From stem cells to pancreatic ß-cells: strategies, applications, and potential treatments for diabetes.

Loss and functional failure of pancreatic ß-cells results in disruption of glucose homeostasis and progression of diabetes. Although whole pancreas or pancreatic islet transplantation serves as a promising approach for ß-cell replenishment and diabetes therapy, the severe scarcity of donor islets makes it unattainable for most diabetic patients. Stem cells, particularly induced pluripotent stem cells (iPSCs), are promising for the treatment of diabetes owing to their self-renewal capacity and ability to differentiate into functional ß-cells. In this review, we first introduce the development of functional ß-cells and their heterogeneity and then turn to highlight recent advances in the generation of ß-cells from stem cells and their potential applications in disease modeling, drug discovery and clinical therapy. Finally, we have discussed the current challenges in developing stem cell-based therapeutic strategies for improving the treatment of diabetes. Although some significant technical hurdles remain, stem cells offer great hope for patients with diabetes and will certainly transform future clinical practice.

Liraglutide ameliorates hepatic steatosis via retinoic acid receptor-related orphan receptor α-mediated autophagy pathway.

Liraglutide, an analog of human glucagon-like peptide-1 (GLP-1), has been found to improve hepatic steatosis in clinical practice. However, the underlying mechanism remains to be fully defined. Increasing evidence suggests that retinoic acid receptor-related orphan receptor α (RORα) is involved in hepatic lipid accumulation. In the current study, we investigated whether the ameliorating impact of liraglutide on lipid-induced hepatic steatosis is dependent on RORα activity and examined the underlying mechanisms. Cre-loxP-mediated, liver-specific Rorα knockout (Rora LKO) mice, and littermate controls with a Roraloxp/loxp genotype were established. The effects of liraglutide on lipid accumulation were evaluated in mice challenged with a high-fat diet (HFD) for 12 weeks. Moreover, mouse AML12 hepatocytes expressing small interfering RNA (siRNA) of Rora were exposed to palmitic acid to explore the pharmacological mechanism of liraglutide. The results showed that liraglutide treatment significantly alleviated HFD-induced liver steatosis, marked by reduced liver weight and triglyceride accumulation, improved glucose tolerance and serum levels of lipid profiles and aminotransferase. Consistently, liraglutide also ameliorated lipid deposits in a steatotic hepatocyte model in vitro. In addition, liraglutide treatment reversed the HFD-induced downregulation of Rora expression and autophagic activity in mouse liver tissues. However, the beneficial effect of liraglutide on hepatic steatosis was not observed in Rora LKO mice. Mechanistically, the ablation of Rorα in hepatocytes diminished liraglutide-induced autophagosome formation and the fusion of autophagosomes and lysosomes, resulting in weakened autophagic flux activation. Thus, our findings suggest that RORα is essential for the beneficial impact of liraglutide on lipid deposition in hepatocytes and regulates autophagic activity in the underlying mechanism.

Lanosterol reverses protein aggregation in cataracts.

The human lens is comprised largely of crystallin proteins assembled into a highly ordered, interactive macro-structure essential for lens transparency and refractive index. Any disruption of intra- or inter-protein interactions will alter this delicate structure, exposing hydrophobic surfaces, with consequent protein aggregation and cataract formation. Cataracts are the most common cause of blindness worldwide, affecting tens of millions of people, and currently the only treatment is surgical removal of cataractous lenses. The precise mechanisms by which lens proteins both prevent aggregation and maintain lens transparency are largely unknown. Lanosterol is an amphipathic molecule enriched in the lens. It is synthesized by lanosterol synthase (LSS) in a key cyclization reaction of a cholesterol synthesis pathway. Here we identify two distinct homozygous LSS missense mutations (W581R and G588S) in two families with extensive congenital cataracts. Both of these mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Engineered expression of wild-type, but not mutant, LSS prevents intracellular protein aggregation of various cataract-causing mutant crystallins. Treatment by lanosterol, but not cholesterol, significantly decreased preformed protein aggregates both in vitro and in cell-transfection experiments. We further show that lanosterol treatment could reduce cataract severity and increase transparency in dissected rabbit cataractous lenses in vitro and cataract severity in vivo in dogs. Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.

Effects of genetic variations in Acads gene on the risk of chronic obstructive pulmonary disease.

Short-chain acyl-CoA dehydrogenase (SCAD), encoded by the Acads gene, functions in the mitochondrial ß-oxidation of saturated short-chain fatty acids. SCAD deficiency results in mitochondrial dysfunction, which is one underlying biological mechanism of chronic obstructive pulmonary disease (COPD) pathogenesis. In this case-control study, we aimed to examine the effects of Acads gene polymorphisms on the susceptibility to COPD. A total of 16 tagging single-nucleotide polymorphisms (SNPs) in Acads gene region was identified and genotyped in 646 unrelated ethnic Chinese Han individuals including 279 patients with COPD and 367 healthy controls, their allelic and genotypic associations with COPD were determined by different genetic models. Furthermore, we estimated the linkage disequilibrium and haplotypes from these tested variants and determined the effects of haplotypes on the risk of COPD. The allelic and genotypic frequencies of SNPs rs2239686 and rs487915 in Acads gene were significantly different between COPD patients and controls, no statistically significant results were observed for other SNPs. Minor alleles A of rs2239686 and T of rs487915 were associated with a decreased pulmonary function and an increased COPD risk in a dominant manner. Functional analysis indicated that the risk allele A of rs2239686 could increase Acads expressions and the intracellular reactive oxygen species content. Haplotype analysis revealed that the haplotypes CTCCT in block 2 (rs3794216-rs3794215-rs34491494-rs558314-rs7312316) as well as GC in block 3 (rs2239686-rs487915) were protective against COPD, while haplotypes CTCGC in block 2 and AT in block 3 exhibited significant associations with the increased susceptibility to COPD. Our results suggest that Acads gene could potentially be a risk factor of COPD and thus its genetic variants might be as genetic biomarkers to predict the COPD susceptibility.

Deficiency in the short-chain acyl-CoA dehydrogenase protects mice against diet-induced obesity and insulin resistance.

Acyl-CoA dehydrogenases (CADs) participate in mitochondrial fatty acid oxidation; abnormal fatty acid oxidation is associated with obesity and related metabolic disorders. We decipher the impact of short-chain CAD (SCAD) on adiposity and insulin resistance. BALB/cBy strain mice derived from BALB/c strain are deficient in SCAD activity because of a spontaneous deletion in the acyl-CoA dehydrogenases (Acads) gene. Adiposity, lipogenesis, and insulin sensitivity were compared in BALB/c and BALB/cBy mice subjected to high-fat diets (HFDs). A whole hepatic transcriptome profiling experiment with microarrays was performed to evaluate the mechanisms by which SCAD deficiency protects against insulin resistance. Acads-deficient mice were significantly resistant to HFD-induced obesity and insulin resistance as compared with control mice. Reduced obesity results from decreased triglyceride content due to activation of AMPK in liver that would reduce hepatic content of malonyl-CoA, resulting in decreased hepatic de novo lipogenesis. Improved insulin sensitivity was associated with reduced diacylglycerol content commensurate with reduced PKC-ε activity and increased protein kinase B (AKT) activation in liver and skeletal muscle. Additionally, Acads-deficient mice displayed significantly higher expression of the endoplasmic chaperone 78-kDa glucose-regulated protein, which was further associated with the AKT activation in the primary hepatocytes. Modulation of SCAD expression may therefore be a novel therapeutic approach to manage and prevent obesity and related metabolic diseases, such as diabetes.-Chen, Y., Chen, J., Zhang, C., Yang, S., Zhang, X., Liu, Y., Su, Z. Deficiency in the short-chain acyl-CoA dehydrogenase protects mice against diet-induced obesity and insulin resistance.

Regulation of hepatic gluconeogenesis by nuclear factor Y transcription factor in mice.

Hepatic gluconeogenesis is essential to maintain blood glucose levels, and its abnormal activation leads to hyperglycemia and type 2 diabetes. However, the molecular mechanisms in the regulation of hepatic gluconeogenesis remain to be fully defined. In this study, using murine hepatocytes and a liver-specific knockout mouse model, we explored the physiological role of nuclear factor Y (NF-Y) in regulating hepatic glucose metabolism and the underlying mechanism. We found that NF-Y targets the gluconeogenesis pathway in the liver. Hepatic NF-Y expression was effectively induced by cAMP, glucagon, and fasting in vivo Lentivirus-mediated NF-Y overexpression in Hepa1-6 hepatocytes markedly raised the gluconeogenic gene expression and cellular glucose production compared with empty vector control cells. Conversely, CRISPR/Cas9-mediated knockdown of NF-Y subunit A (NF-YA) attenuated gluconeogenic gene expression and glucose production. We also provide evidence indicating that CRE-loxP-mediated, liver-specific NF-YA knockout compromises hepatic glucose production. Mechanistically, luciferase reporter gene assays and ChIP analysis indicated that NF-Y activates transcription of the gluconeogenic genes Pck1 and G6pc, by encoding phosphoenolpyruvate carboxykinase (PEPCK) and the glucose-6-phosphatase catalytic subunit (G6Pase), respectively, via directly binding to the CCAAT regulatory sequence motif in their promoters. Of note, NF-Y enhanced gluconeogenesis by interacting with cAMP-responsive element-binding protein (CREB). Overall, our results reveal a previously unrecognized physiological function of NF-Y in controlling glucose metabolism by up-regulating the gluconeogenic genes Pck1 and G6pc Modulation of hepatic NF-Y expression may therefore offer an attractive therapeutic approach to manage type 2 diabetes.

Retinoic acid receptor-related orphan receptor α stimulates adipose tissue inflammation by modulating endoplasmic reticulum stress.

Adipose tissue inflammation has been linked to metabolic diseases such as obesity and type 2 diabetes. However, the molecules that mediate inflammation in adipose tissue have not been addressed. Although retinoic acid receptor-related orphan receptor α (RORα) is known to be involved in the regulation of inflammatory response in some tissues, its role is largely unknown in adipose tissue. Conversely, it is known that endoplasmic reticulum (ER) stress and unfolding protein response (UPR) signaling affect the inflammatory response in obese adipose tissue, but whether RORα regulates these processes remains unknown. In this study, we investigate the link between RORα and adipose tissue inflammation. We showed that the inflammatory response in macrophages or 3T3-L1 adipocytes stimulated by lipopolysaccharide, as well as adipose tissue in obese mice, markedly increased the expression of RORα. Adenovirus-mediated overexpression of RORα or treatment with the RORα-specific agonist SR1078 enhanced the expression of inflammatory cytokines and increased the number of infiltrated macrophages into adipose tissue. Furthermore, SR1078 up-regulated the mRNA expression of ER stress response genes and enhanced phosphorylations of two of the three mediators of major UPR signaling pathways, PERK and IRE1α. Finally, we found that alleviation of ER stress using a chemical chaperone followed by the suppression of RORα induced inflammation in adipose tissue. Our data suggest that RORα-induced ER stress response potentially contributes to the adipose tissue inflammation that can be mitigated by treatment with chemical chaperones. The relationships established here between RORα expression, inflammation, and UPR signaling may have implications for therapeutic targeting of obesity-related metabolic diseases.

Obesity-induced endoplasmic reticulum stress suppresses nuclear factor-Y expression.

Nuclear transcription factor Y (NF-Y) is an evolutionarily conserved transcription factor composed of three subunits, NF-YA, NF-YB, and NF-YC. NF-Y plays crucial roles in pre-adipocyte maintenance and/or commitment to adipogenesis. NF-YA dysfunction in adipocyte resulted in an age-dependent progressive loss of adipose tissue associated with metabolic complications. Endoplasmic reticulum (ER) stress has emerged as an important mediator in the pathogenesis of obesity. However, it is not known if NF-YA is involved in the ER stress-mediated pathogenesis of obesity. We first examined the effects of ER stress on the NF-YA expression in cultured 3T3-L1 adipocytes; then in ob/ob genetic obesity mice, we tested the effect of chemical chaperones alleviating ER stress on the expression levels of NF-YA. Subsequently, we inhibited the new mRNA synthesis using actinomycin D in 3T3-L1 cells to explore the mechanism modulating NF-YA expression. Finally, we evaluated the involvement of PPARg in the regulation of NF-YA expression by ER stress. We demonstrated that both obesity- and chemical chaperone -induced ER stress suppressed NF-YA expression and alleviation of ER stress by chemical chaperone could recover NF-YA expression in ob/ob mice. Moreover, we showed that ER stress suppressed NF-YA mRNA transcription through the involvement of peroxisome proliferator-activated receptor gamma (PPARg). Activation of PPARg ameliorates the ER stress-induced NF-YA suppression. Our findings may point to a possible role of NF-YA in stress conditions that occur in chronic obesity, ER stress might be involved in the pathogenesis of obesity through NF-YA depletion.

[The Mechanisms of Trimetazidine Alleviating the Oxidative Stress in Adipose-derived Mesenchymal Stem Cells].

OBJECTIVES: To investigate the effects of trimetazidine (TMZ) on the oxidative stress injury in adipose-derived mesenchymal stem cells (ADSCs). METHODS: ADSCs derived from adipose tissue of SD rats were characterized by flow cytometry and multiline age differentiation. ADSCs apoptosis was induced by H2O2 in vitro , Dirrerent concentration of TMZ (250 µmol/L, 500 µmol/L) was used to protect ADSCs from apoptosis. The morphological features of apoptotic ADSCs were analyzed by Hoechst 33342, mitochondrial potential and structure was analyzed by JC-1 staining and electron microscope, respectively. The apoptotic proteins were detected by Western blot. The effect of TMZ on antioxidant capacity of ADSCs was evaluated by detecting reactive oxygen species (ROS), superoxide dismutase (SOD), glutathione (GSH) and malondialdehyde (MDA). RESULTS: The isolated ADSCs expressed high levels of CD29 and CD90, low levels of CD34 and CD45 and no expression of CD31. ADSCs could be induced to adipocyte and osteoplastic cells. After being treated by H2O2, ADSCs displayed apoptosis characteristics with increased number of apoptotic cells, decreased mitochondrial transmembrane potential and damaged mitochondria. The expressions of apoptotic proteins, including Bax, Bad, and Caspase3, were dramatically increased compared to the controls; however, the anti-apoptotic protein Bcl2 was decreased. At the meantime, the contents of ROS and MDA were elevated, but the concentrations of SOD and GSH were reduced. The treatment of TMZ could partly reverse above negative impacts to ADSCs. CONCLUSION: TMZ could improve the survival rate of ADSCs by enhancing anti-oxidant defense systems to remove excessive ROS and regulating the expression of protective protein.

Design and Validation of PEG-Derivatized Vitamin E Copolymer for Drug Delivery into Breast Cancer.

This study examined the ability of amphiphilic poly(ethylene glycol) (PEG) derivatives to assemble into micelles for drug delivery. Linear PEG chains were modified on one end with hydrophobic vitamin E succinate (VES), and PEG and VES were mixed in different molar ratios to make amphiphiles, which were characterized in terms of critical micelle concentration (CMC), drug loading capacity (DLC), serum stability, tumor spheroid penetration and tumor targeting in vitro and in vivo. The amphiphile PEG5K-VES6 (PAMV6), which has a wheat-like structure, showed a CMC of 3.03 × 10(-6) M, good serum stability, and tumor accumulation. The model drug, pirarubicin (THP), could be efficiently loaded into PAMV6 micelles at a DLC of 24.81%. PAMV6/THP micelles were more effective than THP solution at inducing cell apoptosis and G2/M arrest in 4T1 cells. THP-loaded PAMV6 micelles also inhibited tumor growth much more than free THP in a syngeneic mouse model of breast cancer. PAMV6-based micellar systems show promise as nanocarriers for improved anticancer chemotherapy.

One-Step Self-Assembling Nanomicelles for Pirarubicin Delivery To Overcome Multidrug Resistance in Breast Cancer.

Tumor cells can acquire multidrug resistance (MDR) as a result of drug efflux mediated by P-glycoprotein (P-gp). Here we report a targeted delivery system to carry pirarubicin (THP) to MDR breast cancer both in vitro and in vivo. PEG-derivatized vitamin E (PAMV6) amphiphiles loaded with THP were self-assembled in a single step. The PAMV6 micelles showed unimodal size distribution and high drug loading efficiency. Cytotoxicity of PAMV6/THP was higher than that of free THP on MCF-7/ADR cells but comparable to that of THP on MCF-7 cells. PAMV6/THP was able to reverse MDR more than free THP in MCF-7/ADR cells, likely reflecting the remarkably higher intracellular THP concentration in micelle-treated cells and PAMV6-mediated inhibition of P-gp activity. PAMV6/THP micelles were internalized into MCF-7/ADR cells via macropinocytosis and caveolin-mediated endocytosis, further avoiding P-gp-mediated efflux. Mechanistic studies revealed that blank PAMV6 micelles inhibited P-gp activity but did not affect P-gp expression, by significantly reducing mitochondrial membrane potential and slightly decreasing intracellular ATP levels. In a nude mouse xenograft model, PAMV6/THP led to much greater THP accumulation in tumors and much slower tumor growth than free THP. At the same time, PAMV6/THP was associated with significantly less severe bone marrow suppression and organ toxicity than free THP. Our results indicate that this PAMV6-based micelle system holds promise for combating MDR in cancer therapy.

Genetic variants of CDH13 determine the susceptibility to chronic obstructive pulmonary disease in a Chinese population.

AIM: Adiponectin has been implicated in the development of chronic obstructive pulmonary disease (COPD). The CDH13 gene encodes T-cadherin that is an adiponectin receptor, and genetic variants of CDH13 determine blood adiponectin levels. The aim of this study was to investigate the effects of CDH13 variants on COPD susceptibility in a Chinese population. METHODS: Ten single-nucleotide polymorphisms (SNP) in CDH13 were screened using the SNaPshot method in 279 COPD patients and 367 control subjects. Association of genotypes or haplotypes constructed from these loci with COPD was analyzed in different genetic models. RESULTS: Among the 10 SNPs tested, rs4783244 and rs12922394 exhibited significant differences in allele or genotype frequencies between COPD patients and control subjects, whereas 8 other SNPs did not. The minor allele T was associated with decreased risk of COPD in the recessive model at rs4783244 (OR=0.42, P=0.023) and in the dominant model at rs12922394 (OR=0.70, P=0.022). The genotype TT at either rs4783244 or rs12922394 was associated with a significantly low level of plasma adiponectin when compared to genotypes GG and CC (P<0.05). Haplotypes GC in block 1 (rs4783244-rs12922394) as well as GTAC and ATGT in block 3 (rs4783266-rs11640522-rs11646849-rs11860282) significantly increased the risk of COPD, whereas haplotypes TT in block 1, TG in block 2 (rs11646011- rs11640875) and ATGC in block 3 were protective against COPD. CONCLUSION: CDH13 genetic variants determine Chinese individuals' susceptibility to COPD and thus are efficient genetic biomarkers for early detection of COPD.

Effects of adiponectin polymorphisms on the risk of advanced age-related macular degeneration.

OBJECTIVE: To determine the relationships between variants in adiponectin gene (ADIPOQ) with advanced forms of age-related macular degeneration (AMD) susceptibility. METHODS: A total of 189 advanced AMD patients and 168 controls were recruited. Seven tagging single-nucleotide polymorphisms in ADIPOQ were genotyped by the SNaPshot method. RESULTS: Alleles or genotypes of rs822396 distributed significantly differently in advanced AMD patients and controls. The minor allele G at rs822396 was associated with an increased risk of advanced AMD in a dominant model. Furthermore, haplotype analysis revealed that haplotypes AGGACCT and TGACCCC were significantly increased the advanced AMD susceptibility, whereas haplotypes AGAACGC, TGAACGT and TGACAGC had protective effects. CONCLUSION: ADIPOQ genetic variant rs822396 might affect an individual's susceptibility to AMD, making it efficient genetic biomarkers for early detection of AMD.

Salidroside protects retinal endothelial cells against hydrogen peroxide-induced injury via modulating oxidative status and apoptosis.

Oxidative stress can cause injury in retinal endothelial cells. Salidroside is a strong antioxidative and cytoprotective supplement in Chinese traditional medicine. In this study, we investigated the effects of salidroside on H2O2-induced primary retinal endothelial cells injury. Salidroside decreased H2O2-induced cell death, and efficiently suppressed cellular ROS production, malondialdehyde generation, and cell apoptosis induced by H2O2 treatment. Salidroside induced the intracellular mRNA expression, protein expression, and enzymatic activities of catalase and Mn-SOD and increased the ratio of Bcl2/Bax. Our results demonstrated that salidroside protected retinal endothelial cells against oxidative injury through increasing the Bcl2/Bax signaling pathway and activation of endogenous antioxidant enzymes. This finding presents salidroside as an attractive agent with potential to attenuate retinopathic diseases.

Complement factor H genotypes impact risk of age-related macular degeneration by interaction with oxidized phospholipids.

The rs1061170T/C variant encoding the Y402H change in complement factor H (CFH) has been identified by genome-wide association studies as being significantly associated with age-related macular degeneration (AMD). However, the precise mechanism by which this CFH variant impacts the risk of AMD remains largely unknown. Oxidative stress plays an important role in many aging diseases, including cardiovascular disease and AMD. A large amount of oxidized phospholipids (oxPLs) are generated in the eye because of sunlight exposure and high oxygen content. OxPLs bind to the retinal pigment epithelium and macrophages and strongly activate downstream inflammatory cascades. We hypothesize that CFH may impact the risk of AMD by modulating oxidative stress. Here we demonstrate that CFH binds to oxPLs. The CFH 402Y variant of the protective rs1061170 genotype binds oxPLs with a higher affinity and exhibits a stronger inhibitory effect on the binding of oxPLs to retinal pigment epithelium and macrophages. In addition, plasma from non-AMD subjects with the protective genotype has a lower level of systemic oxidative stress measured by oxPLs per apolipoprotein B (oxPLs/apoB). We also show that oxPL stimulation increases expression of genes involved in macrophage infiltration, inflammation, and neovascularization in the eye. OxPLs colocalize with CFH in drusen in the human AMD eye. Subretinal injection of oxPLs induces choroidal neovascularization in mice. In addition, we show that the CFH risk allele confers higher complement activation and cell lysis activity. Together, these findings suggest that CFH influences AMD risk by modulating oxidative stress, inflammation, and abnormal angiogenesis.

Genetic variations in RORα are associated with chronic obstructive pulmonary disease.

Retinoic acid receptor-related orphan receptor-α (RORα) plays a key role in the regulation of lipid and cholesterol metabolism that has been implicated in the development of chronic obstructive pulmonary disease (COPD). The aim of this study was to determine the frequencies of single-nucleotide polymorphisms (SNPs) in RORα gene in a Chinese population and their possible association with COPD susceptibility. Nine tagging SNPs, including rs17270181, rs1898413, rs17270216, rs8033552, rs8036966, rs7169364, rs340002, rs340023 and rs11630262, were screened in 279 COPD patients and 367 controls by the SNaPshot method. Association analysis of genotypes and haplotypes constructed from these loci with COPD was conducted under different genetic models. Alleles or genotypes of rs8033552 distributed significantly differently in COPD patients and controls (allele: P=0.0001, false discovery rate (FDR) Q=0.004, odds ratios (OR): 1.62 and 95% confidence interval (CI): 1.27-2.07; genotype: P=0.0005, FDR Q=0.008). The allele A at rs8033552 was potentially associated with an increased risk of COPD in additive model, displaying ORs of 1.62 (95% CI: 1.17-2.26, P=0.004, FDR Q=0.019) in subjects with genotypes AG vs GG and 2.69 (95% CI: 1.47-4.93, P=0.001, FDR Q=0.011) in subjects with genotypes AA vs GG, respectively. In haplotype analysis, we observed haplotypes GGAGATGTG and GGAGCTGTG had protective effects, whereas haplotypes GGAGATACA and GGAGATACG were significantly associated with the increased risk of COPD. These data suggest that RORα may be a potential risk gene for COPD.

Association of five genetic variants with chronic obstructive pulmonary disease susceptibility and spirometric phenotypes in a Chinese Han population.

BACKGROUND AND OBJECTIVE: Recent genome-wide association studies have shown associations between variants at five loci (TNS1, GSTCD, HTR4, AGER and THSD4) and chronic obstructive pulmonary disease (COPD) or lung function. However, their association with COPD has not been proven in Chinese Han population, nor have COPD-related phenotypes been studied. The objective of this study was to look for associations between five single nucleotide polymorphisms (SNP) in these novel candidate genes and COPD susceptibility or lung function in a Chinese Han population. METHODS: Allele and genotype data on 680 COPD patients and 687 healthy controls for sentinel SNP in these five loci were investigated. Allele frequencies and genotype distributions were compared between cases and controls, and odds ratios were calculated. Potential relationships between these SNP and COPD-related lung function were assessed. RESULTS: No significant associations were found between any of the SNP and COPD in cases and controls. The SNP (rs3995090) in HTR4 was associated with COPD (adjusted P = 0.022) in never-smokers, and the SNP (rs2070600) in AGER was associated with forced expiratory volume in 1 s (FEV1 %) predicted (ß = -0.066, adjusted P = 0.016) and FEV1 /forced vital capacity (ß = -0.071, adjusted P = 0.009) in all subjects. CONCLUSIONS: The variant at HTR4 was associated with COPD in never-smokers, and the SNP in AGER was associated with pulmonary function in a Chinese Han population.

Malattia leventinese/Doyne honeycomb retinal dystrophy in a chinese family with mutation of the EFEMP1 gene.

PURPOSE: To characterize the clinical features and molecular genetic findings in a Chinese pedigree with Malattia leventinese/Doyne honeycomb retinal dystrophy. METHODS: All patients underwent ophthalmologic examinations, including Snellen best-corrected visual acuity, fundus photography, fundus autofluorescence imaging, fundus fluorescein angiography, and optical coherence tomography. Genomic DNA was isolated from blood samples. All exons of EFEMP1 were amplified by polymerase chain reaction and sequenced. Possible structural and functional impacts of the protein because of amino acid substitution were predicted by bioinformatics analysis. RESULTS: A heterozygous missense mutation comprising C > T in exon 10 of EFEMP1 was identified in all patients of the pedigree; this resulted in an amino acid substitution at position 345 (Arg345Trp, R345W). Clinically, six patients from the Chinese family were ascertained with varying degrees of early onset drusen. Besides the drusen, choroidal neovascularization and retinal pigment epithelium changes were noted in some patients. Increased autofluorescence corresponding to the drusen was detected in the R345W mutation patients. Intrafamilial patients with Malattia leventinese/Doyne honeycomb retinal dystrophy seem to be phenotypically variable in visual loss, ophthalmoscopic findings, autofluorescence imaging, and optical coherence tomography changes. The amino acid change may have an effect on protein structure and function through bioinformatics analysis. CONCLUSION: The R345W mutation in EFEMP1 caused Malattia leventinese/Doyne honeycomb retinal dystrophy in a Chinese family. This is the first report, as per our knowledge, of the R345W mutation in EFEMP1 in a Chinese pedigree of this disease.

Pancreatic ß-cell failure, clinical implications, and therapeutic strategies in type 2 diabetes.

ABSTRACT: Pancreatic ß-cell failure due to a reduction in function and mass has been defined as a primary contributor to the progression of type 2 diabetes (T2D). Reserving insulin-producing ß-cells and hence restoring insulin production are gaining attention in translational diabetes research, and ß-cell replenishment has been the main focus for diabetes treatment. Significant findings in ß-cell proliferation, transdifferentiation, pluripotent stem cell differentiation, and associated small molecules have served as promising strategies to regenerate ß-cells. In this review, we summarize current knowledge on the mechanisms implicated in ß-cell dynamic processes under physiological and diabetic conditions, in which genetic factors, age-related alterations, metabolic stresses, and compromised identity are critical factors contributing to ß-cell failure in T2D. The article also focuses on recent advances in therapeutic strategies for diabetes treatment by promoting ß-cell proliferation, inducing non-ß-cell transdifferentiation, and reprograming stem cell differentiation. Although a significant challenge remains for each of these strategies, the recognition of the mechanisms responsible for ß-cell development and mature endocrine cell plasticity and remarkable advances in the generation of exogenous ß-cells from stem cells and single-cell studies pave the way for developing potential approaches to cure diabetes.