCHR1 agonist and antagonist GW803430), germline and conditional genetic deletion of MCHR1 and MCH, optogenetic, and chemogenetic (designer receptors exclusively activated by designer drugs (DREADD)) approaches. We found that stimulation of MCH system either directly through MCHR1 activation or indirectly through optogenetic and chemogenetic-mediated excitation of MCH-neuron, caused cilia shortening, detected by the quantification of the presence of ADCY3 protein, a known primary cilia marker. In contrast, inactivation of MCH signaling through pharmacological MCHR1 blockade or through genetic manipulations - germline deletion of MCHR1 and conditional ablation of MCH neurons - induced cilia lengthening. Our study is the first to uncover the causal effects of the MCH system in the regulation of the length of brain neuronal primary cilia. These findings place MCH system at a unique position in the ciliary signaling in physiological and pathological conditions and implicate MCHR1 present at primary cilia as a potential therapeutic target for the treatment of pathological conditions characterized by impaired primary cilia function associated with the modification of its length. Show less

Some patients with inflammatory bowel disease (IBD) who were under mesalamine treatment develop adverse reactions called "mesalamine allergy," which includes high fever and worsening diarrhea. Currently, there is no method to predict mesalamine allergy. Pharmacogenomic approaches may help identify these patients. Here we analyzed the genetic background of mesalamine intolerance in the first genome-wide association study of Japanese patients with IBD. Two independent pharmacogenetic IBD cohorts were analyzed: the MENDEL (n = 1523; as a discovery set) and the Tohoku (n = 788; as a replication set) cohorts. Genome-wide association studies were performed in each population, followed by a meta-analysis. In addition, we constructed a polygenic risk score model and combined genetic and clinical factors to model mesalamine intolerance. In the combined cohort, mesalamine-induced fever and/or diarrhea was significantly more frequent in ulcerative colitis vs Crohn's disease. The genome-wide association studies and meta-analysis identified one significant association between rs144384547 (upstream of RGS17) and mesalamine-induced fever and diarrhea (P = 7.21e-09; odds ratio = 11.2). The estimated heritability of mesalamine allergy was 25.4%, suggesting a significant correlation with the genetic background. Furthermore, a polygenic risk score model was built to predict mesalamine allergy (P = 2.95e-2). The combined genetic/clinical prediction model yielded a higher area under the curve than did the polygenic risk score or clinical model alone (area under the curve, 0.89; sensitivity, 71.4%; specificity, 90.8%). Mesalamine allergy was more common in ulcerative colitis than in Crohn's disease. We identified a novel genetic association with and developed a combined clinical/genetic model for this adverse event. Show less

Ablation of short single cones (SSCs) expressing short-wavelength-sensitive opsin (SWS1) is well analyzed in the field of regenerative retinal cells. In contrast with ablation studies, the phenomena caused by the complete deletion of SWS1 are less well-understood. To assess the effects of SWS1 deficiency on retinal structure, we established and analyzed sws1-mutant medaka. To visualize SWS1, a monoclonal anti-SWS1 antibody and transgenic reporter fish (Tg(sws1:mem-egfp)) were generated. We also developed a CRISPR/Cas-driven sws1-mutant line. Retinal structure of sws1 mutant was visualized using anti-SWS1, 1D4, and ZPR1 antibodies and coumarin derivatives and compared with wild type, Tg(sws1:mem-egfp), and another opsin (lws) mutant. Our rat monoclonal antibody specifically recognized medaka SWS1. Sws1 mutant retained regularly arranged cone mosaic as lws mutant and its SSCs had neither SWS1 nor long wavelength sensitive opsin. Depletion of sws1 did not affect the expression of long wavelength sensitive opsin, and vice versa. ZPR1 antibody recognized arrestin spread throughout double cones and long single cones in wild-type, transgenic, and sws1-mutant lines. Comparative observation of sws1-mutant and wild-type retinas revealed that ZPR1 negativity is not a marker for SSCs with SWS1, but SSCs themselves. Loss of functional sws1 did not cause retinal degeneration, indicating that sws1 is not essential for cone mosaic development in medaka. Our two fish lines, one with visualized SWS1 and the other lacking functional SWS1, offer an opportunity to study neural network synapsing with SSCs and to clarify the role of SWS1 in vision. Show less

Dysregulation of glucagon is associated with the pathophysiology of type 2 diabetes. We previously reported that postprandial hyperglucagonemia is more obvious than fasting hyperglucagonemia in type 2 diabetes patients. However, which nutrient stimulates glucagon secretion in the diabetic state and the underlying mechanism after nutrient intake are unclear. To answer these questions, we measured plasma glucagon levels in diabetic mice after oral administration of various nutrients. The effects of nutrients on glucagon secretion were assessed using islets isolated from diabetic mice and palmitate-treated islets. In addition, we analyzed the expression levels of branched chain amino acid (BCAA) catabolism-related enzymes and their metabolites in diabetic islets. We found that protein, but not carbohydrate or lipid, increased plasma glucagon levels in diabetic mice. Among amino acids, BCAAs, but not the other essential or nonessential amino acids, increased plasma glucagon levels. BCAAs also directly increased the intracellular calcium concentration in α cells. When BCAAs transport was suppressed by an inhibitor of system L-amino acid transporters, glucagon secretion was reduced even in the presence of BCAAs. We also found that the expression levels of BCAA catabolism-related enzymes and their metabolite contents were altered in diabetic islets and palmitate-treated islets compared to control islets, indicating disordered BCAA catabolism in diabetic islets. Furthermore, BCKDK inhibitor BT2 suppressed BCAA-induced hypersecretion of glucagon in diabetic islets and palmitate-treated islets. Taken together, postprandial hypersecretion of glucagon in the diabetic state is attributable to disordered BCAA catabolism in pancreatic islet cells. Show less

Songbirds are one of the few animal taxa that possess vocal learning abilities. Different species of songbirds exhibit species-specific learning programs during song acquisition. Songbirds with open-ended vocal learning capacity, such as the canary, modify their songs during adulthood. Nevertheless, the neural molecular mechanisms underlying open-ended vocal learning are not fully understood. We investigated the singing-driven expression of neural activity-dependent genes (Arc, Egr1, c-fos, Nr4a1, Sik1, Dusp6, and Gadd45β) in the canary to examine a potential relationship between the gene expression level and the degree of seasonal vocal plasticity at different ages. The expression of these genes was differently regulated throughout the critical period of vocal learning in the zebra finch, a closed-ended song learner. In the canary, the neural activity-dependent genes were induced by singing in the song nuclei throughout the year. However, in the vocal motor nucleus, the robust nucleus of the arcopallium (RA), all genes were regulated with a higher induction rate by singing in the fall than in the spring. The singing-driven expression of these genes showed a similar induction rate in the fall between the first year juvenile and the second year adult canaries, suggesting a seasonal, not age-dependent, regulation of the neural activity-dependent genes. By measuring seasonal vocal plasticity and singing-driven gene expression, we found that in RA, the induction intensity of the neural activity-dependent genes was correlated with the state of vocal plasticity. These results demonstrate a correlation between vocal plasticity and the singing-driven expression of neural activity-dependent genes in RA through song development, regardless of whether a songbird species possesses an open- or closed-ended vocal learning capacity. Show less