Gut Microbiota-Tryptophan Metabolism-GLP-1 Axis Participates in β-Cell Regeneration Induced by Dapagliflozin

Sodium-glucose cotransporter 2 inhibitors, efficacious antidiabetic agents that have cardiovascular and renal benefits, can promote pancreatic β-cell regeneration in type 2 diabetic mice. However, the underlying mechanism remains unclear. In this study, we aimed to use multiomics to identify the mediators involved in β-cell regeneration induced by dapagliflozin. We showed that dapagliflozin lowered blood glucose level, upregulated plasma insulin level, and increased islet area in db/db mice. Dapagliflozin reshaped gut microbiota and modulated microbiotic and plasmatic metabolites related to tryptophan metabolism, especially l-tryptophan, in the diabetic mice. Notably, l-tryptophan upregulated the mRNA level of glucagon-like peptide 1 (GLP-1) production-related gene (Gcg and Pcsk1) expression and promoted GLP-1 secretion in cultured mouse intestinal L cells, and it increased the supernatant insulin level in primary human islets, which was eliminated by GPR142 antagonist. Transplant of fecal microbiota from dapagliflozin-treated mice, supplementation of l-tryptophan, or treatment with dapagliflozin upregulated l-tryptophan, GLP-1, and insulin or C-peptide levels and promoted β-cell regeneration in db/db mice. Addition of exendin 9-39, a GLP-1 receptor (GLP-1R) antagonist, or pancreatic Glp1r knockout diminished these beneficial effects. In summary, treatment with dapagliflozin in type 2 diabetic mice promotes β-cell regeneration by upregulating GLP-1 production, which is mediated via gut microbiota and tryptophan metabolism.

ARTICLE HIGHLIGHTS

Positive feedback regulation between glycolysis and histone lactylation drives oncogenesis in pancreatic ductal adenocarcinoma

BACKGROUND

Metabolic reprogramming and epigenetic alterations contribute to the aggressiveness of pancreatic ductal adenocarcinoma (PDAC). Lactate-dependent histone modification is a new type of histone mark, which links glycolysis metabolite to the epigenetic process of lactylation. However, the role of histone lactylation in PDAC remains unclear.

METHODS

The level of histone lactylation in PDAC was identified by western blot and immunohistochemistry, and its relationship with the overall survival was evaluated using a Kaplan-Meier survival plot. The participation of histone lactylation in the growth and progression of PDAC was confirmed through inhibition of histone lactylation by glycolysis inhibitors or lactate dehydrogenase A (LDHA) knockdown both in vitro and in vivo. The potential writers and erasers of histone lactylation in PDAC were identified by western blot and functional experiments. The potential target genes of H3K18 lactylation (H3K18la) were screened by CUT&Tag and RNA-seq analyses. The candidate target genes TTK protein kinase (TTK) and BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) were validated through ChIP-qPCR, RT-qPCR and western blot analyses. Next, the effects of these two genes in PDAC were confirmed by knockdown or overexpression. The interaction between TTK and LDHA was identified by Co-IP assay.

RESULTS

Histone lactylation, especially H3K18la level was elevated in PDAC, and the high level of H3K18la was associated with poor prognosis. The suppression of glycolytic activity by different kinds of inhibitors or LDHA knockdown contributed to the anti-tumor effects of PDAC in vitro and in vivo. E1A binding protein p300 (P300) and histone deacetylase 2 were the potential writer and eraser of histone lactylation in PDAC cells, respectively. H3K18la was enriched at the promoters and activated the transcription of mitotic checkpoint regulators TTK and BUB1B. Interestingly, TTK and BUB1B could elevate the expression of P300 which in turn increased glycolysis. Moreover, TTK phosphorylated LDHA at tyrosine 239 (Y239) and activated LDHA, and subsequently upregulated lactate and H3K18la levels.

CONCLUSIONS

The glycolysis-H3K18la-TTK/BUB1B positive feedback loop exacerbates dysfunction in PDAC. These findings delivered a new exploration and significant inter-relationship between lactate metabolic reprogramming and epigenetic regulation, which might pave the way toward novel lactylation treatment strategies in PDAC therapy.

Coexistence of type 2 diabetes mellitus, arginine vasopressin deficiency, and Marfan syndrome: A case report

Diabetes mellitus (DM) and arginine vasopressin deficiency (AVP-D) are characterized by polyuria. Marfan syndrome is an autosomal dominant disorder caused by pathogenetic variants in FBN1. Here, we report a patient with type 2 diabetes mellitus, AVP-D, and Marfan syndrome. Although the coexistence of type 2 diabetes mellitus and AVP-D is rare, for those patients with type 2 diabetes mellitus, the existence of AVP-D should be considered when polyuria is not in accordance with the blood glucose levels, especially for those with a low urine specific gravity. Specific symptoms or signs help to identify Marfan syndrome early, and genetic testing of the FBN1 pathogenetic variant helps to make a definitive diagnosis.

Recurrent hypoglycemia induced by clopidogrel: A case report and mini review

This report describes a patient who developed recurrent hypoglycemia episodes after 23 days of antiplatelet therapy with clopidogrel for left subclavian artery stent implantation. The patient suffered from palpitation, profuse sweating and weakness on the 23rd day of clopidogrel treatment. The minimum plasma glucose was 2.2 mmol/L, and the hypoglycemia was associated with significantly elevated levels of insulin. A diagnosis of insulin autoimmune syndrome (IAS) was made with the presence of insulin autoantibody and a comprehensive differential diagnosis of other conditions related with hypoglycemia. Clopidogrel was stopped, and the patient was treated with acarbose and had frequent low-carbohydrate meals; his hypoglycemia did not occur within 10 days. To date, seven cases of IAS induced by clopidogrel have been reported. Most reported cases were male aged in their 70s, and the hypoglycemic attack appeared 1-4 weeks after exposure to clopidogrel, characterized by severe hyperinsulinemia hypoglycemia with high titers of insulin autoantibodies. Most IAS cases can resolve spontaneously when they stop using the trigger medicine. Severe cases had been treated with drugs that reduce pancreatic insulin secretion (such as somatostatin and diazoxide), immunosuppressants (glucocorticoids, azathioprine and rituximab) and even immunoadsorption to remove the insulin autoantibody from the body. Considering the hypoglycemic attack might increase the risk of cardiovascular events among patients taking clopidogrel, we recommend that doctors should be aware of IAS as a rare severe adverse effect of clopidogrel, and be vigilant for the symptoms related with hypoglycemia in clopidogrel users.

Fatty acid β-oxidation and mitochondrial fusion are involved in cardiac microvascular endothelial cell protection induced by glucagon receptor antagonism in diabetic mice

INTRODUCTION

The role of cardiac microvascular endothelial cells (CMECs) in diabetic cardiomyopathy is not fully understood. We aimed to investigate whether a glucagon receptor (GCGR) monoclonal antibody (mAb) ameliorated diabetic cardiomyopathy and clarify whether and how CMECs participated in the process.

RESEARCH DESIGN AND METHODS

The db/db mice were treated with GCGR mAb or immunoglobulin G (as control) for 4 weeks. Echocardiography was performed to evaluate cardiac function. Immunofluorescent staining was used to determine microvascular density. The proteomic signature in isolated primary CMECs was analyzed by using tandem mass tag-based quantitative proteomic analysis. Some target proteins were verified by using western blot.

RESULTS

Compared with db/m mice, cardiac microvascular density and left ventricular diastolic function were significantly reduced in db/db mice, and this reduction was attenuated by GCGR mAb treatment. A total of 199 differentially expressed proteins were upregulated in db/db mice versus db/m mice and downregulated in GCGR mAb-treated db/db mice versus db/db mice. The enrichment analysis demonstrated that fatty acid β-oxidation and mitochondrial fusion were the key pathways. The changes of the related proteins carnitine palmitoyltransferase 1B, optic atrophy type 1, and mitofusin-1 were further verified by using western blot. The levels of these three proteins were upregulated in db/db mice, whereas this upregulation was attenuated by GCGR mAb treatment.

CONCLUSION

GCGR antagonism has a protective effect on CMECs and cardiac diastolic function in diabetic mice, and this beneficial effect may be mediated via inhibiting fatty acid β-oxidation and mitochondrial fusion in CMECs.

Impact of polyethylene glycol loxenatide on cardiovascular outcomes in patients with type 2 diabetes: study protocol for a multicentre, randomised, double-blind, placebo-controlled trial (BALANCE-3)

INTRODUCTION

Recent cardiovascular outcomes trials have demonstrated that glucagon-like peptide 1 receptor agonist (GLP-1RA) decreases the incidence of major adverse cardiovascular events (MACEs) in individuals with type 2 diabetes mellitus (T2DM). Polyethylene glycol loxenatide (PEG-Loxe) is a once-weekly GLP-1RA obtained by modifying exendin-4. No clinical trials have been designed to assess the impact of PEG-Loxe on cardiovascular (CV) outcomes in individuals with T2DM. This trial aims to test the hypothesis that compared with placebo, PEG-Loxe treatment does not result in an unacceptable increase in CV risk in individuals with T2DM.

METHODS AND ANALYSIS

This study is a multicentre, randomised, double-blind, placebo-controlled trial. Patients with T2DM who fulfilled the inclusion criteria were randomly divided to receive weekly administration of either PEG-Loxe 0.2 mg or placebo (1:1 ratio). The randomisation was stratified according to utilisation of sodium-glucose cotransporter 2 inhibitors, history of CV disease and body mass index. The research period is expected to be 3 years, with a 1-year recruitment period and a 2-year follow-up period. The primary outcome is the occurrence of the first MACE, described as CV death, non-fatal myocardial infarction or non-fatal stroke. The statistical analyses were undertaken on the intent-to-treat patient. The primary outcome was evaluated using a Cox proportional hazards model with treatment and randomisation strata as the covariates.

ETHICS AND DISSEMINATION

The current research has been authorised by the Ethics Committee of Tianjin Medical University Chu Hsien-I Memorial Hospital (approval number: ZXYJNYYhMEC2022-2). Researchers must acquire informed consent from every participant before conducting any protocol-associated procedures. The findings of this study will be published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

ChiCTR2200056410.

Pancreatic alpha cell glucagon-liver FGF21 axis regulates beta cell regeneration in a mouse model of type 2 diabetes

AIMS/HYPOTHESIS

Glucagon receptor (GCGR) antagonism ameliorates hyperglycaemia and promotes beta cell regeneration in mouse models of type 2 diabetes. However, the underlying mechanisms remain unclear. The present study aimed to investigate the mechanism of beta cell regeneration induced by GCGR antagonism in mice.

METHODS

The db/db mice and high-fat diet (HFD)+streptozotocin (STZ)-induced mice with type 2 diabetes were treated with antagonistic GCGR monoclonal antibody (mAb), and the metabolic variables and islet cell quantification were evaluated. Plasma cytokine array and liver RNA sequencing data were used to screen possible mediators, including fibroblast growth factor 21 (FGF21). ELISA, quantitative RT-PCR and western blot were applied to verify FGF21 change. Blockage of FGF21 signalling by FGF21-neutralising antibody (nAb) was used to clarify whether FGF21 was involved in the effects of GCGR mAb on the expression of beta cell identity-related genes under plasma-conditional culture and hepatocyte co-culture conditions. FGF21 nAb-treated db/db mice, systemic Fgf21-knockout (Fgf21^-/-) diabetic mice and hepatocyte-specific Fgf21-knockout (Fgf21^Hep-/-) diabetic mice were used to reveal the involvement of FGF21 in beta cell regeneration. A BrdU tracing study was used to analyse beta cell proliferation in diabetic mice treated with GCGR mAb.

RESULTS

GCGR mAb treatment improved blood glucose control, and increased islet number (db/db 1.6±0.1 vs 0.8±0.1 per mm², p<0.001; HFD+STZ 1.2±0.1 vs 0.5±0.1 per mm², p<0.01) and area (db/db 2.5±0.2 vs 1.2±0.2%, p<0.001; HFD+STZ 1.0±0.1 vs 0.3±0.1%, p<0.01) in diabetic mice. The plasma cytokine array and liver RNA sequencing data showed that FGF21 levels in plasma and liver were upregulated by GCGR antagonism. The GCGR mAb induced upregulation of plasma FGF21 levels (db/db 661.5±40.0 vs 466.2±55.7 pg/ml, p<0.05; HFD+STZ 877.0±106.8 vs 445.5±54.0 pg/ml, p<0.05) and the liver levels of Fgf21 mRNA (db/db 3.2±0.5 vs 1.8±0.1, p<0.05; HFD+STZ 2.0±0.3 vs 1.0±0.2, p<0.05) and protein (db/db 2.0±0.2 vs 1.4±0.1, p<0.05; HFD+STZ 1.6±0.1 vs 1.0±0.1, p<0.01). Exposure to plasma or hepatocytes from the GCGR mAb-treated mice upregulated the mRNA levels of characteristic genes associated with beta cell identity in cultured mouse islets and a beta cell line, and blockage of FGF21 activity by an FGF21 nAb diminished this upregulation. Notably, the effects of increased beta cell number induced by GCGR mAb were attenuated in FGF21 nAb-treated db/db mice, Fgf21^-/- diabetic mice and Fgf21^Hep-/- diabetic mice. Moreover, GCGR mAb treatment enhanced beta cell proliferation in the two groups of diabetic mice, and this effect was weakened in Fgf21^-/- and Fgf21^Hep-/- mice.

CONCLUSIONS/INTERPRETATION

Our findings demonstrate that liver-derived FGF21 is involved in the GCGR antagonism-induced beta cell regeneration in a mouse model of type 2 diabetes.

Dapagliflozin improves pancreatic islet function by attenuating microvascular endothelial dysfunction in type 2 diabetes

AIMS

Sodium-glucose co-transporter 2 inhibitors, including dapagliflozin, improve ß cell function in type 2 diabetic individuals. Whether dapagliflozin can protect islet microvascular endothelial cells (IMECs) and thus contribute to the improvement of ß cell function remains unknown.

MATERIALS AND METHODS

The db/db mice were treated with dapagliflozin or vehicle for 6 weeks. ß cell function, islet capillaries and the levels of inflammatory chemokines in IMECs were detected. The mouse IMEC cell line MS-1 cells were incubated with palmitate and/or dapagliflozin for 24 h. Angiogenesis and inflammatory chemokine levels were evaluated, and the involved signalling pathways were analysed. The mouse ß cell line MIN6 cells, in the presence or absence of co-culture with MS-1 cells, were treated with palmitate and/or dapagliflozin for 24 h. The expression of ß cell specific markers and insulin secretion in MIN6 cells were determined.

RESULTS

Dapagliflozin significantly improved ß cell function, increased islet capillaries and decreased the levels of inflammatory chemokines of IMECs in db/db mice. In the palmitate-treated MS-1 cells, angiogenesis was enhanced and the levels of inflammatory chemokines were downregulated by dapagliflozin. Either a PI3K inhibitor or mTOR inhibitor eliminated the dapagliflozin-mediated effects. Importantly, dapagliflozin attenuated the palmitate-induced downregulation of ß cell function-related gene expression and insulin secretion in MIN6 cells co-cultured with MS-1 cells but not in those on mono-culture.

CONCLUSIONS

Dapagliflozin restores islet vascularisation and attenuates the inflammation of IMECs in type 2 diabetic mice. The dapagliflozin-induced improvement of ß cell function is at least partially accounted for by its beneficial effects on IMECs in a PI3K/Akt-mTOR-dependent manner.

Cover Image

The cover image is based on the Research Article Dapagliflozin improves pancreatic islet function by attenuating microvascular endothelial dysfunction in type 2 diabetes by Yunyi Le et al., https://doi.org/10.1002/dmrr.3607.

Glucagon Acting at the GLP-1 Receptor Contributes to β-Cell Regeneration Induced by Glucagon Receptor Antagonism in Diabetic Mice

Dysfunction of glucagon-secreting α-cells participates in the progression of diabetes, and glucagon receptor (GCGR) antagonism is regarded as a novel strategy for diabetes therapy. GCGR antagonism upregulates glucagon and glucagon-like peptide-1 (GLP-1) secretion, and notably promotes β-cell regeneration in diabetic mice. Here, we aimed to clarify the role of GLP-1 receptor (GLP-1R) activated by glucagon and/or GLP-1 in the GCGR antagonism-induced β-cell regeneration. We showed that in db/db mice and type 1 diabetic wild-type or Flox/cre mice, GCGR monoclonal antibody (mAb) improved glucose control, upregulated plasma insulin level, and increased β-cell area. Notably, blockage of systemic or pancreatic GLP-1R signaling by exendin 9-39 (Ex9) or Glp1r knockout diminished the above effects of GCGR mAb. Furthermore, glucagon neutralizing antibody (nAb), which prevents activation of GLP-1R by glucagon, also attenuated the GCGR mAb-induced insulinotropic effect and β-cell regeneration. In cultured primary mouse islets isolated from normal mice and db/db mice, GCGR mAb action to increase insulin release, and to upregulate β-cell specific marker expression, was reduced by a glucagon nAb, or by the GLP-1R antagonist Ex9, or by a pancreasspecific Glp1r knockout. These findings suggest that activation of GLP-1R by glucagon participates in β-cell regeneration induced by GCGR antagonism in diabetic mice.

[Analysis of safety and efficacy of laparoscopic surgery for gallbladder carcinoma]

Objective: To examine the efficacy and safety of laparoscopic surgery for gallbladder carcinoma. Methods: The data of 197 gallbladder carcinoma patients admitted at Peking Union Medical College Hospital between January 2012 and September 2022 were analyzed retrospectively. There were 86 males and 111 females,with age of (64.4±9.8)years(range:35 to 89 years). Patients were divided into laparoscopic group(n=53) and open group(n=144) according to different surgical methods. The general information of the two groups were matched by propensity score matching,and the clinical data and prognosis were compared between the two groups. Categorical variables were analyzed using χ2 test or Fisher's exact test,as appropriate. Continuous variables with and without normal distribution were analyzed using t-test and Mann-Whitney U test,respectively. Kaplan-Meier curves with Log-rank test were used to analyze the cumulative survival rates. Results: Forty-eight pairs of patients were matched successfully. There was no difference in general information,cholecystolithiasis,partial hepatectomy,and tumor stage between two groups(all P>0.05). The laparoscopic group had shorter operation time(t=-3.987,P<0.01),less bleeding(Z=-4.862,P<0.01),shorter total(Z=-5.009,P<0.01) and postoperative(Z=-5.412,P<0.01) hospital stay. Seventeen patients had postoperative complications. According to the Clavien-Dindo system,there were 4,11,1,and 1 patient with grade Ⅰ,Ⅱ,Ⅲa,and Ⅲb,respectively. All complications were improved after active treatment. After a median follow-up of 24(36) months(range:3 to 130 months),56 patients(58.3%) survived without tumor,7 patients(7.3%) survived with tumor,and 33 patients(34.4%) died. According to the Kaplan-Meier curves,there was no significant difference between laparoscopic and open groups in disease free(χ2=0.399,P=0.528) and overall(χ2=0.672,P=0.412) survival rates. Conclusions: The laparoscopic surgery is safe and effective in selected patients with gallbladder carcinoma. It can reduce surgical trauma and enhance patient recovery without increasing complication. Its prognosis is similar to that of open surgery.

Epidemiological characteristics and management of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis in China: A narrative review

AIM

With industrialization and spread of the westernized lifestyle, the number of people affected by non-alcoholic fatty liver disease (NAFLD)/non-alcoholic steatohepatitis (NASH) is growing rapidly in China; this has become a major public health concern. To better understand the burden and characteristics of NAFLD/NASH in China, we aim to perform a narrative review of the literature published in this field.

MATERIALS AND METHODS

We carried out a comprehensive electronic search of five English-language and three Chinese-language databases, to identify studies regarding NAFLD or NASH published from inception to November 30, 2022. Epidemiological studies of NAFLD/NASH in China were particularly noticed and summarized. We also searched the www.

CLINICALTRIALS

gov and www.chictr.org.cn websites for the registered trials on the treatment of the disease led by Chinese investigators or located in China.

RESULTS

The increasing rate of NAFLD prevalence in China is strikingly high, reaching more than twice that in western countries. The prevalence of NAFLD is nearly 30% of the general Chinese population, making it the leading cause of chronic liver diseases. The prevalence of NAFLD/NASH varies between provinces/regions, age groups, sexes, and individuals with different metabolic profiles. NAFLD co-exists in many Chinese patients with chronic hepatitis B. Since 2020, more Chinese studies have used the term metabolic-associated fatty liver disease (MAFLD), emphasizing the underlying metabolic disorders that occur concurrently with this disease. Several clinical trials involving lifestyle interventions, antidiabetic drugs, or traditional Chinese medicines, registered by Chinese investigators, have been completed or are ongoing. Moreover, several innovative targeted therapies developed in China are revolutionizing the treatment of NAFLD/NASH.

CONCLUSIONS

NAFLD has cast a heavy burden on the Chinese healthcare system. Chinese scholars are making efforts to achieve the optimal management of this disease.

High Vitamin D Level in Female Mice Increases the Number of Live Fetuses

Little is known about the impact of high-normal range of 25-hydroxyvitamin D [25(OH)D] on reproductive function. The aim of this study was to investigate the effect of different dose vitamin D supplementation in female mice on the pregnancy outcomes. Three groups of female mice were fed with fodder containing different dose of vitamin D at both pre-gestational and gestational stages. Serum 25(OH)D and calcium concentrations were monitored. The expression levels of vitamin D receptor (VDR) mRNA and protein in placenta were determined by real-time RT-PCR and western blot. Pregnancy outcomes were evaluated and compared among the three groups. Compared with the medium and low dose groups, serum 25(OH)D concentration was significantly increased and approximated to high-normal range in the high dose group (pre-gestational: 81.3±5.75 vs 52.8±6.24 and 25.0±3.99 ng/mL; gestational: 86.8±5.99 vs 52.6±9.29 and 27.9±4.96 ng/mL, respectively; all p<0.001). Interestingly, the average number of live fetuses per litter was much larger in the high dose group than in other two groups (19.8±5.31 vs 13.8±1.30 and 12.8±3.55 respectively, both p<0.05). However, no significant differences of the expression levels of VDR mRNA and protein in placenta were identified among the three groups. Supplementation of high dose vitamin D can enhance the female mice reproductive function. Further study is warranted to explore the mechanism by which high level of 25(OH)D in female mice increases the number of fetuses.

Glucagon receptor blockage inhibits β-cell dedifferentiation through FoxO1

Glucagon-secreting pancreatic α-cells play pivotal roles in the development of diabetes. Glucagon promotes insulin secretion from β-cells. However, the long-term effect of glucagon on the function and phenotype of β-cells had remained elusive. In this study, we found that long-term glucagon intervention or glucagon intervention with the presence of palmitic acid downregulated β-cell-specific markers and inhibited insulin secretion in cultured β-cells. These results suggested that glucagon induced β-cell dedifferentiation under pathological conditions. Glucagon blockage by a glucagon receptor (GCGR) monoclonal antibody (mAb) attenuated glucagon-induced β-cell dedifferentiation. In primary islets, GCGR mAb treatment upregulated β-cell-specific markers and increased insulin content, suggesting that blockage of endogenous glucagon-GCGR signaling inhibited β-cell dedifferentiation. To investigate the possible mechanism, we found that glucagon decreased FoxO1 expression. FoxO1 inhibitor mimicked the effect of glucagon, whereas FoxO1 overexpression reversed the glucagon-induced β-cell dedifferentiation. In db/db mice and β-cell lineage-tracing diabetic mice, GCGR mAb lowered glucose level, upregulated plasma insulin level, increased β-cell area, and inhibited β-cell dedifferentiation. In aged β-cell-specific FoxO1 knockout mice (with the blood glucose level elevated as a diabetic model), the glucose-lowering effect of GCGR mAb was attenuated and the plasma insulin level, β-cell area, and β-cell dedifferentiation were not affected by GCGR mAb. Our results proved that glucagon induced β-cell dedifferentiation under pathological conditions, and the effect was partially mediated by FoxO1. Our study reveals a novel cross talk between α- and β-cells and is helpful to understand the pathophysiology of diabetes and discover new targets for diabetes treatment.NEW & NOTEWORTHY Glucagon-secreting pancreatic α-cells can interact with β-cells. However, the long-term effect of glucagon on the function and phenotype of β-cells has remained elusive. Our new finding shows that long-term glucagon induces β-cell dedifferentiation in cultured β-cells. FoxO1 inhibitor mimicks whereas glucagon signaling blockage by GCGR mAb reverses the effect of glucagon. In type 2 diabetic mice, GCGR mAb increases β-cell area, improves β-cell function, and inhibits β-cell dedifferentiation, and the effect is partially mediated by FoxO1.

γ-aminobutyric acid modulates α-cell hyperplasia but not β-cell regeneration induced by glucagon receptor antagonism in type 1 diabetic mice

AIMS

To investigate whether treatment with γ-aminobutyric acid (GABA) alone or in combination with glucagon receptor (GCGR) monoclonal antibody (mAb) exerted beneficial effects on β-cell mass and α-cell mass, and to explore the origins of the regenerated β-cells in mice with type 1 diabetes (T1D).

METHODS

Streptozotocin (STZ)-induced T1D mice were treated with intraperitoneal injection of GABA (250 μg/kg per day) and/or REMD 2.59 (a GCGR mAb, 5 mg/kg per week), or IgG dissolved in PBS for 8 weeks. Plasma hormone levels and islet cell morphology were evaluated by ELISA and immunofluorescence, respectively. The origins of the regenerated β-cells were analyzed by double-immunostaining, α-cell lineage-tracing and BrdU-tracing studies.

RESULTS

After the 8-week treatment, GABA or GCGR mAb alone or in combination ameliorated hyperglycemia in STZ-induced T1D mice. GCGR mAb upregulated plasma insulin level and increased β-cell mass, and GABA appeared to have similar effects in T1D mice. However, combination treatment did not reveal any additive or synergistic effect. Interestingly, the GCGR mAb-induced increment of plasma glucagon level and α-cell mass was attenuated by the combined treatment of GABA. In addition, duct-derived β-cell neogenesis and α-to-β cell conversion but not β-cell proliferation contributed to the increased β-cell mass in T1D mice.

CONCLUSION

These results suggested that GABA attenuated α-cell hyperplasia but did not potentiates β-cell regeneration induced by GCGR mAb in T1D mice. Our findings provide novel insights into a combination treatment strategy for β-cell regeneration in T1D.

Learning Curve for Flow Diversion of Posterior Circulation Aneurysms: A Long-Term International Multicenter Cohort Study

BACKGROUND AND PURPOSE

Flow diversion has gradually become a standard treatment for intracranial aneurysms of the anterior circulation. Recently, the off-label use of the flow diverters to treat posterior circulation aneurysms has also increased despite initial concerns of rupture and the suboptimal results. This study aimed to explore the change in complication rates and treatment outcomes across time for posterior circulation aneurysms treated using flow diversion and to further evaluate the mechanisms and variables that could potentially explain the change and outcomes.

MATERIALS AND METHODS

A retrospective review using a standardized data set at multiple international academic institutions was performed to identify patients with ruptured and unruptured posterior circulation aneurysms treated with flow diversion during a decade spanning January 2011 to January 2020. This period was then categorized into 4 intervals.

RESULTS

A total of 378 procedures were performed during the study period. Across time, there was an increasing tendency to treat more vertebral artery and fewer large vertebrobasilar aneurysms (P = .05). Moreover, interventionalists have been increasingly using fewer overlapping flow diverters per aneurysm (P = .07). There was a trend toward a decrease in the rate of thromboembolic complications from 15.8% in 2011-13 to 8.9% in 2018-19 (P = .34).

CONCLUSIONS

This multicenter experience revealed a trend toward treating fewer basilar aneurysms, smaller aneurysms, and increased usage of a single flow diverter, leading to a decrease in the rate of thromboembolic and hemorrhagic complications.

Association of Time in Range with Endothelial Injury in Patients with Type 2 Diabetes Treated with Exenatide

INTRODUCTION

We aimed to investigate whether treatment with exenatide could increase time in range (TIR) and decrease glycemic variability, and to evaluate the association between TIR and endothelial injury in patients with type 2 diabetes mellitus (T2DM).

METHODS

Two-hundred patients with T2DM treated with exenatide for 16 weeks were included in this study. Seven-point fingerstick blood glucose was used to evaluate derived TIR and glycemic variability. The serum levels of soluble endothelial cell protein C receptor (sEPCR) and von Willebrand factor (vWF) were measured. Ninety-three patients having the data of endothelial injury markers were categorized as derived TIR > 70% or ≤ 70% after the treatment and the association between TIR and endothelial injury were evaluated.

RESULTS

Treatment with exenatide for 16 weeks resulted in a significant reduction in fasting blood glucose, postprandial 2 h blood glucose, and glycated hemoglobin A1c (HbA1c) levels in patients with T2DM. Compared with baseline, derived TIR value was significantly increased [85.7 (57.1, 100.0) % vs. 42.9 (14.9, 71.4) %, P < 0.001], and the parameters of glycemic variability were remarkably decreased after the treatment. After the treatment, serum sEPCR level was significantly decreased from baseline in patients with TIR > 70% [74.5 (32.8, 122.5) ng/mL vs. 96.9 (48.5, 150.9) ng/mL, P = 0.006] but not in those with TIR ≤ 70%; serum vWF level was remarkably decreased in patients with TIR > 70% [from 1166.2 (848.1, 1335.5) mIU/mL to 907.4 (674.3, 1335.1) mIU/mL, P = 0.001] while this effect was modest in those with TIR ≤ 70%.

CONCLUSIONS

Treatment with exenatide increases TIR and decreases glycemic variability in patients with T2DM. Moreover, the amelioration of endothelial injury is more pronounced in patients with TIR > 70% after the treatment.

TRIAL REGISTRATION

ChiCTR-IPR-15006558 (registered, 27 May 2015).

Pro-α-cell-derived β-cells contribute to β-cell neogenesis induced by antagonistic glucagon receptor antibody in type 2 diabetic mice

The deficiency of pancreatic β-cells is the key pathogenesis of diabetes, while glucagon-secreting α-cells are another player in the development of diabetes. Here, we aimed to investigate the effects of glucagon receptor (GCGR) antagonism on β-cell neogenesis in type 2 diabetic (T2D) mice and explore the origins of the neogenic β-cells. We showed that GCGR monoclonal antibody (mAb) elevated plasma insulin level and increased β-cell mass in T2D mice. By using α-cell lineage-tracing (glucagon-cre-β-gal) mice and inducible Ngn3⁺ pancreatic endocrine progenitor lineage-tracing (Ngn3-CreERT2-tdTomato) mice, we found that GCGR mAb treatment promoted α-cell regression to progenitors, and induced Ngn3⁺ progenitor reactivation and differentiation toward β-cells. Besides, GCGR mAb upregulated the expression levels of β-cell regeneration-associated genes and promoted insulin secretion in primary mouse islets, indicative of a direct effect on β-cell identity. Our findings suggest that GCGR antagonism not only increases insulin secretion but also promotes pro-α-cell-derived β-cell neogenesis in T2D mice.

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Blockage of α-cell-derived glucagon promotes β-cell regeneration in situ in type 2 diabetic (T2D) mice

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Glucagon receptor (GCGR) mAb induces the trans-differentiation of α-cells to β-cells

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GCGR mAb promotes α-cell regression to pancreatic endocrine progenitors

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GCGR mAb induces Ngn3⁺ progenitor reactivation and differentiation toward β-cells

Expert consensus on personalized initiation of glucose-lowering therapy in adults with newly diagnosed type 2 diabetes without clinical cardiovascular disease or chronic kidney disease

Since it is difficult for clinicians to make a decision among the various types of antidiabetic medications due to their great discrepancy in mechanisms, pharmacological properties, and cardiovascular/renal protection, a relatively "precision" or personalized hypoglycemic treatment suggestion is practical for type 2 diabetes (T2D) management in adults. This expert consensus makes some recommendations based on the characteristics of adult T2D patients without clinical cardiovascular disease (CVD) or chronic kidney disease (CKD) by evidence from large-scale clinical trials. The main consideration for initiating antidiabetic medications is the safety and benefits for prevention of target organ damage, such as CVD and CKD. The choice of personalized glucose-lowering therapy regarding target organ protection is based on the various effects of antidiabetic medications, patients' clinical characteristics and their key risks, as well as the sociological factors. According to the effects on glucose reduction, cardiovascular protection, renal benefit, body weight change, hypoglycemic risk, and liver function impact, the antidiabetic medications are recategorized in this consensus. Combined with the glucose control target and the different effects of hypoglycemic agents, a significant body of recommendations have been developed for optimal T2D management according to the risk factors for atherosclerotic CVD, heart failure, CKD, primary fatty liver, and hypoglycemia. This consensus gives detailed guidance on personalized antidiabetic therapy initiation in newly diagnosed T2D adults, which attaches great importance to both glucose control and target organ protection.

The Prevalence of Cardiovascular Disease in Adults with Type 2 Diabetes in China: Results from the Cross-Sectional CAPTURE Study

INTRODUCTION

Cardiovascular disease (CVD) is the leading cause of death in Chinese adults with type 2 diabetes (T2D), and treatment guidelines have increasingly focused on the comprehensive management of T2D and CVD. Here, we report data from the Chinese population within the CAPTURE study, including CVD prevalence in patients with T2D and insights into their management.

METHODS

CAPTURE (a multinational, non-interventional, cross-sectional study in adults with T2D) included data from eight centers in China from July to September 2019. Overall CVD prevalence estimates were calculated, and descriptive data regarding CVD subtypes and treatment were collected and reported here.

RESULTS

Of 805 adults with T2D enrolled in China (61.9% male, median age 59 years), 273 had established CVD, with an estimated prevalence (95% CI) of 33.9% (30.6%, 37.3%). Most CVD cases were atherosclerotic (94.9%). Coronary heart disease had the highest estimated prevalence (16.0%), followed by carotid artery disease (9.6%) and cerebrovascular disease (7.7%). Use of glucose-lowering agents (GLAs) with proven cardiovascular benefits (glucagon-like peptide-1 receptor agonists and/or sodium-glucose cotransporter-2 inhibitors) was low in the China sample (7.7%). Approximately half of the CVD subgroup in the China sample was receiving cardiovascular medication, but use of guideline-directed agents was low (e.g., statins: 35.9%; angiotensin II receptor blockers: 15%; angiotensin-converting enzyme inhibitors: 2.6%).

CONCLUSIONS

In the Chinese CAPTURE population, one-third of patients had established CVD, with atherosclerotic CVD largely accounting for the CVD burden; use of GLAs with proven cardiovascular benefits and cardiovascular medications was low, suggesting an unmet need for optimal management in this group.

[Digitalized analysis of the gingival and bone morphology in the maxillary anterior teeth in patient with posterior dental implant]

Objective: To explore and analyze the correlation between labial gingival morphology and alveolar bone morphology of maxillary anterior teeth in patients with posterior dental implant, so as to provide reference basis for restoration design and esthetic reconstruction of anterior teeth. Methods: Sixty-four patients [24 males, 40 females (25.6±3.3) years old] who planned to receive posterior dental implant restoration were recruited randomly with the inclusion and exclusion criteria in Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University from May 2020 to May 2021. According to the visibility of periodontal probe through gingival margin, the subjects were divided into thin and thick gingival biotypes, including 29 cases of thin biotype and 35 cases of thick biotype. The 3Shape software was used to perform oral scanning, and cone beam CT (CBCT) was taken for each patient. Geomagic and Mimics software were used to measure and record the labial crown width and length, gingival papilla height, gingival angle, bone papilla height and bone margin angle of maxillary anterior teeth. Results: The crown width length ratios of maxillary central incisors, lateral incisors and canines were 0.85±0.08, 0.80±0.08 and 0.86±0.09 (F=10.71, P<0.01). The height of gingival papilla between maxillary central incisors, between central incisors and lateral incisors, between lateral incisors and canines were (3.93±0.86), (3.47±0.84) and (3.38±0.91) mm respectively (F=7.44, P<0.01), and the height of corresponding bone papilla were (3.44±0.88), (3.12±0.75) and (2.72±0.63) mm respectively (F=14.26, P<0.01). The gingival margin angles of maxillary central incisors, lateral incisors and canines were 88.3°±7.7°, 84.7°±8.9° and 81.2°±6.6° (F=13.15, P<0.01), and the bone margin angles were 103.2°±13.1°, 99.5°±11.2° and 110.6°±13.0° (F=13.25, P<0.01). The crown width length ratio (0.81±0.08), gingival margin angle (82.2°±7.4°) and bone margin angle (99.4°±12.9°) of thin gingival subjects were significantly lower than those of thick gingival subjects (0.85±0.09, 86.5°±8.6°, 108.5°±11.4°) (t=-2.79, 3.63, 5.20, P<0.01). The height of gingival papilla [(3.93±0.81) mm] and bone papilla [(3.43±0.80) mm] in thin gingival subjects were significantly lower than those in thick gingival subjects [(3.34±0.84) and (2.85±0.71) mm, respectively] (t=-4.89, -5.36, P<0.01). The height of labial gingival papilla of upper anterior teeth was positively correlated with that of bone papilla in all patients (r=0.66, P<0.01); the ratio of crown width to length of upper anterior teeth was positively correlated with the angle of bone margin (r=0.42, P<0.01); the height of anterior gingival papilla was negatively correlated with the angle of bone margin (r=-0.58, P<0.01), and the height of bone papilla was negatively correlated with the angle of bone margin (r=-0.82, P<0.01). Conclusions: The crown shape, gingival shape and alveolar bone shape of maxillary anterior teeth were different in different tooth positions. Patients with different periodontal phenotypes had different crown width length ratio, gingival papilla height, bone papilla height, gingival margin angle, and bone margin angle.

[Application of enhanced recovery after surgery in perioperative management of patients with gallbladder carcinoma]

Objective: To investigate the efficacy and safety of enhanced recovery after surgery (ERAS) in perioperative management of patients with gallbladder carcinoma. Methods: The data of the patients with gallbladder carcinoma admitted at Peking Union Medical College Hospital between January 2017 and December 2021 were analyzed retrospectively. There were 69 males(42.1%) and 95 females(57.9%),with age of (64.0±10.3) years(range:37 to 89 years). Patients were divided into ERAS group(n=53) and normal group(n=111) according to whether they were treated with ERAS measures during the perioperative period.The basic characteristics of the two groups were matched by propensity score matching,and then the perioperative information was compared between the two groups. Categorical variables were presented as absolute numbers or frequencies. Differences between study groups were analyzed using χ² test, Fisher's exact test, t-test, or Mann-Whitney U test, as appropriate. Results: Each group had 45 patients after propensity score matching with well-balanced basic characteristics. There was no difference in basic characteristics, operation time,bleeding,complication,and hospitalization expenses between two groups(all P>0.05). Compared with the normal group,time of ambulation (M(IQR)) (1(1) day vs. 2(2) days;Z=-3.839,P<0.01),postoperative anal exhaust time (2(1) days vs. 3(1) days;Z=-3.013,P=0.003),feeding time(2(1) days vs. 2(1) days;Z=-3.647,P<0.01),postoperative (5(2) days vs. 7(4) days;Z=-3.984,P<0.01) and total(8(4) days vs. 13(6) days;Z=-3.605,P<0.01) hospitalization time were shorter in ERAS group. Postoperative complications occurred in 12 patients. According to the Clavien-Dindo classification,6,4,and 2 patients were classified as grade Ⅰ,Ⅱ,and Ⅲa,respectively. Conclusion: The ERAS measures is safe and effective for perioperative management of patients with gallbladder carcinoma, enhancing patient recovery and shortening hospitalization time without increasing complication or hospitalization cost.

[Digital analysis of the correlation between gingival thickness and alveolar bone thickness in the maxillary anterior teeth region]

Objective: To measure the labial gingival thickness and bone lamella thickness in the maxillary anterior area using digital method, and to analyze the correlation between the two, so as to provide a reference for esthetic restoration and implantation treatment of the upper anterior area. Methods: Fifty-seven patients [23 males, 34 females, (25.8±4.5) years old] who planned to receive posterior dental implant restoration were recruited randomly with the inclusion and exclusion criteria in Department of Prosthodontics, School of Stomatology, The Fourth Military Medical University from May 2020 to October 2020. The 3Shape software was used to perform oral scanning, and cone beam CT (CBCT) was taken for each patient. The image data was fitted and registered by the 3Shape software. The gingival thickness at 2 mm below the gingival margin, bone thickness and gingival thickness at 2 and, 4 mm below the crest of the labial alveolar crest in maxillary central incisors, lateral incisors and canines, were measured. Results: The gingival thickness at 2 mm below the gingival margin of maxillary central incisors, lateral incisors and canines was (1.42±0.21), (1.19±0.17) and (1.23±0.20) mm respectively (F=12.47, P<0.001). The gingival thickness at 2 mm below gingival margin and 4 mm below crest of residual ridge in the male patients were (1.31±0.21) and (0.67±0.22) mm, and those in the female patients were (1.26±0.22) and (0.58±0.19) mm respectively, and there were statistically significant differences in the gingival thickness between the "2 mm below gingival margin" group and the "4 mm below crest of residual ridge" group (t=2.01 and 3.97, P<0.05). There was a positive correlation between gingival thickness and alveolar bone thickness at 2 mm and 4 mm below the crest of residual ridge in maxillary anterior region, and the correlation coefficients (r) were 0.387 and 0.344 respectively (P<0.05). Conclusions: Gingival thickness of maxillary anterior area is related to the tooth position and gender. The gingival thickness of men is greater than that of women.The gingival thickness at 2 and 4 mm below the crest of the alveolar crest is positively correlated with the thickness of the alveolar bone.

Efficacy of Dulaglutide in Chinese Patients with Type 2 Diabetes and Different Glycemic Patterns: a Post-hoc Analysis of the Phase 3 AWARD-CHN2 Trial

INTRODUCTION

We evaluated the effect of dulaglutide on the relative contributions of fasting glucose (FG) and postprandial glucose (PPG) to overall hyperglycemia in patients with type 2 diabetes (T2D), and assessed responses to dulaglutide versus insulin glargine (glargine) in patients with different baseline glycemic patterns.

METHODS

This post-hoc analysis of the phase 3 AWARD-CHN2 trial included data from 560 Chinese patients with uncontrolled T2D who received once-weekly dulaglutide (1.5 or 0.75 mg) or once-daily glargine for 26 weeks. The relative contributions of FG and PPG to overall hyperglycemia across different glycated hemoglobin (HbA1c) categories were calculated using the area under the curve of 7-point self-monitored blood glucose profiles. Patients were also categorized into four subgroups according to median baseline FG (cutoff 8.9 mmol/L) and PPG (cutoff 12.5 mmol/L): low FG/low PPG, low FG/high PPG, high FG/low PPG and high FG/high PPG. Changes in glycemic parameters and body weight were calculated for patients in each subgroup.

RESULTS

Among patients receiving dulaglutide, higher HbA1c was associated with higher relative contributions of FG and lower relative contributions of PPG to overall hyperglycemia at baseline and week 26 of dulaglutide treatment. After 26 weeks, dulaglutide 1.5 mg led to statistically greater decreases in HbA1c from baseline versus glargine in most subgroups, including the high FG subgroups, and a numerically greater decrease in HbA1c was observed in the low FG/high PPG subgroup. Across all subgroups, higher proportions of patients achieved HbA1c ≤ 6.5% with dulaglutide 1.5 mg than with glargine (all P < 0.05). Dulaglutide 1.5 mg showed better control of body weight than glargine in all subgroups (all P < 0.05).

CONCLUSIONS

Dulaglutide reduced HbA1c through reductions in both FG and PPG across HbA1c categories in T2D patients with uncontrolled hyperglycemia. Furthermore, treatment with dulaglutide provided a greater reduction in HbA1c than glargine, regardless of baseline FG and PPG levels.

Identification of key genes and pathways in mild and severe nonalcoholic fatty liver disease by integrative analysis

Background

The global prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing. The pathogenesis of NAFLD is multifaceted, and the underlying mechanisms are elusive. We conducted data mining analysis to gain a better insight into the disease and to identify the hub genes associated with the progression of NAFLD.

Methods

The dataset GSE49541, containing the profile of 40 samples representing mild stages of NAFLD and 32 samples representing advanced stages of NAFLD, was acquired from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were identified using the R programming language. The Database for Annotation, Visualization and Integrated Discovery (DAVID) online tool and Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database were used to perform the enrichment analysis and construct protein–protein interaction (PPI) networks, respectively. Subsequently, transcription factor networks and key modules were identified. The hub genes were validated in a mice model of high fat diet (HFD)-induced NAFLD and in cultured HepG2 cells by real-time quantitative PCR.

Results

Based on the GSE49541 dataset, 57 DEGs were selected and enriched in chemokine activity and cellular component, including the extracellular region. Twelve transcription factors associated with DEGs were indicated from PPI analysis. Upregulated expression of five hub genes (SOX9, CCL20, CXCL1, CD24, and CHST4), which were identified from the dataset, was also observed in the livers of HFD-induced NAFLD mice and in HepG2 cells exposed to palmitic acid or advanced glycation end products.

Conclusion

The hub genes SOX9, CCL20, CXCL1, CD24, and CHST4 are involved in the aggravation of NAFLD. Our results offer new insights into the underlying mechanism of NAFLD progression.

Association between Thyroid Function and Prognosis of COVID-19: A Retrospective Observational Study

Background: Coronavirus disease 2019 (COVID-19) is a severe infectious illness. It has been reported that COVID-19 has an effect on thyroid function. However, the association between thyroid function and prognosis of COVID-19 is still unclear.Methods: This retrospective study included patients with COVID-19 admitted to Tongji Hospital in Wuhan from January 28 to April 4, 2020. Demographic, epidemiological, clinical, laboratory, treatment, and outcome data were collected from patients with laboratory-confirmed COVID-19. Patients without history of thyroid disease who had a thyroid function test at admission were enrolled in the final analysis. Risk factors of in-hospital death were explored using univariable and multivariable Cox regression analyses. Survival differences were assessed with Kaplan-Meier curves and log-rank test.Results: A total of 127 patients were included in this study, with 116 survivors and 11 non-survivors. The serum levels of thyroid stimulating hormone (TSH) [0.8 (0.5-1.7) vs. 1.9 (1.0-3.1) μIU/mL, P = .031] and free triiodothyronine (FT₃) [2.9 (2.8-3.1) vs. 4.2 (3.5-4.7) pmol/L, P < .001] were lower in non-survivors than in survivors, and a low FT₃ state (defined as FT₃ < 3.1 pmol/L) at admission accounted for a higher proportion in non-survivors than in survivors (72.7% vs. 11.2%, P < .001). Univariate Cox regression analysis showed that FT₃ level (HR 0.213, 95% CI: 0.101-0.451, P < .001) and the low FT₃ state (HR 14.607, 95% CI: 3.873-55.081, P < .001) were negatively and positively associated with the risk of in-hospital death, respectively. Furthermore, multivariate Cox regression analysis revealed that a low FT₃ state was associated with an increased risk of in-hospital death after adjusting for confounding factors (HR 13.288, 95% CI: 1.089-162.110, P = .043). Moreover, Kaplan-Meier curves indicated a lower survival probability in COVID-19 patients with a low FT₃ status.Conclusion: Serum FT₃ level is lower in non-survivors among moderate-to-critical patients with COVID-19, and the low FT₃ state is associated with an increased risk of in-hospital mortality of COVID-19.

CAPTURE: a multinational, cross-sectional study of cardiovascular disease prevalence in adults with type 2 diabetes across 13 countries

Background

There is a paucity of global data on cardiovascular disease (CVD) prevalence in people with type 2 diabetes (T2D). The primary objective of the CAPTURE study was to estimate the prevalence of established CVD and its management in adults with T2D across 13 countries from five continents. Additional objectives were to further characterize the study sample regarding demographics, clinical parameters and medication usage, with particular reference to blood glucose-lowering agents (GLAs: glucagon-like peptide-1 receptor agonists and sodium-glucose co-transporter-2 inhibitors) with demonstrated cardiovascular benefit in randomized intervention trials.

Methods

Data were collected from adults with T2D managed in primary or specialist care in Australia, China, Japan, Czech Republic, France, Hungary, Italy, Argentina, Brazil, Mexico, Israel, Kingdom of Saudi Arabia, and Turkey in 2019, using standardized methodology. CVD prevalence, weighted by diabetes prevalence in each country, was estimated for the overall CAPTURE sample and participating countries. Country-specific odds ratios for CVD prevalence were further adjusted for relevant demographic and clinical parameters.

Results

The overall CAPTURE sample included 9823 adults with T2D (n = 4502 from primary care; n = 5321 from specialist care). The overall CAPTURE sample had median (interquartile range) diabetes duration 10.7 years (5.6–17.9 years) and glycated hemoglobin 7.3% (6.6–8.4%) [56 mmol/mol (49–68 mmol/mol)]. Overall weighted CVD and atherosclerotic CVD prevalence estimates were 34.8% (95% confidence interval [CI] 32.7–36.8) and 31.8% (95% CI 29.7–33.8%), respectively. Age, gender, and clinical parameters accounted for some of the between-country variation in CVD prevalence. GLAs with demonstrated cardiovascular benefit were used by 21.9% of participants, which was similar in participants with and without CVD: 21.5% and 22.2%, respectively.

Conclusions

In 2019, approximately one in three adults with T2D in CAPTURE had diagnosed CVD. The low use of GLAs with demonstrated cardiovascular benefit even in participants with established CVD suggested that most were not managed according to contemporary diabetes and cardiology guidelines.

Study registration NCT03786406 (registered on December 20, 2018), NCT03811288 (registered on January 18, 2019).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12933-021-01344-0.

Glucose-lowering pharmacotherapies in Chinese adults with type 2 diabetes and cardiovascular disease or chronic kidney disease. An expert consensus reported by the Chinese Diabetes Society and the Chinese Society of Endocrinology

Patients with type 2 diabetes mellitus (T2DM) are at risk of developing atherosclerotic cardiovascular disease (ASCVD) and chronic kidney disease (CKD), which are important causes of disabling and death in patients with T2DM. For the prevention and management of ASCVD or CKD, cardiovascular risk factors should be systematically evaluated, and ASCVD and CKD should be screened in patients with T2DM. In this consensus, we recommended that metformin should be used as the first-line therapy for patients with T2DM and ASCVD or very high cardiovascular risk, heart failure (HF) or CKD, and should be retained in the treatment regimen unless contraindicated or not tolerated. In patients with T2DM and established ASCVD or very high cardiovascular risk, addition of a glucagon-like peptide 1 receptor agonist (GLP-1RA) or sodium-glucose cotransporter type 2 (SGLT2) inhibitor with proven cardiovascular benefits should be considered independent of individualised glycated haemoglobin (HbA_1C ) targets. In patients with T2DM and HF, an SGLT2 inhibitor should be preferably added regardless of HbA_1C levels. In patients with T2DM and CKD, SGLT2 inhibitors should be preferred for the combination therapy independent of individualised HbA_1C targets, and GLP-1RAs with proven renal benefits would be alternative if SGLT2 inhibitors are contraindicated. Moreover, the prevention of hypoglycaemia and management of multiple risk factors by comprehensive regimen, including lifestyle intervention, antihypertensive therapies, lipid-lowering treatment and antiplatelet therapies, should be kept in mind in treating patients with T2DM and ASCVD, HF or CKD.

High baseline FGF21 levels are associated with poor glucose-lowering efficacy of exenatide in patients with type 2 diabetes

AIMS

To investigate the association between fibroblast growth factor 21 (FGF21) levels and glycemic response to exenatide in patients with type 2 diabetes.

METHODS

The exploratory analysis of a multi-center trial included 190 patients with type 2 diabetes inadequately controlled by monotherapy or combination therapy of metformin and insulin secretagogues. All participants received exenatide twice daily as an add-on therapy for 16 weeks. Serum FGF21 and other information at the baseline and end of follow-ups were obtained. Linear regression analysis was used to determine the correlations between baseline FGF21 levels and HbA1c reduction from baseline after the treatment.

RESULTS

After 16 weeks of treatment with exenatide, a decline in the HbA1c levels from baseline was associated with higher baseline FGF21 levels among all participants (r = 0.193, P = 0.008) and in subgroup of the participants receiving background metformin monotherapy (r = 0.231, P = 0.034). Compared with patients in the lowest FGF21 quartile, patients in the highest FGF21 quartile showed a significantly weakened decline in HbA1c levels from baseline among all participants (β = - 0.16 [95% Cl - 0.31 to - 0.01], P < 0.05) and in subgroup of the participants receiving background metformin monotherapy (β = - 0.23 [95% Cl - 0.43 to - 0.03], P < 0.05), after adjusting for the confounding factors, including age, sex, and baseline HbA1c levels.

CONCLUSIONS

The high baseline FGF21 levels are associated with poor glycemic responses to exenatide in patients with type 2 diabetes. Therefore, FGF21 could be used as a biomarker for predicting the efficacy of exenatide treatment.

TRIAL REGISTRATION

ChiCTR-IPR-15006558, date registered May 27, 2015.

Efficacy and safety of once-weekly dulaglutide in adult Chinese patients with type 2 diabetes and lower baseline body mass index

Highlights In Chinese patients with type 2 diabetes (T2D) and body mass index (BMI) <25 kg/m² , dulaglutide demonstrated great improvements in glycemic control with mild body weight reduction and low hypoglycemia risk. The results indicate that dulaglutide is effective and safe in patients with T2D and lower BMI; therefore, BMI should not be a consideration when dulaglutide is prescribed to Chinese patients with T2D.

Diabetes, even newly defined by HbA1c testing, is associated with an increased risk of in-hospital death in adults with COVID-19

BACKGROUND

Diabetes is associated with poor coronavirus disease 2019 (COVID-19) outcomes. However, little is known on the impact of undiagnosed diabetes in the COVID-19 population. We investigated whether diabetes, particularly undiagnosed diabetes, was associated with an increased risk of death from COVID-19.

METHODS

This retrospective study identified adult patients with COVID-19 admitted to Tongji Hospital (Wuhan) from January 28 to April 4, 2020. Diabetes was determined using patients' past history (diagnosed) or was newly defined if the hemoglobin A1c (HbA1c) level at admission was ≥6.5% (48 mmol/mol) (undiagnosed). The in-hospital mortality rate and survival probability were compared between the non-diabetes and diabetes (overall, diagnosed, and undiagnosed diabetes) groups. Risk factors of mortality were explored using Cox regression analysis.

RESULTS

Of 373 patients, 233 were included in the final analysis, among whom 80 (34.3%) had diabetes: 44 (55.0%) reported a diabetes history, and 36 (45.0%) were newly defined as having undiagnosed diabetes by HbA1c testing at admission. Compared with the non-diabetes group, the overall diabetes group had a significantly increased mortality rate (22.5% vs. 5.9%, p <  0.001). Moreover, the overall, diagnosed, and undiagnosed diabetes groups displayed lower survival probability in the Kaplan-Meier survival analysis (all p <  0.01). Using multivariate Cox regression, diabetes, age, quick sequential organ failure assessment score, and D-dimer ≥1.0 μg/mL were identified as independent risk factors for in-hospital death in patients with COVID-19.

CONCLUSIONS

The prevalence of undiagnosed pre-existing diabetes among patients with COVID-19 is high in China. Diabetes, even newly defined by HbA1c testing at admission, is associated with increased mortality in patients with COVID-19. Screening for undiagnosed diabetes by HbA1c measurement should be considered in adult Chinese inpatients with COVID-19.

Comparison of pegylated liposomal doxorubicin and paclitaxel plus carboplatin-based chemotherapy as first line treatment for patients with ovarian cancer: a systematic review and meta-analysis of randomized controlled trials

We reviewed studies comparing survival outcomes such as overall survival (OS), progression free survival (PFS), and toxicity profile between patients treated with Pegylated Liposomal Doxorubicin (PLD) combination and those treated with paclitaxel combination for ovarian cancer. We conducted systematic searches in various databases including Medline, Cochrane Controlled Register of Trials (CENTRAL), ScienceDirect, and Google Scholar from inception until August 2019. We used the Cochrane risk of bias tool to assess the quality of published trials. We carried out a meta-analysis with random-effects model and reported pooled Hazard ratios (HR) or Risk ratios (RR) with 95% confidence intervals (CIs). In total, we analysed 7 studies including 3,676 participants. All the studies were randomized controlled trials, while majority of studies had low bias risks. We did not find significant evidence for any of these outcomes except progression free survival (favoured PLD combination therapy pooled HR=0.87; 95% CI: 0.77-0.98). Worst grade toxicities like allergy (pooled RR: 1.86; 95% CI: 1.06-3.24) and neurotoxicity (pooled RR: 5.59; 95% CI: 1.43-21.84) were significantly higher among patients receiving paclitaxel combination therapy when compared to patients receiving PLD combination therapy. To summarize, PLD combination therapy is non-inferior to paclitaxel combination therapy in the management of ovarian cancer with respect to survival outcomes and worst grade toxicity profile. However, clinical recommendations cannot be made, as the evidence is not conclusive or significant enough.

Sex differences in the prevalence of obesity in 800,000 Chinese adults with type 2 diabetes

AIMS

To estimate the sex differences in the prevalence of overweight and obesity aged 20-89 in Chinese patients with type 2 diabetes (T2D).

METHODS

811,264 patients with T2D from six hospital-based, cross-sectional studies, and 46,053 subjects from the general population were included in our analysis. Prevalence of underweight, overweight, obesity were calculated in each sex.

RESULTS

In patients with T2D, the standardized prevalence of underweight (BMI <18.5 kg/m2), overweight (24 kg/m2 ≤ BMI < 28 kg/m2), and general obesity (BMI ≥28 kg/m2) were 2.2%, 43.2%, and 11.6%, respectively. Similar trend patterns of the prevalence of underweight and overweight were observed in general and T2D population, in males and females with T2D (all P for trend <0.01). In patients with T2D, patients at a younger age and older age were more likely to be underweight. The prevalence of overweight increased first, then stabilized or decreased with age. However, different trend patterns of the prevalence of obesity in males and females were found. In males, the prevalence of obesity decreased first, and then stabilized after 60 years of age. In females, the prevalence of obesity decreased first, then increased after 50 years of age. In the general population, the prevalence of obesity increased with age in females, while, the trend of prevalence of obesity with age in males was not obvious.

CONCLUSION

Different trends in the prevalence of obesity with age in different sex were found in Chinese patients with T2D.

Non-targeted metabolomic analysis predicts the therapeutic effects of exenatide on endothelial injury in patients with type 2 diabetes

AIMS

We aimed to investigate whether treatment with exenatide could ameliorate endothelial injury in patients with type 2 diabetes mellitus (T2DM), and to identify biomarkers for predicting amelioration of the endothelial injury induced by the treatment.

METHODS

Ninety-three patients with T2DM were recruited and treated with exenatide for 16 weeks. Enzyme-linked immunosorbent assays were performed at baseline and after the treatment to measure serum levels of endothelial injury markers, including soluble thrombomodulin (sTM). Patients were categorized as responders (n = 47) or non-responders (n = 46) based on median changes in their sTM levels. Serum levels of metabolites at baseline were measured with non-targeted liquid chromatography-mass spectrometry. The results obtained were evaluated with multivariate analysis.

RESULTS

Treatment with exenatide for 16 weeks resulted in reduced body weight and improved levels of fasting plasma glucose, 2-hour postprandial plasma glucose, and HbA1c in patients with T2DM (all P < 0.05). Compared with baseline, serum levels of endothelial injury markers including sTM were significantly lowered after the treatment. Metabolites presented at significantly different levels in responders versus non-responders were considered as biomarkers for a therapeutic response of sTM to the exenatide treatment. Among those identified, 4-hydroxyproline and 12-oxo-9(Z)-dodecenoic acid were found to correlate most closely with the exenatide-induced endothelial protection response. The specificity and sensitivity of the multi-metabolite signature model contained higher 4-hydroxyproline and lower 12-oxo-9(Z)-dodecenoic acid were 53.3% and 92.3%, respectively, and the area under receiver operating characteristic curve was 69.2% (P < 0.001).

CONCLUSIONS

Treatment with exenatide for 16 weeks ameliorates endothelial injury in patients with T2DM. Endothelial protection benefit from exenatide treatment was effectively predicted by the specific metabolomic combination of higher 4-hydroxyproline and lower 12-oxo-9(Z)-dodecenoic acid.

Effect of Dipeptidyl Peptidase 4 Inhibitors Used in Combination with Insulin Treatment in Patients with Type 2 Diabetes: A Systematic Review and Meta-analysis

INTRODUCTION

To evaluate the efficacy and safety of dipeptidyl peptidase 4 inhibitors (DPP4i) used in combination with insulin in patients with type 2 diabetes mellitus (T2DM).

METHODS

We searched the MEDLINE, Embase, and Cochrane library databases for randomized controlled trials (RCTs) published through June 2018. Studies with at least a 12-week treatment period were included to compare the addition of DPP4i to insulin with insulin control therapy. Meanwhile, groups on a stable insulin dosage (insulin-stable subgroup) or titrating insulin dosage (insulin-flexible subgroup) were analyzed separately.

RESULTS

Twenty-one RCTs with 3697 patients randomized to a DPP4i/insulin treatment arm and 3538 to an insulin control arm were included. DPP4i, when added to insulin therapy, led to a significantly greater reduction in HbA1c (- 0.57%, 95% CI - 0.66, - 0.48) and provided significantly greater odds of achieving the HbA1c target < 7% (OR 3.45; 95% CI 2.58, 4.63). These effects were achieved in the context of a decrease in the daily insulin requirement, without increases in hypoglycemia risk and body weight, compared with the control treatment. Subgroup analysis showed control-adjusted reductions in HbA1c from baseline in the insulin-stable subgroup (-  0.64%; 95% CI - 0.74, - 0.53) and the insulin-flexible subgroup (- 0.43%; 95% CI - 0.56, - 0.30). Other results occurred similarly in both subgroups.

CONCLUSIONS

The addition of DPP4i to insulin is associated with a statistically significant reduction in glycemic control as measured by HbA1c, fasting plasma glucose, and 2-h postprandial glucose, without increasing the risk of hypoglycemia and weight gain. These conclusions were also observed in both stable-dose and flexible-dose insulin subgroups.

Dapagliflozin promotes beta cell regeneration by inducing pancreatic endocrine cell phenotype conversion in type 2 diabetic mice

BACKGROUND

Clinical trials and animal studies have shown that sodium-glucose co-transporter type 2 (SGLT2) inhibitors improve pancreatic beta cell function. Our study aimed to investigate the effect of dapagliflozin on islet morphology and cell phenotype, and explore the origin and possible reason of the regenerated beta cells.

METHODS

Two diabetic mouse models, db/db mice and pancreatic alpha cell lineage-tracing (glucagon-β-gal) mice whose diabetes was induced by high fat diet combined with streptozotocin, were used. Mice were treated by daily intragastric administration of dapagliflozin (1 mg/kg) or vehicle for 6 weeks. The plasma insulin, glucagon and glucagon-like peptide-1 (GLP-1) were determined by using ELISA. The evaluation of islet morphology and cell phenotype was performed with immunofluorescence. Primary rodent islets and αTC1.9, a mouse alpha cell line, were incubated with dapagliflozin (0.25-25 μmol/L) or vehicle in the presence or absence of GLP-1 receptor antagonist for 24 h in regular or high glucose medium. The expression of specific markers and hormone levels were determined.

RESULTS

Treatment with dapagliflozin significantly decreased blood glucose in the two diabetic models and upregulated plasma insulin and GLP-1 levels in db/db mice. The dapagliflozin treatment increased islet and beta cell numbers in the two diabetic mice. The beta cell proliferation as indicated by C-peptide and BrdU double-positive cells was boosted by dapagliflozin. The alpha to beta cell conversion, as evaluated by glucagon and insulin double-positive cells and confirmed by using alpha cell lineage-tracing, was facilitated by dapagliflozin. After the dapagliflozin treatment, some insulin-positive cells were located in the duct compartment or even co-localized with duct cell markers, suggestive of duct-derived beta cell neogenesis. In cultured primary rodent islets and αTC1.9 cells, dapagliflozin upregulated the expression of pancreatic endocrine progenitor and beta cell specific markers (including Pdx1) under high glucose condition. Moreover, dapagliflozin upregulated the expression of Pcsk1 (which encodes prohormone convertase 1/3, an important enzyme for processing proglucagon to GLP-1), and increased GLP-1 content and secretion in αTC1.9 cells. Importantly, the dapagliflozin-induced upregulation of Pdx1 expression was attenuated by GLP-1 receptor antagonist.

CONCLUSIONS

Except for glucose-lowering effect, dapagliflozin has extra protective effects on beta cells in type 2 diabetes. Dapagliflozin enhances beta cell self-replication, induces alpha to beta cell conversion, and promotes duct-derived beta cell neogenesis. The promoting effects of dapagliflozin on beta cell regeneration may be partially mediated via GLP-1 secreted from alpha cells.

Extended anharmonic collapse of phonon dispersions in SnS and SnSe

The lattice dynamics and high-temperature structural transition in SnS and SnSe are investigated via inelastic neutron scattering, high-resolution Raman spectroscopy and anharmonic first-principles simulations. We uncover a spectacular, extreme softening and reconstruction of an entire manifold of low-energy acoustic and optic branches across a structural transition, reflecting strong directionality in bonding strength and anharmonicity. Further, our results solve a prior controversy by revealing the soft-mode mechanism of the phase transition that impacts thermal transport and thermoelectric efficiency. Our simulations of anharmonic phonon renormalization go beyond low-order perturbation theory and capture these striking effects, showing that the large phonon shifts directly affect the thermal conductivity by altering both the phonon scattering phase space and the group velocities. These results provide a detailed microscopic understanding of phase stability and thermal transport in technologically important materials, providing further insights on ways to control phonon propagation in thermoelectrics, photovoltaics, and other materials requiring thermal management.

The Desire and Status of Gender-Affirming Hormone Therapy and Surgery in Transgender Men and Women in China: A National Population Study

BACKGROUND

Gender-affirming hormone therapy and surgery are important medically necessary approaches to transgender care. However, few related data exist in China.

AIM

To understand the desire and access of transgender cares in the Chinese transgender men and women population.

METHODS

A cross-sectional self-selecting survey targeting the Chinese transgender population was conducted in 2017 using a snowball sampling method. Participants completed an online questionnaire anonymously. Gender identity was verified by specifically designed questions. Data analysis of this study was performed in 2019.

OUTCOMES

The main outcome was the status of receiving transgender medical care, including the desire vs actual state of receiving gender-affirming hormone treatment and gender-affirmation surgery, methods of accessing hormonal therapy and surgery, and risky behaviors associated with obtaining treatments.

RESULTS

Of the total 2060 valid questionnaires, there were 1,304 transgender individuals (626 transgender men and 678 transgender women), with a median age of 22 (interquartile range, 19-26) years. Among them, 1,036 (79.4%) expressed desires for hormonal therapy, but of 1,036, 741 (71.5%) considered it difficult to obtain medications from doctors. Of 1,036 individuals, 275 (26.5%) and 172 (16.6%) had thoughts or behaviors of self-injury, respectively, when lacking access to hormone therapy. Of 1,036 individuals, 602 (58.1%) had used hormones. Of those 602 hormone users, 407 (67.6%) had ever obtained medications from informal drug dealers, and 372 (61.8%) of them did not perform regular monitoring. 868 of 1,303 (66.6%) participants had received or wanted to undergo gender-affirming surgeries, but 710 of 868 (81.8%) considered the surgery resources not adequate or very scarce.

CLINICAL IMPLICATIONS

The transgender medical resources in China are scarce, and many transgender individuals have engaged in high-risk activities to access care.

STRENGTHS & LIMITATIONS

This is the first study to focus on the current status of gender-affirming hormone therapy and surgery in the Chinese transgender population, providing valuable and real-world data for understanding the need for transgender health care in China. But, the online questionnaire could not provide the prevalence and other epidemiologic information about transgender individuals in China, and the survey did not address specific medication regimens, dosages, sex hormone levels, and specific hormone therapy-related or surgery-related adverse events.

CONCLUSION

Significant improvement in access to gender-affirming medical and surgery care is needed in China. Liu Y, Xin Y, Qi J, et al. The Desire and Status of Gender-Affirming Hormone Therapy and Surgery in Transgender Men and Women in China: A National Population Study. J Sex Med 2020;17:2291-2298.

Glucagon receptor antagonism promotes the production of gut proglucagon-derived peptides in diabetic mice

Glucagon is an essential regulator of glucose homeostasis, particularly in type 2 diabetes (T2D). Blocking the glucagon receptor (GCGR) in diabetic animals and humans has been shown to alleviate hyperglycemia and increase circulating glucagon-like peptide-1 (GLP-1) levels. However, the origin of the upregulated GLP-1 remains to be clarified. Here, we administered high-fat diet + streptozotocin-induced T2D mice and diabetic db/db mice with REMD 2.59, a fully competitive antagonistic human GCGR monoclonal antibody (mAb) for 12 weeks. GCGR mAb treatment decreased fasting blood glucose levels and increased plasma GLP-1 levels in the T2D mice. In addition, GCGR mAb upregulated preproglucagon gene expression and the contents of gut proglucagon-derived peptides, particularly GLP-1, in the small intestine and colon. Notably, T2D mice treated with GCGR mAb displayed a higher L-cell density in the small intestine and colon, which was associated with increased numbers of LK-cells coexpressing GLP-1 and glucose-dependent insulinotropic polypeptide and reduced L-cell apoptosis. Furthermore, GCGR mAb treatment upregulated GLP-1 production in the pancreas, which was detected at lower levels than in the intestine. Collectively, these results suggest that GCGR mAb can increase intestinal GLP-1 production and L-cell number by enhancing LK-cell expansion and inhibiting L-cell apoptosis in T2D.

A Single Large Dose of Vitamin D Could be Used as a Means of Coronavirus Disease 2019 Prevention and Treatment

There is no specific and effective medication for coronavirus disease 2019 (COVID-19), and avaccine is not available in recent months. Here, we hypothesize that a single large dose of vitamin D (Vit D) could be an option for trial in COVID-19. Vit D deficiency or insufficiency is very common in the general population as well as in patients with COVID-19. It has been shown that low Vit D level is associated with viral infection, and Vit D supplementation is beneficial for people infected with viruses, such as HIV and hepatitis C virus. Although COVID-19 is a respiratory disease, the morbidity and mortality of this disease are driven by coagulopathy. Clinical studies have shown that Vit D can exert anticoagulant effects. Vit D, a lipid-soluble vitamin, can be administered as a draught. Vit D supplementation is safe and has rare toxic events. In addition, the cost of Vit D is fairly low. Based on these observations, we speculate that a single dose of 300,000 IU Vit D may have a role in the prevention and treatment of COVID-19.

Efficacy and safety of generic exenatide injection in Chinese patients with type 2 diabetes: a multicenter, randomized, controlled, non-inferiority trial

AIMS

This study aimed to compare the efficacy and safety of generic exenatide with branded exenatide Byetta^® in Chinese patients with type 2 diabetes mellitus (T2DM) inadequately controlled on monotherapy or combination therapy of metformin and insulin secretagogues.

METHODS

A multicenter, randomized, controlled, non-inferiority trial was performed. A total of 240 patients with T2DM and glycated hemoglobin (HbA1c) ≥ 7% (53 mmol/mol) to ≤ 9.0% (75 mmol/mol) on monotherapy or combination therapy of metformin and insulin secretagogues for at least 3 months were randomized into generic exenatide or branded exenatide groups with a 1:1 ratio for 16 weeks of treatment. The primary endpoint was the change in HbA1c levels from baseline at week 16, with a non-inferiority margin of - 0.35% (- 3.83 mmol/mol) (lower bound of one-sided 95% confidence interval (CI) > - 0.35% (- 3.83 mmol/mol)). Secondary endpoints included the proportion of participants achieving HbA1c < 7% (53 mmol/mol), the changes in fasting plasma glucose (FPG), 2-h postprandial glucose (2hPG) following a standard meal, 7-point self-monitoring blood glucose (SMBG) profiles, body weight change from baseline at week 16 and the change in HbA1c levels from baseline at week 8. Safety issues were also evaluated.

RESULTS

After 16 weeks of treatment, HbA1c levels decreased significantly from baseline in the two groups, with a reduction of - 1.10% ± 1.31% (- 12.0 mmol/mol ± 14.3 mmol/mol) in the generic exenatide group and - 1.08% ± 1.11% (- 11.8 mmol/mol ± 12.1 mmol/mol) in the branded exenatide group (both P < 0.001). The least-squares mean difference of HbA1c reduction between the two groups was - 0.03% (- 0.33 mmol/mol), with a lower one-sided 95% CI limit of - 0.27% (- 2.95 mmol/mol), which was higher than the prespecified non-inferiority margin of - 0.35% (- 3.83 mmol/mol). Moreover, there were no significant differences in the proportion of participants achieving HbA1c < 7% (53 mmol/mol) and the changes in FPG, 2hPG, 7-point SMBG profiles and body weight at week 16 and the change in HbA1c levels from baseline at week 8 (all P > 0.05) between the two groups. The incidence of adverse events, including the incidence of hypoglycemia (18.3% and 17.5%, respectively), was similar for the generic and branded exenatide groups (P > 0.05).

CONCLUSIONS

In patients with T2DM inadequately controlled on monotherapy or combination therapy of metformin and insulin secretagogues, add-on treatment with generic exenatide demonstrated non-inferiority to branded exenatide in terms of improvements in HbA1c after 16 weeks of treatment. Furthermore, the two drugs were also similar for other efficacy endpoints and safety profile. Trial registration Chinese Clinical Trial Registry: ChiCTR-IPR-15006558, Date registered May 27, 2015.

Coexistence and Interaction of Spinons and Magnons in an Antiferromagnet with Alternating Antiferromagnetic and Ferromagnetic Quantum Spin Chains

In conventional quasi-one-dimensional antiferromagnets with quantum spins, magnetic excitations are carried by either magnons or spinons in different energy regimes: they do not coexist independently, nor could they interact with each other. In this Letter, by combining inelastic neutron scattering, quantum Monte Carlo simulations, and random phase approximation calculations, we report the discovery and discuss the physics of the coexistence of magnons and spinons and their interactions in Botallackite-Cu_{2}(OH)_{3}Br. This is a unique quantum antiferromagnet consisting of alternating ferromagnetic and antiferromagnetic spin-1/2 chains with weak interchain couplings. Our study presents a new paradigm where one can study the interaction between two different types of magnetic quasiparticles: magnons and spinons.

Glucagon receptor antagonist upregulates circulating GLP-1 level by promoting intestinal L-cell proliferation and GLP-1 production in type 2 diabetes

OBJECTIVE

Glucagon receptor (GCGR) blockage improves glycemic control and increases circulating glucagon-like peptide-1 (GLP-1) level in diabetic animals and humans. The elevated GLP-1 has been reported to be involved in the hypoglycemic effect of GCGR blockage. However, the source of this elevation remains to be clarified.

RESEARCH DESIGN AND METHODS

REMD 2.59, a human GCGR monoclonal antibody (mAb), was administrated for 12 weeks in db/db mice and high-fat diet+streptozotocin (HFD/STZ)-induced type 2 diabetic (T2D) mice. Blood glucose, glucose tolerance and plasma GLP-1 were evaluated during the treatment. The gut length, epithelial area, and L-cell number and proliferation were detected after the mice were sacrificed. Cell proliferation and GLP-1 production were measured in mouse L-cell line GLUTag cells, and primary mouse and human enterocytes. Moreover, GLP-1 receptor (GLP-1R) antagonist or protein kinase A (PKA) inhibitor was used in GLUTag cells to determine the involved signaling pathways.

RESULTS

Treatment with the GCGR mAb lowered blood glucose level, improved glucose tolerance and elevated plasma GLP-1 level in both db/db and HFD/STZ-induced T2D mice. Besides, the treatment promoted L-cell proliferation and LK-cell expansion, and increased the gut length, epithelial area and L-cell number in these two T2D mice. Similarly, our in vitro study showed that the GCGR mAb promoted L-cell proliferation and increased GLP-1 production in GLUTag cells, and primary mouse and human enterocytes. Furthermore, either GLP-1R antagonist or PKA inhibitor diminished the effects of GCGR mAb on L-cell proliferation and GLP-1 production.

CONCLUSIONS

The elevated circulating GLP-1 level by GCGR mAb is mainly due to intestinal L-cell proliferation and GLP-1 production, which may be mediated via GLP-1R/PKA signaling pathways. Therefore, GCGR mAb represents a promising strategy to improve glycemic control and restore the impaired GLP-1 production in T2D.

Liraglutide ameliorates palmitate-induced oxidative injury in islet microvascular endothelial cells through GLP-1 receptor/PKA and GTPCH1/eNOS signaling pathways

In type 2 diabetes, lipotoxicity damages islet microvascular endothelial cells (IMECs), leading to pancreatic islet β cell dysfunction directly or indirectly. Glucagon-like peptide-1 (GLP-1) and its analogs have beneficial roles in endothelial cells. However, the protective effects of GLP-1 agents on IMECs and their potential mechanism remained obscure. In this study, exposure of MS-1 (a cell line derived from mouse IMECs) to different concentrations of palmitic acid (PA) was used to establish an injury model. The cells exposed to PA (0.25 mmol/L) were treated with a GLP-1 analog liraglutide (3, 10, 30, and 100 nmol/L). Reactive oxygen species (ROS) generation, apoptosis-related protein level, and endothelin-1 production were detected. The protein levels of signaling molecules were analyzed and specific inhibitors or blockers were used to identify involvement of signaling pathways in the effects of liraglutide. Results showed that PA significantly increased ROS generation and the levels of pro-apoptotic protein Bax, and decreased the levels of anti-apoptotic protein Bcl-2 and the mRNA expression and secretion of endothelin-1. Meanwhile, PA downregulated the protein levels of GLP-1 receptor (GLP-1R), phosphorylated protein kinase A (PKA), guanosine 5'-triphosphate cyclohydrolase 1 (GTPCH1), and endothelial nitric oxide synthase (eNOS). Furthermore, liraglutide ameliorated all these effects of PA in a dose-dependent manner. Importantly, GLP-1R antagonist exendin (9-39), PKA inhibitor H89, GTPCH1 inhibitor 2,4-diamino-6-hydroxypyrimidine, or NOS inhibitor N-nitro-l-arginine-methyl ester abolished the liraglutide-mediated amelioration in PA-impaired MS-1 cells. In conclusion, liraglutide ameliorates the PA-induced oxidative stress, apoptosis, and endothelin-1 secretion dysfunction in mouse IMECs through GLP-1R/PKA and GTPCH1/eNOS signaling pathways.

Myopathy after rapid correction of hyperthyroidism: A case report and review of literature

RATIONALE

Myalgia and elevated creatine kinase (CK) have been reported during the treatment of hyperthyroid patients. The causes of these symptoms are usually considered to be treatments of antithyroid drugs (ATDs), thyroidectomy or radio-iodine (131-I). However, the underlying cause may be the rapid correction of thyrotoxicosis (or relative hypothyroidism), which was usually neglected in clinical practice.

PATIENT CONCERNS

This report describes a case of a 25-year-old female with typical symptoms and laboratory test results of Grave hyperthyroidism. The patient complained about fatigue and myalgia 7 weeks after receiving methimazole (MMI) treatment. Blood tests showed dramatically elevated serum CK level, although free triiodothyronine (FT3) and free thyroxine (FT4) level had returned to the normal reference range. MMI was; therefore, discontinued and the patient's muscular symptoms disappeared quickly with the normalization of CK level and the relapse of hyperthyroidism. Later she received 131-I treatment and suffered similar muscular symptoms when FT3 and FT4 decreased to the normal range. This time, her symptoms were quickly relieved by levothyroxine (L-T4) replacement treatment.

DIAGNOSES

Myopathy induced by rapid correction of hyperthyroidism (or relative hypothyroidism).

INTERVENTIONS

MMI was discontinued after the patient's first episode of muscular symptoms. And for her second episode of muscular injury after 131-I treatment, we initiated L-T4 supplementation.

OUTCOMES

For the 2 episodes of muscular injury after ATDs or 131-I treatment, both of the interventions mentioned above brought a rapid relief of symptoms accompanied with normalization of CK level and restoration of thyroid hormone level.

LESSONS

Myopathy can be caused by a rapid reduction of thyroid hormone during the treatment of hyperthyroidism. This relative hypothyroidism syndrome should be considered if patients make complaints about fatigue and myalgia, even when thyroid hormone level is within the normal range during the antithyroid treatments. Serum CK level and thyroid function should be closely monitored post antithyroid treatments. Reduction of ATD dosage or replacement of thyroid hormone is suggested to relieve muscular symptoms.