Androgen-induced upregulation of CFTR in pancreatic ß-cell contributes to hyperinsulinemia in PCOS model.

PURPOSE: Polycystic ovarian syndrome (PCOS) is an endocrine-metabolic condition affecting 5-10% of reproductive-aged women and characterized by hyperandrogenism, insulin resistance (IR), and hyperinsulinemia. CFTR is known to be regulated by steroid hormones, and our previous study has demonstrated an essential role of CFTR in ß-cell function. This study aims to investigate the contribution of androgen and CFTR to hypersecretion of insulin in PCOS and the underlying mechanism. METHODS: We established a rat PCOS model by subcutaneously implanting silicon tubing containing Dihydrotestosterone (DHT). Glucose tolerance test with insulin levels was performed at 9 weeks after implantation. A rat ß-cell line RINm5F, a mouse ß-cell line ß-TC-6, and mouse islets were treated with DHT, and with or without the androgen antagonist flutamide for CFTR and insulin secretion-related functional assays or mRNA/protein expression measurement. The effect of CFTR inhibitors on DHT-promoted membrane depolarization, glucose-stimulated intracellular Ca2+ oscillation and insulin secretion were examined by membrane potential imaging, calcium imaging and ELISA, respectively. RESULTS: The DHT-induced PCOS model showed increased body weight, impaired glucose tolerance, and higher blood glucose and insulin levels after glucose stimulation. CFTR was upregulated in islets of PCOS model and DHT-treated cells, which was reversed by flutamide. The androgen receptor (AR) could bind to the CFTR promoter region, which was enhanced by DHT. Furthermore, DHT-induced membrane depolarization, enhanced glucose-stimulated Ca2+ oscillations and insulin secretion, which could be abolished by CFTR inhibitors. CONCLUSIONS: Excessive androgen enhances glucose-stimulating insulin secretion through upregulation of CFTR, which may contribute to hyperinsulinemia in PCOS.

Potassium channel-related genes are a novel prognostic signature for the tumor microenvironment of renal clear cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) accounts for 80% of renal cell carcinomas (RCCs), and its morbidity and prognosis are unfavorable. Surgical resection is the first-line treatment for ccRCC, but the oncogenesis of ccRCC is very complex. With the development of high-throughput sequencing technology, it is necessary to analyze the transcriptome to determine more effective treatment methods. The tumor microenvironment (TME) is composed of tumor cells, various immune-infiltrating cells, fibroblasts, many cytokines, and catalysts. It is a complex system with a dynamic balance that plays an essential role in tumor growth, invasion, and metastasis. Previous studies have confirmed that potassium channels can affect the immune system, especially T lymphocytes that require potassium channel activation. However, the effect of potassium channels on the TME of ccRCC remains to be studied. Therefore, this study aims to construct a prognostic signature for ccRCC patients based on potassium ion channel-related genes (PCRGs), assess patient risk scores, and divide patients into high- and low-risk groups based on the cutoff value. In addition, we investigated whether there were differences in immune cell infiltration, immune activator expression, somatic mutations, and chemotherapeutic responses between the high- and low-risk groups. Our results demonstrate that the PCRG signature can accurately assess patient prognosis and the tumor microenvironment and predict chemotherapeutic responses. In summary, the PCRG signature could serve as an auxiliary tool for the precision treatment of ccRCC.

Angiotensin(1-7) activates MAS-1 and upregulates CFTR to promote insulin secretion in pancreatic ß-cells: the association with type 2 diabetes.

Objective: The beneficial effect of angiotensin(1-7) (Ang(1-7)), via the activation of its receptor, MAS-1, has been noted in diabetes treatment; however, how Ang(1-7) or MAS-1 affects insulin secretion remains elusive and whether the endogenous level of Ang(1-7) or MAS-1 is altered in diabetic individuals remains unexplored. We recently identified an important role of cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-activated Cl- channel, in the regulation of insulin secretion. Here, we tested the possible involvement of CFTR in mediating Ang(1-7)'s effect on insulin secretion and measured the level of Ang(1-7), MAS-1 as well as CFTR in the blood of individuals with or without type 2 diabetes. Methods: Ang(1-7)/MAS-1/CFTR pathway was determined by specific inhibitors, gene manipulation, Western blotting as well as insulin ELISA in a pancreatic ß-cell line, RINm5F. Human blood samples were collected from 333 individuals with (n = 197) and without (n = 136) type 2 diabetes. Ang(1-7), MAS-1 and CFTR levels in the human blood were determined by ELISA. Results: In RINm5F cells, Ang(1-7) induced intracellular cAMP increase, cAMP-response element binding protein (CREB) activation, enhanced CFTR expression and potentiated glucose-stimulated insulin secretion, which were abolished by a selective CFTR inhibitor, RNAi-knockdown of CFTR, or inhibition of MAS-1. In human subjects, the blood levels of MAS-1 and CFTR, but not Ang(1-7), were significantly higher in individuals with type 2 diabetes as compared to those in non-diabetic healthy subjects. In addition, blood levels of MAS-1 and CFTR were in significant positive correlation in type-2 diabetic but not non-diabetic subjects. Conclusion: These results suggested that MAS-1 and CFTR as key players in mediating Ang(1-7)-promoted insulin secretion in pancreatic ß-cells; MAS-1 and CFTR are positively correlated and both upregulated in type 2 diabetes.

Involvement of kisspeptin in androgen-induced hypothalamic endoplasmic reticulum stress and its rescuing effect in PCOS rats.

Endoplasmic reticulum (ER) stress, with adaptive unfolded protein response (UPR), is a key link between obesity, insulin resistance and type 2 diabetes, all of which are often present in the most common endocrine-metabolic disorder in women of reproductive age, polycystic ovary syndrome (PCOS), which is characterized with hyperandrogenism. However, the link between excess androgen and endoplasmic reticulum (ER) stress/insulin resistance in patients with polycystic ovary syndrome (PCOS) is unknown. An unexpected role of kisspeptin was reported in the regulation of UPR pathways and its involvement in the androgen-induced ER stress in hypothalamic neuronal cells. To evaluate the relationship of kisspeptin and ER stress, we detected kisspeptin and other factors in blood plasm of PCOS patients, rat models and hypothalamic neuronal cells. We detected higher testosterone and lower kisspeptin levels in the plasma of PCOS than that in non-PCOS women. We established a PCOS rat model by dihydrotestosterone (DHT) chronic exposure, and observed significantly downregulated kisspeptin expression and activated UPR pathways in PCOS rat hypothalamus compared to that in controls. Inhibition or knockdown of kisspeptin completely mimicked the enhancing effect of DHT on UPR pathways in a hypothalamic neuronal cell line, GT1-7. Kp10, the most potent peptide of kisspeptin, effectively reversed or suppressed the activated UPR pathways induced by DHT or thapsigargin, an ER stress activator, in GT1-7 cells, as well as in the hypothalamus in PCOS rats. Similarly, kisspeptin attenuated thapsigargin-induced Ca2+ response and the DHT- induced insulin resistance in GT1-7 cells. Collectively, the present study has revealed an unexpected protective role of kisspeptin against ER stress and insulin resistance in the hypothalamus and has provided a new treatment strategy targeting hypothalamic ER stress and insulin resistance with kisspeptin as a potential therapeutic agent.

[Effect of different pretreatment methods on dentin microleakage and bonding effect in caries].

PURPOSE：To evaluate the effect of different pretreatment methods on dentin microleakage and bonding effect of caries, so as to provide reference for clinical practice. METHODS: Sixty isolated caries were collected from Department of Oral and Maxillofacial Surgery, Affiliated Stomatological Hospital of Nanchang University from January 2020 to December 2020, and 120 dental samples were obtained by grinding them into two halves along the long axis of the precursor teeth. According to different pretreatment methods, they were divided into group A (2%NaClO), group B (2% chlorhexidine) and group C (75% ethanol). The bond strength, microtensile test and microleakage of the three groups of teeth were compared. SPSS 24.0 software package was used for statistical analysis of the data. RESULTS: The bond strength of the three groups from high to low was group A, group B and group C(P＜0.05); the fracture type of the three groups was compared, mixed damage of group A was lower than that of group B and group C； microleakage of the three groups was compared, and microleakage of group A was better than that of group B and group C(P＜0.05). CONCLUSIONS: Pre-treatment with 2%NaClO can reduce dentin microleakage and significantly improve the bonding strength of teeth, which is conducive to the promotion and application in the treatment of dental diseases.

Moderate Hydrogen Peroxide Postconditioning Ameliorates Ischemia/Reperfusion Injury in Cardiomyocytes via STAT3-Induced Calcium, ROS, and ATP Homeostasis.

INTRODUCTION: Moderate hydrogen peroxide postconditioning (H2O2PoC) activates signal transducer and activator of transcription 3 (STAT3) to alleviate mitochondrial calcium overload during cardiac ischemia/reperfusion (I/R). However, the initial time window of STAT3-induced calcium hemostasis, the production of reactive oxygen species (ROS) and adenosine triphosphate (ATP) in H2O2PoC, and its regulated mechanism remain unknown. This study aimed to investigate H2O2PoC-induced homeostasis of calcium, ROS and ATP, and the role of STAT3 in the regulation. METHODS: Isolated rat cardiomyocytes were exposed to H2O2PoC and Janus kinase 2 (JAK2)/STAT3 inhibitor AG490 during I/R. Ca2+ transients, cell contraction, intracellular calcium concentration, ROS production, ATP contents, phosphorylation of STAT3, gene and protein expression of manganese superoxide dismutase (MnSOD), metallothionein 1 (MT1) and metallothionein 2 (MT2), as well as activities of mitochondrial complex I and complex II were detected. RESULTS: Moderate H2O2PoC improved post-ischemic Ca2+ transients and cell contraction recovery as well as alleviated cytosolic and mitochondrial calcium overload, which were abrogated by AG490 in rat cardiomyocytes. Moderate H2O2PoC increased ROS production and rate of ROS production at early reperfusion in rat I/R cardiomyocytes, and this phenomenon was also abrogated by AG490. Notably, the expression of phosphorylated nuclear STAT3; gene and protein expression of MnSOD, MT1, and MT2; and activities of mitochondrial complex I and complex II were upregulated by moderate H2O2PoC but downregulated by AG490. CONCLUSION: These findings indicated that the cardioprotection of moderate H2O2PoC against cardiac I/R could be associated with activated STAT3 at early reperfusion to maintain calcium, ROS, and ATP homeostasis in rat cardiomyocytes.

[LncRNA NEAT1 regulates proliferation, migration and invasion of tongue squamous cell carcinoma cells by regulating miR-339-5p/ITGA3 axis].

PURPOSE: To investigate the molecular mechanism of LncRNA NEAT1 regulating proliferation, migration and invasion of tongue squamous cell carcinoma cells by regulating miR-339-5p/ITGA3 axis. METHODS: qRT-PCR and Western blot were used to detect the expression of NEAT1, miR-339-5p, ITGA3 mRNA and ITGA3 protein in 25 cases of human tongue squamous cell carcinoma, its corresponding adjacent tissues, human normal oral mucosal cell line HOK and human tongue squamous cell carcinoma cell lines TSCCA, CAL27, SCC15 and HN13. CAL27 cell lines that inhibited NEAT1 and overexpressed miR-339-5p were constructed, respectively. Cell viability was detected by MTT assay, cell numbers of migration and invasion were detected by Transwell assay, and the expression of Cyclin D1 and MMP-9 proteins were detected by Western blotting. The dual luciferase reporter gene was used to verify the targeting relationship of NEAT1, miR-339-5p and ITGA3, and the regulatory relationship was detected by Western blotting and qRT-PCR. SPSS 17.0 software package was used for statistical analysis of the data. RESULTS: Compared with normal human oral mucosal cell line HOK, the expression of NEAT1 and ITGA3 was up-regulated, while the expression of miR-339-5p was down-regulated in human tongue squamous cell carcinoma cell lines. Inhibition of NEAT1 or over-expression of miR-339-5p significantly inhibited proliferation, migration and invasion of CAL27 cells, and significantly inhibited expression of Cyclin D1 and MMP-9 proteins. Dual luciferase reporter gene assay confirmed that NEAT1 directly interacted with miR-339-5p and suppressed its expression. miR-339-5p negatively regulated ITGA3 expression. Inhibition of NEAT1 reversed the inhibitory effect of the inhibition of miR-339-5p on proliferation, migration and invasion of CAL27 cells. CONCLUSIONS: LncRNA NEAT1 promotes proliferation, migration and invasion of tongue squamous cell carcinoma cells by down-regulating miR-339-5p/ITGA3 axis.

MRP4 sustains Wnt/ß-catenin signaling for pregnancy, endometriosis and endometrial cancer.

Rationale: Abnormal Wnt/ß-catenin signaling in the endometrium can lead to both embryo implantation failure and severe pathogenic changes of the endometrium such as endometrial cancer and endometriosis. However, how Wnt/ß-catenin signaling is regulated in the endometrium remains elusive. We explored possible regulation of Wnt/ß-catenin signaling by multi-drug resistance protein 4 (MRP4), a potential target in cancer chemotherapy, and investigated the mechanism. Methods: Knockdown of MRP4 was performed in human endometrial cells in vitro or in a mouse embryo-implantation model in vivo. Immunoprecipitation, immunoblotting and immunofluorescence were used to assess protein interaction and stability. Wnt/ß-catenin signaling was assessed by TOPflash reporter assay and quantitative PCR array. Normal and endometriotic human endometrial tissues were examined. Data from human microarray or RNAseq databases of more than 100 participants with endometriosis, endometrial cancer or IVF were analyzed. In vitro and in vivo tumorigenesis was performed. Results: MRP4-knockdown, but not its transporter-function-inhibition, accelerates ß-catenin degradation in human endometrial cells. MRP4 and ß-catenin are co-localized and co-immunoprecipitated in mouse and human endometrium. MRP4-knockdown in mouse uterus reduces ß-catenin levels, downregulates a series of Wnt/ß-catenin target genes and impairs embryo implantation, which are all reversed by blocking ß-catenin degradation. Analysis of human endometrial biopsy samples and available databases reveals significant and positive correlations of MRP4 with ß-catenin and Wnt/ß-catenin target genes in the receptive endometrium in IVF, ectopic endometriotic lesions and endometrial cancers. Knockdown of MRP4 also inhibits in vitro and in vivo endometrial tumorigenesis. Conclusion: A previously undefined role of MRP4 in stabilizing ß-catenin to sustain Wnt/ß-catenin signaling in endometrial cells is revealed for both embryo implantation and endometrial disorders, suggesting MRP4 as a theranostic target for endometrial diseases associated with Wnt/ß-catenin signaling abnormality.

Activation of the epithelial sodium channel (ENaC) leads to cytokine profile shift to pro-inflammatory in labor.

The shift of cytokine profile from anti- to pro-inflammatory is the most recognizable sign of labor, although the underlying mechanism remains elusive. Here, we report that the epithelial sodium channel (ENaC) is upregulated and activated in the uterus at labor in mice. Mechanical activation of ENaC results in phosphorylation of CREB and upregulation of pro-inflammatory cytokines as well as COX-2/PGE2 in uterine epithelial cells. ENaC expression is also upregulated in mice with RU486-induced preterm labor as well as in women with preterm labor. Interference with ENaC attenuates mechanically stimulated uterine contractions and significantly delays the RU486-induced preterm labor in mice. Analysis of a human transcriptome database for maternal-fetus tissue/blood collected at onset of human term and preterm births reveals significant and positive correlation of ENaC with labor-associated pro-inflammatory factors in labored birth groups (both term and preterm), but not in non-labored birth groups. Taken together, the present finding reveals a pro-inflammatory role of ENaC in labor at term and preterm, suggesting it as a potential target for the prevention and treatment of preterm labor.

Abnormal CFTR Affects Glucagon Production by Islet α Cells in Cystic Fibrosis and Polycystic Ovarian Syndrome.

Glucagon, produced by islet α cells, functions to increase blood glucose. Abnormal glucose levels are often seen in cystic fibrosis (CF), a systematic disease caused by mutations of the CF transmembrane conductance regulator (CFTR), and in polycystic ovarian syndrome (PCOS), an endocrine disorder featured with hyperandrogenism affecting 5-10% women of reproductive age. Here, we explored the role of CFTR in glucagon production in α cells and its possible contribution to glucagon disturbance in CF and PCOS. We found elevated fasting glucagon levels in CFTR mutant (DF508) mice compared to the wildtypes. Glucagon and prohormone convertase 2 (PC2) were also upregulated in CFTR inhibitor-treated or DF508 islets, as compared to the controls or wildtypes, respectively. Dihydrotestosterone (DHT)-induced PCOS rats exhibited significantly lower fasting glucagon levels with higher CFTR expression in α cells compared to that of controls. Treatment of mouse islets or αTC1-9 cells with DHT enhanced CFTR expression and reduced the levels of glucagon and PC2. The inhibitory effect of DHT on glucagon production was blocked by CFTR inhibitors in mouse islets, and mimicked by overexpressing CFTR in αTC1-9 cells with reduced phosphorylation of the cAMP/Ca2+ response element binding protein (p-CREB), a key transcription factor for glucagon and PC2. These results revealed a previously undefined role of CFTR in suppressing glucagon production in α-cells, defects in which may contribute to glucose metabolic disorder seen in CF and PCOS.

Glucose-Sensitive CFTR Suppresses Glucagon Secretion by Potentiating KATP Channels in Pancreatic Islet α Cells.

The secretion of glucagon by islet α cells is normally suppressed by high blood glucose, but this suppressibility is impaired in patients with diabetes or cystic fibrosis (CF), a disease caused by mutations in the gene encoding CF transmembrane conductance regulator (CFTR), a cyclic adenosine monophosphate-activated Cl- channel. However, precisely how glucose regulates glucagon release remains controversial. Here we report that elevated glucagon secretion, together with increased glucose-induced membrane depolarization and Ca2+ response, is found in CFTR mutant (DF508) mice/islets compared with the wild-type. Overexpression of CFTR in AlphaTC1-9 cells results in membrane hyperpolarization and reduced glucagon release, which can be reversed by CFTR inhibition. CFTR is found to potentiate the adenosine triphosphate-sensitive K+ (KATP) channel because membrane depolarization and whole-cell currents sensitive to KATP blockers are significantly greater in wild-type/CFTR-overexpressed α cells compared with that in DF508/non-overexpressed cells. KATP knockdown also reverses the suppressive effect of CFTR overexpression on glucagon secretion. The results reveal that by potentiating KATP channels, CFTR acts as a glucose-sensing negative regulator of glucagon secretion in α cells, a defect of which may contribute to glucose intolerance in CF and other types of diabetes.

Incidence and risk factors of leukoaraiosis from 4683 hospitalized patients: A cross-sectional study.

Leukoaraiosis (LA) refers to white matter hyperintensities or white matter lesions (WMLs) on magnetic resonance imaging (MRI) scans of the brain; this disease is associated with an increased risk of stroke, dementia, and cognitive decline. The aims of the study are to assess the incidence of LA and its associated risk factors in a Chinese population.A hospital-based cross-sectional study was conducted that included 4683 patients who were 40 years or older. Data collected included age, sex, hypertension, diabetes, smoking, drinking, homocysteine (HCY), and low-density lipoprotein cholesterol (LDL-C) levels in the blood in addition to brain MRI information. We examined the relationship of those putative risk factors with LA, LA occurrence, and LA progression through single-factor and multivariate analyses.Of the total subjects, 58.3% (2731/4683 cases) suffered from LA. LA was more frequent amongst elderly females, particularly in those older than 60, compared to men. The incidence of LA increased with age. Age, sex, hypertension, diabetes, smoking, and HCY levels all were risk factors for LA. Amongst those risk factors, both smoking and high HCY levels were associated with the onset process of LA. Moreover, the multivariate logistic analysis revealed that both drinking and abnormal LDL-C levels were positive regulators in the progression process of LA.This study revealed that the incidence of LA is high in hospitalized patients in China; moreover, age, sex, hypertension, diabetes mellitus, smoking, drinking, and abnormal HCY and LDL-C levels were found to be associated with overall LA risk, LA onset, or LA progression. These results provide insight into strategies for the prevention and treatment of LA.

Analysis of genetic polymorphisms associated with leukoaraiosis in the southern Chinese population: A case-control study.

Leukoaraiosis (LA) is a frequent neuroimaging finding commonly observed on brain MRIs of elderly people with prevalence ranging from 50% to 100%. Multiple susceptibility genes or genetic risk factors for LA have been identified in subjects of European descent. Here, we report the first replication study on several common and novel genetic variations in the Chinese population. In this study, a total of 244 subjects (201 LA patients and 43 controls) were enrolled according to our new and strict definition for LA. Subsequently, 6 genetic variants at 5 genes, rs3744028 in TRIM65, rs1055129 in TRIM47, rs1135889 in FBF1, rs1052053 in PMF1, and rs1801133 (C677T) and rs1801131(A1298C) in MTHFR, were selected for genotyping using polymerase chain reaction (PCR)-based pyrosequencing and restriction fragment length polymorphism (RFLP) together with capillary electrophoresis (CE) and agarose gel electrophoresis. Finally, Pearson's χ and multivariate logistic regression tests were used to examine the associations between the genotypes and LA. Among these candidate polymorphisms, except for rs1052053 and rs1801131, rs1135889 (P = 0.012) showed significant associations with LA in the dominant model, and the other 3 SNPs, rs3744028 (P = 0.043), rs1055129 (P = 0.038), and rs1801133 (P = 0.027), showed significant associations with LA in the recessive model. However, these differences no longer remained significant after adjusting for age, gender, hypertension, and diabetes mellitus and applying Bonferroni correction or Sidak correction for multiple testing. These results suggest that the above-mentioned genetic variants are not associated with LA risk. In summary, the study did not replicate the susceptibility of rs3744028, rs1055129, and rs1135889 at the Chr17q25 locus for LA nor did it find any other significant results for rs1052053, rs1801133, and rs1801131 in the Chinese population. It strongly indicated the ethnic differences in the genetics of LA. However, the associations of rs3744028 (TRIM65), rs1055129 (TRIM47), rs1135889 (FBF1), and rs1801133 (MTHFR) with LA before Bonferroni correction and Sidak correction for multiple testing are worth highlighting. Thus, we believe that a genome-wide association study and candidate gene association studies are needed to reassess the previous findings and screen novel risk genes for LA in China.

Ultrasonic integrated backscatter in assessing liver steatosis before and after liver transplantation.

BACKGROUND: Liver steatosis affects 20%-30% of adults. Because of the increasing gap between graft supplies and demands, livers with steatosis are frequently used in liver transplantation. But severely steatotic liver grafts are associated with a high risk of intraoperative and postoperative complications. Accurate assessment of fat content of donor livers and monitoring of the extent of steatosis in recipients are required for liver transplantation. The present study aimed to determine the correlation between liver echogenicity and fat content, and to evaluate the use of an ultrasonic integrated backscatter system (IBS) in the assessment of changes in fat content after liver transplantation. METHODS: Seventy-nine consecutive patients receiving liver grafts from living donors were evaluated in our center. Of these recipients, 67 survived for more than two years and were included in this study. Each liver graft was evaluated with IBS and ultrasound before operation and the fat content was estimated. The fat content of the grafts in the recipients was again assessed with ultrasound at 18 months after surgery. RESULTS: A correlation was detected between each graft's IBS value and its fat content (P=0.001). The IBS value in fatty grafts with various degrees of steatosis was significantly decreased in 3 (P=0.02), 12, 15 and 18 (P=0.001) months after orthotopic liver transplantation. The IBS value returned to normal in all patients in 18 months after liver transplantation. CONCLUSIONS: Decreased fat content in steatotic grafts can be observed in all recipients. Ultrasonic IBS is useful in determining the steatotic degree of grafts in donors as well as in monitoring the grafts after liver transplantation.

Structure, function, and pathogenesis of SHP2 in developmental disorders and tumorigenesis.

Src homology 2 (SH2)-containing protein tyrosine phosphatase 2 (SHP2), encoded by the human PTPN11 gene, is a ubiquitously expressed protein tyrosine phosphatase (PTP) that consists of two tandem Src homology (SH2) domains (N-SH2 and C-SH2), a PTP catalytic domain, and a C-terminal tail with tyrosyl phosphorylation sites. It plays critical roles in numerous cellular processes through the regulation of various signaling pathways in PTP catalytic activity-dependent and -independent manners. Dysfunction of SHP2 resulting from pathogenic mutations and aberrant expression leads to the dysregulation of multiple signaling pathways, thus contributing to different human disorders. Germline and somatic mutations in PTPN11 are involved in Noonan syndrome (NS), LEOPARD syndrome (LS), and hematological malignancies, as well as several solid tumors. In this report, we provide an overview of the current knowledge of the structure and function of SHP2, and further discuss the molecular and pathogenic mechanism of SHP2 in human diseases, with a special focus on tumorigenesis. Furthermore, we summarize that SHP2 might itself represent a potential drug target for cancer prevention and treatment. Ongoing research and development of SHP2-specific inhibitors would enhance this potential.

Glucose-induced electrical activities and insulin secretion in pancreatic islet ß-cells are modulated by CFTR.

The cause of insulin insufficiency remains unknown in many diabetic cases. Up to 50% adult patients with cystic fibrosis (CF), a disease caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR), develop CF-related diabetes (CFRD) with most patients exhibiting insulin insufficiency. Here we show that CFTR is a regulator of glucose-dependent electrical acitivities and insulin secretion in ß-cells. We demonstrate that glucose elicited whole-cell currents, membrane depolarization, electrical bursts or action potentials, Ca(2+) oscillations and insulin secretion are abolished or reduced by inhibitors or knockdown of CFTR in primary mouse ß-cells or RINm5F ß-cell line, or significantly attenuated in CFTR mutant (DF508) mice compared with wild-type mice. VX-809, a newly discovered corrector of DF508 mutation, successfully rescues the defects in DF508 ß-cells. Our results reveal a role of CFTR in glucose-induced electrical activities and insulin secretion in ß-cells, shed light on the pathogenesis of CFRD and possibly other idiopathic diabetes, and present a potential treatment strategy.

New mutations and polymorphisms of the ATP7B gene in sporadic Wilson disease.

Wilson's disease (WD) is a rare autosomal recessive genetic disorder of copper metabolism resulting in brain damage, liver failure, and neurological impairment and psychiatric disturbances, as a result of excessive copper accumulation in the brain, liver, kidneys and eyes. ATP7B, encoding a copper transporter P-ATPase was identified as the causative gene of WD. Mutations in the ATP7B gene lead to the defection of the transmembrane transporter so that it can not metabolize copper effectively. We reported the clinical and molecular features of three unrelated and non-consanguineous WD patients. We performed molecular genetic analysis of the ATP7B gene in all cases by DNA sequencing, and revealed 7 novel single nucleotide polymorphisms (SNPs) and 8 well known mutations. Among them, that novel SNP (c. -520 C>T) and two well known mutations (c. 2310 C>G/p. Leu700Leu, c. 2333 G>T/A/p. Arg778Leu/Gln) coexisted in all patients and they were heterozygous and homozygous in the youngest case, respectively, indicating that they may be correlated to the pathogenesis and potentially used as a genetic biomarker for early WD diagnosis.

Vigilin is overexpressed in hepatocellular carcinoma and is required for HCC cell proliferation and tumor growth.

Vigilin contains multiple KH domains and is an evolutionarily conserved RNA-binding protein from yeast to the human. Its reported roles in human carcinogenesis are controversial in different types of human cancers. To obtain the specific expression profiles of vigilin in human hepatocellular carcinomas (HCCs), we examined vigilin protein levels in normal human liver, liver cirrhosis, adjacent non-tumor liver and HCC tumor tissues as well as in several HCC cell lines. We discovered that vigilin expression increased progressively from the liver cirrhosis tissue to adjacent non-tumor liver tissue and then to HCC tumor cells. Vigilin protein was also overexpressed in all three HCC cell lines examined, HepG2, BEL7402 and SMMC7721, when compared with the vigilin expression level in the L-02 human embryonic hepatocyte cell line. We further investigated the impact of vigilin knockdown on HCC cell proliferation, survival, motility, tumor growth and sensitivity to chemotherapy. We found that knockdown of vigilin in the BEL7402 HCC cells significantly inhibited their proliferation, colony formation and migration, but largely enhanced the cisplatin treatment-induced growth inhibition of these cells in culture. We also found that vigilin knockdown effectively inhibited the growth of BEL7402 cell-derived xenograft tumors in nude mice by decreasing the proliferation and increasing the apoptosis of the BEL7402 HCC cells. Taken together, these results suggest that progressively upregulated vigilin may serve as a molecular risk marker for HCC development, and targeting vigilin may help to inhibit HCC cell growth, survival and migration.

[Expression of vigilin in cell lines and human hepatocellular carcinoma].

OBJECTIVE: To explore the expression status of Vigilin (high density lipoprotein binding protein) in various cell lines and human hepatocellular carcinoma (HCC) tissues. METHODS: The expression of Vigilin was measured semiquantitatively with western blot in hepatic cancer, cervical cancer and normal cell lines. The samples of 59 hepatocellular carcinoma tissues, 59 adjacent liver tissues and 33 distant non-tumor liver tissues were collected, Vigilin expression in the above samples was detected by immunohistochemistry. RESULTS: Vigilin expressed in all cell lines, but no expression was found in peripheral blood lymphocytes. The expression levels of Vigilin in tumor cell lines were higher than those in normal cell lines (P < 0.05). Most of the hepatic cells expressed Vigilin, but the expression levels were different (tumor tissues: 0.2226 +/- 0.054, adjacent tissues: 0.2060 +/- 0.056, distant tissues: 0.1820 +/- 0.038, P < 0.001). Highly expression of Vigilin was observed in 54% of tumor tissues, 35% adjacement tissues, and 6% of distant non-tumor tissues, respectively. CONCLUSION: Vigilin may have relationship with HCC progression and proliferation.