RNA G-quadruplexes (RG4s) appear to be important in post-transcriptional gene regulation, but their pathophysiological functions remain unknown. MicroRNA-26a (miR-26a) is emerging as a therapeutic tar Show more
RNA G-quadruplexes (RG4s) appear to be important in post-transcriptional gene regulation, but their pathophysiological functions remain unknown. MicroRNA-26a (miR-26a) is emerging as a therapeutic target for various human diseases, however the mechanisms underlying endogenous miR-26a regulation are poorly understood. Herein, we study the role of RG4 in miR-26a expression and function in vitro and in vivo. Putative RG4s within liver-enriched miRNAs were predicted by bioinformatic analysis, and the presence of an RG4 structure in the miR-26a-1 precursor (pre-miR-26a-1) was further analyzed by biophysical and biochemical methods. RG4 stabilizers, pre-miR-26a-1 overexpression plasmids, and luciferase reporter assays were used to assess the effect of RG4 on pre-miR-26a-1 maturation. Both miR-26a knock-in and knockout mouse models were employed to investigate the influence of this RG4 on miR-26a expression and function. Moreover, the interaction between RG4 in pre-miR-26a-1 and DEAH-box helicase 36 (DHX36) was determined by biophysical and molecular methods. Finally, miR-26a processing and DHX36 expression were quantified in the livers of obese mice. We identify a guanine-rich sequence in pre-miR-26a-1 that can fold into an RG4 structure. This RG4 impairs pre-miR-26a-1 maturation, resulting in a decrease in miR-26a expression and subsequently an increase in miR-26a cognate targets. In line with known miR-26a functions, this RG4 can regulate hepatic insulin sensitivity and lipid metabolism in vitro and in vivo. Furthermore, we reveal that DHX36 can bind and unwind this RG4 structure, thereby enhancing miR-26a maturation. Intriguingly, there is a concordant decrease of miR-26a maturation and DHX36 expression in obese mouse livers. Our findings define a dynamic DHX36/RG4/miR-26a regulatory axis during obesity, highlighting an important role of RG4 in physiology and pathology. Specific RNA sequences called G-quadruplexes (or RG4) appear to be important in post-transcriptional gene regulation. Obesity leads to the formation of these RG4 structures in pre-miR-26a-1 molecules, impairing the maturation and function of miR-26a, which has emerged as a therapeutic target in several diseases. This contributes to hepatic insulin resistance and the dysregulation of liver metabolism. Show less
Long noncoding RNAs (lncRNAs) are considered critical regulators in cancers; however, the clinical significance and mechanisms of MAPKAPK5-AS1 (hereinafter referred to as MK5-AS1) in colorectal cancer Show more
Long noncoding RNAs (lncRNAs) are considered critical regulators in cancers; however, the clinical significance and mechanisms of MAPKAPK5-AS1 (hereinafter referred to as MK5-AS1) in colorectal cancer (CRC) remain mostly unknown. In this study, quantitative real-time PCR (qPCR) and western blotting were utilized to detect the levels of MK5-AS1, let-7f-1-3p and MK5 (MAPK activated protein kinase 5) in CRC tissues and cell lines. The biological functions of MK5-AS1, let-7f-1-3p and MK5 in CRC cells were explored using Cell Counting Kit-8 (CCK8), colony formation and transwell assays. The potential mechanisms of MK5-AS1 were evaluated by RNA pull-down, RNA immunoprecipitation (RIP), dual luciferase reporter assay, chromatin immunoprecipitation (ChIP) and bioinformatics analysis. The effects of MK5-AS1 and MK5 on CRC were investigated by a xenotransplantation model. We confirmed that MK5-AS1 was significantly increased in CRC tissues. Knockdown of MK5-AS1 suppressed cell migration and invasion in vitro and inhibited lung metastasis in mice. Mechanistically, MK5-AS1 regulated SNAI1 expression by sponging let-7f-1-3p and cis-regulated the adjacent gene MK5. Moreover, MK5-AS1 recruited RBM4 and eIF4A1 to promote the translation of MK5. Our study verified that MK5 promoted the phosphorylation of c-Jun, which activated the transcription of SNAI1 by directly binding to its promoter. MK5-AS1 cis-regulated the nearby gene MK5 and acted as a let-7f-1-3p sponge, playing a vital role in CRC tumorigenesis. This study could provide novel insights into molecular therapeutic targets of CRC. Show less
Thyroid hormone is crucial for regulating lipid and glucose metabolism, which plays essential role in maintaining the health of pregnant women and their offspring. However, the current literature is j Show more
Thyroid hormone is crucial for regulating lipid and glucose metabolism, which plays essential role in maintaining the health of pregnant women and their offspring. However, the current literature is just focusing on the development of offspring born to the untreated mothers with hypothyroidism, rather than mothers themselves. Additionally, the interaction between hypothyroidism and pregnancy, and its impact on the women's health are still elusive. Therefore, this study was designed to compare the metabolic differences in dams with hypothyroidism starting before pregnancy and after pregnancy. Pre-pregnant hypothyroidism was generated in 5-week-old female C57/BL/6J mice using iodine-deficient diet containing 0.15% propylthiouracil for 4 weeks, and the hypothyroidism was maintained until delivery. Gestational hypothyroidism was induced in dams after mating, using the same diet intervention until delivery. Compared with normal control, gestational hypothyroidism exhibited more prominent increase than pre-pregnant hypothyroidism in plasma total cholesterol and low-density lipoprotein cholesterol, and caused hepatic triglycerides accumulation. Similarly, more significant elevations of protein expressions of SREBP1c and p-ACL, while more dramatic inhibition of CPT1A and LDL-R levels were also observed in murine livers with gestational hypothyroidism than those with pre-pregnant hypothyroidism. Moreover, the murine hepatic levels of total cholesterol and gluconeogenesis were dramatically and equally enhanced in two hypothyroid groups, while plasma triglycerides and protein expressions of p-AKT, p-FoxO1 and APOC3 were reduced substantially in two hypothyroid groups. Taken together, our current study illuminated that gestational hypothyroidism may elicit more pronounced lipid dysregulation in dams than dose the pre-pregnant hypothyroidism. Show less
Melanocortin-4 receptors (MC4Rs) are key regulators of energy homeostasis and adipose deposition in the central nervous system. Considering that MC4R expression regions and function-related research m Show more
Melanocortin-4 receptors (MC4Rs) are key regulators of energy homeostasis and adipose deposition in the central nervous system. Considering that MC4R expression regions and function-related research mainly focus on the paraventricular nucleus (PVN), little is known about their distribution throughout the mouse brain, although its messenger RNA distribution has been analyzed in the rat. Therefore, MC4R protein localization in mouse neurons was the focus of this study. MC4R protein distribution was assessed in mice through immunofluorescence and Western blotting. MC4R was differentially expressed throughout the arcuate nucleus (ARC), nucleus of the solitary tract (NTS), raphe pallidus (RPa), medial cerebellar nucleus, intermediolateral nucleus, and brainstem. The highest MC4R protein levels were found in the ARC and ventromedial hypothalamic nucleus, while they were significantly lower in the parabrachial nucleus and NTS. The lowest MC4R protein levels were found in the PVN; there was no difference in the protein levels between the area postrema and RPa. These data provide a basic characterization of MC4R-expressing neurons and protein distribution in the mouse brain and may aid further research on its role in energy homeostasis. Show less
Aging-related cognitive ability impairments are one of the main threats to public health, and impaired hippocampal neurogenesis is a major cause of cognitive decline during aging. However, the regulat Show more
Aging-related cognitive ability impairments are one of the main threats to public health, and impaired hippocampal neurogenesis is a major cause of cognitive decline during aging. However, the regulation of adult neurogenesis in the hippocampus requires further study. Here, we investigated the role of microRNA-153 (miR-153), a highly conserved microRNA in mice and humans, in adult neurogenesis. During the passaging of neural stem cells (NSCs) in vitro, endogenous miR-153 expression was downregulated, with a decrease in neuronal differentiation ability. In addition, miR-153 overexpression increased the neurogenesis of NSCs. Further studies showed that miR-153 regulated neurogenesis by precisely targeting the Notch signaling pathway through inhibition of Jagged1 and Hey2 translation. In vivo analysis demonstrated that miR-153 expression was decreased in the hippocampi of aged mice with impaired cognitive ability, and that miR-153 overexpression in the hippocampus promoted neurogenesis and markedly increased the cognitive abilities of the aged mice. Overall, our findings revealed that miR-153 affected neurogenesis by regulating the Notch signaling pathway and elucidated the function of miR-153 in aging-related, hippocampus-dependent cognitive ability impairments, and neurodegenerative diseases. Show less
The Jianchang duck is mainly distributed in Southwest China, and has the characteristics of fast growth rate and strong abilities in lipid deposition in the liver. In order to investigate the effects Show more
The Jianchang duck is mainly distributed in Southwest China, and has the characteristics of fast growth rate and strong abilities in lipid deposition in the liver. In order to investigate the effects of domestication process on formation of the unique characteristics of Jianchang duck, the whole genome of sixteen individuals and three pooling of Jianchang duck were re-sequenced, and genome data of 70 mallards and 83 domestic ducks from thirteen different places in China were obtained from NCBI. The population stratification and evolution analysis showed gene exchanges existed between the Jianchang and other domestic duck populations, as well as Jianchang ducks and mallards. Genomic comparison between mallards and Jianchang ducks showed genes, including Show less
An AP2 family gene CBX1 is involved in mycorrhizal symbiosis and growth of Lotus japonicus. APETALA 2 (AP2) transcriptional regulator is highly conserved in plants. CBX1 from Lotus japonicus is a memb Show more
An AP2 family gene CBX1 is involved in mycorrhizal symbiosis and growth of Lotus japonicus. APETALA 2 (AP2) transcriptional regulator is highly conserved in plants. CBX1 from Lotus japonicus is a member of AP2 family. AMF (Arbuscular mycorrhizal fungi) inoculation experiment demonstrated that expression of CBX1 was significantly induced by AMF. Further promoter analysis showed that the - 764 to - 498 bp region of the CBX1 promoter containing CTTC motif is the AMF responsive region. Functional analysis of cbx1 mutant suggested CBX1 is critical for mycorrhizal symbiosis, especially for arbuscule formation. Moreover, under noncolonized condition, overexpression of CBX1 reduced the root length of L. japonicus but increased the size of root system and shoot length, whereas cbx1 mutant reduced the root size and shoot length, but not effect on root length. In addition, cbx1 altered activity of monolignol biosynthetic gene and increased lignin levels. Collectively, these data indicated that CBX1 is a positive regulator of symbiotic activity and plays roles in the growth of L. japonicus. Show less
Visceral obesity and fatty liver are prevalent in postmenopausal women. The stilbene-rich extract of Cajanus cajan (L.) Millsp. has been reported to prevent ovariectomy-induced and diet-induced weight Show more
Visceral obesity and fatty liver are prevalent in postmenopausal women. The stilbene-rich extract of Cajanus cajan (L.) Millsp. has been reported to prevent ovariectomy-induced and diet-induced weight gain in animal models, and stilbenoids from C. cajan are thought to have the potential to prevent postmenopausal obesity and fatty liver. Cajanolactone A (CLA) is the main stilbenoid from C. cajan with osteoblastogenic promoting activity. This study investigated the potential of CLA to prevent postmenopausal obesity and fatty liver. Underlying mechanisms were also investigated. Ovariectomized C57BL/6 mice fed a regular diet were used as mimics of postmenopausal women and given 10, 20, or 40 mg/kg/d of CLA, 0.1 mg/kg/d of estradiol valerate (EV, positive control), or vehicle (OVX) orally for 16 weeks. Mice of the same age subjected to a sham operation were used as control (Sham). Body weights were recorded every 2 weeks for 16 weeks. Body compositions were analyzed via micro-CT. Serum levels of lipids, adipocytokines and aminotransferases were measured using the relevant kits. mRNA levels of genes of interest were detected by RT-qPCR. Proteomic study of perigonadal white adipose tissue (pWAT) was performed using tandem-mass-tags-based proteomic technology combined with Parallel-Reaction-Monitoring (PRM) validation. CLA showed potential equivalent to that of EV to prevent ovariectomy-induced overweight, obesity, dyslipidemia, liver steatosis and liver dysfunction, but did not prevent uterine atrophy. In the liver, CLA significantly inhibited ovariectomy-induced upregulation in expression of lipogenic genes SREBP-1c and ChREBP, and stimulated the mRNA expression of apolipoprotein B gene ApoB. In pWAT, CLA reversed, or partially reversed ovariectomy-induced downregulation in the expression of a number of metabolism- and mitochondrial-function-related proteins, including Ndufa3, Pcx, Pdhb, Acly, Acaca, Aldh2, Aacs and Echs1. In addition, ovariectomy-inhibited mRNA expression of Pdhb, Aacs, Acsm5, Echs1, and Aldh2 genes in pWAT was also reversed. CLA was demonstrated to be a potential non-estrogen-like drug candidate for prevention of postmenopausal obesity and fatty liver. The underlying mechanism might involve the inhibition of lipogenesis and promotion of triglycerides output in the liver, and the promotion of metabolism and mitochondrial functions of visceral white adipose tissue. Show less
APOA5 is a low-abundance exchangeable apolipoprotein that plays critical roles in human triglyceride (TG) metabolism. Indeed, aberrations in the plasma concentration or structure of APOA5 are linked t Show more
APOA5 is a low-abundance exchangeable apolipoprotein that plays critical roles in human triglyceride (TG) metabolism. Indeed, aberrations in the plasma concentration or structure of APOA5 are linked to hypertriglyceridemia, hyperchylomicronemia, myocardial infarction risk, obesity, and coronary artery disease. While it has been successfully produced at low yield in bacteria, the resulting protein had limitations for structure-function studies due to its low solubility under physiological buffer conditions. We hypothesized that the yield and solubility of recombinant APOA5 could be increased by: Show less
The metastasis of cervical cancer has always been a clinical challenge. We investigated the effects of low-dose naltrexone (LDN) on the epithelial mesenchymal transition of cervical cancer cells in vi Show more
The metastasis of cervical cancer has always been a clinical challenge. We investigated the effects of low-dose naltrexone (LDN) on the epithelial mesenchymal transition of cervical cancer cells in vitro as well as its influence on macrophage polarization and associated cytokines in vivo. The results suggested that LDN supressed the proliferation, migration and invasion abilities and promote their apoptosis in Hela cells, whereas the opioid growth factor receptor (OGFr) silenced significantly reversed these effects in vitro. Knockdown the expression of OGFr, the inhibitory of LDN on EMT was weakened. LDN could inhibit cervical cancer progression in nude mice. In additon, LDN indirectly reduced the number of tumor-associated macrophages (TAMs), mainly M2 macrophages, and decreased expression of anti-inflammatory factor IL-10 in the serum of nude mice. These findings demonstrate that LDN could be a potential treatment for cervical cancer. Show less
Recent studies have demonstrated that commercially available lipid-lowering drugs cause various side effects; therefore, searching for anti-hyperlipidaemic compounds with lower toxicity is a research Show more
Recent studies have demonstrated that commercially available lipid-lowering drugs cause various side effects; therefore, searching for anti-hyperlipidaemic compounds with lower toxicity is a research hotspot. This study was designed to investigate whether the marine-derived compound, 5-hydroxy-3-methoxy-5-methyl-4-butylfuran-2(5H)-one, has an anti-hyperlipidaemic activity, and the potential underlying mechanism in vitro. Results showed that the furanone had weaker cytotoxicity compared to positive control drugs. In RAW 264.7 cells, the furanone significantly lowered ox-LDL-induced lipid accumulation (~50%), and its triglyceride (TG)-lowering effect was greater than that of liver X receptor (LXR) agonist T0901317. In addition, it significantly elevated the protein levels of peroxisome proliferator-activated receptors (PPARα) and ATP-binding cassette (ABC) transporters, which could be partially inhibited by LXR antagonists, GSK2033 and SR9243. In HepG2 cells, it significantly decreased oleic acid-induced lipid accumulation, enhanced the protein levels of low-density lipoprotein receptor (LDLR), ABCG5, ABCG8 and PPARα, and reduced the expression of sterol regulatory element-binding protein 2 (~32%). PPARα antagonists, GW6471 and MK886, could significantly inhibit the furanone-induced lipid-lowering effect. Furthermore, the furanone showed a significantly lower activity on the activation of the expression of lipogenic genes compared to T0901317. Taken together, the furanone exhibited a weak cytotoxicity but had powerful TC- and TG-lowering effects most likely through targeting LXRα and PPARα, respectively. These findings indicate that the furanone has a potential application for the treatment of dyslipidaemia. Show less
Melanocortin-4 receptor (MC4R) plays important roles in regulation of multiple physiological processes, and interaction of MC4R and melanocortin receptor accessory protein 2 (MRAP2) is suggested to pl Show more
Melanocortin-4 receptor (MC4R) plays important roles in regulation of multiple physiological processes, and interaction of MC4R and melanocortin receptor accessory protein 2 (MRAP2) is suggested to play pivotal role in energy balance of vertebrates. Topmouth culter ( Show less
Mlxipl regulates glucose metabolism, lipogenesis and tumorigenesis and has a wide-ranging impact on human health and disease. However, the role of Mlxipl in neuropathic pain remains unknown. In this s Show more
Mlxipl regulates glucose metabolism, lipogenesis and tumorigenesis and has a wide-ranging impact on human health and disease. However, the role of Mlxipl in neuropathic pain remains unknown. In this study, we found that Mlxipl was increased in the ipsilateral L4-L6 spinal dorsal horn after Spared Nerve Injury surgery. Knockdown of Mlxipl in the ipsilateral L4-L6 spinal dorsal horn by intraspinal microinjection aggravated Spared Nerve Injury-induced mechanical allodynia and inflammation in the spinal dorsal horn, on the contrary, overexpression of Mlxipl inhibited mechanical allodynia and inflammation. Subsequently, the rat Mlxipl promoter was analyzed using bioinformatics methods to predict the upstream transcription factor cJun. Luciferase assays and ChIP-qPCR confirmed that cJun bound to the promoter of Mlxipl and enhanced its expression. Finally, we demonstrated that Mlxipl inhibited the inflammatory responses of lipopolysaccharide-induced microglia and that Mlxipl was regulated by the transcription factor cJun. These findings suggested that cJun-induced Mlxipl upregulation in the spinal dorsal horn after peripheral nerve injury provided a protective mechanism for the development and progression of neuropathic pain by inhibiting microglial-derived neuroinflammation. Targeting Mlxipl in the spinal dorsal horn might represent an effective strategy for the treatment of neuropathic pain. Show less
Transarterial chemoembolization (TACE) has been considered the standard treatment for intermediate-stage hepatocellular carcinoma according to BCLC algorithm. However, it has been unclear about the TA Show more
Transarterial chemoembolization (TACE) has been considered the standard treatment for intermediate-stage hepatocellular carcinoma according to BCLC algorithm. However, it has been unclear about the TACE-related predictive bio-markers and underlying molecular mechanisms. This investigation revealed that HCCs with higher HIF-1α suffered from unfavorable OS after TACE. mRNA expression microarray revealed that HIF-1α was potential target of p-STAT3 which was verified by ChIP and immunoblotting assay. Activation of IL-6/STAT3/HIF-1α signaling was found to promote EMT and chemoresistance to Doxorubicin Show less
Zhi Liu, Fuyun Sun, Zitian Liu+8 more · 2020 · Medical science monitor : international medical journal of experimental and clinical research · added 2026-04-24
BACKGROUND The mechanism by which sleeve gastrectomy (SG) improves glycometabolism has remained unclear so far. Increasing evidence has demonstrated that bone is a regulator of glucose metabolism, and Show more
BACKGROUND The mechanism by which sleeve gastrectomy (SG) improves glycometabolism has remained unclear so far. Increasing evidence has demonstrated that bone is a regulator of glucose metabolism, and osteoblast-derived forkhead box O1 (FoxO1) and lipocalin-2 (LCN2) are regulators of energy metabolism. The aim of this study was to investigate whether the FOXO1/LCN2 signaling pathway is involved in the anti-diabetic effect of SG. MATERIAL AND METHODS Insulin resistance was induced in Wistar rats, which were then intraperitoneally injected with streptozotocin to induce a type 2 diabetic state. Levels of fasting blood glucose, serum insulin, HbA1c, and LCN2 were analyzed at corresponding time points after SG and sham surgeries. The expressions of FOXO1, LCN2, and the melanocortin 4 receptor (MC4R) in bone and hypothalamus were detected by immunofluorescence. FOXO1 siRNA was applied to downregulate FOXO1 expression in osteoblasts of rats. The influence of FOXO1 gene on expression of LCN2 was investigated in cultured osteoblasts by western blot and PCR. RESULTS Glucose metabolism in the SG group was significantly improved. The LCN2 expression in bone in the SG group was higher than that in the sham group, whereas FOXO1 expression in the SG group was lower than that in the sham group. The binding rate of LCN2 and MC4R in the hypothalamus was also higher in the SG group compared with that in the sham group. The downregulation of FOXO1 expression in osteoblasts was accompanied by upregulation of LCN2 expression. CONCLUSIONS These results suggest that the FOXO1/LCN2 signaling pathway participates in the anti-diabetic effect of SG. Show less
Fusobacterium nucleatum, an anaerobic oral opportunistic pathogen associated with periodontitis, has been considered to be associated with the development of oral squamous cell carcinoma (OSCC). Howev Show more
Fusobacterium nucleatum, an anaerobic oral opportunistic pathogen associated with periodontitis, has been considered to be associated with the development of oral squamous cell carcinoma (OSCC). However, the initial host molecular alterations induced by F. nucleatum infection which may promote predisposition to malignant transformation through epithelial-mesenchymal transition (EMT) have not yet been clarified. In the present study, we monitored the ability of F. nucleatum to induce EMT-associated features, and our results showed that F. nucleatum infection promoted cell migration in either noncancerous human immortalized oral epithelial cells (HIOECs) or the two OSCC cell lines SCC-9 and HSC-4, but did not accelerate cell proliferation or cell cycle progression. Mesenchymal markers, including N-cadherin, Vimentin, and SNAI1, were upregulated, while E-cadherin was decreased and was observed to translocate to the cytoplasm. Furthermore, FadA adhesin and heat-inactivated F. nucleatum were found to cause a similar effect as the viable bacterial cells. The upregulated lncRNA MIR4435-2HG identified by the high-throughput sequencing was demonstrated to negatively regulate the expression of miR-296-5p, which was downregulated in F. nucleatum-infected HIOECs and SCC-9 cells. The binding of MIR4435-2HG and miR-296-5p was validated via a dual-luciferase reporter assay. Additionally, knockdown of MIR4435-2HG with siRNA leads to a decrease in SNAI1 expression, while miR-296-5p could further negatively and indirectly regulate SNAI1 expression via Akt2. Therefore, our study demonstrated that F. nucleatum infection could trigger EMT via lncRNA MIR4435-2HG/miR-296-5p/Akt2/SNAI1 signaling pathway, and EMT process may be a probable link between F. nucleatum infection and initiation of oral epithelial carcinomas. Show less
WW domain containing E3 Ub-protein ligase 2 (WWP2) plays an important role in tumor progression as an E3 ligase of PTEN. Here, we investigated the role of WWP2 in gastric cancer (GC). We found that WW Show more
WW domain containing E3 Ub-protein ligase 2 (WWP2) plays an important role in tumor progression as an E3 ligase of PTEN. Here, we investigated the role of WWP2 in gastric cancer (GC). We found that WWP2 is overexpressed in GC tissues, which is closely related to poor prognosis of GC patients. Using a WWP2-shRNA lentivirus expressing system, we established WWP2 stable-knockdown GC cell lines and found that knockdown of WWP2 inhibits the proliferation of GC cells both in vitro and in vivo. Also, WWP2 silencing induced the up-regulation of PTEN protein level and down-regulation of AKT phosphorylation level. We further investigated the role of PTEN in this regulating process by performing rescue assay and found that PTEN is essential for WWP2-mediated regulation of GC cells proliferation. Taken together, our results demonstrated that WWP2 promotes proliferation of GC cells by downregulating PTEN, which may provide new therapeutic targets for GC. Show less
Plasticity of neoplasia, whereby cancer cells attain stem-cell-like properties, is required for disease progression and represents a major therapeutic challenge. We report that in breast cancer cells Show more
Plasticity of neoplasia, whereby cancer cells attain stem-cell-like properties, is required for disease progression and represents a major therapeutic challenge. We report that in breast cancer cells NANOG, SNAIL and NODAL transcripts manifest multiple isoforms characterized by different 5' Untranslated Regions (5'UTRs), whereby translation of a subset of these isoforms is stimulated under hypoxia. The accumulation of the corresponding proteins induces plasticity and "fate-switching" toward stem cell-like phenotypes. Mechanistically, we observe that mTOR inhibitors and chemotherapeutics induce translational activation of a subset of NANOG, SNAIL and NODAL mRNA isoforms akin to hypoxia, engendering stem-cell-like phenotypes. These effects are overcome with drugs that antagonize translational reprogramming caused by eIF2α phosphorylation (e.g. ISRIB), suggesting that the Integrated Stress Response drives breast cancer plasticity. Collectively, our findings reveal a mechanism of induction of plasticity of breast cancer cells and provide a molecular basis for therapeutic strategies aimed at overcoming drug resistance and abrogating metastasis. Show less
Macroautophagy/autophagy plays key roles in development, oncogenesis, and cardiovascular and metabolic diseases. Autophagy-specific class III phosphatidylinositol 3-kinase complex I (PtdIns3K-C1) is e Show more
Macroautophagy/autophagy plays key roles in development, oncogenesis, and cardiovascular and metabolic diseases. Autophagy-specific class III phosphatidylinositol 3-kinase complex I (PtdIns3K-C1) is essential for autophagosome formation. However, the regulation of this complex formation requires further investigation. Here, we discovered that STYK1 (serine/threonine/tyrosine kinase 1), a member of the receptor tyrosine kinases (RTKs) family, is a new upstream regulator of autophagy. We discovered that STYK1 facilitated autophagosome formation in human cells and zebrafish, which was characterized by elevated LC3-II and lowered SQSTM1/p62 levels and increased puncta formation by several marker proteins, such as ATG14, WIPI1, and ZFYVE1. Moreover, we observed that STYK1 directly binds to the PtdIns3K-C1 complex as a homodimer. The binding with this complex was promoted by Tyr191 phosphorylation, by means of which the kinase activity of STYK1 was elevated. We also demonstrated that STYK1 elevated the serine phosphorylation of BECN1, thereby decreasing the interaction between BECN1 and BCL2. Furthermore, we found that STYK1 preferentially facilitated the assembly of the PtdIns3K-C1 complex and was required for PtdIns3K-C1 complex kinase activity. Taken together, our findings provide new insights into autophagy induction and reveal evidence of novel crosstalk between the components of RTK signaling and autophagy. Show less
Growth differentiation factor 15 (GDF15), a member of the transforming growth factor β (TGF-β) superfamily, is a prognostic biomarker of cervical cancer. In addition, GDF15 has been reported to enhanc Show more
Growth differentiation factor 15 (GDF15), a member of the transforming growth factor β (TGF-β) superfamily, is a prognostic biomarker of cervical cancer. In addition, GDF15 has been reported to enhance the migration of colorectal cancer cells and liver cancer stem-like cells. However, the mechanism by which GDF15 promotes cervical cancer cell migration is not completely understood. Here, we report that GDF15 expression is enhanced in cervical cancer tissues, as well as in cultured cervical cancer cells. ShGDF15 transfection markedly inhibited expression of Vimentin, N-cadherin and Snail1, and resulted in up-regulation of E-cadherin expression in HT-3 and HeLa cells. Moreover, knockdown of GDF15 suppressed wound healing rate and reduced the number of invasive cells. Furthermore, knockdown of GDF15 significantly suppressed the expression of phosphorylated Smad2 and Smad3. The addition of TGF-β1 partially abolished the inhibitory effects of GDF15 knockdown on the migration and invasion of cervical cancer cells. In summary, we report here that GDF15 knockdown inhibits migration and invasion of cervical cancer cells in vitro through the TGF-β/Smad2/3/Snail1 pathway. Show less
Juvenile neuronal ceroid lipofuscinosis (JNCL, aka. juvenile Batten disease or CLN3 disease) is a lysosomal storage disease characterized by progressive blindness, seizures, cognitive and motor failur Show more
Juvenile neuronal ceroid lipofuscinosis (JNCL, aka. juvenile Batten disease or CLN3 disease) is a lysosomal storage disease characterized by progressive blindness, seizures, cognitive and motor failures, and premature death. JNCL is caused by mutations in the Ceroid Lipofuscinosis, Neuronal 3 (CLN3) gene, whose function is unclear. Although traditionally considered a neurodegenerative disease, CLN3 disease displays eye-specific effects: Vision loss not only is often one of the earliest symptoms of JNCL, but also has been reported in non-syndromic CLN3 disease. Here we described the roles of CLN3 protein in maintaining healthy retinal pigment epithelium (RPE) and normal vision. Using electroretinogram, fundoscopy and microscopy, we showed impaired visual function, retinal autofluorescent lesions, and RPE disintegration and metaplasia/hyperplasia in a Cln3 ~ 1 kb-deletion mouse model [1] on C57BL/6J background. Utilizing a combination of biochemical analyses, RNA-Seq, Seahorse XF bioenergetic analysis, and Stable Isotope Resolved Metabolomics (SIRM), we further demonstrated that loss of CLN3 increased autophagic flux, suppressed mTORC1 and Akt activities, enhanced AMPK activity, and up-regulated gene expression of the autophagy-lysosomal system in RPE-1 cells, suggesting autophagy induction. This CLN3 deficiency induced autophagy induction coincided with decreased mitochondrial oxygen consumption, glycolysis, the tricarboxylic acid (TCA) cycle, and ATP production. We also reported for the first time that loss of CLN3 led to glycogen accumulation despite of impaired glycogen synthesis. Our comprehensive analyses shed light on how loss of CLN3 affect autophagy and metabolism. This work suggests possible links among metabolic impairment, autophagy induction and lysosomal storage, as well as between RPE atrophy/degeneration and vision loss in JNCL. Show less
DUSP6 functions as an important negative feedback component of the MAPK/ERK signaling pathway. Although DUSP6 expression is tightly regulated by ERK1/2 signaling, the molecular mechanism of this regul Show more
DUSP6 functions as an important negative feedback component of the MAPK/ERK signaling pathway. Although DUSP6 expression is tightly regulated by ERK1/2 signaling, the molecular mechanism of this regulation remains partially understood. In this work, we show that the transcriptional repressor CIC functions downstream of the ERK1/2 signaling to negatively regulate DUSP6 expression. CIC directly represses DUSP6 transcription by binding to three Show less
Gonadotropin-releasing hormone (GnRH) controls synthesis of sex steroid hormones through hypothalamic-pituitary-gonadal (HPG) axis in vertebrates. But in mollusks, research on GnRH and steroidogenesis Show more
Gonadotropin-releasing hormone (GnRH) controls synthesis of sex steroid hormones through hypothalamic-pituitary-gonadal (HPG) axis in vertebrates. But in mollusks, research on GnRH and steroidogenesis pathways is still limited. In this study, we first identified two gonadotropin receptor like genes (LGR and LGR5L) and four steroidogenesis-related genes (CYP17A, HSD17B12, HSD3B1 and HSD3B2) in the scallop Patinopecten yessoensis. By examining the expression of 11 genes in the ganglia and/or gonad as well as the concentration of progesterone, testosterone and estradiol in the gonad, we postulate that a potential GnRH signaling pathway (GnRH-GnRHR-GPB5-LGR/LGR5L) in the cerebral and pedal ganglia (CPG) and steroidogenesis pathway (CYP17A, HSD17B12 and HSD3B1) in the gonad are involved in regulating sex steroid hormones. E Show less
Cip1, a newly identified yeast analog of p21, is a Cln3-CDK inhibitor that negatively regulates cell-cycle START. However, its function remains poorly understood. In this study, we found that deletion Show more
Cip1, a newly identified yeast analog of p21, is a Cln3-CDK inhibitor that negatively regulates cell-cycle START. However, its function remains poorly understood. In this study, we found that deletion of Show less
Imbalanced mitochondrial fission/fusion, a major cause of apoptotic cell death, often results from dysregulation of Drp1 phosphorylation of two serines, S616 and S637. Whereas kinases for Drp1-S616 ph Show more
Imbalanced mitochondrial fission/fusion, a major cause of apoptotic cell death, often results from dysregulation of Drp1 phosphorylation of two serines, S616 and S637. Whereas kinases for Drp1-S616 phosphorylation are well-described, phosphatase(s) for its dephosphorylation remains unclear. Here, we show that dual-specificity phosphatase 6 (DUSP6) dephosphorylates Drp1-S616 independently of its known substrates ERK1/2. DUSP6 keeps Drp1-S616 phosphorylation levels low under normal conditions. The stability and catalytic function of DUSP6 are maintained through conjugation of small ubiquitin-like modifier-1 (SUMO1) and SUMO2/3 at lysine-234 (K234), which is disrupted during oxidation through transcriptional up-regulation of SUMO-deconjugating enzyme, SENP1, causing DUSP6 degradation by ubiquitin-proteasome. deSUMOylation underlies DUSP6 degradation, Drp1-S616 hyperphosphorylation, mitochondrial fragmentation, and apoptosis induced by H Show less
Clinical studies have demonstrated that trimetazidine (TMZ) possesses a synergistic hypolipidemic effect together with statins, but the underlying mechanism remains to be elucidated. The present study Show more
Clinical studies have demonstrated that trimetazidine (TMZ) possesses a synergistic hypolipidemic effect together with statins, but the underlying mechanism remains to be elucidated. The present study aimed to investigate the role of TMZ in non‑alcoholic fatty liver disease (NAFLD). By investigating the TMZ treatment of NAFLD, it was identified that high‑fat diet (HFD) mice exhibit significant changes in several physiologic indices, including body weight, plasma lipids and glucose tolerance. Notably, hepatocyte bullous steatosis and fibrosis in HFD mice are greatly attenuated by 8 weeks of TMZ treatments. The results of the present study also indicated that the expression of carbohydrate‑responsive element‑binding protein (ChREBP), fatty acid synthase and acetyl‑CoA carboxylase were all significantly reduced in the HFD + TMZ group compared with the HFD group. In order to confirm the hypothesis in vitro, the palmitate‑treated liver cancer cell line (HepG2) was employed and similar results were obtained in TMZ‑treated HepG2 cells. Furthermore, TMZ markedly upregulated the AMP‑activated protein kinase (AMPK) signaling pathway and reduced the expression of forkhead box O1 (FOXO1) in the cells, while these effects controlled by TMZ were abolished by the AMPK inhibitor Compound C. The present study reported that knockdown of FOXO1 expression by FOXO1 small interfering RNA resulted in a reduction of ChREBP protein expression and post‑transcriptional activity. In summary, for the first time, to the best of the authors' knowledge, the present study revealed a novel role of TMZ in hepatic steatosis; TMZ ameliorated ChREBP‑induced de novo lipogenesis by activating the AMPK‑FOXO1 pathway. Show less