The pathobiology of diabetic complications: a unifying mechanism

New Insights on Dietary Polyphenols for the Management of Oxidative Stress and Neuroinflammation in Diabetic Retinopathy

Diabetic retinopathy (DR) is a neurodegenerative and vascular pathology that is considered one of the leading causes of blindness worldwide, resulting from complications of advanced diabetes mellitus (DM). Current therapies consist of protocols aiming to alleviate the existing clinical signs associated with microvascular alterations limited to the advanced disease stages. In response to the low resolution and limitations of the DR treatment, there is an urgent need to develop more effective alternative therapies to optimize glycemic, vascular, and neuronal parameters, including the reduction in the cellular damage promoted by inflammation and oxidative stress. Recent evidence has shown that dietary polyphenols reduce oxidative and inflammatory parameters of various diseases by modulating multiple cell signaling pathways and gene expression, contributing to the improvement of several chronic diseases, including metabolic and neurodegenerative diseases. However, despite the growing evidence for the bioactivities of phenolic compounds, there is still a lack of data, especially from human studies, on the therapeutic potential of these substances. This review aims to comprehensively describe and clarify the effects of dietary phenolic compounds on the pathophysiological mechanisms involved in DR, especially those of oxidative and inflammatory nature, through evidence from experimental studies. Finally, the review highlights the potential of dietary phenolic compounds as a prophylactic and therapeutic strategy and the need for further clinical studies approaching the efficacy of these substances in DR management.

Association between Severity of Diabetic Retinopathy and Cardiac Function in Patients with Type 2 Diabetes

Background

The purpose of this research was to assess the relationship between the severity of diabetic retinopathy (DR) and indexes of left ventricle (LV) structure and function in type 2 diabetes mellitus (T2DM).

Methods

Retrospective analysis of 790 patients with T2DM and preserved LV ejection fraction. Retinopathy stages were classified as no DR, early nonproliferative DR, moderate to severe nonproliferative DR, or proliferative DR. The electrocardiogram was used to assess myocardial conduction function. Echocardiography was used to evaluate myocardial structure and function.

Results

Patients were divided into three groups based on the DR status: no DR group (NDR, n = 475), nonproliferative DR group (NPDR, n = 247), and proliferative DR group (PDR, n = 68). LV interventricular septal thickness (IVST) increased significantly with more severe retinopathy (NDR: 10.00 ± 1.09; NPDR: 10.42 ± 1.21; and PDR: 10.66 ± 1.58; P < 0.001). Multivariate logistic regression analysis showed that the significant correlation of IVST persisted between subjects with no retinopathy and proliferative DR (odds ratio = 1.35, P = 0.026). Indices of myocardial conduction function were assessed by electrocardiogram differences among groups of retinopathy (all P < 0.001). In multiple-adjusted linear regression analyses, the increasing degree of retinopathy was closely correlated with heart rate (β = 1.593, P = 0.027), PR interval (β = 4.666, P = 0.001), and QTc interval (β = 8.807, P = 0.005).

Conclusion

The proliferative DR was independently associated with worse cardiac structure and function by echocardiography. Furthermore, the severity of retinopathy significantly correlated with abnormalities of the electrocardiogram in patients with T2DM.

MicroRNA 9 Is a Regulator of Endothelial to Mesenchymal Transition in Diabetic Retinopathy

Purpose

Diabetic retinopathy (DR) is a significant cause of blindness. Most research around DR focus on late-stage developments rather than early changes such as early endothelial dysfunction. Endothelial-to-mesenchymal transition (EndMT), an epigenetically regulated process whereby endothelial cells lose endothelial characteristics and adopt mesenchymal-like phenotypes, contributes to early endothelial changes in DR. The epigenetic regulator microRNA 9 (miR-9) is suppressed in the eyes during DR. MiR-9 plays a role in various diseases and regulates EndMT-related processes in other organs. We investigated the role miR-9 plays in glucose-induced EndMT in DR.

Methods

We examined the effects of glucose on miR-9 and EndMT using human retinal endothelial cells (HRECs). We then used HRECs and an endothelial-specific miR-9 transgenic mouse line to investigate the effect of miR-9 on glucose-induced EndMT. Finally, we used HRECs to probe the mechanisms through which miR-9 may regulate EndMT.

Results

We found that miR-9 inhibition was both necessary and sufficient for glucose-induced EndMT. Overexpression of miR-9 prevented glucose-induced EndMT, whereas suppressing miR-9 caused glucose-like EndMT changes. We also found that preventing EndMT with miR-9 overexpression improved retinal vascular leakage in DR. Finally, we showed that miR-9 regulates EndMT at an early stage by regulating EndMT-inducing signals such as proinflammatory and TGF-β pathways.

Conclusions

We have shown that miR-9 is an important regulator of EndMT in DR, potentially making it a good target for RNA-based therapy in early DR.

Research progress on the mechanism of ferroptosis and its role in diabetic retinopathy

Ferroptosis is iron-dependent regulatory cell death (RCD). Morphologically, ferroptosis is manifested as mitochondrial atrophy and increased mitochondrial membrane density. Biochemically, ferroptosis is characterized by the depletion of glutathione (GSH), the inactivation of glutathione peroxidase 4 (GPX4), and an increase in lipid peroxides (LPO)and divalent iron ions. Ferroptosis is associated with various diseases, but the relationship with diabetic retinopathy(DR) is less studied. DR is one of the complications of diabetes mellitus and has a severe impact on visual function. The pathology of DR is complex, and the current treatment is unsatisfactory. Therefore, exploring pathogenesis is helpful for the clinical treatment of DR. This paper reviews the pathological mechanism of ferroptosis and DR in recent years and the involvement of ferroptosis in the pathology of DR. In addition, we propose problems that need to be addressed in this research field. It is expected to provide new ideas for treating DR by analyzing the role of ferroptosis in DR.

Mitochondrial Oxidative Metabolism: An Emerging Therapeutic Target to Improve CKD Outcomes

Chronic kidney disease (CKD) predisposes one toward end-stage renal disease (ESRD) and its associated morbidity and mortality. Significant metabolic perturbations in conjunction with alterations in redox status during CKD may induce increased production of reactive oxygen species (ROS), including superoxide (O₂^●-) and hydrogen peroxide (H₂O₂). Increased O₂^●- and H₂O₂ may contribute to the overall progression of renal injury as well as catalyze the onset of comorbidities. In this review, we discuss the role of mitochondrial oxidative metabolism in the pathology of CKD and the recent developments in treating CKD progression specifically targeted to the mitochondria. Recently published results from a Phase 2b clinical trial by our group as well as recently released data from a ROMAN: Phase 3 trial (NCT03689712) suggest avasopasem manganese (AVA) may protect kidneys from cisplatin-induced CKD. Several antioxidants are under investigation to protect normal tissues from cancer-therapy-associated injury. Although many of these antioxidants demonstrate efficacy in pre-clinical models, clinically relevant novel compounds that reduce the severity of AKI and delay the progression to CKD are needed to reduce the burden of kidney disease. In this review, we focus on the various metabolic pathways in the kidney, discuss the role of mitochondrial metabolism in kidney disease, and the general involvement of mitochondrial oxidative metabolism in CKD progression. Furthermore, we present up-to-date literature on utilizing targets of mitochondrial metabolism to delay the pathology of CKD in pre-clinical and clinical models. Finally, we discuss the current clinical trials that target the mitochondria that could potentially be instrumental in advancing the clinical exploration and prevention of CKD.

The "sweet" path to cancer: focus on cellular glucose metabolism

The hypoxia-inducible factor-1α (HIF-1α), a key player in the adaptive regulation of energy metabolism, and the M2 isoform of the glycolytic enzyme pyruvate kinase (PKM2), a critical regulator of glucose consumption, are the main drivers of the metabolic rewiring in cancer cells. The use of glycolysis rather than oxidative phosphorylation, even in the presence of oxygen (i.e., Warburg effect or aerobic glycolysis), is a major metabolic hallmark of cancer. Aerobic glycolysis is also important for the immune system, which is involved in both metabolic disorders development and tumorigenesis. More recently, metabolic changes resembling the Warburg effect have been described in diabetes mellitus (DM). Scientists from different disciplines are looking for ways to interfere with these cellular metabolic rearrangements and reverse the pathological processes underlying their disease of interest. As cancer is overtaking cardiovascular disease as the leading cause of excess death in DM, and biological links between DM and cancer are incompletely understood, cellular glucose metabolism may be a promising field to explore in search of connections between cardiometabolic and cancer diseases. In this mini-review, we present the state-of-the-art on the role of the Warburg effect, HIF-1α, and PKM2 in cancer, inflammation, and DM to encourage multidisciplinary research to advance fundamental understanding in biology and pathways implicated in the link between DM and cancer.

Retinal Microvascular Changes after Intravitreal Triamcinolone Acetonide in Diabetic Macular Edema

Intravitreal injection of triamcinolone acetonide (TA) is essential for clinical treatment in patients who insufficiently respond to vascular endothelial factor inhibitors for diabetic macular edema (DME). The aim of this study was to investigate microvascular changes treated with TA using optical coherence tomography angiography (OCTA). After TA in twelve eyes of eleven patients with central retinal thickness (CRT), there was a 20% or more reduction observed. Visual acuity, the number of microaneurysms, vessel density, and the foveal avascular zone (FAZ) area were compared before and at 2 months after TA. At baseline, the number of microaneurysms was 2.1 ± 1.1 in the superficial capillary plexuses (SCP) and 2.0 ± 1.1 in the deep capillary plexuses (DCP), with a significant decrease post-treatment to 1.0 ± 1.0 for SCP and 0.8 ± 0.8 for DCP (SCP; p = 0.018, DCP; p = 0.008). There was significant enlargement of the FAZ area from 0.28 ± 0.11 mm² to 0.32 ± 0.14 mm² (p = 0.041). There was no significant difference in the visual acuity and vessel density of SCP and DCP. Results indicated that OCTA was useful for the evaluation of qualitative and morphological retinal microcirculation and that intravitreal TA may decrease microaneurysms.

Effects of Two- and Twelve-Weeks Sodium-Glucose Cotransporter 2 Inhibition on DNA and RNA Oxidation: Two Randomized, Placebo-Controlled Trials

Animal studies have shown that SGLT2 inhibition decreases oxidative stress, which may explain the cardiovascular protective effects observed following SGLT2 inhibition treatment. Thus, we investigated the effects of two and twelve weeks SGLT2 inhibition on DNA and RNA oxidation. Individuals with type 2 diabetes (n = 31) were randomized to two weeks of treatment with the SGLT2 inhibitor empagliflozin treatment (25 mg once daily) or placebo. The primary outcome was changes in DNA and RNA oxidation measured as urinary excretion of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) and 8-oxo-7,8-dihydroguanosine (8-oxoGuo), respectively. In another trial, individuals with type 2 diabetes (n = 35) were randomized to twelve weeks of dapagliflozin treatment (10 mg once daily) or placebo in a crossover study. Changes in urinary excretion of 8-oxodG and 8-oxoGuo were investigated as a post-hoc analysis. Compared with placebo treatment, two weeks of empagliflozin treatment did not change urinary excretion of 8-oxodG (between-group difference: 0.3 nmol/24-hour (95% CI: -4.2 to 4.8)) or 8-oxoGuo (1.3 nmol/24-hour (95% CI: -4.7 to 7.3)). From a mean baseline 8-oxodG/creatinine urinary excretion of 1.34 nmol/mmol, dapagliflozin-treated individuals changed 8-oxodG/creatinine by -0.17 nmol/mmol (95% CI: -0.29 to -0.04) following twelve weeks of treatment, whereas placebo-treated individuals did not change 8-oxodG/creatinine (within-group effect: 0.10 nmol/mmol (95% CI: -0.02 to 0.22)) resulting in a significant between-group difference (P = 0.01). Urinary excretion of 8-oxoGuo was unaffected by dapagliflozin treatment. In conclusion, two weeks of empagliflozin treatment did not change DNA or RNA oxidation. However, a post-hoc analysis revealed that longer term dapagliflozin treatment decreased DNA oxidation. Clinicaltrials.gov: NCT02890745 and NCT02914691.HighlightsPlasma ferritin correlated with DNA and RNA oxidation in individuals with T2DTwelve weeks dapagliflozin treatment decreased DNA oxidationDapagliflozin and empagliflozin treatment did not change RNA oxidationLipid peroxidation was unaffected by two weeks empagliflozin treatment.

Epidermal Growth Factor Receptor in Hepatic Endothelial Cells Suppresses MCP-1-Dependent Monocyte Recruitment in Diabetes

Insulin resistance is a compromised response to insulin in target tissues such as liver. Emerging evidence shows that vascular endothelial cells (ECs) are critical in mediating glucose metabolism. However, how liver ECs can regulate inflammation in the setting of insulin resistance is still unknown. Using genome-wide transcriptome analysis of ECs isolated from diabetic mice, we found enrichment of the genes involved in epidermal growth factor receptor (Egfr) signaling. In line with this, hepatic sinusoidal ECs in diabetic mice had elevated levels of Egfr expression. Interestingly, we found an increased number of hepatic myeloid cells, especially macrophages, and systemic glucose intolerance in Cdh5Cre/+Egfrfl/fl mice lacking Egfr in ECs compared with littermate control mice with type II diabetes. Egfr deficiency upregulated the expression of MCP-1 in hepatic sinusoidal ECs. This resulted in augmented monocyte recruitment and macrophage differentiation in Cdh5Cre/+Egfrfl/fl mice compared with littermate control mice as determined by a mouse model of parabiosis. Finally, MCP-1 neutralization and hepatic macrophage depletion in Cdh5Cre/+Egfrfl/fl mice resulted in a reduced number of hepatic macrophages and ameliorated glucose intolerance compared with the control groups. Collectively, these results demonstrate a protective endothelial Egfr signaling in reducing monocyte-mediated hepatic inflammation and glucose intolerance in type II diabetic mice.

Unraveling the Crosstalk between Lipids and NADPH Oxidases in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a serious complication of diabetes mellitus and a leading cause of end-stage renal disease. Abnormal lipid metabolism and intrarenal accumulation of lipids have been shown to be strongly correlated with the development and progression of diabetic kidney disease (DKD). Cholesterol, phospholipids, triglycerides, fatty acids, and sphingolipids are among the lipids that are altered in DKD, and their renal accumulation has been linked to the pathogenesis of the disease. In addition, NADPH oxidase-induced production of reactive oxygen species (ROS) plays a critical role in the development of DKD. Several types of lipids have been found to be tightly linked to NADPH oxidase-induced ROS production. This review aims to explore the interplay between lipids and NADPH oxidases in order to provide new insights into the pathogenesis of DKD and identify more effective targeted therapies for the disease.

Type 2 Diabetes (T2DM) and Parkinson's Disease (PD): a Mechanistic Approach

Growing evidence suggest that there is a connection between Parkinson's disease (PD) and insulin dysregulation in the brain, whilst the connection between PD and type 2 diabetes mellitus (T2DM) is still up for debate. Insulin is widely recognised to play a crucial role in neuronal survival and brain function; any changes in insulin metabolism and signalling in the central nervous system (CNS) can lead to the development of various brain disorders. There is accumulating evidence linking T2DM to PD and other neurodegenerative diseases. In fact, they have a lot in common patho-physiologically, including insulin dysregulation, oxidative stress resulting in mitochondrial dysfunction, microglial activation, and inflammation. As a result, initial research should focus on the role of insulin and its molecular mechanism in order to develop therapeutic outcomes. In this current review, we will look into the link between T2DM and PD, the function of insulin in the brain, and studies related to impact of insulin in causing T2DM and PD. Further, we have also highlighted the role of various insulin signalling pathway in both T2DM and PD. We have also suggested that T2DM-targeting pharmacological strategies as potential therapeutic approach for individuals with cognitive impairment, and we have demonstrated the effectiveness of T2DM-prescribed drugs through current PD treatment trials. In conclusion, this investigation would fill a research gap in T2DM-associated Parkinson's disease (PD) with a potential therapy option.

Effect of Low Protein Diet Supplemented with Ketoanalogs on Endothelial Function and Protein-Bound Uremic Toxins in Patients with Chronic Kidney Disease

Studies have demonstrated that a low-protein diet supplemented with ketoanalogs (KAs) could significantly retard progression of renal function in patients with chronic kidney disease (CKD) stages 3-5. However, its effects on endothelial function and serum levels of protein-bound uremic toxins remain elusive. Therefore, this study explored whether a low-protein diet (LPD) supplemented with KAs affects kidney function, endothelial function, and serum uremic toxin levels in a CKD-based cohort. In this retrospective cohort, we enrolled 22 stable CKD stage 3b-4 patients on LPD (0.6-0.8 g/day). Patients were categorized into control (LPD only) and study groups (LPD + KAs 6 tab/day). Serum biochemistry, total/free indoxyl sulfate (TIS/FIS), total/free p-cresyl sulfate (TPCS/FPCS), and flow-mediated dilation (FMD) were measured before and after 6 months of KA supplementation. Before the trial, there were no significant differences in kidney function, FMD, or uremic toxin levels between the control and study groups. When compared with the control group, the paired t-test showed a significant decrease in TIS and FIS (all p < 0.05) and a significant increase in FMD, eGFR, and bicarbonate (all p < 0.05). In multivariate regression analysis, an increase in FMD (p < 0.001) and a decrease in FPCS (p = 0.012) and TIS (p < 0.001) remained persistent findings when adjusted for age, systolic blood pressure (SBP), sodium, albumin, and diastolic blood pressure (DBP). LPD supplemented with KAs significantly preserves kidney function and provides additional benefits on endothelial function and protein-bound uremic toxins in patients with CKD.

The mechanisms of NLRP3 inflammasome/pyroptosis activation and their role in diabetic retinopathy

In the working-age population worldwide, diabetic retinopathy (DR), a prevalent complication of diabetes, is the main cause of vision impairment. Chronic low-grade inflammation plays an essential role in DR development. Recently, concerning the pathogenesis of DR, the Nod-Like Receptor Family Pyrin Domain Containing 3 (NLRP3) inflammasome in retinal cells has been determined as a causal factor. In the diabetic eye, the NLRP3 inflammasome is activated by several pathways (such as ROS and ATP). The activation of NPRP3 leads to the secretion of inflammatory cytokines interleukin-1β (IL-1β) and interleukin-18 (IL-18), and leads to pyroptosis, a rapid inflammatory form of lytic programmed cell death (PCD). Cells that undergo pyroptosis swell and rapture, releasing more inflammatory factors and accelerating DR progression. This review focuses on the mechanisms that activate NLRP3 inflammasome and pyroptosis leading to DR. The present research highlighted some inhibitors of NLRP3/pyroptosis pathways and novel therapeutic measures concerning DR treatment.

Targeting the NLRP3 inflammasome in diabetic retinopathy: From Pathogenesis to Therapeutic Strategies

Diabetic retinopathy (DR) is a common diabetic microvascular complication and the main cause of vision loss in working-aged people. The NLRP3 inflammasome is a cytosolic multimeric complex that plays a significant role in innate immunity. After sensing injury, the NLRP3 inflammasome induces inflammatory mediator secretion and triggers a form of inflammatory cell death known as pyroptosis. Studies over the past five years have shown increased expression of NLRP3 and related inflammatory mediators in vitreous samples from DR patients at different clinical stages. Many NLRP3-targeted inhibitors have shown great antiangiogenic and anti-inflammatory effects in diabetes mellitus models, suggesting that the NLRP3 inflammasome is involved in the progression of DR. This review covers the molecular mechanisms of NLRP3 inflammasome activation. Furthermore, we discuss the implications of the NLRP3 inflammasome in DR, including the induction of pyroptosis and inflammation and the promotion of microangiopathy and retinal neurodegeneration. We also summarize the research progress on targeting the NLRP3 inflammasome in DR therapeutics with the expectation of providing new insights into DR progression and treatment.

Randomized, double-blind, placebo-controlled crossover trial of once daily empagliflozin 25 mg for the treatment of postprandial hypoglycaemia after Roux-en-Y gastric bypass

Aims To investigate the effect of empagliflozin on glucose dynamics in individuals suffering from postbariatric hypoglycaemia (PBH) after Roux-en-Y gastric bypass (RYGB). Methods Twenty-two adults with PBH after RYGB were randomized to empagliflozin 25 mg or placebo once daily over 20 days in a randomized, double-blind, placebo-controlled, crossover trial. The primary efficacy outcome was the amplitude of plasma glucose excursion (peak to nadir) during a mixed meal tolerance test (MMTT). Outcomes of the outpatient period were assessed using continuous glucose monitoring (CGM) and an event-tracking app. Results The amplitude of glucose excursion during the MMTT was 8.1±2.4 mmol/L with empagliflozin vs 8.1±2.6 mmol/L with placebo (mean±SD, p=0.807). CGM-based mean amplitude of glucose excursion (MAGE) during the 20 day-period was lower with empagliflozin than placebo (4.8±1.3 vs 5.2±1.6. p=0.028). Empagliflozin reduced the time spent with CGM values >10.0 mmol/L (3.8±3.5 % vs. 4.7±3.8 %, p =0.009), but not the time spent with CGM values <3.0 mmol/L (1.7±1.6 % vs. 1.5±1.5 %, p=0.457). No significant difference was observed in the quantity and quality of recorded symptoms. Eleven adverse events occurred with empagliflozin (three drug-related) and six with placebo. Conclusions Empagliflozin 25 mg reduces glucose excursions but not hypoglycaemia in individuals with PBH.

Cassiae Semen: A comprehensive review of botany, traditional use, phytochemistry, pharmacology, toxicity, and quality control

ETHNOPHARMACOLOGICAL RELEVANCE

Cassiae Semen, belonging to the family Leguminosae, is derived from the dry mature seeds of Cassia obtusifolia L. or Cassia tora L. and has long been used as a laxative, hepatoprotective, improve eyesight, and antidiabetic complications medicine or functional food in Asia.

AIMS OF THE REVIEW

This review summarizes the integrated research progress of botany, traditional uses, phytochemistry, pharmacology, toxicity, and quality control of Cassiae Semen. Additionally, the emerging challenges and possible developing directions are discussed as well.

MATERIALS AND METHODS

The information on Cassiae Semen was collected from published scientific materials, including ancient books of traditional Chinese Medicine; Ph.D. and M. Sc. dissertations; monographs on medicinal plants; pharmacopoeia of various countries and electronic databases, such as PubMed, Web of Science, ACS, Science Direct, J-STAGE, Springer link, Taylor, CNKI and Google Scholar, etc. RESULTS: First, the traditional uses and plant origins of Cassiae Semen are outlined. Secondly, approximately 137 compounds, including anthraquinones, naphthopyranones, naphthalenes, flavones, polysaccharides and other compounds, have been isolated and identified from Cassia obtusifolia L. and Cassia tora L. Third, the pharmacological activities and mechanisms of crude extract of Cassiae Semen and its main bioactive compounds are summarized. Moreover, the processing, toxicity, and quality control are introduced briefly.

CONCLUSIONS

Cassiae Semen is a frequently used Chinese Materia Medica with pharmacological effects that mainly affect the digestive system, cardiovascular systems and nervous system. This review summarized its botany, traditional uses, phytochemistry, and pharmacology, it also exhibited recent scientific research advances and gaps, which provide a deeper insight into the understanding and application of Cassiae Semen. In future research on Cassiae Semen, more attention should be given to the pharmacological activities of naphthopyranones and polysaccharides and the mechanism of action for improving eye diseases. Meanwhile, it is essential to focus on strengthening the study on the pharmacokinetics research and the safety evaluation of related health products research.

Substance P Alleviates Retinal Pigment Epithelium Dysfunction Caused by High Glucose-Induced Stress

When the retina is constantly affected by high glucose (HG) due to diabetes, the barrier function of the retinal pigment epithelium (RPE) is impaired, accompanied by unnecessary vascularization. This eventually leads to the development of diabetic retinopathy (DR). This study investigated the recovery effect of substance P (SP) on RPE injured by HG. RPE was treated with HG for 24 h, and HG-induced cellular injuries were confirmed. SP was added to the dysfunctional RPE. Compared to RPE in low glucose (LG) conditions, HG-damaged RPE had large, fibrotic cell shapes, and its cellular viability decreased. HG treatment reduced tight junction protein expression levels and caused oxidative stress by interrupting the antioxidant system; this was followed by inflammatory factor intracellular adhesion molecule-1 (ICAM-1), Monocyte chemotactic protein-1 (MCP-1), and angiogenesis factor vascular endothelial growth factor (VEGF) expression. SP treatment contributed to RPE recovery by enhancing cell viability, tight junction protein expression, and RPE function under HG conditions, possibly by activating the Akt signaling pathway. Importantly, SP treatment reduced ICAM-1, MCP-1, and VEGF expression. Collectively, SP activated survival signals to suppress oxidative stress and improve retinal barrier function in RPE, accompanied by immune suppression. This suggests the possible application of SP to diabetic retinal injuries.

Preliminary study of the interactive effects of coronary heart disease and lacunar infarction on renal function in patients with type 2 diabetes mellitus by gender

BACKGROUND

Coronary heart disease (CHD) and lacunar infarction (LI) are the most common cardio- cerebrovascular complications of type 2 diabetes mellitus (T2DM) and a recognized risk factor for renal injury. Although a unidirectional association of CHD or LI with T2DM or the kidney has been demonstrated, however, it remains unknown whether there is an interactive effect of the coexistence of CHD and LI on renal function in T2DM patients. The aim of our study was to investigate the interaction between CHD and LI on renal function in gender-specific patients with T2DM and the association between cardio-cerebrovascular disease-related conventional serum markers and the estimated glomerular filtration rate (eGFR).

METHODS

We conducted a cross-sectional study in Beijing and Tianjin from April 2019 to August 2021. Participants with T2DM aged ≥18 years were asked to complete a one-to-one questionnaire and physical examination.

RESULTS

In this study, 389 eligible patients with T2DM were included, with a mean age of 63.04 ± 9.41 years, of whom 200 (51.41 %) were male. The proportions of patients with CHD, LI, and both CHD and LI were 28.53 %, 24.42 %, and 11.05 %, respectively. Compared to T2DM patients without either CHD or LI, those with both CHD and LI were found to have a significantly greater risk of reduced eGFR (OR: 12.82, 95 % CI 5.06-32.52, P < 0.001) than those with CHD alone (OR: 2.42, 95 % CI 1.37-3.00, P = 0.004) or LI alone (OR: 1.15, 95 % CI 0.61-2.18, P = 0.664). The combined presence of CHD and LI is associated with a significantly greater risk of decreased eGFR in female T2DM patients compared to their male counterparts. We found both multiplicative and additive effects in all T2DM patients; however, when stratified by sex, only multiplicative effects were observed. After controlling for interference from CHD, LI, and age, we found that total cholesterol (TC) was negatively correlated with eGFR in females (r = -0.156, P = 0.034), and low-density lipoprotein cholesterol (LDL-C) was negatively correlated with eGFR in males (r = -0.229, P = 0.001).

CONCLUSION

This study provides novel evidence that the synergistic effect of CHD and LI on renal injury in patients with T2DM is significantly greater than their individual effects. Women with T2DM who have both CHD and LI are at a 4.85-fold higher risk of decreased eGFR than men. Therefore, increased clinical attention should be given to preventing and treating vascular complications in T2DM patients, as well as aggressively reducing lipid levels, particularly TC and LDL-C, to delay or prevent renal dysfunction in T2DM patients.

Moringa oleifera impedes protein glycation and exerts reno-protective effects in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Moringa oleifera is a valued plant with wide distribution in tropical and subtropical regions of the world. It is traditionally used for the treatment of fever, infections, rheumatism, cancer, improving cardiac, renal and hepatic functions, and regulating blood glucose level. The plant has been scientifically reported for the anti-inflammatory, antioxidant, renoprotective, and anti-diabetic properties. Diabetic patients are prone to develop end-stage renal diseases due to incidence of diabetes-induced renal dysfunctions. Given that, increased production and accumulation of advanced glycation end-products (AGEs) play a conspicuous role in the development of diabetes-linked renal dysfunctions, nature-based interventions with AGEs inhibitory activity can prevent renal dysfunctions leading to renoprotection.

AIM OF THE STUDY

The study aimed to demonstrate the preventive effects of the ethanolic extract of the leaves of Moringa oleifera (EEMO) on protein glycation and its further assessment for the renoprotective effect in diabetic rats.

MATERIALS AND METHODS

Antiglycation activity of EEMO was assessed in vitro using bovine serum albumin. For reno-protective activity assessment, streptozotocin (STZ)-induced diabetic rats were orally treated with EEMO (100 mg/kg) or standard antiglycation agent aminoguanidine (100 mg/kg) for consecutive 8 weeks. The effects on glucose homeostasis, renal functions, and renal morphology were assessed by clinical biochemistry, molecular and histological examination.

RESULTS

Presence of EEMO efficiently prevented glucose-, fructose- or methylglyoxal-mediated glycation of protein. Under in vivo set-up, compared to diabetic control rats, EEMO treatment effectively improved the glucose tolerance and body weight, and reduced the serum levels of triglycerides and total cholesterol. Additionally, EEMO administration significantly ameliorated renal dysfunctions in diabetic rats characterized by improved levels of creatinine, urea nitrogen, and uric acid in serum, and total protein level in urine, accompanied by improved kidney morphology. The diabetes-associated pro-inflammatory response characterized by upregulated expression of the inducible nitric oxide synthase (iNos), activation of nuclear factor kappa B (NF-κB) and the raised levels of inflammatory factors, interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) in renal tissue was significantly attenuated in EEMO-treated rats. Moreover, EEMO treatment diminished renal reactive oxygen species (ROS) levels in diabetic animals.

CONCLUSIONS

Our study demonstrated that EEMO prevented AGEs formation and ameliorated renal dysfunctions in diabetic rats by blocking inflammatory/oxidative pathways. Our observations justify M. oleifera as a potential source of therapeutic interventions for diabetic nephropathy management.

AGEs-RAGE-KCa3.1 pathway mediates palmitic acid-induced migration of PBMCs from patients with type 2 diabetes

Type 2 diabetes mellitus (T2DM) is characterized by chronic low-grade systemic inflammation. Tissue infiltration by monocyte migration contributes to the pathogenesis of vascular complications in T2DM. We studied the role of intermediate-conductance Ca²⁺-activated K⁺ (K_Ca3.1) channels in the palmitic acid (PA)-induced migration of peripheral blood mononuclear cells (PBMCs) from T2DM patients and the influence of advanced glycation endproducts (AGEs). A total of 49 T2DM patients and 33 healthy subjects was recruited into this study. Using flow cytometry and Western blotting analysis as well as cell migration assay, we found that there was a significant decrease in frequency of T lymphocytes and monocytes in CD45⁺ leukocyte population. PA at 100 μM stimulated migration of PBMCs from T2DM individuals, which was inhibited by the specific K_Ca3.1 channel blocker TRAM-34 (1 μM). The PBMC migration was positively correlated with glycosylated hemoglobin A1 chain (HbA1c) level of T2DM patients, an indicator of AGEs, and PBMCs with higher level of HbA1c showed upregulated expression of toll-like receptor (TLR) 2/4 and K_Ca3.1 channels. In THP-1 cells, AGEs at 200 μg/ml increased protein expression of TLR 2/4 and K_Ca3.1 channels, and were synergistically involved in PA-induced migration through receptors of AGEs (RAGE)-mediated K_Ca3.1 upregulation. In conclusion, in PBMCs of T2DM patients, AGEs promotes PA-induced migration via upregulation of TLR2/4 and K_Ca3.1 channels.

Relationship of Glycated Hemoglobin A1c with All-Cause and Cardiovascular Mortality among Patients with Hypertension

Both low and high glycated hemoglobin A1c (HbA1c) levels are well-established causal risk factors for all-cause and cardiovascular mortality in the general population and diabetic patients. However, the relationship between HbA1c with all-cause and cardiovascular mortality among patients with hypertension is unclear. We used NHANES data from 1999 to 2014 as the basis for this population-based cohort study. Based on HbA1c levels (HbA1c > 5, HbA1c > 5.5, HbA1c > 6, HbA1c > 6.5, HbA1c > 7%), hypertensive patients were divided into five groups. An analysis of multivariable Cox proportional hazards was conducted based on hazard ratios (HRs) and respective 95% confidence intervals (CIs). The relationship between HbA1c and mortality was further explored using Kaplan–Meier survival curves, restricted cubic spline curves, and subgroup analyses. In addition, 13,508 patients with hypertension (average age 58.55 ± 15.56 years) were included in the present analysis, with 3760 (27.84%) all-cause deaths during a follow-up of 127.69 ± 57.9 months. A U-shaped relationship was found between HbA1c and all-cause and cardiovascular mortality (all p for likelihood ratio tests were 0.0001). The threshold value of HbA1c related to the lowest risk for all-cause and cardiovascular mortality was 5.3% and 5.7%, respectively. Below the threshold value, increased HbA1c levels reduced the risk of all-cause mortality (HR 0.68, 95% CI 0.51–0.90, p = 0.0078) and cardiovascular mortality (HR 0.77, 95% CI 0.57–1.05, p = 0.0969). Inversely, above the threshold value, increased HbA1c levels accelerated the risk of all-cause mortality (HR 1.14, 95% CI 1.11–1.18, p < 0.0001) and cardiovascular mortality (HR 1.22, 95% CI 1.16–1.29, p < 0.0001). In conclusion, A U-shape relationship was observed between HbA1c and all-cause and cardiovascular mortality among hypertensive patients.

The association between fasting plasma glucose variability and incident eGFR decline: evidence from two cohort studies

BACKGROUND

Glycemic variability (GV) is developing as a marker of glycemic control, which can be utilized as a promising predictor of complications. To determine whether long-term GV is associated with incident eGFR decline in two cohorts of Tehran Lipid and Glucose Study (TLGS) and Multi-Ethnic Study of Atherosclerosis (MESA) during a median follow-up of 12.2 years.

METHODS

Study participants included 4422 Iranian adults (including 528 patients with T2D) aged ≥ 20 years from TLGS and 4290 American adults (including 521 patients with T2D) aged ≥ 45 years from MESA. The Multivariate Cox proportional hazard models were used to assess the risk of incident eGFR decline for each of the fasting plasma glucose (FPG) variability measures including standard deviation (SD), coefficient of variation (CV), average real variability (ARV), and variability independent of the mean (VIM) both as continuous and categorical variables. The time of start for eGFR decline and FPG variability assessment was the same, but the event cases were excluded during the exposure period.

RESULTS

In TLGS participants without T2D, for each unit change in FPG variability measures, the hazards (HRs) and 95% confidence intervals (CI) for eGFR decline ≥ 40% of SD, CV, and VIM were 1.07(1.01-1.13), 1.06(1.01-1.11), and 1.07(1.01-1.13), respectively. Moreover, the third tertile of FPG-SD and FPG-VIM parameters was significantly associated with a 60 and 69% higher risk for eGFR decline ≥ 40%, respectively. In MESA participants with T2D, each unit change in FPG variability measures was significantly associated with a higher risk for eGFR decline ≥ 40%.Regarding eGFR decline ≥ 30% as the outcome, in the TLGS, regardless of diabetes status, no association was shown between FPG variability measures and risk of eGFR decline in any of the models; however, in the MESA the results were in line with those of GFR decline ≥ 40%.Using pooled data from the two cohorts we found that generally FPG variability were associated with higher risk of eGFR decline ≥ 40% only among non-T2D individuals.

CONCLUSIONS

Higher FPG variability was associated with an increased risk of eGFR decline in the diabetic American population; however, this unfavorable impact was found only among the non-diabetic Iranian population.

BaoShenTongLuo formula protects against podocyte injury by regulating AMPK-mediated mitochondrial biogenesis in diabetic kidney disease

BACKGROUND

Mitochondrial dysfunction is considered to be an important contributor in podocyte injury under diabetic conditions. The BaoShenTongLuo (BSTL) formula has been shown to reduce podocyte damage and postpone the progression of diabetic kidney disease (DKD). The potential mechanisms underlying the effects of BSTL, however, have yet to be elucidated. In this study, we aimed to investigate whether the effects of BSTL are related to the regulation of mitochondrial biogenesis via the adenosine monophosphate-activated protein kinase (AMPK) pathway.

METHODS

High-Performance Liquid Chromatography Electrospray Ionization Mass Spectrometer (HPLC-ESI-MS) analysis was performed to investigate the characteristics of pure compounds in BSTL. db/db mice and mouse podocyte clone-5 (MPC5) cells were exposed to high glucose (HG) to induce DKD and podocyte damage. Body weight, random blood glucose, urinary albumin/creatinine ratio (UACR), indicators of renal function and renal histological lesions were measured. Markers of podocyte injury, mitochondrial morphology, mitochondrial deoxyribonucleic acid (mtDNA) content, mitochondrial respiratory chain complexes activities, reactive oxygen species (ROS) production, and mitochondrial membrane potential (MMP) levels were assessed. Protein expressions of AMPK, peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α), transcription factor A (TFAM), mitochondrial fusion protein 2 (MFN2) and dynamin-related protein 1 (DRP1) were also detected. MPC5 cells were transfected with AMPKα small interfering RNA (AMPKα siRNA) to determine the underlying mechanisms of BSTL improvement of mitochondrial function under diabetic conditions.

RESULTS

In vivo, treatment with BSTL reduced the UACR levels, reversed the histopathological changes in renal tissues, and alleviated the podocyte injury observed in db/db mice. After BSTL treatment, the decreased mtDNA content and mitochondrial respiratory chain complex I, III, and IV activities were significantly improved, and these effects were accompanied by maintenance of the protein expression of p-AMPKαT172, PGC-1α, TFAM and MFN2. The in vitro experiments also showed that BSTL reduced podocyte apoptosis, suppressed excessive cellular ROS production, and reversed the decreased in MMP that were observed under HG conditions. More importantly, the effects of BSTL in enhancing mitochondrial biogenesis and reducing podocyte apoptosis were inhibited in AMPKα siRNA-treated podocytes.

CONCLUSION

BSTL plays a crucial role in protecting against podocyte injury by regulating the AMPK-mediated mitochondrial biogenesis in DKD.

Single Nucleotide Polymorphisms of the RAC1 Gene as Novel Susceptibility Markers for Neuropathy and Microvascular Complications in Type 2 Diabetes

Single nucleotide polymorphisms (SNP) in the RAC1 (Rac family small GTPase 1) gene have recently been linked to type 2 diabetes (T2D) and hyperglycemia due to their contribution to impaired redox homeostasis. The present study was designed to determine whether the common SNPs of the RAC1 gene are associated with diabetic complications such as neuropathy (DN), retinopathy (DR), nephropathy, angiopathy of the lower extremities (DA), and diabetic foot syndrome. A total of 1470 DNA samples from T2D patients were genotyped for six common SNPs by the MassArray Analyzer-4 system. The genotype rs7784465-T/C of RAC1 was associated with an increased risk of DR (p = 0.016) and DA (p = 0.03) in males, as well as with DR in females (p = 0.01). Furthermore, the SNP rs836478 showed an association with DR (p = 0.005) and DN (p = 0.025) in males, whereas the SNP rs10238136 was associated with DA in females (p = 0.002). In total, three RAC1 haplotypes showed significant associations (FDR < 0.05) with T2D complications in a sex-specific manner. The study's findings demonstrate, for the first time, that the RAC1 gene's polymorphisms represent novel and sex-specific markers of neuropathy and microvascular complications in type 2 diabetes, and that the gene could be a new target for the pharmacological inhibition of oxidative stress as a means of preventing diabetic complications.

Pune GSH supplementation study: Analyzing longitudinal changes in type 2 diabetic patients using linear mixed-effects models

Oral GSH supplementation along with antidiabetic treatment was shown to restore the body stores of GSH significantly and reduce oxidative DNA damage (8-OHdG) in Indian Type 2 diabetic (T2D) patients over 6 months in our recent clinical study. Post hoc analysis of the data also suggested that elder patients benefit from improved HbA1c and fasting insulin. We modeled longitudinal changes in diabetic individuals using a linear mixed-effects (LME) framework and obtained i) the distribution of individual trajectories with and without GSH supplementation and ii) the overall rates of changes in the different study arms. Serial changes in elder and younger diabetic individuals were also modeled independently to examine differences in their progression. The average linear trajectories obtained from the model explain how biochemical parameters in T2D patients progress over 6 months on GSH supplementation. Model estimates show improvements in erythrocytic GSH of 108 µM per month and a reduction in 8-OHdG at a rate of 18.5 ng/μg DNA per month in T2D patients. GSH replenishes faster in younger people than in the elder. 8-OHdG reduced more rapidly in the elder (24 ng/μg DNA per month) than in younger (12 ng/μg DNA per month) individuals. Interestingly, elder individuals show a substantial reduction in HbA1c (0.1% per month) and increased fasting insulin (0.6 µU/mL per month). Changes in GSH correlate strongly with changes in HbA1c, 8-OHdG, and fasting insulin in the elder cohort. The model estimates strongly suggest it improves the rate of replenishment in erythrocytic GSH stores and reduces oxidative DNA damage. Elder and younger T2D patients respond differently to GSH supplementation: It improves the rate of reduction in HbA1c and increases fasting insulin in elder patients. These model forecasts have clinical implications that aid in personalizing treatment targets for using oral GSH as adjuvant therapy in diabetes.

Overview and New Insights into the Metabolic Syndrome: Risk Factors and Emerging Variables in the Development of Type 2 Diabetes and Cerebrocardiovascular Disease

Metabolic syndrome (MetS) is considered a metabolic disorder that has been steadily increasing globally and seems to parallel the increasing prevalence of obesity. It consists of a cluster of risk factors which traditionally includes obesity and hyperlipidemia, hyperinsulinemia, hypertension, and hyperglycemia. These four core risk factors are associated with insulin resistance (IR) and, importantly, the MetS is known to increase the risk for developing cerebrocardiovascular disease and type 2 diabetes mellitus. The MetS had its early origins in IR and syndrome X. It has undergone numerous name changes, with additional risk factors and variables being added over the years; however, it has remained as the MetS worldwide for the past three decades. This overview continues to add novel insights to the MetS and suggests that leptin resistance with hyperleptinemia, aberrant mitochondrial stress and reactive oxygen species (ROS), impaired folate-mediated one-carbon metabolism with hyperhomocysteinemia, vascular stiffening, microalbuminuria, and visceral adipose tissues extracellular vesicle exosomes be added to the list of associated variables. Notably, the role of a dysfunctional and activated endothelium and deficient nitric oxide bioavailability along with a dysfunctional and attenuated endothelial glycocalyx, vascular inflammation, systemic metainflammation, and the important role of ROS and reactive species interactome are discussed. With new insights and knowledge regarding the MetS comes the possibility of new findings through further research.

Clinical Application of Intravitreal Aflibercept Injection for Diabetic Macular Edema Comparing Two Loading Regimens

Background and Objectives: We investigated and compared the efficacy of three and five monthly loading regimens of an intravitreal aflibercept injection (IVA) in patients with diabetic macular edema (DME). Materials and Methods: This was a retrospective study that included patients diagnosed with DME and treated with an either three or five monthly aflibercept loading regimen from July 2018 to March 2022. Information on clinical characteristics and changes in the central retinal thickness (CRT) were obtained from medical records. Results: In total, 44 eyes of 44 patients with DME treated with IVA were included in this study, with 30 eyes treated with 3-monthly loadings (three-loading group) and 14 eyes with 5-monthly loadings (five-loading group). The mean CRT significantly decreased from the baseline one month after loading in both the three-loading and five-loading groups (p < 0.001). Four cases were refractory to treatment in the three-loading group, while there were no cases of refractory DME in the five-loading group. The stability rate was significantly higher in the five-loading group at three months after loading (p = 0.033). Conclusions: Five-monthly loading regimens of IVA might be favorable for DME considering the rate of refractory cases, stable duration, and the importance of early responsiveness to IVA in DME.

Benefits of Whey Proteins on Type 2 Diabetes Mellitus Parameters and Prevention of Cardiovascular Diseases

Type 2 diabetes mellitus (T2DM) is a major cause of morbidity and mortality, and it is a major risk factor for the early onset of cardiovascular diseases (CVDs). More than genetics, food, physical activity, walkability, and air pollution are lifestyle factors, which have the greatest impact on T2DM. Certain diets have been shown to be associated with lower T2DM and cardiovascular risk. Diminishing added sugar and processed fats and increasing antioxidant-rich vegetable and fruit intake has often been highlighted, as in the Mediterranean diet. However, less is known about the interest of proteins in low-fat dairy and whey in particular, which have great potential to improve T2DM and could be used safely as a part of a multi-target strategy. This review discusses all the biochemical and clinical aspects of the benefits of high-quality whey, which is now considered a functional food, for prevention and improvement of T2DM and CVDs by insulin- and non-insulin-dependent mechanisms.

Transgenic type2 diabetes mouse models for in vivo redox measurement of hepatic mitochondrial oxidative stress

BACKGROUND

Oxidative stress is involved in the progression of diabetes and its associated complications. However, it is unclear whether increased oxidative stress plays a primary role in the onset of diabetes or is a secondary indicator caused by tissue damage. Previous methods of analyzing oxidative stress have involved measuring the changes in oxidative stress biomarkers. Our aim is to identify a novel approach to clarify whether oxidative stress plays a primary role in the onset of diabetes.

METHODS

We constructed transgenic type 2 diabetes mouse models expressing redox-sensitive green fluorescent proteins (roGFPs) that distinguished between mitochondria and whole cells. Pancreas, liver, skeletal muscle, and kidney redox states were measured in vivo.

RESULTS

Hepatic mitochondrial oxidation increased when the mice were 4 weeks old and continued to increase in an age-dependent manner. The increase in hepatic mitochondrial oxidation occurred simultaneously with weight gain and increased blood insulin levels before the blood glucose levels increased. Administering the oxidative stress inducer acetaminophen increased the vulnerability of the liver mitochondria to oxidative stress.

CONCLUSIONS

This study demonstrates that oxidative stress in liver mitochondria in mice begins at the onset of diabetes rather than after the disease has progressed.

GENERAL SIGNIFICANCE

RoGFP-expressing transgenic type 2 diabetes mouse models are effective and convenient tools for measuring hepatic mitochondrial redox statuses in vivo. These models may be used to assess mitochondria-targeting antioxidants and establish the role of oxidative stress in type 2 diabetes.

Influence of fasting plasma glucose-lowering rate on BNP levels in type 2 diabetes mellitus patients with coronary microcirculation dysfunction

AIM

The aim was to analyze the influence of fasting plasma glucose-lowering rate (FPGLR) on plasma BNP levels in type 2 diabetes mellitus (T2DM) patients with coronary microcirculation dysfunction (CMD) and to determine the optimal FPGLR for these patients.

METHODS

A total of 170 T2DM patients who received intensive glucose-lowering therapy during hospitalization in the First Affiliated Hospital of Harbin Medical University were enrolled. Ninety-two patients with CMD and 78 patients without CMD were assigned to a study and a control group, respectively. The study group was stratified as S1 (4.1 ~ 6.0 mmol·L^-1·day^-1), S2 (2.1 ~ 4.0 mmol·L^-1·day^-1), and S3 (≤ 2.0 mmol·L^-1·day^-1) by different FPGLR, and the same in the control group (C1, C2, and C3). The plasma BNP levels with the same FPGLR were compared between the study and the control group, and patients with a different FPGLR in the study group were also compared.

RESULTS

In the study and the control group, the BNP level in S1 was significantly higher than that in C1 (87 vs. 12 pg/ml, P < 0.001), although there was no significant difference between S2 and C2, S3 and C3. In the study group, the BNP level in S1 was significantly higher than that in S2 (87 vs. 22 pg/ml, P < 0.001) and S3 (87 vs. 15 pg/ml, P < 0.001), but there was no significant difference between S2 and S3.

CONCLUSION

Rapid intensive glucose-lowering may lead to increased plasma BNP levels in T2DM patients with CMD. Optimal FPGLR for these patients was determined to be no more than 4.0 mmol·L^-1·day^-1.

Pathophysiology and diagnosis of diabetic retinopathy: a narrative review

Diabetes is an endocrine disorder which is known by abnormal high blood glucose levels. There are two main categories of diabetes: type I (10%-15%) and type II (85%-90%). Although type II is more common, type I is the most common form in children. Diabetic retinopathy (DR), which remains the foremost cause of losing vision in working-age populations, can be considered as the main complication of diabetes mellitus. So choosing the best method for diagnosing, tracking, and treating the DR is vital to enhance the quality of life and decrease the medical expenses. Each method for diagnosing DR has some advantages and the best way must be selected according to the points that we need to find. For writing this manuscript, we made a list of relevant keywords including diabetes, DR, pathophysiology, ultrawide field imaging, fluorescein angiography, optical coherence tomography, and optical coherence tomography-angiography, and then we started searching for studies in PubMed, Scopus, and Web of Science databases. This review article covers the pathophysiology of DR and medical imaging techniques to monitor DR. First, we introduce DR and its pathophysiology and then we present the medical imaging techniques to monitor it.

Diabetic peripheral neuropathy is associated with diabetic kidney disease and cardiovascular disease – The Silesia Diabetes-Heart Project

Microvascular complications of diabetes seem to be clustered and put patients at higher risk of developing cardiovascular disease (CVD). This was a questionnaire-based study designed to screen for the presence of diabetic peripheral neuropathy (DPN), defined as the score in the Michigan Neuropathy Screening Instrument (MNSI) above 2, and to evaluate its association with other complication of diabetes, including CVD. There were 184 patients included into the study. The prevalence of DPN in the study group was 37.5%. The regression model analysis revealed that the presence of DPN was significantly associated with the presence of diabetic kidney disease (DKD) (P = 0.0034;) and patient's age (P < 0.0001). Thirty-four patients (49.3%) with MNSI score >2 were diagnosed with CVD in comparison to 24 (20.1%) subjects with MNSI score ≤ 2 (P = 0.00006). In case of having one diabetes complication diagnosed, it is important to screen for others, including macrovascular ones.

Effect of eugenol on lipid profile, oxidative stress, sex hormone, liver injury, ovarian failure, and expression of COX-2 and PPAR-α genes in a rat model of diabetes

BACKGROUND

Diabetes is among the leading causes of reproductive system failure and infertility in both women and men. Inflammation and oxidative stress have a main role in the development of diabetes. Eugenol or clove oil is a phenolic monoterpenoid with antioxidant and anti-inflammatory properties. Here, the effects of eugenol on diabetes features and ovarian function were investigated.

METHODS AND RESULTS

Streptozotocin-induced diabetes rats were treated with 12 and 24 mg/kg of eugenol for 4 weeks. The biochemical and histological assay was done to evaluate the effects of eugenol on ovary and pancreas function, liver injury, oxidative status, sex hormones, lipid profile, and mRNA levels of cyclooxygenase-2 (COX-2) and peroxisome proliferator-activated receptor alpha (PPAR-α) genes. Streptozotocin increased levels of serum glucose, total cholesterol, triglyceride, low-density lipoprotein, aspartate transaminase, alanine transaminase, alkaline phosphatase, malondialdehyde, pancreas necrosis and inflammation, COX-2 expression, ovarian cystic, and anovulation. It decreased the levels of insulin, high-density lipoprotein, Superoxide dismutase, estradiol, progesterone, testosterone, luteinizing hormone, follicle-stimulating hormone, and PPAR-α expression. Eugenol administration ameliorated diabetes features through the improvement of lipid profile, oxidative status, insulin and glucose levels, sex hormone levels, liver markers, COX-2 and PPAR-α expression, and pancreas histology. It had no effect on ovarian cystic and follicular development.

CONCLUSIONS

Therefore, eugenol may be useful for ameliorating some adverse features of diabetes and used as an adjunct treatment or protective agent accompany by other chemicals in diabetes patients.

Exercise in the Prevention and Treatment of Type 2 Diabetes

Type 2 diabetes is a systemic, multifactorial disease that is a leading cause of morbidity and mortality globally. Despite a rise in the number of available medications and treatments available for management, exercise remains a first-line prevention and intervention strategy due to established safety, efficacy, and tolerability in the general population. Herein we review the predisposing risk factors for, prevention, pathophysiology, and treatment of type 2 diabetes. We emphasize key cellular and molecular adaptive processes that provide insight into our evolving understanding of how, when, and what types of exercise may improve glycemic control. © 2023 American Physiological Society. Compr Physiol 13:1-27, 2023.

Low serum dehydroepiandrosterone levels are associated with diabetic retinopathy in patients with type 2 diabetes mellitus

AIMS

This cross-sectional study assessed the association of serum dehydroepiandrosterone levels with the risk of diabetic retinopathy in patients with type 2 diabetes mellitus in China.

MATERIALS AND METHODS

Patients with type 2 diabetes mellitus were included in a multivariate logistic regression analysis to assess the association of dehydroepiandrosterone with diabetic retinopathy after adjusting for confounding factors. A restricted cubic spline was also used to model the association of serum dehydroepiandrosterone level with the risk of diabetic retinopathy and to describe the overall dose-response correlation. Additionally, an interaction test was conducted in the multivariate logistic regression analysis to compare the effects of dehydroepiandrosterone on diabetic retinopathy among age, sex, obesity status, hypertension, dyslipidemia, and glycosylated hemoglobin level subgroups.

RESULTS

In total, 1,519 patients were included in the final analysis. Low serum dehydroepiandrosterone was significantly associated with diabetic retinopathy in patients with type 2 diabetes mellitus after adjustment for confounding factors (odds ratio [quartile 4 vs quartile 1]: 0.51; 95% confidence interval: 0.32-0.81; P = 0.012 for the trend). Additionally, the restricted cubic spline indicated that the odds of diabetic retinopathy decreased linearly as the dehydroepiandrosterone concentration increased (P-overall = 0.044; P-nonlinear = 0.364). Finally, the subgroup analyses showed that the dehydroepiandrosterone level stably affected diabetic retinopathy (all P for interaction >0.05).

CONCLUSIONS

Low serum dehydroepiandrosterone levels were significantly associated with diabetic retinopathy in patients with type 2 diabetes mellitus, suggesting that dehydroepiandrosterone contributes to the pathogenesis of diabetic retinopathy.

Characterization of Antioxidant and α-Glucosidase Inhibitory Compounds of Cratoxylum formosum ssp. pruniflorum and Optimization of Extraction Condition

Cratoxylum formosum ssp. pruniflorum (Kurz.) Gogel (Guttiferae), called kuding tea, is widely distributed in Southeast Asia. In this study, the constituents and biological activity of C. formosum ssp. pruniflorum were investigated. Extract of its leaves, roots and stems showed antioxidant and α-glucosidase inhibitory activity. Interestingly, comparison of the metabolite profiles of leaves, roots and stems of C. formosum ssp. pruniflorum by LC-MS analysis showed a great difference between the roots and leaves, whereas the roots and stems were quite similar. Purification of the roots and leaves of C. formosum ssp. pruniflorum through various chromatographic techniques resulted in the isolation of 25 compounds. The structures of isolated compounds were elucidated on the basis of spectroscopic analysis as 18 xanthones, 5 flavonoids, a benzophenone and a phenolic compound. Among them, a xanthone (16) and a benzophenone (19) were first reported from nature. Evaluation of biological activity revealed that xanthones had a potent α-glucosidase inhibitory activity, while flavonoids were responsible for the antioxidant activity. To maximize the biological activity, yield and total phenolic content of C. formosum ssp. pruniflorum, extraction conditions such as extraction solvent, time and temperature were optimized using response surface methodology with Box-Behnken Design (BBD). Regression analysis showed a good fit of the experimental data, and the optimal condition was obtained as MeOH concentration in EtOAc, 88.1%; extraction time, 6.02 h; and extraction temperature 60.0 °C. α-Glucosidase inhibitory activity, yield and total phenolic content under the optimal condition were found to be 72.2% inhibition, 10.3% and 163.9 mg GAE/g extract, respectively. These results provide useful information about C. formosum ssp. pruniflorum as functional foods for oxidative stress-related metabolic diseases.

Diabetic Neuropathy Assessed with Multifrequency Vibrometry Develops Earlier than Nephropathy but Later than Retinopathy

BACKGROUND

Diabetes is associated with systemic complications. Prevalence of diabetic nephropathy, and retinopathy, in type 1 diabetes mellitus (T1DM) is declining, but it is not known if this is true also for diabetic neuropathy.

AIM

To investigate the relationship between large fibre diabetic neuropathy and other diabetic complications.

MATERIALS AND METHODS

Neuropathy, defined here as large fibre neuropathy, was assessed by measuring vibration perception thresholds at four different frequencies on the sole of the foot, using a standard VibroSense Meter and/or neuropathic symptoms, in 599 individuals with T1DM. Retinopathy status was graded using the International Clinical Disease Severity Scale. Grade of albuminuria and previous history of any macrovascular complications were registered.

RESULTS

Diabetic individuals without retinopathy had similar vibration thresholds as age- and gender-matched control participants without diabetes, whereas those without microalbuminuria had higher thresholds than controls. Two individuals out of 599 (0.3%) had microalbuminuria, but not retinopathy or neuropathy, and 12/134 (9%) without retinopathy had signs of neuropathy. Totally 119/536 (22%) of the patients without microalbuminuria had neuropathy. Vibration thresholds increased with the rising severity of retinopathy and grade of albuminuria. In a multinomial logistic regression analysis, neuropathy was associated with retinopathy (OR 2.96 [1.35-6.49], p=0.007), nephropathy (OR 6.25 [3.21-12.15]; p=6.7×10-8) and macrovascular disease (OR 2.72 [1.50-4.93], p=0.001).

CONCLUSIONS

Despite recent changes in the incidence of diabetic complications, the onset of large fibre neuropathy follows that of retinopathy but precedes the onset of nephropathy in T1DM.

Characterization and potential function of 7-dehydrocholesterol reductase (dhcr7) and lathosterol 5-desaturase (sc5d) in Cynoglossus semilaevis sexual size dimorphism

The typical sexual size dimorphism (SSD) phenomenon of Chinese tongue sole (Cynoglossus semilaevis) seriously restricts the sustainable development of the fishing industry. Previous transcriptome analysis has found a close relationship between the steroid biosynthesis and C. semilaevis SSD. The 7-dehydrocholesterol reductase (dhcr7) and lathosterol 5-desaturase (sc5d) are two genes in the steroid biosynthesis pathway, playing important roles in lipid synthesis, cellular metabolism, and growth. The present study assessed their roles in the mechanism of C. semilaevis SSD. The quantitative polymerase chain reaction (qPCR) results showed that C. semilaevis dhcr7 was mainly expressed in female livers, and C. semilaevis sc5d was highly expressed in female livers and gonads. Dual-luciferase experiment showed that dhcr7 and sc5d promoters had strong transcriptional activity. The transcription factors E2F transcription factor 1 (E2F1), and CCAAT enhancer binding protein alpha (C/EBPα) significantly regulated the transcriptional activity of dhcr7 and sc5d promoters, respectively. Furthermore, small interfering RNA (siRNA) knockdown results showed that expression levels of several genes [SREBF chaperone (scap), membrane-bound transcription factor peptidase, site 1 (mbtps1), fatty acid synthase (fasn), sonic hedgehog (shh), bone morphogenetic protein 2b (bmp2b) and AKT serine/threonine kinase 1 (akt1)] were suppressed. Protein subcellular localization results indicated that Dhcr7 and Sc5d were both specifically distributed in the cytoplasm, with co-localization been observed. The present study provides evidence that dhcr7 and sc5d might regulate C. semilaevis sexual size dimorphism by involving in energy homeostasis and cell cycle, or by affecting PI3K-Akt and Shh signaling pathways. The detailed roles of these steroid biosynthesis genes regulating C. semilaevis SSD needed more information.

Antidiabetic effects of Andrographis paniculata supplementation on biochemical parameters, inflammatory responses, and oxidative stress in canine diabetes

Introduction: Diabetes mellitus is a common endocrine disorder that causes hyperglycemia in dogs. Persistent hyperglycemia can induce inflammation and oxidative stress. This study aimed to investigate the effects of A. paniculata (Burm.f.) Nees (Acanthaceae) (A. paniculata) on blood glucose, inflammation, and oxidative stress in canine diabetes. A total of 41 client-owned dogs (23 diabetic and 18 clinically healthy) were included in this double-blind, placebo-controlled trial. Methods: The diabetic dogs were further divided into two treatments protocols: group 1 received A. paniculata extract capsules (50 mg/kg/day; n = 6) or received placebo for 90 days (n = 7); and group 2 received A. paniculata extract capsules (100 mg/kg/day; n = 6) or received a placebo for 180 days (n = 4). Blood and urine samples were collected every month. No significant differences in fasting blood glucose, fructosamine, interleukin-6, tumor necrosis factor-alpha, superoxide dismutase, and malondialdehyde levels were observed between the treatment and placebo groups (p > 0.05). Results and Discussion: The levels of alanine aminotransferase, alkaline phosphatase, blood urea nitrogen, and creatinine were stable in the treatment groups. The blood glucose levels and concentrations of inflammatory and oxidative stress markers in the client-owned diabetic dogs were not altered by A. paniculata supplementation. Furthermore, treatment with this extract did not have any adverse effects on the animals. Non-etheless, the effects of A. paniculata on canine diabetes must be appropriately evaluated using a proteomic approach and involving a wider variety of protein markers.

Exploring various novel diagnostic and therapeutic approaches in treating diabetic retinopathy

Diabetic retinopathy is regarded as a common manifestation of diabetes mellitus, being a prominent cause of visual impairment and blindness. This microvascular complication is marked by the appearance of microaneurysms, elevated vascular permeability, capillary blockage, and proliferation of neovasculature. The etiology behind retinopathy is ambiguous and the efficacy of current treatment strategies is minimal. Early diagnosis of this complication using a biomarker with high sensitivity and specificity is very essential for providing better therapeutic strategies. The current available therapeutic options are limited with various adverse effects. Laser treatment is not beneficial in all the situations, economic constraints being the major challenge. Surgical interventions are employed when pharmacotherapy and laser treatment fail. New pharmacological treatments are becoming a necessity for treating the condition. This review highlights the use of various diagnostic tools, emerging biomarkers for early detection of diabetic retinopathy, pathological mechanisms associated with the disease, current therapeutic approaches used and future strategies for more enhanced treatment options and more potent pharmacological actions.

Inflammatory, Metabolic, and Coagulation Effects on Medial Arterial Calcification in Patients with Peripheral Arterial Disease

Calcium deposits in the vessel wall in the form of hydroxyapatite can accumulate in the intimal layer, as in atherosclerotic plaque, but also in the medial layer, as in medial arterial calcification (MAC) or medial Möenckeberg sclerosis. Once considered a passive, degenerative process, MAC has recently been shown to be an active process with a complex but tightly regulated pathophysiology. Atherosclerosis and MAC represent distinct clinical entities that correlate in different ways with conventional cardiovascular risk factors. As both entities coexist in the vast majority of patients, it is difficult to estimate the relative contribution of specific risk factors to their development. MAC is strongly associated with age, diabetes mellitus, and chronic kidney disease. Given the complexity of MAC pathophysiology, it is expected that a variety of different factors and signaling pathways may be involved in the development and progression of the disease. In this article, we focus on metabolic factors, primarily hyperphosphatemia and hyperglycemia, and a wide range of possible mechanisms by which they might contribute to the development and progression of MAC. In addition, we provide insight into possible mechanisms by which inflammatory and coagulation factors are involved in vascular calcification processes. A better understanding of the complexity of MAC and the mechanisms involved in its development is essential for the development of potential preventive and therapeutic strategies.

Dissociation Mode of the O-H Bond in Betanidin, pKa-Clusterization Prediction, and Molecular Interactions via Shape Theory and DFT Methods

Betanidin (Bd) is a nitrogenous metabolite with significant bioactive potential influenced by pH. Its free radical scavenging activity and deprotonation pathway are crucial to studying its physicochemical properties. Motivated by the published discrepancies about the best deprotonation routes in Bd, this work explores all possible pathways for proton extractions on that molecule, by using the direct approach method based on pK_a. The complete space of exploration is supported by a linear relation with constant slope, where the pK_a is written in terms of the associated deprotonated molecule energy. The deprotonation rounds 1, …, 6 define groups of parallel linear models with constant slope. The intercepts of the models just depend on the protonated energy for each round, and then the pK_a can be trivially ordered and explained by the energy. We use the direct approximation method to obtain the value of pK_a. We predict all possible outcomes based on a linear model of the energy and some related verified assumptions. We also include a new measure of similarity or dissimilarity between the protonated and deprotonated molecules, via a geometric-chemical descriptor called the Riemann-Mulliken distance (RMD). The RMD considers the cartesian coordinates of the atoms, the atomic mass, and the Mulliken charges. After exploring the complete set of permutations, we show that the successive deprotonation process does not inherit the local energy minimum and that the commutativity of the paths does not hold either. The resulting clusterization of pK_a can be explained by the local acid and basic groups of the BD, and the successive deprotonation can be predicted by using the chemical explained linear models, which can avoid unnecessary optimizations. Another part of the research uses our own algorithm based on shape theory to determine the protein's active site automatically, and molecular dynamics confirmed the results of the molecular docking of Bd in protonated and anionic form with the enzyme aldose reductase (AR). Also, we calculate the descriptors associated with the SET and SPLET mechanisms.

Diabetic retinopathy in the pediatric population: Pathophysiology, screening, current and future treatments

Diabetic retinopathy (DR) is a sight threatening complication of diabetes mellitus (DM). The incidence of DR in the pediatric population has increased in the last two decades and it is expected to further rise in the future, following the increase in DM prevalence and obesity in youth. As early stages of the retinal disease are asymptomatic, screening programs are of extreme importance to guarantee a prompt diagnosis and avoid progression to more advanced, sight threatening stages. The management of DR comprises a wide range of actions starting from glycemic control, continuing with systemic and local medical treatments, up to para-surgical and surgical approaches to deal with the more aggressive complications. In this review we will describe the pathophysiology of DR trying to understand all the possible targets for currently available or future treatments. We will briefly consider the impact of screening techniques, screening strategies and their social and economic impact. Finally a large part of the review will be dedicated to medical and surgical treatments for DR including both currently available and under development therapies. Most of the available data in the literature on DR are focused on the adult population. The aim of our work is to provide clinicians and researchers with a comprehensive overview of the state of the art regarding DR in the pediatric population, considering the increasing numbers of this diseases in youth and the inevitable consequences that such a chronic disease could have if poorly managed in children.

Thioredoxin-Interacting Protein Inhibited Vascular Endothelial Cell-Induced HREC Angiogenesis Treatment of Diabetic Retinopathy

Diabetic retinopathy is the most common reason for blindness among employed adults worldwide. Hyperglycemia and the overaccumulation of vascular endothelial growth factor (VEGF) lead to diabetic retinopathy, pathological angiogenesis in diabetic retinopathy, and consequent visual impairment. Expression levels of thioredoxin-interacting protein (TXNIP) substantially increase in retinal endothelial cells in diabetic circumstances. The part of TXNIP in retinal angiogenesis combined with diabetes remains unclear. This study examined the effect of reduced TXNIP expression levels and determined how it affects diabetic retinal angiogenesis. Display of human retinal vascular endothelial cells (HRECs) to moderately high glucose (MHG) encouraged tube formation and cell migration, not cell proliferation. In response to MHG conditions, in HRECs, TXNIP knockdown inhibited the production of reactive oxygen species (ROS), cell migration, tube formation, and the Akt/mTOR activation pathway. In addition, gene silencing of TXNIP decreased the VEGF-triggered angiogenic response in HRECs by preventing activation of both VEGF receptor 2 and the downstream components of the Akt/mTOR pathway signaling. Furthermore, TXNIP knockout mice reduced VEGF-induced or VEGF- and MHG-triggered ex vivo retinal angiogenesis compared to wild-type mice. Finally, our findings revealed that TXNIP knockdown suppressed VEGF- and MHG-triggered angiogenic responses in HRECs and mouse retinas, indicating that TXNIP is a promising therapeutic window against the proliferation of diabetic patients' retinopathy.

Rationale and design of the Aldose Reductase Inhibition for Stabilization of Exercise Capacity in Heart Failure Trial (ARISE-HF) in patients with high-risk diabetic cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DbCM) is a specific form of heart muscle disease that may result in substantial morbidity and mortality in individuals with type 2 diabetes mellitus (T2DM). Hyperactivation of the polyol pathway is one of the primary mechanisms in the pathogenesis of diabetic complications, including development of DbCM. There is an unmet need for therapies targeting the underlying metabolic abnormalities that drive this form of Stage B heart failure (HF).

METHODS

Aldose reductase (AR) catalyzes the first and rate-limiting step in the polyol pathway, and AR inhibition has been shown to reduce diabetic complications, including DbCM in animal models and in patients with DbCM. Previous AR inhibitors (ARIs) were limited by poor specificity resulting in unacceptable tolerability and safety profile. AT-001 is a novel investigational highly specific ARI with higher binding affinity and greater selectivity than previously studied ARIs. ARISE-HF (NCT04083339) is an ongoing Phase 3 randomized, placebo-controlled, double blind, global clinical study to investigate the efficacy of AT-001 (1000 mg twice daily [BID] and 1500 mg BID) in 675 T2DM patients with DbCM at high risk of progression to overt HF. ARISE-HF assesses the ability of AT-001 to improve or prevent decline in exercise capacity as measured by functional capacity (changes in peak oxygen uptake [peak VO₂]) over 15 (and possibly 27) months of treatment. Additional endpoints include percentage of patients progressing to overt HF, health status metrics, echocardiographic measurements, and changes in cardiacbiomarkers.

RESULTS

The ARISE-HF Trial is fully enrolled.

CONCLUSIONS

This report describes the rationale and study design of ARISE-HF.

A Review on Autonomic Functional Assessment in Diabetic Patients

In today's world, science has progressed significantly, yet most people are still unaware of diabetes. Lack of obesity, physical work, and lifestyle changes are the main factors. Diabetes is becoming more common all around the globe. Type 2 diabetes may go unnoticed for years, resulting in serious consequences and high healthcare expenses. The goal of this study is to look at a wide range of studies in which the autonomic function of diabetic people has been studied with the help of various autonomic function tests (AFTs). AFT is a non-invasive approach to assessing patients for testing sympathetic and parasympathetic responses to stimuli. AFT findings give us comprehensive knowledge of the autonomic physiology reactions in normal and in autonomic diseases like diabetes. This review will concentrate on AFTs that are scientifically valid, trustworthy, and clinically beneficial, according to experts.

Dysregulation of Krüppel-like Factor 2 and Myocyte Enhancer Factor 2D Drive Cardiac Microvascular Inflammation and Dysfunction in Diabetes

Cardiovascular complications are the main cause of morbidity and mortality from diabetes. Herein, vascular inflammation is a major pathological manifestation. We previously characterized the cardiac microvascular inflammatory phenotype in diabetic patients and highlighted micro-RNA 92a (miR-92a) as a driver of endothelial dysfunction. In this article, we further dissect the molecular underlying of these findings by addressing anti-inflammatory Krüppel-like factors 2 and 4 (KLF2 and KLF4). We show that KLF2 dysregulation in diabetes correlates with greater monocyte adhesion as well as migratory defects in cardiac microvascular endothelial cells. We also describe, for the first time, a role for myocyte enhancer factor 2D (MEF2D) in cardiac microvascular dysfunction in diabetes. We show that both KLFs 2 and 4, as well as MEF2D, are dysregulated in human and porcine models of diabetes. Furthermore, we prove a direct interaction between miR-92a and all three targets. Altogether, our data strongly qualify miR-92a as a potential therapeutic target for diabetes-associated cardiovascular disease.

Role of Oxidative Stress in Ocular Diseases: A Balancing Act

Redox homeostasis is a delicate balancing act of maintaining appropriate levels of antioxidant defense mechanisms and reactive oxidizing oxygen and nitrogen species. Any disruption of this balance leads to oxidative stress, which is a key pathogenic factor in several ocular diseases. In this review, we present the current evidence for oxidative stress and mitochondrial dysfunction in conditions affecting both the anterior segment (e.g., dry eye disease, keratoconus, cataract) and posterior segment (age-related macular degeneration, proliferative vitreoretinopathy, diabetic retinopathy, glaucoma) of the human eye. We posit that further development of therapeutic interventions to promote pro-regenerative responses and maintenance of the redox balance may delay or prevent the progression of these major ocular pathologies. Continued efforts in this field will not only yield a better understanding of the molecular mechanisms underlying the pathogenesis of ocular diseases but also enable the identification of novel druggable redox targets and antioxidant therapies.

Herbal Products and Their Active Constituents for Diabetic Wound Healing-Preclinical and Clinical Studies: A Systematic Review

The purpose of this review is to provide verified data on the current knowledge acquired in preclinical and clinical studies regarding topically used herbal products and their active constituents (formulations and dressings) with diabetic wound healing activity. Moreover, herbal products and their active constituents used for diabetic wound infections, and various cellular and molecular mechanisms of their actions will also be described. The electronic databases were searched for articles published from 2012 to 2022. Publications with oral or systemic administration of herbal products in diabetic wound healing, published before 2012, available only as an abstract, or in languages other than English were excluded from the study. The 59 articles comparing topically used herbal products in diabetic wound healing treatment versus control treatments (placebo or active therapy) were selected. Herbal products through different mechanisms of action, including antimicrobial, anti-inflammatory, antioxidant activity, stimulation of angiogenesis, production of cytokines and growth factors, keratinocytes, and fibroblast migration and proliferation may be considered as an important support during conventional therapy or even as a substitute for synthetic drugs used for diabetic wound treatment.