1.3 GHz 9-cell高性能超导腔高阶模耦合器电磁及热分析研究

中国科学院高能物理研究所于2023年6月完成了高品质因数1.3 GHz超导加速模组研发,在国际上率先实现了中温退火高品质因数超导腔模组技术路线。模组中集成了八只经过中温退火工艺处理的1.3 GHz9-cell超导腔,在模组的测试过程中超导腔的高阶模耦合器温升异常,导致超导腔无法在高梯度下稳定工作。通过HFSS软件和CST软件中的微波仿真模块对高阶模耦合器进行电磁分析,再通过理论和Ansys Workbench软件对高阶模耦合器进行热仿真分析,并结合模组的高功率实验,找到了超导腔性能异常的原因,并对超导腔高阶模耦合器的冷却方式进行了进一步的优化,解决了模组中超导腔高梯度下的不稳定性。

Insufficient TRPM5 Mediates Lipotoxicity-induced Pancreaticβ-cell Dysfunction

Objective:While the reduction of transient receptor potential channel subfamily M member 5(TRPM5)has been reported in islet cells from type 2 diabetic(T2D)mouse models,its role in lipotoxicity-induced pancreaticβ-cell dysfunction remains unclear.This study aims to study its role.Methods:Pancreas slices were prepared from mice subjected to a high-fat-diet(HFD)at different time points,and TRPM5 expression in the pancreaticβcells was examined using immunofluorescence staining.Glucose-stimulated insulin secretion(GSIS)defects caused by lipotoxicity were mimicked by saturated fatty acid palmitate(Palm).Primary mouse islets and mouse insulinoma MIN6 cells were treated with Palm,and the TRPM5 expression was detected using qRT-PCR and Western blotting.Palm-induced GSIS defects were measured following siRNA-based Trpm5 knockdown.The detrimental effects of Palm on primary mouse islets were also assessed after overexpressing Trpm5 via an adenovirus-derived Trpm5(Ad-Trpm5).Results:HFD feeding decreased the mRNA levels and protein expression of TRPM5 in mouse pancreatic islets.Palm reduced TRPM5 protein expression in a time-and dose-dependent manner in MIN6 cells.Palm also inhibited TRPM5 expression in primary mouse islets.Knockdown of Trpm5 inhibited insulin secretion upon high glucose stimulation but had little effect on insulin biosynthesis.Overexpression of Trpm5 reversed Palm-induced GSIS defects and the production of functional maturation molecules unique toβcells.Conclusion:Our findings suggest that lipotoxicity inhibits TRPM5 expression in pancreaticβcells both in vivo and in vitro and,in turn,drivesβ-cell dysfunction.

Upregulation of α-ENaC induces pancreatic β-cell dysfunction,ER stress,and SIRT2 degradation

Islet beta cells(β-cells)produce insulin in response to high blood glucose levels,which is essential for preserving glucose homeostasis.Voltage-gated ion channels inβ-cells,including Na+,K+,and Ca2+channels,aid in the release of insulin.The epithelial sodium channel alpha subunit(α-ENaC),a voltage-independent sodium ion channel,is also expressed in human pancreatic endocrine cells.However,there is no reported study on the function of ENaC in theβ-cells.In the current study,we found thatα-ENaC was expressed in human pancreatic glandule and pancreatic isletβ-cells.In the pancreas of db/db mice and high-fat diet-induced mice,and in mouse isletβ-cells(MIN6 cells)treated with palmitate,α-ENaC expression was increased.Whenα-ENaC was overexpressed in MIN6 cells,insulin content and glucose-induced insulin secretion were significantly reduced.On the other hand,palmitate injured isletβ-cells and suppressed insulin synthesis and secretion,but increasedα-ENaC expression in MIN6 cells.However,α-ENaC knockout(Scnn1a−/−)in MIN6 cells attenuatedβ-cell disorder induced by palmitate.Furthermore,α-ENaC regulated the ubiquitylation and degradation of sirtuin 2 inβ-cells.α-ENaC also modulatedβ-cell function in correlation with the inositol-requiring enzyme 1 alpha/X-box binding protein 1(IRE1α/XBP1)and protein kinase RNA-like endoplasmic reticulum kinase/C/EBP homologous protein(PERK/CHOP)endoplasmic reticulum stress pathways.These results suggest thatα-ENaC may play a novel role in insulin synthesis and secretion in theβ-cells,and the upregulation ofα-ENaC promotes isletβ-cell dysfunction.In conclusion,α-ENaC may be a key regulator involved in isletβ-cell damage and a potential therapeutic target for type 2 diabetes mellitus.

The Effect of Tuberculosis Infection on Pancreatic Beta-Cell Function in Patients with Type 2 Diabetes Mellitus

Objective: The aim of this study is to investigate how individuals with type 2 diabetes mellitus’ pancreatic β-cell function index and insulin resistance index are affected by tuberculosis infection. Methods: The study group consisted of 89 patients with type 2 diabetes mellitus and tuberculosis infection who were admitted to Jingzhou Chest Hospital between March 2019 and March 2021. Gender and duration of diabetes were matching conditions. The control group was made up of 89 patients with type 2 diabetes who were admitted to Jingzhou Central Hospital’s endocrinology department during the same period. The two patient groups provided general information such as gender, age, length of diabetes, and blood biochemical indexes such as glycosylated hemoglobin (HbA1c), fasting glucose (FPG), and fasting C-peptide (FC-P). The HOMA calculator was used to calculate the HOMA-β and the HOMA-IR, and intergroup comparisons and correlation analyses were carried out. Results: Regarding gender, age, disease duration, FC-P, and HbA1c, the differences between the two groups were not statistically significant (P > 0.05). However, BMI, FPG, HOMA-β, and HOMA-IR showed statistically significant differences (P < 0.05). In comparison to the control group, the study group’s HOMA-β was lower and its HOMA-IR was greater. According to Spearman’s correlation analysis, HOMA-β had a negative association (P th FPG, HbA1c, and the length of the disease, and a positive correlation with BMI and FC-P. A positive correlation was found between HOMA-IR and BMI, FPG, and FC-P (P < 0.01), as well as a correlation with the length of the disease (P > 0.05) and HbA1c. Conclusions: In type 2 diabetes mellitus combined with tuberculosis infection, the patients had higher FPG levels and lower FC-P levels, the secretory function of pancreatic β-cells was more severely impaired, and insulin resistance was more obvious.

Pancreaticβ-cell dysfunction in type 2 diabetes:Implications of inflammation and oxidative stress

Insulin resistance and pancreaticβ-cell dysfunction are major pathological mechanisms implicated in the development and progression of type 2 diabetes(T2D).Beyond the detrimental effects of insulin resistance,inflammation and oxidative stress have emerged as critical features of T2D that defineβ-cell dysfunction.Predominant markers of inflammation such as C-reactive protein,tumor necrosis factor alpha,and interleukin-1βare consistently associated withβ-cell failure in preclinical models and in people with T2D.Similarly,important markers of oxidative stress,such as increased reactive oxygen species and depleted intracellular antioxidants,are consistent with pancreaticβ-cell damage in conditions of T2D.Such effects illustrate a pathological relationship between an abnormal inflammatory response and generation of oxidative stress during the progression of T2D.The current review explores preclinical and clinical research on the pathological implications of inflammation and oxidative stress during the development ofβ-cell dysfunction in T2D.Moreover,important molecular mechanisms and relevant biomarkers involved in this process are discussed to divulge a pathological link between inflammation and oxidative stress duringβ-cell failure in T2D.Underpinning the clinical relevance of the review,a systematic analysis of evidence from randomized controlled trials is covered,on the potential therapeutic effects of some commonly used antidiabetic agents in modulating inflammatory makers to improveβ-cell function.

Association of point in range withβ-cell function and insulin sensitivity of type 2 diabetes mellitus in cold areas

Background and Objective:Self-monitoring of blood glucose(SMBG)is crucial for achieving a glycemic target and upholding blood glucose stability,both of which are the primary purpose of anti-diabetic treatments.However,the association between time in range(TIR),as assessed by SMBG,andβ-cell insulin secretion as well as insulin sensitivity remains unexplored.Therefore,this study aims to investigate the connections between TIR,derived from SMBG,and indices representingβ-cell functionality and insulin sensitivity.The primary objective of this study was to elucidate the relationship between short-term glycemic control(measured as points in range[PIR])and bothβ-cell function and insulin sensitivity.Methods:This cross-sectional study enrolled 472 hospitalized patients with type 2 diabetes mellitus(T2DM).To assessβ-cell secretion capacity,we employed the insulin secretion-sensitivity index-2(ISSI-2)and(ΔC-peptide_(0-120)/Δglucose_(0-120))×Matsuda index,while insulin sensitivity was evaluated using the Matsuda index and HOMA-IR.Since SMBG offers glucose data at specific point-in-time,we substituted TIR with PIR.According to clinical guidelines,values falling within the range of 3.9-10 mmol were considered"in range,"and the corresponding percentage was calculated as PIR.Results:We observed significant associations between higher PIR quartiles and increased ISSI-2,(ΔC-peptide_(0-120)/Δglucose_(0-120))×Matsuda index,Matsuda index(increased)and HOMA-IR(decreased)(all P<0.001).PIR exhibited positive correlations with log ISSI-2(r=0.361,P<0.001),log(ΔC-peptide_(0-120)/Δglucose_(0-120))×Matsuda index(r=0.482,P<0.001),and log Matsuda index(r=0.178,P<0.001)and negative correlations with log HOMA-IR(r=-0.288,P<0.001).Furthermore,PIR emerged as an independent risk factor for log ISSI-2,log(ΔC-peptide_(0-120)/Δglucose_(0-120))×Matsuda index,log Matsuda index,and log HOMA-IR.Conclusion:PIR can serve as a valuable tool for assessingβ-cell function and insulin sensitivity.

μ-cell法测定农药对男性精子机能影响的分析

目的研究农药对生育生殖的影响。方法采用μ－ｃｅｌ测定方法。结果暴露组精子的质量与数量都受到了影响，均呈下降趋势。结论长期暴露于农药污染，可能引起生育生殖功能的下降。

Glucagon-like peptide-1 receptor agonists as a possible intervention to delay the onset of type 1 diabetes:A new horizon

Type 1 diabetes(T1D)is a chronic autoimmune condition that destroys insulinproducing beta cells in the pancreas,leading to insulin deficiency and hyperglycemia.The management of T1D primarily focuses on exogenous insulin replacement to control blood glucose levels.However,this approach does not address the underlying autoimmune process or prevent the progressive loss of beta cells.Recent research has explored the potential of glucagon-like peptide-1 receptor agonists(GLP-1RAs)as a novel intervention to modify the disease course and delay the onset of T1D.GLP-1RAs are medications initially developed for treating type 2 diabetes.They exert their effects by enhancing glucose-dependent insulin secretion,suppressing glucagon secretion,and slowing gastric emptying.Emerging evidence suggests that GLP-1RAs may also benefit the treatment of newly diagnosed patients with T1D.This article aims to highlight the potential of GLP-1RAs as an intervention to delay the onset of T1D,possibly through their potential immunomodulatory and anti-inflammatory effects and preservation of beta-cells.This article aims to explore the potential of shifting the paradigm of T1D management from reactive insulin replacement to proactive disease modification,which should open new avenues for preventing and treating T1D,improving the quality of life and long-term outcomes for individuals at risk of T1D.

Targeting neuronal PAS domain protein 2 and KN motif/ankyrin repeat domains 1:Advances in type 2 diabetes therapy

This editorial summarizes the latest literature on the roles of neuronal PAS domain protein 2 and KN motif/ankyrin repeat domain 1 in type 2 diabetes(T2D).We highlight their involvement inβ-cell dysfunction,explore their potential as therapeutic targets,and discuss the implications for new treatment strategies.We offer valuable insights into relevant gene regulation and cellular mechanisms relevant for the targeted management of T2D.

9-cell超导腔快速预调谐方法研究

对频率和场平坦度的预调谐是9-cell超导腔耗时最多的后处理工序之一,很快将成为国内相关大科学工程9-cell腔批量生产的瓶颈。首先介绍了9-cell超导腔两种常用的预调谐方法,即DESY方法和Cornell方法的原理,建模分析和比较了两种方法的计算精度和误差来源,给出Cornell方法调谐量计算的修正。然后结合9-cell超导腔预调谐实验研究,给出了快速预调谐方法:DESY的重建算法在低场平时精度较高且收敛迅速,可作为粗调;Cornell微扰算法在高场平时精度较高且测量迅速,可作为微调。结合两种调谐方式,将预调谐分为粗调和微调两步,可有效提升9-cell超导腔预调谐的速度。

β-cell dysfunction: Its critical role in prevention and management of type 2 diabetes

Type 2 diabetes(T2DM) is characterized by insulin resistance and β-cell dysfunction. Although, in contrast to type 1 diabetes, insulin resistance is assumed to be a major pathophysiological feature of T2 DM, T2 DM never develops unless β-cells fail to compensate insulin resistance. Recent studies have revealed that a deficit of β-cell functional mass is an essential component of the pathophysiology of T2 DM, implying that β-cell deficit is a common feature of both type 1 and type 2 diabetes. β-cell dysfunction is present at the diagnosis of T2 DM and progressively worsens with disease duration. β-cell dysfunction is associated with worseningof glycemic control and treatment failure; thus, it is important to preserve or recover β-cell functional mass in the management of T2 DM. Since β-cell regenerative capacity appears somewhat limited in humans, reducing β-cell workload appears to be the most effective way to preserve β-cell functional mass to date, underpinning the importance of lifestyle modification and weight loss for the treatment and prevention of T2 DM. This review summarizes the current knowledge on β-cell functional mass in T2 DM and discusses the treatment strategy for T2 DM.

2-cell超导腔的高阶模分析

阐述了2-cell Telsa腔的设计。用3维程序HFSS分析了其高阶模的特点,给出了高阶模的主要参数频率、品质因数、分路阻抗以及模式的电场分布,并且π模的电场分布与Superfish的模拟结果相比较,两者是一致的。最后,简要分析了各高阶模对电子加速的影响,分析表明高阶模降低了电子加速效率和束流的稳定性。

Roux-en-Y gastric bypass promotes expression of PDX-1 and regeneration of β-cells in Goto-Kakizaki rats

AIM:To study the effects of Roux-en-Y gastric bypass(RYGB) on the expression of pancreatic duodenal homeobox-1(PDX-1) and pancreatic β-cell regeneration/neogenesis,and their possible mechanisms in diabetics.METHODS:Three groups of randomly selected nonobese diabetic Goto-Kakizaki(GK) rats were subjected to RYGB,sham-RYGB and sham-operation(sham-op) surgery,respectively.The rats were euthanized at postoperative 1,2,4 and 12 wk.Their pancreases were resected and analyzed using reverse transcription polymerase chain reaction to detect the mRNA of PDX-1.Anti-PDX-1 immunohistochemical(IHC) staining and Western blotting were used to detect the protein of PDX-1.Double IHC staining of anti-Brdu and-insulin was performed to detect regenerated β-cells.The index of double Brdu and insulin positive cells was calculated.RESULTS:In comparison with sham-RYGB and sham-op groups,a significant increase in the expressions of PDX-1 mRNA in RYGB group was observed at all experimental time points(1 wk:0.378 ± 0.013 vs 0.120 ± 0.010,0.100 ± 0.010,F = 727.717,P < 0.001;2 wk:0.318 ± 0.013 vs 0.110 ± 0.010,0.143 ± 0.015,F = 301.509,P < 0.001;4 wk:0.172 ± 0.011 vs 0.107 ± 0.012,0.090 ± 0.010,F = 64.297,P < 0.001;12 wk:0.140 ± 0.007 vs 0.120 ± 0.010,0.097 ± 0.015,F = 16.392,P < 0.001);PDX-1 protein in RYGB group was also increased significantly(1 wk:0.61 ± 0.01 vs 0.21 ± 0.01,0.15 ± 0.01,F = 3031.127,P < 0.001;2 wk:0.55 ± 0.00 vs 0.15 ± 0.01,0.17 ± 0.01,F = 3426.455,P < 0.001;4 wk:0.39 ± 0.01 vs 0.18 ± 0.01,0.22 ± 0.01,F = 882.909,P < 0.001;12 wk:0.41 ± 0.01 vs 0.20 ± 0.01,0.18 ± 0.01,F = 515.833,P < 0.001).PDX-1 mRNA and PDX-1 protein production showed no statistical significance between the two sham groups.Many PDX-1 positive cells could be found in the pancreatic islets of the rats in RYGB group at all time points.In addition,the percentage of Brdu-insulin double staining positive cells was higher in RYGB group than in the other two groups(1 wk:0.22 ± 0.13 vs 0.03 ± 0.06,0.03 ± 0.06,P < 0.05;2 wk:0.28 ± 0.08 vs 0.00 ± 0.00,0.03 ± 0.06,P < 0.05;4 wk:0.24 ± 0.11 vs 0.07 ± 0.06,0.00 ± 0.00,P < 0.001;12 wk:0.20 ± 0.07 vs 0.03 ± 0.06,0.00 ± 0.00,P < 0.05).CONCLUSION:RYGB can increase the expression of pancreatic PDX-1 and induce the regeneration of β-cells in GK rats.The associated regeneration of islet cells may be a possible mechanism that how RYGB could improve type 2 diabetes mellitus.

Visfatin Protects Rat Pancreatic β-cells against IFN-γ-Induced Apoptosis through AMPK and ERK1/2 Signaling Pathways

Objective Interferon-γ （IFN-γ） plays an important role in apoptosis and was shown to increase the riskof diabetes. Visfatin, an adipokine, has anti-diabetic, anti-tumor, and regulating inflammatoryproperties. In this study we investigated the effect of visfatin on IFN-γ-induced apoptosis in ratpancreatic β-cells.Methods The RINm5F （rat insulinoma cell line） cells exposed to IFN-γ were treated with or withoutvisfatin. The viability and apoptosis of the cells were assessed by using MTT and flow cytometry. Theexpressions of mRNA and protein were detected by using real-time PCR and western blot analysis.Results The exposure of RINm5F cells to IFN-γ for 48 h led to increased apoptosis percentage of thecells. Visfatin pretreatment significantly increased the cell viability and reduced the cell apoptosisinduced by IFN-γ. IFN-γ-induced increase in expression of p53 mRNA and cytochrome c protein,decrease in mRNA and protein levels of anti-apoptotic protein Bcl-2 were attenuated by visfatinpretreatment. Visfatin also increased AMPK and ERK1/2 phosphorylation and the anti-apoptotic actionof visfatin was attenuated by the AMPK and ERK1/2 inhibitor.Conclusion These results suggested that visfatin protected pancreatic islet cells against IFN-γ-inducedapoptosis via mitochondria-dependent apoptotic pathway. The anti-apoptotic action of visfatin ismediated by activation of AMPK and ERK1/2 signaling molecules.

The relationship between insulin resistance/β-cell dysfunction and diabetic retinopathy in Chinese patients with type 2 diabetes mellitus： the Desheng Diabetic Eye Study

AIM： To investigate the relationship between insulin resistance （IR）/β-cell dysfunction and diabetic retinopathy （DR） in Chinese patients with type 2 diabetes mellitus （T2DM）, and to explore further whether there were differences in the relationship among diabetic patients with higher and lower body mass index （BMI）. METHODS： Cross-sectional study. A total of 1466 subjects with T2DM were recruited in a local Desheng Community of urban Beijing from November 2009 to June 2012 for the cohort of Beijing Desheng Diabetic Eye Study. Standardized evaluation was carried out for each participant, including questionnaire, ocular and anthropometric examinations, and laboratory tests. Seven fields 30° color fundus photographs were used for DR grading according to the Early Treatment Diabetic Retinopathy Study protocols. Homeostatis Model Assessment （HOMA） method was employed for IR and β-cell function assessment. RESULTS： After excluding those participants who were treated with insulin （n=352） or had missing data of fasting insulin （n=96）, and further excluding those with poor quality of retinal photographs （n=10）, a total of 1008 subjects were included for the final analysis, 406 （40.3%） were men and 602 （59.7%） were women, age ranging fiom 34 to 86 （64.87±8.28）y. Any DR （levels 14 and above） was present in 278 （27.6%） subjects. After adjusting for possible covariates, the presence of any DR did not correlate with HOMA IR [odds ratio （OR） 1.51, 95% confidence interval （Cl） 0.87-2.61, P=0.14] or HOMA β-cell （OR 0.71, 95%CI 0.40-1.26, P=0.25）. After stratification by BMI, the presence of any DR was associated positively with HOMA IR （OR 2.46, 95%CI： 1.18-5.12, P=0.016）, and negatively with HOMA β-cell （OR 0.40, 95%CI： 0.19-0.87, P=0.021） in the group of patients with higher BMI （225 kg/m2）. In the group of patients with lower BMI （〈25 kg/m2）, the presence of any DR was not associated with HOMA IR （OR 1.00, 95%C1： 0.43-2.33, P=I.00） or HOMA β-cell （OR 1.41, 95%CI： 0.60-3.32, P=0.43）. CONCLUSION： The data suggest that higher IR and lower 13-cell function are associated with the presence of DR in the subgroup of diabetic patients with higher BMI. However, this association is not statistically significant in diabetic patients with lower BMI.

Betatrophin:A liver-derived hormone for the pancreatic β-cell proliferation

The pancreaticβ-cell failure which invariably accompanies insulin resistance in the liver and skeletal muscle is a hallmark of type-2 diabetes mellitus(T2DM).The persistent hyperglycemia of T2DM is often treated with anti-diabetic drugs with or without subcutaneous insulin injections,neither of which mimic the physiological glycemic control seen in individuals with fully functional pancreas.A sought after goal for the treatment of T2DM has been to harness the regenerative potential of pancreaticβ-cells that might obviate a need for exogenous insulin injections.A new study towards attaining this aim was reported by Yi et al,who have characterized a liver-derived protein,named betatrophin,capable of inducing pancreaticβ-cell proliferation in mice.Using a variety of in vitro and in vivo methods,Yi et al,have shown that betatrophin was expressed mainly in the liver and adipose tissue of mice.Exogenous expression of betatrophin in the liver led to dramatic increase in the pancreaticβ-cell mass and higher output of insulin in mice that also concomitantly elicited improved glucose tolerance.The authors discovered that betatrophin was also present in the human plasma.Surprisingly,betatrophin has been previously described by three other names,i.e.,re-feeding-induced fat and liver protein,lipasin and atypical angiopoeitin-like 8,by three independent laboratories,as nutritionally regulated liver-enriched factors that control serum triglyceride levels and lipid metabolism.Yi et al demonstration of betatrophin,as a circulating hormone that regulatesβ-cell proliferation,if successfully translated in the clinic,holds the potential to change the course of current therapies for diabetes.

Transdifferentiation of pancreatic α-cells into insulinsecreting cells: From experimental models to underlying mechanisms

Pancreatic insulin-secreting β-cells are essential regulators of glucose metabolism. New strategies are cur-rently being investigated to create insulin-producing β cells to replace deficient β cells, including the differentiation of either stem or progenitor cells, and the newly uncovered transdifferentiation of mature non-β islet cell types. However, in order to correctly drive any cell to adopt a new β-cell fate, a better understanding of the in vivo mechanisms involved in the plasticity and biology of islet cells is urgently required. Here, we review the recent studies reporting the phenomenon of transdifferentiation of α cells into β cells by focusing on the major candidates and contexts revealed to be involved in adult β-cell regeneration through this process. The possible underlying mechanisms of transdifferentiation and the interactions between several key factors involved in the process are also addressed. We propose that it is of importance to further study the molecular and cellular mechanisms underlying α- to β-cell transdifferentiation, in order to make β-cell regeneration from α cells a relevant and realizable strategy for developing cell-replacement therapy.

Serum insulin, insulin resistance, p-cell dysfunction, and gallstone disease among type 2 diabetics in Chinese population: A community-based study in Kinmen, Taiwan

AIM: To explore the association of serum insulin, insulin resistance, and β-cell dysfunction with gallstone disease (GSD) in type 2 diabetics. METHODS: We used a community-based study conducted between 1991 and 1993 in Kinmen, Taiwan to identify type 2 diabetics. A screening program for GSD was performed in 2001 by a panel of specialists who employed real-time ultrasound sonography to examine the abdominal region after the patient had fasted for at least 8 h. Screening was conducted in 2001 on 848 patients diagnosed with type 2 diabetes. The HOMA method was used to compare the profile differences for insulin resistance (HOMA IR) and β-cell dysfunction (HOMA β-cell). RESULTS: We studied 440 type 2 diabetics who attended sonography check-ups. After excluding eight insulin-treated diabetics, the prevalence of GSD among the remaining 432 was 13.9% (26/187) among males and 14.7% (36/245) among females. After adjustment for other GSD-associated risk factors in addition to age and obesity, GSD risk increased among females with levels of serum insulin [4th vs 1st quartile odds ratios (OR) = 4.46 (95%CI: 1.71-11.66)] and HOMA IR [4th vs 1st quartile OR = 4.46 (95%CI: 1.71-11.66)]. Better HOMA β-cell function was significantly related to decreased risk of GSD [4th vs 1st quartile OR = 0.16 (95%CI: 0.03-1.70)]. Among males, age and central obesity were the most significant risk factors for GSD. No association of GSD with serum insulin, HOMA IR, and HOMA β-cell was observed among males. CONCLUSION: Serum insulin, insulin resistance, and β-cell dysfunction are risk factors for GSD in females, but not males with type 2 diabetes.

Nutritional programming of pancreatic β-cell plasticity

Nutritional insufficiency during pregnancy has been shown to alter the metabolism of the offspring and can increase the risk of type 2 diabetes. The phenotype in the offspring involves changes to the morphology and functional capacity of the endocrine pancreas, and in the supporting islet microvasculature. Pancreatic β-cells possess a plastic potential and can partially recover from catastrophic loss. This is partly due to the existence of progenitors within the islets and the ability to generate new islets by neogenesis from the pancreatic ducts. This regenerative capacity is induced by bone marrow-derived stem cells, including endothelial cell progenitors and is associated with increased angiogenesis within the islets. Nutritional insults in early life, such as feeding a low protein diet to the mother, impair the regenerative capacity of the β-cells. The mechanisms underlying this include a reduced ability of β-cells to differentiate from the progenitor population, changes in the inductive signals from the microvasculature and an altered presence of endothelial progenitors. Statin treatment within animal models was associated with angiogenesis in the islet microvasculature, improved vascular function and an increase in β-cell mass. This demonstrates that reversal of the impaired β-cell phenotype observed following nutritional insult in early life is potentially possible.

The Influence of the Pro12Ala Mutation of PPARγ2 Receptor Gene on β-cells Restoration and Insulin Resistance in Type 2 Diabetes with Hypertension

The aim of this investigation was to determine whether a PPAR72 Prol2Ala polymorphism was associated with insulin resistance, β-cellfunction and hypertension in Chinese populations. 289 unrelated Chinese subjects first diagnosed Type 2 diabetes （HbAC1〈6.0） were investigated, including 132 hypertensive diabetic （HTD） subjects, 157 normotensive diabetic （NTD） subjects. Blood pressure and anthropometric measurements were collected from all participants, as well as several venous blood samples during oral glucose tolerance test （OGTT）. Biochemical measurements （high-density lipoprotein （HDL） and low-density lipoprotein-cholesterol （LDL）, triglycerides） and PPARγ2 Pro12Ala genotype were also determined. And insulin resistance and β-cells function was assessed by HOMA-IR and HOMA-β respectively. The frequency of subjects bearing the Pro12Ala was lower in the hypertension group （3. 03 %） than in the non-hypertension group （5.7 %） （P〈0.05） after adjusted for age, BMI and gender. Hypertensive diabetic Pro12Ala subjects had lower fasting plasma glucose level （P=0. 0127）, and better glucose tolerance 60 min after oral glucose （P=0. 0361）. Moreover, plasma insulin concentrations at 60 min was lower than those without A variant （P = 0. 0275）, and both hypertensive Ala/Pro in HOMA-β （P ： 0. 0455） and AUC for insulin （P=0. 0473） were higher, and HOMA-IR was lower （P=0. 0375） as compared with hypertensive Pro/Pro subjects. No association was observed between Prol2Ala genotype and BMI, total cholesterol, HDL- cholesterol or triglycerides in either group. Our findings suggested that the Ala 12 allele of the PPARγ2 gene may improve insulin resistance and ameliorate β-cell function reserves in T2DM with hypertension, and protect patients from hypertension in T2DM. As an important thrifty gene, environment factors may exerts an effect of PPARγ2 on glucose homeostasis and insulin resistance.