Highlighting Diabetes Mellitus: The Epidemic Continues

Novel Therapeutics for Diabetic Retinopathy and Diabetic Macular Edema: A Pathophysiologic Perspective

Diabetic retinopathy (DR) and diabetic macular edema (DME) are retinal complications of diabetes that can lead to loss of vision and impaired quality of life. The current gold standard therapies for treatment of DR and DME focus on advanced disease, are invasive, expensive, and can trigger adverse side-effects, necessitating the development of more effective, affordable, and accessible therapies that can target early stage disease. The pathogenesis and pathophysiology of DR is complex and multifactorial, involving the interplay between the effects of hyperglycemia, hyperlipidemia, hypoxia, and production of reactive oxygen species (ROS) in the promotion of neurovascular dysfunction and immune cell polarization to a proinflammatory state. The pathophysiology of DR provides several therapeutic targets that have the potential to attenuate disease progression. Current novel DR and DME therapies under investigation include erythropoietin-derived peptides, inducers of antioxidant gene expression, activators of nitric oxide/cyclic GMP signaling pathways, and manipulation of arginase activity. This review aims to aid understanding of DR and DME pathophysiology and explore novel therapies that capitalize on our knowledge of these diabetic retinal complications.

The effect of adenosine monophosphate-activated protein kinase on lipolysis in adipose tissue: an historical and comprehensive review

CONTEXT

Lipolysis is one of the most important pathways for energy management, its control in the adipose tissue (AT) is a potential therapeutic target for metabolic diseases. Adenosine Mono Phosphate-activated Protein Kinase (AMPK) is a key regulatory enzyme in lipids metabolism and a potential target for diabetes and obesity treatment.

OBJECTIVE

The aim of this work is to analyse the existing information on the relationship of AMPK and lipolysis in the AT.

METHODS

A thorough search of bibliography was performed in the databases Scopus and Web of Knowledge using the terms lipolysis, adipose tissue, and AMPK, the unrelated publications were excluded, and the documents were analysed.

RESULTS

Sixty-three works were found and classified in 3 categories: inhibitory effects, stimulatory effect, and diverse relationships; remarkably, the newest researches support an upregulating relationship of AMPK over lipolysis.

CONCLUSION

The most probable reality is that the relationship AMPK-lipolysis depends on the experimental conditions.

Silencing LncRNA PVT1 Reverses High Glucose-Induced Regulation of the High Expression of PVT1 in HRMECs by Targeting miR-128-3p

This paper aims to discuss the possibility of lncRNA PVT1 as a diagnostic biomarker for diabetic retinopathy (DR) and explore the underlying mechanism. Real-time quantitative polymerase chain reaction (RT-qPCR) was selected to determine the expression level of lncRNA PVT1 in the serum of all subjects. The receiver operating characteristic (ROC) curve reflected the diagnostic significance of PVT1 for DR patients. The Cell Counting Kit-8 (CCK-8) and Transwell assays were used to evaluate the effect of PVT1 expression on the proliferation and migration of human retinal microvascular endothelial cells (HRMECs). The luciferase reporter gene was selected to verify the interaction between PVT1 and miR-128-3p. The relative expression level of PVT1 in serum was higher in both the DB and DR group than in the healthy controls group (HC), and it was highest in the DR group. ROC curve indicated that serum PVT1 could distinguish between HC and DB patients, DB patients and DR patients, respectively. In vitro, high glucose induction significantly increased the proliferation and migration capabilities of HRMECs, but silencing PVT1 (si-PVT1) downregulated the proliferation and migration capabilities of HRMECs. The detection of luciferase reporter gene showed that lncRNA PVT1 targeted miR-128-3p, and there was a negative correlation in the serum of DR patients. In conclusion, this study confirmed that lncRNA PVT1 might regulate the process of DR by targeting miR-128-3p, and has the potential as a biomarker for the diagnosis of DR.

Physalis pubescens L. alleviates testicular disruptions associated with streptozotocin-induced diabetes in male Wistar rats, Rattus norvegicus

Testicular impairment is a serious complication of diabetes that is mediated by oxidative stress and inflammation. Physalis has antioxidative and anti-inflammatory actions. Thus, the present study investigated the ameliorative role of Physalis juice (PJ) prepared from the fruits against testicular damages in streptozotocin (STZ)-induced diabetic rats. Adult male Wistar rats were divided randomly into five groups (n=6): control, orally administered 5 mL PJ/kg daily (PJ), injected intraperitoneally with a single dose of 55 mg STZ/kg without treatment (STZ), or treated daily with PJ (STZ+PJ) or with 500 mg metformin/kg (STZ+Met), for 28 days. The STZ group showed a marked elevation in the blood glucose level by 230%, whereas remarkable declines in the serum levels of testosterone (44%), follicle-stimulating hormone (FSH) (48%), and luteinizing hormone (LH) (36%), as compared to controls. In comparison to controls, the testis of the STZ group showed remarkable declines in the testis weight (15%), the glutathione (GSH) content (45%), mRNA and protein levels of B-cell lymphoma-2 (Bcl-2) (48 and 35%), mRNA and activities of superoxide dismutase (SOD) (63 and 40%), catalase (CAT) (56 and 31%), glutathione peroxidase (GPx) (51 and 44%), and glutathione reductase (GR) (62 and 43%), whereas marked elevations in the levels of interleukin-1 beta (IL-1β (169%), tumor necrosis factor-alfa (TNFα) (85%), nitric oxide (NO) (96%), malondialdehyde (MDA) (83%), mRNA and protein levels of Bcl-2-associated X protein (Bax) (400 and 61%), and mRNA level of caspase-3 (Cas-3) (370%). Some histopathological alterations were observed in the testicular tissue of the STZ group. In contrast, PJ markedly alleviated all the abovementioned disturbances. In conclusion, PJ at a dose of 5 mL/kg attenuated the diabetes-associated testicular impairments, which may be due to its antioxidative, anti-inflammatory, and antiapoptotic actions.

Effects of Creatine Supplementation on Histopathological and Biochemical Parameters in the Kidney and Pancreas of Streptozotocin-Induced Diabetic Rats

Diabetes mellitus (DM) is a worldwide health concern, and projections state that cases will reach 578 million by 2030. Adjuvant therapies that can help the standard treatment and mitigate DM effects are necessary, especially those using nutritional supplements to improve glycemic control. Previous studies suggest creatine supplementation as a possible adjuvant therapy for DM, but they lack the evaluation of potential morphological parameters alterations and tissue injury caused by this compound. The present study aimed to elucidate clinical, histomorphometric, and histopathological consequences and the cellular oxidative alterations of creatine supplementation in streptozotocin (STZ)-induced type 1 DM rats. We could estimate whether the findings are due to DM or the supplementation from a factorial experimental design. Although creatine supplementation attenuated some biochemical parameters, the morphological analyses of pancreatic and renal tissues made clear that the supplementation did not improve the STZ-induced DM1 injuries. Moreover, creatine-supplemented non-diabetic animals were diagnosed with pancreatitis and showed renal tubular necrosis. Therefore, even in the absence of clinical symptoms and unaltered biochemical parameters, creatine supplementation as adjuvant therapy for DM should be carefully evaluated.

miR-27b-3p Improved High Glucose-Induced Spermatogenic Cell Damage via Regulating Gfpt1/HBP Signaling

INTRODUCTION

Diabetes mellitus (DM)-induced testicular damage is characterized by abnormal apoptosis of spermatogenic cells. Here, we clarified the roles and the molecular mechanism of microRNA (miR)-27b-3p in high glucose (HG)-induced spermatogenic cell damage.

METHODS

GC-1 spg cells were treated with 30 mmol/L glucose for 24 h. Cell viability was assessed by 2.3 3-(4, 5-dimethylthiazolyl2)-2, 5-diphenyltetrazolium bromide (MTT) assay. And, levels of O-linked N-acetylglucosamine (OGT), apoptosis-related proteins, and autophagy-related proteins were evaluated using Western blot. Levels of tumor necrosis factor-α (TNF-α), IL-1β, IL-6, and UDP-N-acetylglucosamine (UDP-GlcNAc) were assessed by enzyme linked immunosorbent (ELISA) assay. Levels of reactive oxygen species (ROS), malonic dialdehyde (MDA) and activity of superoxide dismutase (SOD) in cells were determined using kits. Cell apoptosis was determined using flow cytometry assay. Besides, dual luciferase reporter assay was employed to verify the binding relationship between miR-27b-3p and glutamine-fructose-6-phosphate transaminase 1 (Gfpt1).

RESULTS

miR-27b-3p was markedly downregulated in HG-treated GC-1 spg cells. HG treatment caused decreased cell viability, increased oxidative stress and inflammation, and induced autophagy and apoptosis, which were abolished by miR-27b-3p overexpression. miR-27b-3p suppressed the activation of hexosamine biosynthetic pathway (HBP) signaling in HG-treated spermatogenic cells. miR-27b-3p directly bound to Gfpt1 and negatively regulated its expression.

CONCLUSION

miR-27b-3p could improve HG-induced spermatogenic cell damage via regulating Gfpt1/HBP signaling, providing a new treatment strategy for the treatment of DM-induced testicular damage.

Circulating miRNA as potential biomarkers for diabetes mellitus type 2: should we focus on searching for sex differences?

microRNAs are non-coding molecules, approximately 22 nucleotides in length, that regulate various cellular processes. A growing body of evidence has suggested that their dysregulated expression is involved in the pathogenesis of diverse diseases, including diabetes mellitus type 2 (DM2). Early onset of this chronic and complex metabolic disorder is frequently undiagnosed, leading to the development of severe diabetic complications. Notably, DM2 prevalence is rising globally and an increasing number of articles demonstrate that DM2 susceptibility, development, and progression differ between males and females. Therefore, this paper discusses the role of microRNAs as a source of novel diagnostic biomarkers for DM2 and aims to underline the importance of sex disparity in biomarkers research. Taking into account an urgent need for the development of sex-specific diagnostic strategies in DM2, recent results have shown that circulating miRNAs are promising candidates for sex-biased biomarkers.

Impact of Pharmaceutical Education on Medication Adherence and Its Clinical Efficacy in Patients with Type 2 Diabetes and Systemic Arterial Hypertension

PURPOSE

To evaluate the impact of pharmaceutical education on medication adherence in patients with Type 2 Diabetes and Systemic Arterial Hypertension.

PATIENTS AND METHODS

This randomized clinical trial enrolled patients with a diagnosis of Type 2 Diabetes Mellitus and Systemic Arterial Hypertension treated in an internal medicine outpatient clinic of a teaching hospital. One hundred and three patients were randomly assigned to the study groups; 51 to the control group and 52 to the intervention group with a 6 months follow-up. Medication adherence was assessed using the Morisky 8-item medication adherence scale. To improve patient adherence to treatment, a wallet card was provided with an up-to-date list of prescribed medications along with recommendations for follow-up care.

RESULTS

One hundred and seventy-nine patients were screened for eligibility, of which 103 (57.5%) participated in the study. The intervention group showed a statistically significant decrease in capillary glucose levels, glycated hemoglobin, systolic and diastolic blood pressure, total cholesterol and triglycerides compared to the control group. The frequencies on medication adherence levels at 3 and 6 months in the control group remained similar to baseline, while in the intervention group the frequency of high adherence increased significantly at 6 months (8.7% to 43.5%).

CONCLUSION

A high percentage of patients are not achieving optimal control of their diabetes. Medication adherence rates were between 45-50% in patients at the baseline of the study, but after receiving education and support from a pharmacist, the intervened group showed a significant increase in their adherence.

Life-course blood pressure trajectories and incident diabetes: A longitudinal cohort in a Chinese population

BACKGROUND

Blood pressure levels are correlated with diabetes among middle-aged or older adults. However, longitudinal trajectories of blood pressure during young adulthood and their impact on diabetes have been insufficiently studied.

METHODS

The longitudinal cohort consisted of 4,625 adults who had blood pressure and body mass index (BMI) repeatedly measured five to nine times during 18-60 years of age. Distinct systolic blood pressure (SBP) trajectories were identified by a group-based trajectory model. Logistic regression analyses were used to investigate the association between trajectory patterns or quartiles of area under the curve values of SBP trajectories and incident diabetes, respectively.

RESULTS

Four distinct trajectory groups were identified for SBP: normotensive-stable (n = 761, 16.5%), prehypertension-stable (n = 2,381, 51.5%), stage I hypertension-increasing (n = 1,231, 26.6%), and stage II hypertension-increasing (n = 251, 5.4%). Compared with subjects who remained at SBP <120 mmHg in the normotensive-stable group, individuals in the prehypertension-stable trajectory exhibited a normal SBP range (<140 mmHg), and they still had a significantly higher risk of diabetes (adjusted OR = 1.82, p = 0.029). Individuals had a greater risk of diabetes in the stage I hypertension-increasing group (adjusted OR = 2.31, p = 0.006) and the highest risk in the stage II hypertension-increasing group (adjusted OR = 3.91, p < 0.001) relative to the normotensive-stable group. Furthermore, compared with the first quartile, adjusted ORs (95% CIs) of the fourth quartile of SBP incremental and total AUC were 2.50 (1.61-3.97) and 1.82 (1.15-2.94), respectively.

CONCLUSIONS

Long-term SBP trajectory is a significant predictor for incident diabetes, which is independent of baseline SBP and body weight, attaching importance to maintaining optimal blood pressure levels and controlling changing slopes of SBP for preventing diabetes.

The roles of mesenchymal stem cell-derived exosomes in diabetes mellitus and its related complications

Diabetes mellitus is a type of metabolic disease characterized by hyperglycemia, primarily caused by defects in insulin secretion, insulin action, or both. Long-term chronic hyperglycemia can lead to diabetes-related complications, causing damage, dysfunction, and failure of different organs. However, traditional insulin and oral drug therapy can only treat the symptoms but not delay the progressive failure of pancreatic beta cells or prevent the emergence of diabetic complications. Mesenchymal stem cells have received extensive attention due to their strong immunoregulatory functions and regeneration effects. Mesenchymal stem cell-derived exosomes (MSC-Exos) have been proposed as a novel treatment for diabetic patients as they have demonstrated superior efficiency to mesenchymal stem cells. This review summarizes the therapeutic effects, mechanisms, challenges, and future prospects of MSC-Exos in treating diabetes mellitus and its related complications. This review supports the potential use of MSC-Exos in future regenerative medicine to overcome the current difficulties in clinical treatment, particularly in treating diabetes.

THE IMPACT OF THE DIABETES ON ORAL HEALTH - AN OBSERVATIONAL STUDY

OBJECTIVE

The aim: To evaluate the impact of diabetes mellitus on the oral health.

PATIENTS AND METHODS

Materials and methods: This is an observational study. In the present research were taken into consideration 300 patients. The study sample consisted of 191 males, respectively (63.7%) of them and 109 females (36.3%) of the participants.

RESULTS

Results: In the current study, we analyzed the oral health of diabetic patients within the age class of 11-80 years. We divided them into seven age groups: 11-20, 21-30, 31-40, 41-50, 51-60, 61-70, and 71-80 years. Based on the results of the current study it was observed that 83.7% of patients were affected by gingivitis. The results of our study show that dental caries prevalence was 68.7 % and the prevalence of missing teeth among patients with diabetes mellitus was 78.7%. According to the ANOVA test, high blood sugar values had a direct impact on the manifestation of gingivitis and there it was a strong correlation between them P-value = .000. Males with diabetes mellitus were more affected by dental caries and this was indicated by the P-value= .02, in comparison to females who recorded a P-value = .03. The relation between gender males and missing teeth was highly significant P-value = .001.

CONCLUSION

Conclusions: The present study proved that diabetes mellitus is risk factor for oral health. The authors studied this group of patients exposed to high blood glucose levels and found out that oral diseases were high in these patients.

Association between the RETN -420C/G polymorphism and type 2 diabetes mellitus susceptibility: A meta-analysis of 23 studies

BACKGROUND

The published findings on the link between the resistin (RETN) gene polymorphism and type 2 diabetes mellitus (T2DM) risk are still contradictory. Here, through a meta-analysis, we summarized a more precise evaluation of their connection by synthesizing existing research.

METHODS

PubMed, Google Scholar, and Web of Science were electronically searched, and all cited sources were manually searched. The heterogeneity of effects was tested and all statistical analyses were performed in Stata 12.0.

RESULTS

A total of 23 studies with 10,651 cases and 14,366 controls on RETN -420C/G polymorphism were included. The overall results showed that the association of RETN -420C/G polymorphism and T2DM susceptibility was not significant [for the allelic model: odds ratio (OR) = 0.98, 95% confidence interval (CI) = 0.87-1.10, p_{heterogeneity} <.001; I ² = 84.6%; for the dominant model: OR = 0.96, 95% CI = 0.80-1.15, p_{heterogeneity} <.001; I ² = 87.1%; and for the recessive model: OR = 0.96, 95% CI = 0.82-1.12, p_{heterogeneity} <.001; I ² = 56.9%] but with high heterogeneity across studies (p <.0001). Meta-regression found that the median age of T2DM participants (using age 50 as the cutoff) could be a factor in the observed variation. The RETN -420C/G polymorphism seems to be linked to an increased risk of T2DM in younger individuals [for dominant: OR = 0.84 (95% CI, 0.72-0.98; p_{heterogeneity} <.001; I ² = 80.9%)] and decreased risk in older people [for dominant: OR = 3.14 (95% CI, 2.35-4.19; p_{heterogeneity} = .98; I ² = 0.0%)].

CONCLUSIONS

Current results found no evidence that the RETN -420C/G variant was linked to T2DM susceptibility, but the patient's age appears to be a potential factor that contributed to high heterogeneity across studies. Additional high-quality and well-designed investigations are required to confirm these results.

Diagnostic and Therapeutic Application of Exosomal microRNAs Inducing Inflammation in Type 2 Diabetes Mellitus

Diabetes mellitus is a class of noncommunicable chronic metabolic disorders marked by hyperglycemia due to insulin production, insulin action or both and has reached epidemic levels around the world. The two most frequent types of diabetes are type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). Despite substantial improvements in the knowledge and treatment of DM, the associated incidence and mortality rates remain steadily increased. Reliable markers for the early detection, monitoring and focused treatment of DM are desperately required. Conversely, microRNAs (miRNAs) have received much significance due to their regulatory involvement in gene expression. Fascinatingly, exosomes can be enclosed into miRNAs to transport or distribute them into the target cells or tissues in which they have a physiological regulatory action. Thus, exosomal miRNAs are proving to be important regulators in the establishment and maintenance of DM, however, further mode of action will be needed to investigate in order to fully comprehend the pathophysiological process. Hereby, this review outlines the recent findings on the role of exosomal miRNAs intending to understand the precise function in diagnostic and therapeutic aspects in T2DM disease.

MiR-423-5p activated by E2F1 promotes neovascularization in diabetic retinopathy by targeting HIPK2

BACKGROUND

Diabetic retinopathy (DR) is a diabetic complication and the primary cause of blindness in the world. However, the treatments of DR are challenging given its complicated pathogenesis. Here, we investigated the molecular mechanisms of DR by focusing on the function of E2F1/miR-423-5p/HIPK2/HIF1α/VEGF axis.

METHODS

Cultured retinal endothelial cells (hRMECs, hRECs) were treated with 25 mM glucose to mimic the high glucose-induced DR in vitro. Streptozotocin (STZ) was injected into mice to induce DR in mice. qRT-PCR, western blotting, immunohistochemistry, and ELISA were employed to measure levels of E2F1, miR-423-5p, HIPK2, HIF1α, and VEGF. H&E staining was utilized to examine retinal neovascularization. CCK-8 assay, transwell assay, and vascular tube formation assay were used to assess the cell viability, migration, and angiogenesis. Dual luciferase assay was performed to validate interactions between E2F1 and miR-423-5p, miR-423-5p and HIPK2.

RESULTS

HG treatment increased the cell viability, migration, and angiogenesis accompanied by upregulation of E2F1, miR-423-5p, HIF1α, and VEGF levels, but reduction in HIPK2 expression. Knockdown of E2F1 or miR-423-5p suppressed the HG-induced increases in cell viability, migration, and angiogenesis. E2F1 transcriptionally activated miR-423-5p expression and miR-423-5p mimics blocked the effects of E2F1 knockdown on angiogenesis. Moreover, miR-423-5p directly targeted HIPK2 to disinhibit HIF1α/VEGF signaling. Knockdown of HIPK2 reversed the effects of miR-423-5p inhibitor on cell viability, migration, and angiogenesis. Knockdown of E2F1 suppressed neovascularization during DR in vivo.

CONCLUSIONS

E2F1 activates miR-423-5p transcription during DR to promote angiogenesis via suppressing HIPK2 expression to disinhibit HIF1α/VEGF signaling. Strategies targeting E2F1/miR-423-5p/HIPK2 axis could be potentially used for DR treatment.

Effects of Melatonin on Diabetic Neuropathy and Retinopathy

Diabetes mellitus (DM) leads to complications, the majority of which are nephropathy, retinopathy, and neuropathy. Redox imbalance and inflammation are important components of the pathophysiology of these complications. Many studies have been conducted to find a specific treatment for these neural complications, and some of them have investigated the therapeutic potential of melatonin (MEL), an anti-inflammatory agent and powerful antioxidant. In the present article, we review studies published over the past 21 years on the therapeutic efficacy of MEL in the treatment of DM-induced neural complications. Reports suggest that there is a real prospect of using MEL as an adjuvant treatment for hypoglycemic agents. However, analysis shows that there is a wide range of approaches regarding the doses used, duration of treatment, and treatment times in relation to the temporal course of DM. This wide range hinders an objective analysis of advances and prospective vision of the paths to be followed for the unequivocal establishment of parameters to be used in an eventual therapeutic validation of MEL in neural complications of DM.

Collagen matrix perturbations in corneal stroma of Ossabaw mini pigs with type 2 diabetes

Purpose

Diabetes mellitus (DM) is a metabolic disorder that affects over 450 million people worldwide. DM is characterized by hyperglycemia, causing severe systemic damage to the heart, kidneys, skin, vasculature, nerves, and eye. Type 2 diabetes (T2DM) constitutes 90% of clinical cases and is the most common cause of blindness in working adults. Also, about 70% of T2DM patients show corneal complications including delayed wound healing, often described as diabetic keratopathy (DK). Despite the increasing severity of DM, the research on DK is bleak. This study investigated cellular morphology and collagen matrix alterations of the diabetic and non-diabetic corneas collected from Ossabaw mini pigs, a T2DM animal model with a "thrifty genotype."

Methods

Pig corneas were collected from six-month-old Ossabaw miniature pigs fed on a western diet (WD) for ten weeks. The tissues were processed for immunohistochemistry and analyzed using hematoxylin and eosin staining, Mason Trichrome staining, Picrosirus Red staining, Collage I staining, and TUNEL assay. mRNA was prepared to quantify fibrotic gene expression using quantitative reverse-transcriptase PCR (qRT-PCR). Transmission electron microscopy (TEM) was performed to evaluate stromal fibril arrangements to compare collagen dynamics in WD vs. standard diet (SD) fed Ossabaw pig corneas.

Results

Ossabaw mini pigs fed on a WD for 10 weeks exhibit classic symptoms of metabolic syndrome and hyperglycemia seen in T2DM patients. We observed significant disarray in cornea stromal collagen matrix in Ossabaw mini pigs fed on WD compared to the age-matched mini pigs fed on a standard chow diet using Masson Trichome and Picrosirius Red staining. Furthermore, ultrastructure evaluation using TEM showed alterations in stromal collagen fibril size and organization in diabetic corneas compared to healthy age-matched corneas. These changes were accompanied by significantly decreased levels of Collagen IV and increased expression of matrix metallopeptidase 9 in WD-fed pigs.

Conclusions

This pilot study indicates that Ossabaw mini pigs fed on WD showed collagen disarray and altered gene expression involved in wound healing, suggesting that corneal stromal collagens are vulnerable to diabetic conditions.

Impact of pharmacist-involved collaborative care on diabetes management in a primary healthcare setting using real-world data

Background Diabetes mellitus is a complex multi-system disorder, requiring multi-disciplinary care. The conventional care model, where physicians are the sole caregivers may not be optimal. Addition of other healthcare team members improves healthcare outcomes for patients with diabetes. Aim To evaluate the impact of pharmacist-involved collaborative care on diabetes-related outcomes among patients with diabetes attending a primary healthcare setting  in Qatar using real-world data. Method A retrospective cohort study was conducted among patients with diabetes attending Qatar Petroleum Diabetes Clinic. Patients were categorized as either receiving pharmacist-involved collaborative care (intervention group) or usual care (control group). Data were analyzed using SPSS^®. Glycemic control (glycated hemoglobin A₁c, HbA₁c), blood pressure, lipid profile, and body mass index were evaluated at baseline and up to 17 months of follow-up. Results After 17 months of follow-up, pharmacist-involved collaborative care compared to usual care resulted in a significant decrease in HbA₁c (6.8 ± 1.2% vs. 7.1 ± 1.3%, p < 0.01). Moreover, compared to baseline, pharmacist-involved collaborative care significantly improved (p < 0.05) the levels of HbA_1c (7.5% vs. 6.8%), low-density lipoprotein cholesterol (3.7 mmol/L vs. 2.8 mmol/L), total cholesterol (5.43 mmol/L vs. 4.34 mmol/L), and body mass index (30.42 kg/m² vs. 30.17 kg/m²) after 17 months within the intervention group. However, no significant changes for these parameters occurred within the control group. Conclusion The implementation of pharmacist-involved collaborative care in a primary healthcare setting improved several diabetes-related outcomes over 17 months. Future studies should determine the long-term impact of this care model.

Time-restricted feeding improves blood glucose and insulin sensitivity in overweight patients with type 2 diabetes: a randomised controlled trial

Background

Time-restricted feeding is an emerging dietary intervention that is becoming increasingly popular. There are, however, no randomised clinical trials of time-restricted feeding in overweight patients with type 2 diabetes. Here, we explored the effects of time-restricted feeding on glycaemic regulation and weight changes in overweight patients with type 2 diabetes over 12 weeks.

Methods

Overweight adults with type 2 diabetes (n = 120) were randomised 1:1 to two diet groups: time-restricted feeding (n = 60) or control (n = 60). Sixty patients participated in a 10-h restricted feeding treatment program (ad libitum feeding from 8:00 to 18:00 h; fasting between 18:00 and 8:00 h) for 12 weeks.

Results

Haemoglobin A1c and body weight decreased in the time-restricted feeding group (− 1.54% ± 0.19 and − 2.98 ± 0.43 kg, respectively) relative to the control group over 12 weeks (p < 0.001). Homeostatic model assessment of β-cell function and insulin resistance changed in the time-restricted feeding group (0.73 ± 0.21, p = 0.005; − 0.51 ± 0.08, p = 0.02, respectively) compared with the control group. The medication effect score, SF-12 score, and the levels of triglycerides, total cholesterol and low-density lipoprotein cholesterol were improved in the time-restricted feeding group (− 0.66 ± 0.17, p = 0.006; 5.92 ± 1.38, p < 0.001; − 0.23 ± 0.08 mmol/L, p = 0.03; − 0.32 ± 0.07 mmol/L, p = 0.01; − 0.42 ± 0.13 mmol/L, p = 0.02, respectively) relative to the control group. High-density lipoprotein cholesterol was not significantly different between the two groups.

Conclusion

These results suggest that 10-h restricted feeding improves blood glucose and insulin sensitivity, results in weight loss, reduces the necessary dosage of hypoglycaemic drugs and enhances quality of life. It can also offer cardiovascular benefits by reducing atherosclerotic lipid levels.

Trial registration: This study was registered with the Chinese Clinical Trial Registry (ChiCTR-IPR-15006371).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12986-021-00613-9.

Effectiveness and safety of ertugliflozin for type 2 diabetes: A meta-analysis of data from randomized controlled trials

Aims/Introduction

To evaluate the effectiveness and safety of the novel sodium–glucose cotransporter inhibitor, ertugliflozin, compared with a placebo or other antihyperglycemic agents for type 2 diabetes patients.

Materials and Methods

We carried out a meta‐analysis of randomized controlled trials to assess the benefits and harms of ertugliflozin. Online database searches were carried out in PubMed, EMBASE, WEB OF SCIENCE and Cochrane from inception up to 11 March 2021. Our end‐points were glycated hemoglobin, fasting plasma glucose and bodyweight. We analyzed the results using a random effects model, computed weighted mean differences and risk ratios.

Result

A total of 10 randomized controlled trials with 13,223 patients met the inclusion criteria. Compared with a placebo, the weighted mean differences in glycated hemoglobin were −0.77% (95% confidence interval [CI] −0.86 to −0.68%) for ertugliflozin 5 mg, and −0.82% (95% CI −1.01 to −0.63%) for ertugliflozin 15 mg. Ertugliflozin 5 mg daily was also associated with bodyweight loss (weighted mean difference −1.87 kg, 95% CI −2.12 to −1.6). When compared with a placebo, ertugliflozin significantly reduced fasting plasma glucose by −1.62 mmol/L (weighted mean difference, 95% CI −1.82 to −1.42 for 5 mg ertugliflozin). Yet, we observed a rising risk for genital mycotic infections (risk ratio 4.34, 95% CI 2.78–6.76). The results were similar for the 15 mg ertugliflozin group.

Conclusion

Ertugliflozin effectively reduces glycated hemoglobin levels and provides extra clinical benefits including bodyweight and fasting plasma glucose. Common adverse effects, including genital mycotic infections and so on, were reviewed.

Relationship Between Estimated Average Glucose (eAG) and Fasting Plasma Glucose in a Cohort of Pakistani Diabetic Subjects

Introduction Scientific literature is scarce on the utility of estimated average glucose (eAG) from Pakistan. Hence, there is a dire need to evaluate the relationship between eAG and fasting plasma glucose (FPG), in order to enhance our understanding of eAG and its usefulness. This study aims to investigate the relationship between FPG and eAG in diabetic patients calculated using HbA1C. Materials and methods A retrospective study was conducted at the Aga Khan University, Karachi, Pakistan. The medical records of both genders in the age range of 18-60 years, presenting as outpatients at the endocrine clinic, labeled as DM, were reviewed from January 2013 to December 2019. The subjects were divided into three groups A (<130 mg/dL), B (130-179 mg/dL), and C (>180 mg/dL) based on FPG levels. A correlation was compared using Spearman's correlation. Box, whisker plots, and scatter plots were computed by R studio. Results After excluding those with missing values for either serum Cr, FPG, and HbA1c and sub-optimal renal function based on estimated glomerular filtration rate (eGFR) a total of 4,673 cases were analyzed. Subgroup A showed good glycemic control, whereas subgroup C showed poor glycemic control. The difference between eAG and FPG was significant (p < 0.0001). eAG values were found to be elevated than FPG values in groups A and B and almost the same in group C, whereas a moderately significant correlation with eAG and FPG in all three groups. Conclusion The correlation between eAG and FPG varies with blood glucose control and was significantly higher in the poorly controlled diabetes group. As the association between the FPG and eAG levels varies with the extent of blood glucose control, reporting eAG with HbA1c by a simple formula, at no additional cost will prove to be beneficial for clinical care.

Glucose fluctuation accelerates cardiac injury of diabetic mice via sodium-dependent glucose cotransporter 1 (SGLT1)

Recent studies have shown that blood glucose fluctuation is associated with complications of diabetes mellitus (DM). SGLT1 (sodium-dependent glucose cotransporter 1), is highly expressed in pathological conditions of heart, and is expressed in cardiomyocytes induced by high glucose. Herein, we constructed a diabetic mouse model with glucose fluctuation to investigate whether SGLT1 is involved in glucose fluctuation-induced cardiac injury. Echocardiography, histology examination, and TUNEL staining were performed to evaluate cardiac dysfunction and damage. To assess glucose fluctuation-induced oxidative stress, reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were measured. To assess mitochondrial dysfunction, mitochondrial membrane potential (MMP), ATP content, mitochondrial respiratory chain complex activity, and expression of mitochondrial fusion and fission proteins were determined. The results indicated that diabetic mice with glucose fluctuation showed elevation of cardiac SGLT1 expression, left ventricular dysfunction, oxidative stress and mitochondrial dysfunction. Knockdown of SGLT1 could abrogate the effects of glucose fluctuation on cardiac injury. Thus, our study highlighted that SGLT1 plays an important role in glucose fluctuation induced cardiac injury through oxidative stress and mitochondrial dysfunction.

C1q/TNF-related Protein 9 Inhibits High Glucose-Induced Oxidative Stress and Apoptosis in Retinal Pigment Epithelial Cells Through the Activation of AMPK/Nrf2 Signaling Pathway

Diabetic retinopathy (DR) is one of the common complications of diabetes mellitus. C1q/TNF-related protein 9 (CTRP9) has been demonstrated to be associated with the progression of diabetes and relative complications. However, its role in DR and underlying action of mechanism are not yet well understood. In the present study, human retinal pigment epithelial ARPE-19 cells were cultured under high concentration of glucose to simulate hyperglycemia condition in vitro. Our results showed that the expression of CTRP9 was significantly decreased in high glucose (HG)–stimulated ARPE-19 cells. CTRP9 overexpression improved HG-caused reduction in cell viability of ARPE-19 cells. CTRP9 overexpression significantly attenuated HG-induced oxidative stress, as proved by decreased levels of reactive oxygen species and malondialdehyde, and increased superoxide dismutase activity. Moreover, CTRP9 also prevented apoptosis in ARPE-19 cells in response to HG stimulation with decreased caspse-3 activity and bax expression, as well as increased bcl-2 expression. In contrast, knockdown of CTRP9 aggravated HG-induced oxidative stress and apoptosis. Furthermore, CTRP9 significantly induced the activation of AMPK/Nrf2 pathway in HG-induced ARPE-19 cells. Notably, inhibiting AMPK or Nrf2 blocked the protective effect of CTRP9 on ARPE-19 cells exposed to HG stimulation. Taken together, our findings suggested a protective effect of CTRP9 on HG-induced ARPE-19 cells and a putative mechanism involving the activation of AMPK/Nrf2 signaling pathway.

Different Roles of TP53 Codon 72 Polymorphism in Type 2 Diabetes and Its Complications: Evidence from a Case-Control Study on a Chinese Han Population

Objective

The purpose of this study was to investigate the relationships between TP53 Pro72Arg (rs1042522) polymorphism and susceptibility to type 2 diabetes (T2DM) and its related complications.

Methods

The TP53 Pro72Arg polymorphism was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 206 T2DM patients and 446 healthy controls. Mitochondrial DNA (mtDNA) content, mtDNA transcriptional level and large-scale mtDNA deletion were evaluated in leukocytes of T2DM patients using fluorescence-based quantitative PCR (FQ-PCR), reverse transcriptase-quantitative PCR (RT-qPCR) and long-range PCR approaches, respectively. The data of our study were processed by GraphPad Prism software (version 7.00).

Results

The distribution of TP53 Pro72Arg differed in T2DM patients from the controls, with a moderately increased proportion of TP53 Arg72 variant carriers (Pro/Arg and Arg/Arg genotypes) (88.3% vs 81.2%, p=0.022; OR=1.089, 95% CI=1.018–1.164). T2DM patients with Arg/Arg genotype had significantly decreased prevalences of diabetic neuropathy and retinopathy compared to those without (6.5% vs 19.4%, p=0.018 and 14.8% vs 30.7%, p=0.018, respectively). T2DM patients with Arg/Arg genotype had higher mtDNA content and mtRNA expression level than those who were not Arg/Arg genotype (p<0.05 for all), and we did not observe mtDNA 4977-base pair (bp) deletion mutations in the leukocytes of T2DM patients.

Conclusion

There was a significant association of the TP53 Pro72Arg polymorphism with susceptibility to T2DM, and the homozygous Arg/Arg genotype of this gene locus might be a protective factor for diabetic complications. Those results suggested that the TP53 Arg72 variant had a different association with type 2 diabetes and its complications, and it might be related to mtDNA maintenance of the TP53 Arg72 variant under hyperglycemia-induced stress.

The P2X7 Receptor: A Promising Pharmacological Target in Diabetic Retinopathy

Diabetes is a worldwide emergency. Its chronic complications impose a heavy burden on patients, health systems, and on society as a whole. Diabetic retinopathy is one of the most common and serious complications of diabetes, and an established risk factor for blindness in adults. Over 15 years of investigation led to the identification of vascular endothelial growth factor (VEGF) as a main pathogenic factor in diabetic retinopathy and to the introduction of highly effective anti-VEGF-based therapies, such as the monoclonal antibody bevacizumab or its fragment ranibizumab, which helped to prevent diabetes-related blindness in millions of patients. Recently, a pathogenic role for uncontrolled increases in the extracellular ATP concentration (eATP) and for overactivation of the purinergic receptor P2X7 (P2X7R) has been suggested. The P2X7R is an eATP-gated plasma membrane channel expressed in multiple tissues and organs, with a pleiotropic function in inflammation, immunity, cancer, and hormone and growth factor release. P2X7R stimulation or overexpression positively regulate the secretion and buildup of VEGF, thus promoting neo-angiogenesis in a wide variety of disease processes. In this review, we explore current evidence that supports the role of P2X7R receptor signaling in the pathogenesis of diabetic retinopathy, as well as the most appealing current therapeutical options for P2X7R targeting.

Type 1 Diabetes Patients' Practice, Knowledge and Attitudes towards Influenza Immunization

Diabetic patients are at higher risk of developing infectious diseases and severe complications, compared to the general population. Almost no data is available in the literature on influenza immunization in people with type 1 diabetes mellitus (T1DM). As part of a broader project on immunization in diabetic patients, we conducted a cross-sectional study to: (i) report on seasonal influenza coverage rates in T1DM patients, (ii) explore knowledge, attitudes, and practices (KAPs) towards seasonal influenza in this population, and (iii) identify factors associated with vaccine uptake, including the role of family doctors and diabetologists. A survey was administered to 251 T1DM patients attending the Diabetes Clinic at San Raffaele Research Hospital in Milan, Italy and individual-level coverage data were retrieved from immunization registries. Self-reported seasonal influenza immunization coverage was 36%, which decreased to 21.7% when considering regional immunization registries, far below coverage target of 75%. More than a third (36.2%) of T1DM patients were classified as pro-vaccine, 30.7% as hesitant, 17.9% as uninformed, and 15.1% as anti-vaccine. Diabetologists resulted to be the most trusted source of information on vaccines’ benefits and risks (85.3%) and should be more actively involved in preventive interventions. Our study highlights the importance of developing tailored vaccination campaigns for people with diabetes, including hospital-based programs involving diabetes specialists.

Mechanism of Ferroptosis and Its Role in Type 2 Diabetes Mellitus

Ferroptosis is a novel form of nonapoptotic regulated cell death (RCD). It features iron-dependent lipid peroxide accumulation accompanied by inadequate redox enzymes, especially glutathione peroxidase 4 (GPX4). RAS-selective lethal 3 (RSL3), erastin, and ferroptosis inducing 56 (FIN56) induce ferroptosis via different manners targeting GPX4 function. Acyl-CoA synthetase long-chain family 4 (ACSL4), lysophosphatidylcholine acyltransferase 3 (LPCAT3), and lipoxygenases (LOXs) participate in the production of lipid peroxides. Heat shock protein family B member 1 (HSPB1) and nuclear receptor coactivator 4 (NCOA4) regulate iron homeostasis preventing ferroptosis caused by the high concentration of intracellular iron. Ferroptosis is ubiquitous in our body as it exists in both physiologic and pathogenic processes. It is involved in glucose-stimulated insulin secretion (GSIS) impairment and arsenic-induced pancreatic damage in the pathogenesis of diabetes. Moreover, iron and the iron-sulfur (Fe-S) cluster influence each other, causing mitochondrial iron accumulation, more reactive oxygen species (ROS) production, endoplasmic reticulum (ER) stress, failure in biosynthesis of insulin, and ferroptosis in β-cells. In addition, ferroptosis also engages in the pathogenesis of diabetic complications such as myocardial ischemia and diabetic cardiomyopathy (DCM). In this review, we summarize the mechanism of ferroptosis and especially its association with type 2 diabetes mellitus (T2DM).

Construction of lncRNA-related ceRNA regulatory network in diabetic subdermal endothelial cells

Long non-coding RNAs (lncRNAs) were considered to be involved in vascular complications in diabetes mellitus, but still only limited knowledge in this regard has been obtained. Herein, we further explored the roles of lncRNAs and mRNAs in diabetic vasculopathy (DV) through conducting bioinformatics analysis using data set downloaded from GEO database. The differentially expressed lncRNAs and mRNAs were identified by edge package. GO enrichment analysis and KEGG pathway analysis were performed based on clusterprofiler package. The relationship between lncRNA and miRNA was predicted using starBase database, and the potential mRNAs targeted by miRNAs were predicted by TargetScan, miRTarbase and miRDB database. The string database was used to analyze the protein-protein interaction (PPI). As a result, a total of 12 lncRNAs and 711 mRNAs were found to be differentially expressed in the diabetic subdermal endothelial cells compared with normal controls. A ceRNA network was established, which was composed of seven lncRNA nodes, 49 miRNA nodes, 58 mRNA nodes and 183 edges, and MSC-AS1 and LINC01550 may serve as key nodes. GO function enrichment analysis showed enrichments of epithelial cell proliferation, intercellular junction, and cell adhesion molecule binding. KEGG pathway analysis revealed 33 enriched pathways. PPI protein interaction analysis identified 57 potential ceRNA-related proteins. Overall, this study suggests that multiple lncRNAs, specifically MSC-AS1 and LINC01550, may play an important role in DV development and they are like to be developed as the therapeutic targets for DV. However, further experiments in vitro and in vivo should be conducted to validate our results.

Silencing circANKRD36 inhibits streptozotocin-induced insulin resistance and inflammation in diabetic rats by targeting miR-145 via XBP1

BACKGROUND

Diabetes mellitus (DM) is defined as a group of metabolic diseases characterized by hyperglycemia, which results from a deficiency in insulin secretion and/or insulin action. In diabetic patients, type 2 diabetes mellitus (T2DM) is in the majority. We explored the effects of circANKRD36 on streptozotocin (STZ)-induced insulin resistance and inflammation in diabetic rats with the aim of uncovering the underlying mechanism.

METHODS

STZ was used to induce the in vivo T2DM rat model. After circANKRD36 interference, blood glucose, insulin and adiponectin were respectively detected. Hematoxylin and eosin (H&E), enzyme-linked immunosorbent assay (ELISA) and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) were conducted to examine inflammation and apoptosis in T2DM rats, and western blot was used for detecting apoptosis-related proteins. The binding relationships among circANKRD36, miR-145 and XBP1 were examined by luciferase reporter assay.

RESULTS

Results showed that circANKRD36 was expressed at a high level in T2DM rats, while silencing circANKRD36 led to decreased blood glucose and insulin, accompanied by increased adiponectin level, and ameliorating insulin resistance. Silencing circANKRD36 alleviated the inflammation and suppressed cell apoptosis in the pancreatic tissues of T2DM rats, which was abated by miR-145 inhibitor. The binding of miR-145 to XBP1 was then confirmed. Additionally, miR-145 inhibitor increased the level of XBP1 in T2DM rats, which was decreased in the presence of circANKRD36 silencing.

CONCLUSION

This study is the first to prove that silencing circANKRD36 inhibits STZ-induced insulin resistance and inflammation in diabetic rats by targeting miR- 145 via XBP1. The results warrant the importance of circRNAs as drug target and thereby pave way for the development of newer therapeutic measures for T2DM.

Influence of glucose, insulin fluctuation, and glycosylated hemoglobin on the outcome of sarcopenia in patients with type 2 diabetes mellitus

AIMS

To explore the effects of glucose, insulin, and glycosylated hemoglobin (HbA1c) levels on the outcome of sarcopenia in patients with type 2 diabetes mellitus (T2DM).

METHODS

A total of 482 T2DM patients were enrolled in the follow-up study. The median follow-up time was 36 months. Muscle mass and HbA1c were measured in all participants. And glucose, C-peptide and insulin levels were measured at 0 min, 30 min, and 120 min after glucose load. We subsequently analyzed daily glucose fluctuations and islet function before and after readmission as well as the influence of their changes on sarcopenia outcome.

RESULTS

After glucose load, incident sarcopenia patients showed greater glucose fluctuations and worse islet function than did non-sarcopenia patients. As HbA1c and standard deviation of blood glucose (SDBG) increased, readmitted non-sarcopenia patients showed a significantly increased odds ratio of incident sarcopenia; however, only patients with higher quartiles were statistically significant. Increased ΔAUC-C-peptide reduced the risk of incident sarcopenia (P < 0.05).

CONCLUSIONS

Patients with incident sarcopenia have poor glucose regulation and insufficient insulin secretion. Furthermore, as HbA1c and SDBG increased, AUC-C-peptide and AUC-insulin decreased in readmitted non-sarcopenia patients, the risk of incident sarcopenia increased.

Isoquercitrin protects HUVECs against high glucose‑induced apoptosis through regulating p53 proteasomal degradation

High glucose (HG)-induced endothelial apoptosis serves an important role in the vascular dysfunction associated with diabetes mellitus (DM). It has been reported that isoquercitrin (IQC), a flavonoid glucoside, possesses an anti-DM effect, but the mechanism requires further investigation. The present study investigated the effect of IQC against HG-induced apoptosis in human umbilical vein endothelial cells (HUVECs) and explored its molecular mechanism. HUVECs were treated with 5 or 30 mM glucose for 48 h. Endothelial cell viability was monitored using the Cell Counting Kit-8 assay. Mitochondrial membrane potential was detected by JC-1 staining. Apoptosis was observed by TUNEL staining and flow cytometry. Western blotting was used for the analysis of apoptosis-associated proteins Bax, Bcl-2, cleaved (C)-caspase3, total-caspase3, p53 and phosphorylated p53. Reverse transcription-quantitative PCR was used to analyze the mRNA expression levels of Bax, Bcl-2 and p53. Immunofluorescence staining was utilized to detect the expression levels and distribution of p53 and ubiquitin specific peptidase 10 (USP10) in HUVECs. The results revealed that IQC significantly attenuated HG-induced endothelial apoptosis, as shown by decreased apoptotic cells observed by TUNEL, JC-1 staining and flow cytometry. Moreover, under HG stress, IQC treatment markedly inhibited the increased expression levels of the pro-apoptotic proteins p53, Bax and C-caspase3, and increased the expression levels of the anti-apoptotic protein Bcl-2 in HUVECs. However, the anti-apoptotic effect of IQC against HG was partially blunted by increasing p53 protein levels in vitro. IQC influenced the mRNA expression levels of Bax and Bcl-2 in response to HG, but it did not affect the transcription of p53. Notably, IQC inhibited the HG-induced phosphorylation of p53 at Ser15 and the nuclear transport of USP10, destabilizing p53 and increasing the proteasomal degradation of the p53 protein. The current findings revealed that IQC exerted a protective effect against the HG-induced apoptosis of endothelial cells by regulating the proteasomal degradation of the p53 protein, suggesting that IQC may be used as a novel therapeutic compound to ameliorate DM-induced vascular complications.

Utility of Fatty Liver Index to predict reversion to normoglycemia in people with prediabetes

Background

Fatty Liver Index (FLI) is strongly associated with changes in glycemic status and incident Type 2 Diabetes (T2D). The probability of reverting to normoglycemia from a state prediabetes could be determined by FLI, however such relationship remains poorly understood.

Aim

To determine the clinical interest of using FLI to estimate prediabetes reversion at 5 years in patients with impaired fasting plasma glucose at baseline, and identify those factors associated with changes in FLI, that could contribute to the reversion of prediabetes.

Methods

This 5-year cohort study included 16,648 Spanish working adults with prediabetes. Prediabetes was defined as fasting plasma glucose (FPG) between 100 and 125 mg/dl according to the ADA criteria, while prediabetes reversion was defined as a FPG <100 mg/dL. The population was classified as: FLI <30 (no hepatic steatosis), FLI 30–59 (intermediate status), and FLI ≥60 (hepatic steatosis).

Results

At 5 years follow-up, 33.7% of subjects reverted to normoglycemia (annual rate of 6.7%). The adjusted binomial logistic regression model showed that scoring FLI <30 (OR 1.544; 95% CI 1.355–1.759), performing at least 150 min/week of physical activity (OR 4.600; 95% CI 4.088–5.177) and consuming fruits and vegetables daily (OR 1.682; 95% CI 1.526–1.855) were associated with the probability of reverting form prediabetes to normoglycemia. The ROC curve for prediction of reversion showed that FLI (AUC 0.774;95% CI 0.767–0.781) was a better predictor than FPG (AUC 0.656; 95% CI 0.648–0.664).

Conclusions

Regular physical activity, healthy dietary habits and absence of hepatic steatosis are independently associated with the probability of reversion to normoglycemia in adult workers with prediabetes at baseline. Low FLI values (especially FLI< 30) may be useful to predict the probability of prediabetes reversion, especially in active subjects with healthy eating habits, and thus identify those who might benefit from early lifestyle intervention.

Salvianic Acid A Regulates High-Glucose-Treated Endothelial Progenitor Cell Dysfunction via the AKT/Endothelial Nitric Oxide Synthase (eNOS) Pathway

BACKGROUND The primary cause of death in patients with diabetes mellitus (DM) is diabetic macroangiopathy, a complication that related to the function and number of endothelial progenitor cells (EPCs). Salvianic acid A (SAA) is a water-soluble active ingredient of Salvia miltiorrhiza, a traditional Chinese medicine used to treat cardiovascular diseases. The purpose of this study was to explore the effects of SAA on the function of rat EPCs cultured in vitro in a high-glucose environment. MATERIAL AND METHODS Bone marrow-derived EPCs from 40 Sprague-Dawley rats were identified by fluorescence staining. Cell viability, apoptosis, tube formation, lactated dehydrogenase (LDH) release, and nitric oxide (NO) production were detected by 3-[4,5-dimethylthylthiazol-2-yl]-2,5 diphenyltetrazolium bromide assay, flow cytometry, tube formation, LDH, and 3-amino,4-aminomethyl-2',7'-difluorescein, and diacetate assays, respectively. The expression levels of proteins were examined by western blotting. RESULTS Cultured EPCs showed a cobblestone morphology and positive expression of Dil-ac-LDL and FITC-UEA-1. High glucose impaired cell viability. Different concentrations of SAA had no significant effect on EPC viability. SAA reduced the apoptosis rate and LDH release, but promoted tube formation, viability, and NO production in high-glucose-treated EPCs. The ratios of p-AKT/AKT and p-eNOS/eNOS in high-glucose-treated EPCs were elevated by SAA. Phosphoinositide 3-kinase inhibitor LY294002 blocked the rescue effects of SAA on high-glucose-treated EPCs. CONCLUSIONS SAA protected EPCs against high-glucose-induced dysfunction via the AKT/eNOS pathway.

The contribution of dietary glycemic index and glycemic load to the development of microvascular complications of diabetes

Lifestyle modification, including a healthy diet, is of paramount importance in the management of diabetes mellitus. To this end, diets have been proposed with low glycemic index (an index of carbohydrate food expressing how quickly this nutrient can increase blood glucose) and glycemic load (an index obtained by multiplying the glycemic index by the grams of carbohydrate, then dividing by 100). The aim of this review was to discuss the potential contribution of diets with low glycemic index and glycemic load in diabetic microvascular complications. Currently, their role to the prevention and delay of microvascular complications in diabetes mellitus remains unclear, and further knowledge is desirable.

Systemic diseases and the cornea

There is a number of systemic diseases affecting the cornea. These include endocrine disorders (diabetes, Graves' disease, Addison's disease, hyperparathyroidism), infections with viruses (SARS-CoV-2, herpes simplex, varicella zoster, HTLV-1, Epstein-Barr virus) and bacteria (tuberculosis, syphilis and Pseudomonas aeruginosa), autoimmune and inflammatory diseases (rheumatoid arthritis, Sjögren's syndrome, lupus erythematosus, gout, atopic and vernal keratoconjunctivitis, multiple sclerosis, granulomatosis with polyangiitis, sarcoidosis, Cogan's syndrome, immunobullous diseases), corneal deposit disorders (Wilson's disease, cystinosis, Fabry disease, Meretoja's syndrome, mucopolysaccharidosis, hyperlipoproteinemia), and genetic disorders (aniridia, Ehlers-Danlos syndromes, Marfan syndrome). Corneal manifestations often provide an insight to underlying systemic diseases and can act as the first indicator of an undiagnosed systemic condition. Routine eye exams can bring attention to potentially life-threatening illnesses. In this review, we provide a fairly detailed overview of the pathologic changes in the cornea described in various systemic diseases and also discuss underlying molecular mechanisms, as well as current and emerging treatments.

The Interplay Between Sugar and Yeast Infections: Do Diabetics Have a Greater Predisposition to Develop Oral and Vulvovaginal Candidiasis?

Diabetes mellitus (DM) is one of the most common chronic diseases impacting individuals of both developing and developed nations. DM patients have a weaker immune system in comparison to healthy subjects, rendering them more prone to develop infections. Even the typical gut microflora can become pathogenic in such immunocompromised conditions. Microorganisms belonging to Candida species are capable of causing infections in DM subjects. A comprehensive review of the literature was undertaken. The PubMed database was searched using well-defined search terms. Predefined inclusion and exclusion criteria were applied to classify relevant manuscripts. The results of the review show that DM patients have an increased susceptibility to Candida sp. This paper will summarize the previously conducted research discussing the relationship between DM and candidiasis, features specific to Candida species that make it pathogenic, and compare oral and vulvovaginal candidiasis (VVC) morbidity in diabetics versus healthy subjects.

Diabetes mellitus: a primary metabolic disturbance. Metabolomics underlying vascular responses to stress and ischemia?

Diabetes mellitus (DM) is a primary metabolic disorder and the impact of this entity on maladaptive tissue and organ responses may be mediated through alter metabolomic profile and signatures at steady state or at stress. To this point of view Beckman et al. (Clin. Sci. (Lond.) (2020) 134, 2369-2379), in a hypothesis-generated study, investigated how metabolomic profile is affected following branchial artery ischemia. Interestingly, they found that there is a dynamic and altered change of metabolites associated with energy substrate and with glycolysis/glyconeogenesis in patients with DM. This evidence may shed light on the impaired muscle tolerance in subjects with DM and on impaired vasoreactivity. However, these data lack the ability to be conclusive and further steps should be explored to understand how metabolomic profile is implicated in the response of muscle tissue to ischemia and to the clinical profile of subjects with DM.

Ginkgo biloba leaf extract prevents diabetic nephropathy through the suppression of tissue transglutaminase

The present study aimed to investigate the preventive effects of Ginkgo biloba leaf extract (GBE) against extracellular matrix (ECM) accumulation in a streptozotocin (STZ)-induced rat model of diabetic nephropathy (DN), and to determine its underlying molecular mechanism. In vivo, a rat model of DN was established by intraperitoneal injection of STZ, and the rats were subsequently administered GBE. The results demonstrated that GBE significantly decreased blood glucose, the urine protein excretion rate and ECM accumulation in DN rats. In addition, the development of DN significantly induced tissue transglutaminase (tTG) protein expression, which was detected by immunohistochemistry, western blotting and PCR analyses, while GBE administration decreased tTG expression in the diabetic kidney. In vitro, rat glomerular mesangial cells (HBZY-1 cells) cultured with high glucose were also treated with GBE. The concentrations of tTG, fibronectin, type IV collagen, transforming growth factor (TGF)-β and connective tissue growth factor (CTGF) were detected via ELISA. The results demonstrated that GBE notably decreased the concentration of these proteins, and tTG expression was positively associated with TGF-β. GBE also suppressed tTG expression of high glucose-treated HBZY-1 cells in a concentration-dependent manner. Furthermore, tTG protein expression was detected in high glucose-treated HBZY-1 cells transfected with small interfering RNA (siRNA) oligonucleotides against TGF-β and CTGF to investigate a possible mechanism of GBE-mediated inhibition of tTG. The results demonstrated that the tTG levels remained unchanged in CTGF siRNA-transfected cells, but were decreased in the GBE + CTGF siRNA group compared with the control siRNA group, suggesting that tTG may not be regulated by CTGF, and the inhibitory effect of GBE on tTG may not be associated with the direct inhibition of CTGF. However, tTG expression was decreased following the transfection with TGF-β siRNA, in which levels of tTG were similar compared with both the GBE group and GBE + TGF-β siRNA group, indicating that tTG may be regulated by TGF-β, and that the GBE-induced repression of tTG expression may be associated with the downregulation of TGF-β. Taken together, the results of the present study suggest that GBE prevented ECM accumulation by suppressing tTG expression in DN, which was predominantly mediated by TGF-β.

Diabetes: a silent player in musculoskeletal interventional radiology response

Diabetes has an important role in the development of several musculoskeletal disorders, such as adhesive capsulitis of the shoulder (ACs) and stenosing flexor tenosynovitis of the finger (SfTf). The etiopathophysiology of ACs and SfTf in diabetic patients is associated with both chronic hyperglycemia, increased amounts of visceral adiposity and chronic inflammation. Chronic hyperglycemia stimulates the creation of cross-links between collagen molecules, impairing degradation and resulting in the build-up of excessive collagen deposits in the cartilage, ligaments, tendon sheaths and tendons. Increased adipocytes in diabetic patients secrete proteins and cytocines such as TNF-α, IL-6 and IL-13 which result in overproduction of pro-inflammatory factors, destruction of normal tissue architecture and fibrosis. Both hyperglycemia and adipocytes inhibit efferocytosis, limiting natural resolution. Recently, multiple image-guided interventional radiology musculoskeletal treatment options have been developed, such as ultrasound-guided glenohumeral capsule hydrodistension for ACs and ultrasound-guided percutaneous pulley release for trigger finger. Diabetes can negatively influence outcomes in patients with ACs and SfTf and may impact the decision of which specific procedure technique should be employed. Further studies are necessary to define how diabetes influences response to interventional radiology treatments of these disorders, as well as the extent to which control of blood sugar levels can contribute towards the personalization and optimization of patient follow up.

Impact of abdominal aortic calcification on 90-day mortality in sepsis patients: a pilot retrospective cohort study

Aim

We aimed to investigate the association between aortic calcification and 90-day mortality in sepsis patients admitted to the intensive care unit.

Methods

We evaluated adult patients (≥18 years) diagnosed with sepsis based on the Sepsis-3 criteria and admitted to our intensive care unit between April 2011 and March 2015. They were classified according to the degree of abdominal aortic calcification (severe and non-severe), grouped per age (<65, 65-75, and >75 years), and matched. Survival curves were generated, and between-group differences were evaluated.

Results

Overall, 164 patients were included. The Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were not significantly different between the severity groups, whereas there were significant differences in age (P < 0.001), sex (P = 0.017), and presence of diabetes mellitus (P < 0.001), hypertension (P < 0.001), dyslipidemia (P = 0.048), and maintenance dialysis (P = 0.001). The severe abdominal aortic calcification group showed significantly poorer prognosis than the non-severe group (log-rank P = 0.009). The adjusted odds ratio of severe calcification was the highest in patients aged <65 years (7.167; 95% confidence interval, 1.042-49.28, P = 0.045). Twenty-eight patients from each group were matched. The 90-day survival rate of the severe calcification group remained significantly lower than that of the non-severe calcification group (53.6% [15/28] versus 82.1% [23/28], P = 0.022).

Conclusions

Severe abdominal aortic calcification is associated with the 90-day mortality of sepsis patients, particularly among those aged <65 years. Thus, caution is necessary in patients younger than 65 years; they may need to be treated with as much care as the elderly.

Characteristics and Therapeutic Potential of Human Amnion-Derived Stem Cells

Stem cells including embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and adult stem cells (ASCs) are able to repair/replace damaged or degenerative tissues and improve functional recovery in experimental model and clinical trials. However, there are still many limitations and unresolved problems regarding stem cell therapy in terms of ethical barriers, immune rejection, tumorigenicity, and cell sources. By reviewing recent literatures and our related works, human amnion-derived stem cells (hADSCs) including human amniotic mesenchymal stem cells (hAMSCs) and human amniotic epithelial stem cells (hAESCs) have shown considerable advantages over other stem cells. In this review, we first described the biological characteristics and advantages of hADSCs, especially for their high pluripotency and immunomodulatory effects. Then, we summarized the therapeutic applications and recent progresses of hADSCs in treating various diseases for preclinical research and clinical trials. In addition, the possible mechanisms and the challenges of hADSCs applications have been also discussed. Finally, we highlighted the properties of hADSCs as a promising source of stem cells for cell therapy and regenerative medicine and pointed out the perspectives for the directions of hADSCs applications clinically.

Development of Predictive Nomograms for Clinical Use to Quantify the Risk of Amputation in Patients with Diabetic Foot Ulcer

OBJECTIVE

To determine the novel proposed nomogram model accuracy in the prediction of the lower-extremity amputations (LEA) risk in diabetic foot ulcer (DFU).

METHODS AND MATERIALS

In this retrospective study, data of 125 patients with diabetic foot ulcer who met the research criteria in Zhongnan Hospital of Wuhan University from January 2015 to December 2019 were collected by filling in the clinical investigation case report form. Firstly, univariate analysis was used to find the primary predictive factors of amputation in patients with diabetic foot ulcer. Secondly, single factor and multiple factor logistic regression analysis were employed to screen the independent influencing factors of amputation introducing the primary predictive factors selected from the univariate analysis. Thirdly, the independent influencing factors were applied to build a prediction model of amputation risk in patients with diabetic foot ulcer by using R4.3; then, the nomogram was established according to the selected variables visually. Finally, the performance of the prediction model was evaluated and verified by receiver working characteristic (ROC) curve, corrected calibration curve, and clinical decision curve.

RESULTS

7 primary predictive factors were selected by univariate analysis from 21 variables, including the course of diabetes, peripheral angiopathy of diabetic (PAD), glycosylated hemoglobin A1c (HbA1c), white blood cells (WBC), albumin (ALB), blood uric acid (BUA), and fibrinogen (FIB); single factor logistic regression analysis showed that albumin was a protective factor for amputation in patients with diabetic foot ulcer, and the other six factors were risk factors. Multivariate logical regression analysis illustrated that only five factors (the course of diabetes, PAD, HbA1c, WBC, and FIB) were independent risk factors for amputation in patients with diabetic foot ulcer. According to the area under curve (AUC) of ROC was 0.876 and corrected calibration curve of the nomogram displayed good fitting ability, the model established by these 5 independent risk factors exhibited good ability to predict the risk of amputation. The decision analysis curve (DCA) indicated that the nomogram model was more practical and accurate when the risk threshold was between 6% and 91%.

CONCLUSION

Our novel proposed nomogram showed that the course of diabetes, PAD, HbA1c, WBC, and FIB are the independent risk factors of amputation in patients with DFU. This prediction model was well developed and behaved a great accurate value for LEA so as to provide a useful tool for screening LEA risk and preventing DFU from developing into amputation.

Bioresponsive Functional Phenylboronic Acid-Based Delivery System as an Emerging Platform for Diabetic Therapy

The glucose-sensitive self-adjusting drug delivery system simulates the physiological model of the human pancreas-secreting insulin and then precisely regulates the release of hypoglycemic drugs and controls the blood sugar. Thus, it has good application prospects in the treatment of diabetes. Presently, there are three glucose-sensitive drug systems: phenylboronic acid (PBA) and its derivatives, concanavalin A (Con A), and glucose oxidase (GOD). Among these, the glucose-sensitive polymer carrier based on PBA has the advantages of better stability, long-term storage, and reversible glucose response, and the loading of insulin in it can achieve the controlled release of drugs in the human environment. Therefore, it has become a research hotspot in recent years and has been developed very rapidly. In order to further carry out a follow-up study, we focused on the development process, performance, and application of PBA and its derivatives-based glucose-sensitive polymer drug carriers, and the prospects for the development of this field.

Clinical Characteristics and Outcomes of Acute Ischemic Stroke in Patients with Type 2 Diabetes: A Single-Center, Retrospective Study in Southern China

OBJECTIVE

To explore the associations between type 2 diabetes mellitus (DM) and stroke by evaluating the clinical risk factors, characteristics, and outcomes of acute ischemic stroke (AIS) patients with and without type 2 DM.

METHODS

A total of 1,156 AIS patients (including 410 with type 2 DM (AIS-DM group)) and 746 without type 2 DM (AIS-NDM group)) were included. Patients' demographics, auxiliary examinations, clinical manifestations, and treatment outcomes were recorded and analyzed.

RESULTS

Among the included AIS patients, 35.46% had type 2 DM. The AIS-DM group had less males (59.76% versus 70.64%), less smokers (33.90% versus 41.96%), more patients with hypertension (72.93% versus 63.94%; p=0.002), higher triglyceride levels (42.93% versus 25.08%; p ≤ 0.01), and lower total cholesterol (147.06 mg/dl versus 175.31 mg/dl) than the AIS-NDM group. The proportion of patients with large artery atherosclerosis (LAA) in the AIS-DM group was lower (77.56% versus 85.92%; p < 0.05) than that in the AIS-NDM group, and the proportion of patients with small arterial occlusions (SAO) in the AIS-DM group was higher (27.07% versus 13.67%; p < 0.05) than that in the AIS-NDM group. The mean National Institutes of Health Stroke Scale (NIHSS) score at admission in the AIS-DM group was lower than that in the AIS-NDM group (4.39 versus 5.00; p=0.008), but there was no significant difference in the NIHSS score or the modified Rankin Scale score between the two groups at discharge. A total of 85 AIS patients underwent intravenous thrombolysis treatment with recombinant tissue plasminogen activator (rtPA). The door-to-needle time (DNT) did not differ significantly between the groups (49.39 ± 30.40 min versus 44.25 ± 15.24 min; p=0.433). In addition, there were no significant differences in the baseline NIHSS score, 7-day NIHSS score, and mRS score at discharge between the groups. After intravenous thrombolysis with rtPA, the AIS-NDM group had better recovery (44.30% versus 29.20%; p=0.017) and a higher ratio of good treatment outcome at discharge (65.60% versus 54.20%; p=0.762).

CONCLUSIONS

Type 2 DM is associated with AIS and its risk factors, such as dyslipidemia and hypertension. Patients in the AIS-DM group had less LAA and smaller arterial occlusions, and DM could exacerbate the short-term clinical outcomes in AIS patients.

1α,25-Dihydroxyvitamin D3 ameliorates diabetes-induced bone loss by attenuating FoxO1-mediated autophagy

Autophagy is vital for maintaining cellular homeostasis through removing impaired organelles. It has recently been found to play pivotal roles in diabetes mellitus (DM), which is associated with increased bone fracture risk and loss of bone density. However, the mechanism whereby autophagy modulates DM-induced bone loss is not fully elucidated. Previous work has shown that 1α,25-Dihydroxyvitamin D3 (1,25D) exerts positive effects on autophagy, thus affecting bone metabolism. Here, we investigated whether autophagy was involved in the regulation of diabetic bone metabolism. Using Micro-CT, Elisa, histology, and histomorphometry analysis, we demonstrated that 1,25D rescues glucose metabolism dysfunction and ameliorates bone loss in diabetic mice. In vitro, 1,25D alleviated primary osteoblast dysfunction and intracellular oxidative stress through reducing prolonged high-glucose-mediated excessive autophagy in primary osteoblasts, reflected by decreased protein level of Beclin1 and LC3. Of note, the autophagy activator rapamycin (RAP) ablated the positive effects of 1,25D in diabetic environment, leading to a marked increase in autolysosomes and autophagosomes, examined by mRFP-GFP-LC3 fluorescence double labeling. The excessive autophagy induced by high glucose was deleterious to proliferation and differentiation of primary osteoblasts. Additionally, biochemical studies identified that PI3K/Akt signaling could be activated by 1,25D, resulting in the inhibition of FoxO1. We confirmed that FoxO1 deficiency alleviated high-glucose-induced autophagy and improved biological functions of primary osteoblasts. Together, our results suggest that the PI3K/Akt/FoxO1 signaling pathway is involved in the osteoprotective effect of 1,25D by attenuating autophagy in diabetes, providing a novel insight for the prevention and treatment of diabetes-caused bone loss.

Role and Risk Factors of Glycosylated Hemoglobin Levels in Early Disease Screening

OBJECTIVE

To clarify the correlation among glycosylated hemoglobin (HbA1c), gender, age, fatty liver, and biochemical indicators through the analysis of big database, and to further investigate the risk factors affecting HbA1c, so as to lay a foundation for the study of HbA1c-related diseases and disease management.

METHODS

People who have been examined in Health Promotion Center from July 2018 to June 2019 were selected as the research objects. All data were analyzed using the Windows R software (version 3.5.1). Detailed medical history inquiry, laboratory examination, and B-ultrasound examination were carried out for the selected sample population. We determined the sample population according to the inclusion and exclusion criteria and, then, further grouped and analyzed the data. T-test or Mann-Whitney U test was used for continuous variable comparison, and chi-square test was used to compare categorical variables. Logistic regression analysis was used to analyze the risk factors of HbA1c.

RESULTS

A total of 23,933 subjects were included in this study. The HbA1c level of men was significantly higher than that of women, the HbA1c level of the group with diabetes was higher than that of the group with no diabetes, and the HbA1c level of the group with fatty liver was higher than that of the group with no fatty liver. In the group with no diabetes, the HbA1c level increased with weight gain. Age, gender (male), fatty liver, waist circumference, systolic blood pressure (SBP), triglyceride (TG), blood urea nitrogen (BUN), free thyroxine (FT4), and red blood cell (RBC) were the risk factors for elevated HbA1c level, while high-density lipoprotein cholesterol (HDL-C), uric acid (UA), creatinine (Cr), free triiodothyronine (FT3), and hemoglobin were protective factors.

CONCLUSION

Blood glucose, age, weight, gender, fatty liver, blood lipids, and UA are related to the increase of HbA1c level. HbA1c is related to many metabolic indexes and may be used as a marker for early detection of chronic diseases.

RPS4Y1 Promotes High Glucose-Induced Endothelial Cell Apoptosis and Inflammation by Activation of the p38 MAPK Signaling

AIM

Endothelial dysfunction is a key pathological basis for diabetes mellitus complications, including diabetic nephropathy, diabetic retinopathy, and diabetic cardiomyopathy. This study aimed to reveal the functional role of ribosomal protein S4 Y-linked 1 (RPS4Y1) in endothelial dysfunction.

METHODS

Human umbilical vein endothelial cells (HUVECs) were subjected to high glucose. The expression of RPS4Y1 in cells was overexpressed or silenced by plasmid or siRNA transfection. MTT assay, flow cytometry, JC-1 probe, scratch test, tube formation, and ELISA were conducted to assess the effects of RPS4Y1 on cell. Western blot was performed to assay the downstream signaling of RPS4Y1. The inhibitors of p38, ERK, and Jnk were used to treat cells to validate the involvement of them in RPS4Y1-mediated endothelial dysfunction.

RESULTS

RPS4Y1 was upregulated in HUVECs in response to high glucose in both dose- and time-dependent manners. Overexpression of RPS4Y1 induced viability loss, apoptosis, and inflammation, but inhibited cell migration and tube formation. Silence of RPS4Y1 impacted these aspects in a contrary trend. The phosphorylation of p38 rather than ERK and Jnk was activated by RPS4Y1. In addition, the dysfunction of HUVECs mediated by RPS4Y1 was attenuated by SB203580 (a specific inhibitor of p38 signaling).

CONCLUSION

The highly expressed RPS4Y1 in endothelial cells may contribute to high glucose-induced dysfunction through regulating p38 MAPK signaling. RPS4Y1 might be a potential therapeutic target for treating diabetes mellitus complications.

Mitochondrial dysfunction and pancreatic islet β-cell failure (Review)

Pancreatic β-cells are the only source of insulin in humans. Mitochondria uses pyruvate to produce ATP as an intermediate link between glucose intake and insulin secretion in β-cells, in a process known as glucose-stimulated insulin secretion (GSIS). Previous studies have demonstrated that GSIS is negatively regulated by various factors in the mitochondria, including tRNA^Leu mutations, high p58 expression, reduced nicotinamide nucleotide transhydrogenase activity, abnormal levels of uncoupling proteins and reduced expression levels of transcription factors A, B1 and B2. Additionally, oxidative stress damages mitochondria and impairs antioxidant defense mechanisms, leading to the increased production of reactive oxygen species, which induces β-cell dysfunction. Inflammation in islets can also damage β-cell physiology. Inflammatory cytokines trigger the release of cytochrome c from the mitochondria via the NF-κB pathway. The present review examined the potential factors underlying mitochondrial dysfunction and their association with islet β-cell failure, which may offer novel insights regarding future strategies for the preservation of mitochondrial function and enhancement of antioxidant activity for individuals with diabetes mellitus.

miR-122 promotes diabetic retinopathy through targeting TIMP3

Diabetic retinopathy (DR) is a primary complication of diabetes mellitus. DR can cause severe vision loss for patients. miR-122 is elevated in DR patients, while its role in DR is unclear. Hence, the purpose of this study was to analyze the effect of miR-122 on the function of high glucose-induced REC cells and the underlying molecular mechanisms. In this study, our results revealed that miR-122 was up-regulated in high glucose-induced human retinal pigment epithelial cells (ARPE-19). High glucose decreased the cell viability of ARPE-19 cells, which was then restored by miR-122 knockdown. In addition, miR-122 knockdown suppressed apoptosis of high glucose-induced ARPE-19 cells. High glucose also inhibited B-cell lymphoma-2 (Bcl-2) level and increased cleaved caspase-3 level in ARPE-19 cells, which were reversed by miR-122 knockdown. Tissue inhibitor of metalloproteinases-3 (TIMP3) was a direct target of miR-122. TIMP3 was decreased in high glucose-induced ARPE-19 cells, and the decrease was abrogated by miR-122 knockdown. In addition, the effects of miR-122 overexpression in cell viability and apoptosis of high glucose-induced ARPE-19 were abolished by overexpression of TIMP3. In conclusion, the effect and mechanism of miR-122 on high glucose-induced ARPE-19 cells were demonstrated for the first time. miR-122 promoted diabetic retinopathy through targeting TIMP3, making miR-122 a promising target for diabetic retinopathy therapy.