Protein kinase C-dependent increase in reactive oxygen species (ROS) production in vascular tissues of diabetes: role of vascular NAD(P)H oxidase

Protective effects of benfotiamine on cyfluthrin-induced testicular damage and sperm characteristics during the prepubertal period

Cyfluthrin, a widely used synthetic pyrethroid insecticide, poses potential risks to both human health and the environment due to its extensive application in residential, agricultural, and outdoor settings. Conversely, benfotiamine, a fat-soluble derivative of vitamin B1, offers versatile therapeutic potential. This experimental study aimed to investigate the impact of cyfluthrin exposure during the prepubertal period on sperm characteristics and testicular tissue integrity in male rats, as well as to assess the protective effects of benfotiamine. A total of 32 4-week-old Wistar albino male rats were divided into four groups. Group I received daily oral gavage of 1 ml/kg/day of olive oil (control). Group II was administered cyfluthrin (54 mg/kg/day) dissolved in 1 ml of olive oil. Group III received both cyfluthrin (54 mg/kg/day) and benfotiamine (100 mg/kg/day) in olive oil. Group IV was given benfotiamine (100 mg/kg/day) in olive oil. After 5 weeks of treatment, the rats underwent evaluations for sperm motility, epididymal sperm density, and abnormal sperm rates. Additionally, their testicular tissues were examined histologically and immunohistochemically. This study underscores the potential hazards of cyfluthrin exposure on male reproductive health and highlights the protective role of benfotiamine in mitigating these effects. It emphasizes the importance of careful pesticide usage and dosage considerations to prevent potential public health issues, including infertility, associated with long-term exposure to pesticides like cyfluthrin.

Role and Mechanism of Growth Differentiation Factor 15 in Chronic Kidney Disease

GDF-15 is an essential member of the transforming growth factor-beta superfamily. Its functions mainly involve in tissue injury, inflammation, fibrosis, regulation of appetite and weight, development of tumor, and cardiovascular disease. GDF-15 is involved in various signaling pathways, such as MAPK pathway, PI3K/AKT pathway, STAT3 pathway, RET pathway, and SMAD pathway. In addition, several factors such as p53, ROS, and TNF-α participate the regulation of GDF-15. However, the specific mechanism of these factors regulating GDF-15 is still unclear and more research is needed to explore them. GDF-15 mainly improves the function of kidneys in CKD and plays an important role in the prediction of CKD progression and cardiovascular complications. In addition, the role of GDF-15 in the kidney may be related to the SMAD and MAPK pathways. However, the specific mechanism of these pathways remains unclear. Accordingly, more research on the specific mechanism of GDF-15 affecting kidney disease is needed in the future. In conclusion, GDF-15 may be a therapeutic target for kidney disease.

Metabolic reprogramming and interventions in angiogenesis

BACKGROUND

Endothelial cell (EC) metabolism plays a crucial role in the process of angiogenesis. Intrinsic metabolic events such as glycolysis, fatty acid oxidation, and glutamine metabolism, support secure vascular migration and proliferation, energy and biomass production, as well as redox homeostasis maintenance during vessel formation. Nevertheless, perturbation of EC metabolism instigates vascular dysregulation-associated diseases, especially cancer.

AIM OF REVIEW

In this review, we aim to discuss the metabolic regulation of angiogenesis by EC metabolites and metabolic enzymes, as well as prospect the possible therapeutic opportunities and strategies targeting EC metabolism.

KEY SCIENTIFIC CONCEPTS OF REVIEW

In this work, we discuss various aspects of EC metabolism considering normal and diseased vasculature. Of relevance, we highlight that the implications of EC metabolism-targeted intervention (chiefly by metabolic enzymes or metabolites) could be harnessed in orchestrating a spectrum of pathological angiogenesis-associated diseases.

Hydrogen sulfide improves endothelial barrier function by modulating the ubiquitination degradation of KLF4 through TRAF7 S-sulfhydration in diabetic aorta

Anomalous vascular endothelium significantly contributes to various cardiovascular diseases. VE-cadherin plays a vital role in governing the endothelial barrier. Krüppel-like factor 4(KLF4), as a transcription factor, which binds the VE-cadherin promoter and enhances its transcription. Tumor necrosis factor receptor-associated factor 7 (TRAF7) is an E3 ubiquitin ligase that has been shown to modulate the degradation of KLF4. H2S can covalently modify cysteine residues on proteins through S-sulfhydration, thereby influencing the structure and functionality of the target protein. However, the role of S-sulfhydration on endothelial barrier integrity remains to be comprehensively elucidated. This study aims to investigate whether protein S-sulfhydration in the endothelium regulates endothelial integrity and its underlying mechanism. In this study, we observed that protein S-sulfhydration was reduced in the endothelium during diabetes and TRAF7 was the main target. Overexpression of TRAF7-Cys327 mutant could mitigate the endothelial barrier damage by weakening TRAF7 interaction with KLF4 and reducing ubiquitination degradation of KLF4. In conclusion, our research demonstrates that H2S plays a pivotal role in regulating S-sulfhydration of TRAF7 at Cys327. This regulation effectively inhibits the ubiquitin-mediated degradation of KLF4, resulting in an upregulation of VE-cadherin levels. This molecular mechanism contributes to the prevention of endothelial barrier damage.

Composition of the gut microbiome, role of diet, lifestyle, and antioxidant therapies in diabetes mellitus and diabetic retinopathy

The gut microbiome is a complex ecosystem in the gastrointestinal tract composed of trillions of bacteria, viruses, fungi, and protozoa. Disruption of this delicate ecosystem, formally called "dysbiosis", has been linked to a variety of metabolic and inflammatory pathologies. Several studies have focused on abnormal microbiome composition and correlated these findings with the development of type 2 diabetes mellitus (T2DM) and diabetic retinopathy (DR). However, given the complexity of this ecosystem, the current studies are narrow in design and present variable findings. Composition of the gut microbiome in patients with DR significantly differs from patients with diabetes without retinopathy as well as from healthy controls. Additionally, the gut microbiome has been shown to modify effects of medication, diet, exercise, and antioxidant use on the development and progression of DR. In this paper, we present a comprehensive review of literature on the effect of oxidative stress, antioxidant therapies, and dysbiosis on DR.

SGLT2i relieve proteinuria in diabetic nephropathy patients potentially by inhibiting renal oxidative stress rather than through AGEs pathway

AIMS

To estimate the effects of the sodium-glucose cotransporter 2 inhibitor (SGLT2i) on proteinuria and oxidative stress expression in type 2 diabetes patients.

MATERIALS AND METHODS

68 patients with type 2 diabetes mellitus (T2DM) were divided into three groups according urinary albumin-to-creatinine ratio (UACR), including T2DM with non-albuminuria group (UACR < 30 mg/g), T2DM with microalbuminuria group (30 ≤ UACR ≤ 300 mg/g), T2DM with macroalbuminuria group (UACR>300 mg/g). They all received SGLT2 inhibitors (SGLT2i) treatment for 12 weeks. The expression of advanced glycation end products (AGEs) in plasma and 8-hydroxy-2-deoxyguanosine (8-OHdG) in urine were measured as indications of oxidative stress. The 24-hour urine samples were collected to measure the concentration of proteinuria and 8-OHdG before and after 12 weeks SGLT2i treatment. Plasma renin activity (PRA), angiotensin II (Ang II) and Aldosterone (ALD) were measured to evaluate renin angiotensin aldosterone system (RASS) levels.

RESULTS

After 12 weeks SGLT2 inhibitors treatment, the median values of 24-hour proteinuria decreased in macroalbuminuria compared to baseline (970 vs. 821 mg/d, P = 0.006). The median values of AGEs and 8-OHdG decreased in microalbuminuria and macroalbuminuria groups when compared to baseline, AGEs (777 vs. 136 ug/ml, P = 0.003) and (755 vs. 210 ug/ml, P = 0.001), 8-OHdG (8.00 vs. 1.88 ng/ml, P = 0.001) and (11.18 vs. 1.90 ng/ml, P < 0.001), respectively. Partial correlations showed that 8-OHdG were relevant to the baseline 24-h proteinuria (r = 0.389, p = 0.001), the reduction of OHdG (Δ8-OHdG) were positively correlated with the decrease of 24-h proteinuria (Δ24-h proteinuria) after 12 weeks of SGLT2i treatment (r = 0.283, P = 0.031). There was no significant correlation between 24-h proteinuria and AGEs in baseline (r = -0.059, p = 0.640) as well as between ΔAGEs and Δ24-h proteinuria (r = 0.022, p = 0.872) after12 weeks of SGLT2i treatment in T2DM patients.

CONCLUSIONS

SGLT2i may reduce proteinuria in diabetic nephropathy patients, potentially by inhibiting renal oxidative stress, but not through the AGEs pathway and does not induce RAAS activation.

TRIAL REGISTRATION

This clinical trial was registered on 15/10/2019, in ClinicalTrials.gov, and the registry number is NCT04127084.

Role of Oxygen and Its Radicals in Peripheral Nerve Regeneration: From Hypoxia to Physoxia to Hyperoxia

Oxygen is compulsory for mitochondrial function and energy supply, but it has numerous more nuanced roles. The different roles of oxygen in peripheral nerve regeneration range from energy supply, inflammation, phagocytosis, and oxidative cell destruction in the context of reperfusion injury to crucial redox signaling cascades that are necessary for effective axonal outgrowth. A fine balance between reactive oxygen species production and antioxidant activity draws the line between physiological and pathological nerve regeneration. There is compelling evidence that redox signaling mediated by the Nox family of nicotinamide adenine dinucleotide phosphate (NADPH) oxidases plays an important role in peripheral nerve regeneration. Further research is needed to better characterize the role of Nox in physiological and pathological circumstances, but the available data suggest that the modulation of Nox activity fosters great therapeutic potential. One of the promising approaches to enhance nerve regeneration by modulating the redox environment is hyperbaric oxygen therapy. In this review, we highlight the influence of various oxygenation states, i.e., hypoxia, physoxia, and hyperoxia, on peripheral nerve repair and regeneration. We summarize the currently available data and knowledge on the effectiveness of using hyperbaric oxygen therapy to treat nerve injuries and discuss future directions.

Relationship between Biochemical Pathways and Non-Coding RNAs Involved in the Progression of Diabetic Retinopathy

Diabetic retinopathy (DR) is a progressive blinding disease, which affects the vision and quality of life of patients, and it severely impacts the society. This complication, caused by abnormal glucose metabolism, leads to structural, functional, molecular, and biochemical abnormalities in the retina. Oxidative stress and inflammation also play pivotal roles in the pathogenic process of DR, leading to mitochondrial damage and a decrease in mitochondrial function. DR causes retinal degeneration in glial and neural cells, while the disappearance of pericytes in retinal blood vessels leads to alterations in vascular regulation and stability. Clinical changes include dilatation and blood flow changes in response to the decrease in retinal perfusion in retinal blood vessels, leading to vascular leakage, neovascularization, and neurodegeneration. The loss of vascular cells in the retina results in capillary occlusion and ischemia. Thus, DR is a highly complex disease with various biological factors, which contribute to its pathogenesis. The interplay between biochemical pathways and non-coding RNAs (ncRNAs) is essential for understanding the development and progression of DR. Abnormal expression of ncRNAs has been confirmed to promote the development of DR, suggesting that ncRNAs such as miRNAs, lncRNAs, and circRNAs have potential as diagnostic biomarkers and theranostic targets in DR. This review provides an overview of the interactions between abnormal biochemical pathways and dysregulated expression of ncRNAs under the influence of hyperglycemic environment in DR.

Signature precursor and mature microRNAs in cervical ripening during gestational diabetes mellitus lead to pre-term labor and other impediments in future

Gestational diabetes mellitus (GDM) is a pathological condition in which the placenta releases a hormone called human placental lactogen that prevents maternal insulin uptake. GDM is characterised by varying degrees of carbohydrate intolerance and is first identified during pregnancy. Around 5-17% of pregnancies are GDM pregnancies. Older or obese women have a higher risk of developing GDM during gestation. Hyperglycemia is a classic manifestation of GDM and leads to alterations in eNOS and iNOS expression and subsequently causes ROS and RNS overproduction. ROS and RNS play an important role in maintaining normal physiology, when present in low concentrations. Increased concentrations of ROS is harmful and can cause cellular and tissue damage. Oxidative stress is defined as an imbalance between pro-oxidant and antioxidant molecules that manifests due to hyperglycemia. miRNAs are short, non-coding RNAs that play a critical role in regulating gene expression. Studies have shown that the placenta expresses more than 500 miRNAs, which play a crucial role in trophoblast division, movement, and apoptosis. Latest research has revealed that hyperglycemic conditions and increased oxidative stress, characteristic of GDM, can lead to the dysregulation of miRNAs. The placenta also releases miRNAs into the maternal circulation. The secreted miRNAs are encapsulated in exosomes or vesicles. These exosomes interact with tissues and organs at distant sites, releasing their cargo intracellularly. This crosstalk between hyperglycemia, ROS and miRNA expression in GDM has detrimental effects on both foetal and maternal health. One of the complications of GDM is preterm labour. GDM induced iNOS expression has been implicated in cervical ripening, which in turn causes preterm birth. This article focuses on the speculations of oxidative and nitrative stress markers that lead to detrimental effects in GDM. We have also envisaged the role of non-coding miRNA interactions in regulating gene expression for oxidative damage.

Graphical Abstract

Holistic view of miRNA in GDM. I)(A) Placenta as a metabolic organ that provides the foetus with nutrients, oxygen and hormones to maintain pregnancy. Human placental lactogen (hPL) is one such hormone that is released into maternal circulation. hPL is known to induce insulin resistance. (B) ß-cell dysfunction leads to reduced glucose sensing and insulin production. Insulin resistance, a characteristic of GDM, exacerbates insulin ß cell dysfunction leading to maternal hyperglycemia. Hyperglycemia leads to increased ROS and RNS production through several mechanisms. Consequently, GDM is characterised by increased oxidative and nitrative stress.II)Exposure to maternal hyperglycemia causes increased ROS and RNS production in trophoblast cells. Oxidative stress caused by hyperglycemia may lead to eNOS uncoupling, causing eNOS to behave as a superoxide producing enzyme. iNOS expression in trophoblast cells leads to increased NO production. iNOS-derived NO reacts with ROS to produce RNS, thereby increasing nitrosative stress. Expression of antioxidant defences are reduced. Hyperglycemia and oxidative stress may alter the expression of some miRNAs. Some miRNAs are upregulated while others are downregulated. Some miRNAs are secreted into maternal circulation in the form of exosomes. Oxidative stress markers, nitrative stress markers and circulating miRNAs are found to be increased in maternal circulation.

A protein kinase C α and β inhibitor blunts hyperphagia to halt renal function decline and reduces adiposity in a rat model of obesity-driven type 2 diabetes

Type 2 diabetes (T2D) and its complications can have debilitating, sometimes fatal consequences for afflicted individuals. The disease can be difficult to control, and therapeutic strategies to prevent T2D-induced tissue and organ damage are needed. Here we describe the results of administering a potent and selective inhibitor of Protein Kinase C (PKC) family members PKCα and PKCβ, Cmpd 1, in the ZSF1 obese rat model of hyperphagia-induced, obesity-driven T2D. Although our initial intent was to evaluate the effect of PKCα/β inhibition on renal damage in this model setting, Cmpd 1 unexpectedly caused a marked reduction in the hyperphagic response of ZSF1 obese animals. This halted renal function decline but did so indirectly and indistinguishably from a pair feeding comparator group. However, above and beyond this food intake effect, Cmpd 1 lowered overall animal body weights, reduced liver vacuolation, and reduced inguinal adipose tissue (iWAT) mass, inflammation, and adipocyte size. Taken together, Cmpd 1 had strong effects on multiple disease parameters in this obesity-driven rodent model of T2D. Further evaluation for potential translation of PKCα/β inhibition to T2D and obesity in humans is warranted.

Mitochondria and Oxidative Stress as a Link between Alzheimer's Disease and Diabetes Mellitus

This review is devoted to the problems of the common features linking metabolic disorders and type 2 diabetes with the development of Alzheimer's disease. The pathogenesis of Alzheimer's disease closely intersects with the mechanisms of type 2 diabetes development, and an important risk factor for both pathologies is aging. Common pathological mechanisms include both factors in the development of oxidative stress, neuroinflammation, insulin resistance, and amyloidosis, as well as impaired mitochondrial dysfunctions and increasing cell death. The currently available drugs for the treatment of type 2 diabetes and Alzheimer's disease have limited therapeutic efficacy. It is important to note that drugs used to treat Alzheimer's disease, in particular acetylcholinesterase inhibitors, show a positive therapeutic potential in the treatment of type 2 diabetes, while drugs used in the treatment of type 2 diabetes can also prevent a number of pathologies characteristic for Alzheimer's disease. A promising direction in the search for a strategy for the treatment of type 2 diabetes and Alzheimer's disease may be the creation of complex multi-target drugs that have neuroprotective potential and affect specific common targets for type 2 diabetes and Alzheimer's disease.

Proteomic analysis of signaling pathways modulated by FABP5 in macrophages

Background

While acute inflammation serves essential functions in maintaining tissue homeostasis, chronic inflammation is causally linked to many diseases. Macrophages are a major cell-type that orchestrates inflammatory processes. During inflammation, macrophages undergo polarization and activation, thereby mobilizing pro-inflammatory and anti-inflammatory transcriptional programs that regulate ensuing macrophage functions. Fatty acid binding protein 5 (FABP5) is a lipid chaperone that is highly expressed in macrophages. FABP5 deletion is implicated in driving macrophages towards an anti-inflammatory phenotype, yet the signaling pathways regulated by macrophage FABP5 have not been systematically profiled. Herein, we leveraged proteomic and phosphoproteomic approaches to characterize pathways modulated by FABP5 in M1 and M2 polarized bone marrow derived macrophages (BMDMs).

Results

Stable isotope labeling by amino acids (SILAC) based analysis of M1 and M2 polarized wild-type (WT) and FABP5 knockout (KO) BMDMs revealed numerous differentially regulated proteins and phosphoproteins. FABP5 deletion impacted several downstream pathways associated with inflammation, cytokine production, oxidative stress, and kinase activity. Kinase enrichment analysis based on phosphorylated sites revealed key kinases, including members of the GRK family, that were altered in FABP5 KO BMDMs. Reactive oxygen species (ROS) levels were elevated in M1 polarized KO macrophages, consistent with the differential protein expression profiles.

Conclusions

This study represents a comprehensive characterization of the impact of FABP5 deletion upon the proteomic and phosphoproteomic landscape of M1 and M2 polarized BMDMs. Loss of FABP5 altered multiple pathways implicated in inflammatory responses and macrophage function. This work provides a foundation for future studies seeking to investigate the therapeutic potential of FABP5 inhibition in pathophysiological states resulting from dysregulated inflammatory signaling.

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.

Hydrogen sulfide donor AP123 restores endothelial nitric oxide-dependent vascular function in hyperglycemia via a CREB-dependent pathway

Diabetes is associated with severe vascular complications involving the impairment of endothelial nitric oxide synthase (eNOS) as well as cystathionine γ-lyase (CSE) activity. eNOS function is suppressed in hyperglycaemic conditions, resulting in reduced NO bioavailability, which is paralleled by reduced levels of hydrogen sulfide (H₂S). Here we have addressed the molecular basis of the interplay between the eNOS and CSE pathways. We tested the impact of H₂S replacement by using the mitochondrial-targeted H₂S donor AP123 in isolated vessels and cultured endothelial cells in high glucose (HG) environment, at concentrations not causing any vasoactive effect per se. Aorta exposed to HG displayed a marked reduction of acetylcholine (Ach)-induced vasorelaxation that was restored by the addition of AP123 (10 nM). In HG condition, bovine aortic endothelial cells (BAEC) showed reduced NO levels, downregulation of eNOS expression, and suppression of CREB activation (p-CREB). Similar results were obtained by treating BAEC with propargylglycine (PAG), an inhibitor of CSE. AP123 treatment rescued eNOS expression, as well as NO levels, and restored p-CREB expression in both the HG environment and the presence of PAG. This effect was mediated by a PI3K-dependent activity since wortmannin (PI3K inhibitor) blunted the rescuing effects operated by the H₂S donor. Experiments performed in the aorta of CSE^-/- mice confirmed that reduced levels of H₂S not only negatively affect the CREB pathway but also impair Ach-induced vasodilation, significantly ameliorated by AP123. We have demonstrated that the endothelial dysfunction due to HG involves H₂S/PI3K/CREB/eNOS route, thus highlighting a novel aspect of the H₂S/NO interplay in the vasoactive response.

Effect of Topiroxostat on Reducing Oxidative Stress in the Aorta of Streptozotocin-Induced Diabetic Rats

Xanthine oxidoreductase exists both intracellularly and extracellularly and induces vascular injury by producing reactive oxygen species (ROS). Here, we investigated the effects and mechanism of action of topiroxostat, a xanthine oxidase inhibitor, on ROS using an animal model of type 1 diabetes with persistent hyperglycemia. Six-week-old male Sprague-Dawley rats were administered 50 mg/kg streptozotocin to induce diabetes; at 8 weeks of age, animals were administered topiroxostat (0.3, 1, or 3 mg/kg) for 2 weeks through mixed feeding after which the aorta was sampled. The production of superoxide, a type of ROS, was measured by chemiluminescence and dihydroethidium staining. Cytotoxicity was evaluated by nitrotyrosine staining. Topiroxostat at 3 mg/kg significantly decreased blood urea nitrogen, e-selectin, urinary malondialdehyde, and the urinary albumin/creatinine ratio compared with the streptozotocin group. Superoxide production by xanthine oxidase anchored to the cell membrane was significantly decreased by topiroxostat at both 1 mg/kg and 3 mg/kg compared with the streptozotocin group. Dihydroethidium staining revealed no significant effect of topiroxostat administration on superoxide production. The fluorescence intensity of nitrotyrosine staining was significantly suppressed by 3 mg/kg topiroxostat. Topiroxostat was found to inhibit the production of ROS in the thoracic aorta and suppress vascular endothelial damage. The antioxidant effect of topiroxostat appears to be exerted via the inhibition of anchored xanthine oxidase.

Effects of antioxidants on diabetic kidney diseases: mechanistic interpretations and clinical assessment

Diabetic kidney disease (DKD) is more prevalent with an increase in diabetes mellitus. Oxidative stress is a major factor in the occurrence and progression of DKD. Defending against oxidative stress and restoring antioxidant defense might be key to preventing and treating DKD. The purpose of this article is to provide an explanation of how oxidative stress affects DKD, conduct a systematic review and meta-analysis on DKD, and examine the effect of antioxidants on the disease. An analysis of 19 randomized controlled trials showed that the use of antioxidants could reduce UAE (albumin excretion rate) in patients with DKD (SMD: - 0.31; 95% CI [- 0.47, - 0.14], I² = 0%), UACR (urine albumin/creatinine ratio) (SMD: - 0.60; 95% CI [- 1.15, - 0.06], I² = 89%), glycosylated hemoglobin (hbA1c) (MD: - 0.61; 95% CI [- 1.00, - 0.21], I² = 93%) and MDA (malonaldehyde) (SMD:-1.05; 95% CI [- 1.87, - 0.23], I² = 94%), suggesting that antioxidants seemed to have therapeutic effects in patients with DKD, especially in reducing proteinuria and hbA1c. The purpose of this study is to provide new targets and ideas for drug research and clinical treatment of DKD.

Puerarin: A review of its mechanisms of action and clinical studies in ophthalmology

BACKGROUND

Pueraria is the common name of the dried root of either Pueraria montana var. lobata (Willd.) Maesen & S.M.Almeida ex Sanjappa & Predeep (syn. Pueraria lobata (Willd.) Ohwi) or Pueraria montana var. thomsonii (Benth.) M.R.Almeida (syn. Pueraria thomsonii Benth.). Puerarin is a C-glucoside of the isoflavone daidzein extracted from Pueraria. It has been widely investigated to explore its therapeutic role in eye diseases and the molecular mechanisms.

PURPOSE

To collect the available literature from 2000 to 2022 on puerarin in the treatment of ocular diseases and suggest the future required directions to improve its medicinal value.

METHOD

The content of this review was obtained from databases such as Web of Science, PubMed, Google Scholar, China National Knowledge Infrastructure (CNKI), and the Wanfang Database.

RESULTS

The search yielded 428 articles, of which 159 articles were included after excluding duplicate articles and articles related to puerarin but less relevant to the topic of the review. In eleven articles, the bioavailability of puerarin was discussed. Despite puerarin possesses diverse biological activities, its bioavailability on its own is poor. There are 95 articles in which the therapeutic mechanisms of puerarin in ocular diseases was reported. Of these, 54 articles discussed the various signalling pathways related to occular diseases affected by puerarin. The other 41 articles discussed specific biological activities of puerarin. It plays a therapeutic role in ophthalmopathy via regulating nuclear factor kappa-B (NF-ĸB), mitogen-activated protein kinases (MAPKs), PI3K/AKT, JAK/STAT, protein kinase C (PKC) and other related pathways, affecting the expression of tumour necrosis factor α (TNF-α), interleukin-1β (IL-1β), intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), superoxide dismutase (SOD), B-cell lymphoma-2 (Bcl-2) and other cytokines resulting in anti-inflammatory, antioxidant and anti-apoptotic effects. The clinical applications of puerarin in ophthalmology were discussed in 25 articles. Eleven articles discussed the toxicity of puerarin. The literature suggests that puerarin has a good curative effect and can be used safely in clinical practice.

CONCLUSION

This review has illustrated the diverse applications of puerarin acting on ocular diseases and suggested that puerarin can be used for treating diabetic retinopathy, retinal vascular occlusion, glaucoma and other ocular diseases in the clinic. Some ocular diseases are the result of the combined action of multiple factors, and the effect of puerarin on different factors needs to be further studied to improve a more complete mechanism of action of puerarin. In addition, it is necessary to increase the number of subjects in clinical trials and conduct clinical trials for other ocular diseases. The information presented here will guide future research studies.

mTOR contributes to endothelium-dependent vasorelaxation by promoting eNOS expression and preventing eNOS uncoupling

Clinically used inhibitors of mammalian target of rapamycin (mTOR) negatively impacts endothelial-dependent vasodilatation (EDD) through unidentified mechanisms. Here we show that either the endothelium-specific deletion of Mtor to inhibit both mTOR complexes, or depletion of Raptor or Rictor to disrupt mTORC1 or mTORC2, causes impaired EDD, accompanied by reduced NO in the serum of mice. Consistently, inhibition of mTOR decreases NO production by human and mouse EC. Specifically, inhibition of mTORC1 suppresses eNOS gene expression, due to impairment in p70S6K-mediated posttranscriptional regulation of the transcription factor KLF2 expression. In contrast to mTORC1 inhibition, a positive-feedback between MAPK (p38 and JNK) activation and Nox2 upregulation contributes to the excessive generation of reactive oxygen species (ROS), which causes eNOS uncoupling and decreased NO bioavailability in mTORC2-inhibited EC. Adeno-associated virus-mediated EC-specific overexpression of KLF2 or suppression of Nox2 restores EDD function in endothelial mTORC1- or mTORC2-inhibited mice.

The endothelium-specific inhibition of either of mammalian target of rapamycin (mTOR) complexes impairs endothelial-dependent vasodilatation (EDD), accompanied by decreased nitric oxide bioavailability in both human and mice endothelial cells.

Diabetic Nephropathy: Pathogenesis to Cure

Diabetic nephropathy (DN) is a leading cause of end-stage renal disorder (ESRD). It is defined as the increase in urinary albumin excretion (UAE) when no other renal disease is present. DN is categorized into microalbuminuria and macroalbuminuria. Factors like high blood pressure, high blood sugar levels, genetics, oxidative stress, hemodynamic and metabolic changes affect DN. Hyperglycemia causes renal damage through activating protein kinase C (PKC), producing advanced end glycation products (AGEs) and reactive oxygen species (ROS). Growth factors, chemokines, cell adhesion molecules, inflammatory cytokines are found to be elevated in the renal tissues of the diabetic patient. Many different and new diagnostic methods and treatment options are available due to the increase in research efforts and progression in medical science. However, until now, no permanent cure is available. This article aims to explore the mechanism, diagnosis, and therapeutic strategies in current use for increasing the understanding of DN.

NOX1 promotes myocardial fibrosis and cardiac dysfunction via activating the TLR2/NF-κB pathway in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a prevalent complication in patients with diabetes, resulting in high morbidity and mortality. However, the molecular mechanisms of diabetic cardiomyopathy have yet to be fully elucidated. In this study, we investigated a novel target, NOX1, an isoform of superoxide-producing NADPH oxidase with key functional involvement in the pathophysiology of DCM. The DCM rat model was established by a high-fat diet combined with streptozotocin injections. DCM rats elicited myocardial fibrosis exacerbation, which was accompanied by a marked elevation of NOX1 expression in cardiac tissue. In particular, a specific NOX1 inhibitor, ML171, effectively decreased myocardial fibrosis and protected against cardiac dysfunction in DCM rats. Rat neonatal cardiac fibroblasts were incubated with high glucose (HG, 33 mM) as an in vitro model of DCM. We also observed that the expression of NOX1 was upregulated in HG-cultured cardiac fibroblasts. Silencing of NOX1 was found to attenuate myocardial fibrosis and oxidative stress in HG-induced cardiac fibroblasts. Furthermore, the upregulation of NOX1 by hyperglycemia induced activation of the TLR2/NF-κB pathway both in vitro and in vivo, whereas these effects were significantly attenuated with NOX1 gene silencing and further enhanced with NOX1 gene overexpression. In summary, we demonstrated that NOX1 induced activation of the TLR2/NF-κB pathway and increased reactive oxygen species production accumulation, which ultimately increased myocardial fibrosis and deteriorated cardiac function in diabetic cardiomyopathy. Our study revealed that NOX1 was a potential therapeutic target for DCM.

The Impact of Oxidative Stress and AKT Pathway on Cancer Cell Functions and Its Application to Natural Products

Oxidative stress and AKT serine-threonine kinase (AKT) are responsible for regulating several cell functions of cancer cells. Several natural products modulate both oxidative stress and AKT for anticancer effects. However, the impact of natural product-modulating oxidative stress and AKT on cell functions lacks systemic understanding. Notably, the contribution of regulating cell functions by AKT downstream effectors is not yet well integrated. This review explores the role of oxidative stress and AKT pathway (AKT/AKT effectors) on ten cell functions, including apoptosis, autophagy, endoplasmic reticulum stress, mitochondrial morphogenesis, ferroptosis, necroptosis, DNA damage response, senescence, migration, and cell-cycle progression. The impact of oxidative stress and AKT are connected to these cell functions through cell function mediators. Moreover, the AKT effectors related to cell functions are integrated. Based on this rationale, natural products with the modulating abilities for oxidative stress and AKT pathway exhibit the potential to regulate these cell functions, but some were rarely reported, particularly for AKT effectors. This review sheds light on understanding the roles of oxidative stress and AKT pathway in regulating cell functions, providing future directions for natural products in cancer treatment.

Nutraceutical Prevention of Diabetic Complications—Focus on Dicarbonyl and Oxidative Stress

Oxidative and dicarbonyl stress, driven by excess accumulation of glycolytic intermediates in cells that are highly permeable to glucose in the absence of effective insulin activity, appear to be the chief mediators of the complications of diabetes. The most pathogenically significant dicarbonyl stress reflects spontaneous dephosphorylation of glycolytic triose phosphates, giving rise to highly reactive methylglyoxal. This compound can be converted to harmless lactate by the sequential activity of glyoxalase I and II, employing glutathione as a catalyst. The transcription of glyoxalase I, rate-limiting for this process, is promoted by Nrf2, which can be activated by nutraceutical phase 2 inducers such as lipoic acid and sulforaphane. In cells exposed to hyperglycemia, glycine somehow up-regulates Nrf2 activity. Zinc can likewise promote glyoxalase I transcription, via activation of the metal-responsive transcription factor (MTF) that binds to the glyoxalase promoter. Induction of glyoxalase I and metallothionein may explain the protective impact of zinc in rodent models of diabetic complications. With respect to the contribution of oxidative stress to diabetic complications, promoters of mitophagy and mitochondrial biogenesis, UCP2 inducers, inhibitors of NAPDH oxidase, recouplers of eNOS, glutathione precursors, membrane oxidant scavengers, Nrf2 activators, and correction of diabetic thiamine deficiency should help to quell this.

Use of Ferulic Acid in the Management of Diabetes Mellitus and Its Complications

Diabetes mellitus, a metabolic disease mainly characterized by hyperglycemia, is becoming a serious social health problem worldwide with growing prevalence. Many natural compounds have been found to be effective in the prevention and treatment of diabetes, with negligible toxic effects. Ferulic acid (FA), a phenolic compound commonly found in medicinal herbs and the daily diet, was proved to have several pharmacological effects such as antihyperglycemic, antihyperlipidemic and antioxidant actions, which are beneficial to the management of diabetes and its complications. Data from PubMed, EM-BASE, Web of Science and CNKI were searched with the keywords ferulic acid and diabetes mellitus. Finally, 28 articles were identified after literature screening, and the research progress of FA for the management of DM and its complications was summarized in the review, in order to provide references for further research and medical applications of FA.

Profile of crosstalk between glucose and lipid metabolic disturbance and diabetic cardiomyopathy: Inflammation and oxidative stress

In recent years, the risk, such as hypertension, obesity and diabetes mellitus, of cardiovascular diseases has been increasing explosively with the development of living conditions and the expansion of social psychological pressure. The disturbance of glucose and lipid metabolism contributes to both collapse of myocardial structure and cardiac dysfunction, which ultimately leads to diabetic cardiomyopathy. The pathogenesis of diabetic cardiomyopathy is multifactorial, including inflammatory cascade activation, oxidative/nitrative stress, and the following impaired Ca2+ handling induced by insulin resistance/hyperinsulinemia, hyperglycemia, hyperlipidemia in diabetes. Some key alterations of cellular signaling network, such as translocation of CD36 to sarcolemma, activation of NLRP3 inflammasome, up-regulation of AGE/RAGE system, and disequilibrium of micro-RNA, mediate diabetic oxidative stress/inflammation related myocardial remodeling and ventricular dysfunction in the context of glucose and lipid metabolic disturbance. Here, we summarized the detailed oxidative stress/inflammation network by which the abnormality of glucose and lipid metabolism facilitates diabetic cardiomyopathy.

MARCKS Is an Essential Regulator of Reactive Oxygen Species Production in the Monocytic Cell Type

Myristoylated alanine-rich C-kinase substrate (MARCKS) is a ubiquitous protein mediating versatile effects in a variety of cell types, including actin crosslinking, signal transduction, and intracellular transport processes. MARCKS’s functional role in monocyte/macrophages, however, has not yet been adequately addressed. Thus, the aim of this study was to further elucidate the impact of MARCKS on central cellular functions of monocytic cells. To address this topic, we generated monocytic THP-1 (Tohoku Hospital Pediatrics-1)-derived MARCKS wildtype and knockout (KO) cells using the CRISPR/Cas9 technique. Remarkably, in the absence of MARCKS, both total and intracellular reactive oxygen species (ROS) production were strongly suppressed but restored following transient MARCKS re-transfection. In contrast, proliferation, differentiation, cytokine expression, and phagocytosis remained unaltered. A complete inhibition of ROS production could also be achieved in THP-1-derived PKCβ KO cells or in PKC inhibitor Staurosporine-treated primary human monocytes. MARCKS deficiency also involved reduced basal Akt phosphorylation and delayed re-phosphorylation. Further analyses indicated that long-term TNF pre-incubation strongly enhances monocytic ROS production, which was completely blocked in MARCKS and PKCβ KO cells. Collectively, our study demonstrates that MARCKS is an essential molecule enabling ROS production by monocytic cells and suggests that MARCKS is part of a signal cascade involved in ROS formation.

The Role of PKC-MAPK Signalling Pathways in the Development of Hyperglycemia-Induced Cardiovascular Complications

Cardiovascular disease is the most common cause of death among diabetic patients worldwide. Hence, cardiovascular wellbeing in diabetic patients requires utmost importance in disease management. Recent studies have demonstrated that protein kinase C activation plays a vital role in the development of cardiovascular complications via its activation of mitogen-activated protein kinase (MAPK) cascades, also known as PKC-MAPK pathways. In fact, persistent hyperglycaemia in diabetic conditions contribute to preserved PKC activation mediated by excessive production of diacylglycerol (DAG) and oxidative stress. PKC-MAPK pathways are involved in several cellular responses, including enhancing oxidative stress and activating signalling pathways that lead to uncontrolled cardiac and vascular remodelling and their subsequent dysfunction. In this review, we discuss the recent discovery on the role of PKC-MAPK pathways, the mechanisms involved in the development and progression of diabetic cardiovascular complications, and their potential as therapeutic targets for cardiovascular management in diabetic patients.

Assessing the risk factors for myocardial infarction in diet-induced prediabetes: myocardial tissue changes

Background

Hyperglycaemia is known to result in oxidative stress tissue injury and dysfunction. Interestingly, studies have reported hepatic and renal oxidative stress injury during prediabetes; however, any injury to the myocardium during prediabetes has not been investigated. Hence this study aims to assess changes in the myocardial tissue in an HFHC diet-induced model of prediabetes.

Methods

Male Sprague Dawley rats were randomly grouped into non-prediabetes and prediabetes (n = 6 in each group) and consumed a standard rat chow or fed a high-fat-high-carbohydrate diet respectively for a 20-week prediabetes induction period. Post induction, prediabetes was confirmed using the ADA criteria. Aldose reductase, NADH oxidase 1, superoxide dismutase, glutathione peroxide, cardiac troponins were analysed in cardiac tissue homogenate using specific ELISA kits. Lipid peroxidation was estimated by determining the concentration of malondialdehyde in the heart tissue homogenate according to the previously described protocol. Myocardial tissue sections were stained with H&E stain and analysed using Leica microsystem. All data were expressed as means ± SEM. Statistical comparisons were performed with Graph Pad instat Software using the Student's two-sided t-test. Pearson correlation coefficient was calculated to assess the association. Value of p < 0.05 was considered statistically significant.

Results

The prediabetes group showed a markedly high oxidative stress as indicated by significantly increased NADH oxidase 1 and malondialdehyde while superoxide dismutase and glutathione peroxide were decreased compared to non-prediabetes group. There was no statistical difference between cardiac troponin I and T in the non-prediabetes and prediabetes groups. Cardiac troponins had a weak positive association with glycated haemoglobin.

Conclusion

The findings of this study demonstrate that prediabetes is associated with myocardial injury through oxidative stress. Future studies are to investigate cardiac contractile function and include more cardiac biomarkers.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02758-8.

Impact of SGLT2 inhibitors on the kidney in people with type 2 diabetes and severely increased albuminuria

INTRODUCTION

Diabetes is the most common cause of end stage kidney disease. Therapies such as sodium-glucose co-transporter-2 inhibitors have been identified over the last decade as effective oral hypoglycemic agents that also confer additional cardio and kidney protection. Knowledge of their mechanism of action and impact on patients with diabetes and albuminuria is vital in galvanizing prescriber confidence and increasing clinical uptake.

AREAS COVERED

This manuscript discusses the pathophysiology of diabetic kidney disease, patho-physiological mechanisms for sodium-glucose co-transporter-2 inhibitors, and their impact on patients with Type 2 diabetes mellitus and albuminuric kidney disease.

EXPERT OPINION

Sodium-glucose co-transporter-2 inhibitors reduce albuminuria with consequent benefits on cardiovascular and kidney outcomes in patients with diabetes and severe albuminuria. Whilst they have been incorporated into guidelines, the uptake of these agents into clinical practice has been slow. Increasing the uptake of these agents into clinical practice is necessary to improve outcomes for the large number of patients with diabetic kidney disease globally.

A simplified prediction model for end-stage kidney disease in patients with diabetes

This study aimed to develop a simplified model for predicting end-stage kidney disease (ESKD) in patients with diabetes. The cohort included 2549 individuals who were followed up at Kyushu University Hospital (Japan) between January 1, 2008 and December 31, 2018. The outcome was a composite of ESKD, defined as an eGFR < 15 mL min⁻¹ [1.73 m]⁻², dialysis, or renal transplantation. The mean follow-up was 5.6 \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\pm$$\end{document}± 3.7 years, and ESKD occurred in 176 (6.2%) individuals. Both a machine learning random forest model and a Cox proportional hazard model selected eGFR, proteinuria, hemoglobin A1c, serum albumin levels, and serum bilirubin levels in a descending order as the most important predictors among 20 baseline variables. A model using eGFR, proteinuria and hemoglobin A1c showed a relatively good performance in discrimination (C-statistic: 0.842) and calibration (Nam and D’Agostino \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\chi$$\end{document}χ² statistic: 22.4). Adding serum albumin and bilirubin levels to the model further improved it, and a model using 5 variables showed the best performance in the predictive ability (C-statistic: 0.895, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\chi$$\end{document}χ² statistic: 7.7). The accuracy of this model was validated in an external cohort (n = 5153). This novel simplified prediction model may be clinically useful for predicting ESKD in patients with diabetes.

Chlorpromazine and Promethazine (C+P) Reduce Brain Injury after Ischemic Stroke through the PKC-δ/NOX/MnSOD Pathway

Cerebral ischemia-reperfusion (I/R) incites neurologic damage through a myriad of complex pathophysiological mechanisms, most notably, inflammation and oxidative stress. In I/R injury, nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) produces reactive oxygen species (ROS), which promote inflammatory and apoptotic pathways, augmenting ROS production and promoting cell death. Inhibiting ischemia-induced oxidative stress would be beneficial for reducing neuroinflammation and promoting neuronal cell survival. Studies have demonstrated that chlorpromazine and promethazine (C+P) induce neuroprotection. This study investigated how C+P minimizes oxidative stress triggered by ischemic injury. Adult male Sprague-Dawley rats were subject to middle cerebral artery occlusion (MCAO) and subsequent reperfusion. 8 mg/kg of C+P was injected into the rats when reperfusion was initiated. Neurologic damage was evaluated using infarct volumes, neurological deficit scoring, and TUNEL assays. NOX enzymatic activity, ROS production, protein expression of NOX subunits, manganese superoxide dismutase (MnSOD), and phosphorylation of PKC-δ were assessed. Neural SHSY5Y cells underwent oxygen-glucose deprivation (OGD) and subsequent reoxygenation and C+P treatment. We also evaluated ROS levels and NOX protein subunit expression, MnSOD, and p-PKC-δ/PKC-δ. Additionally, we measured PKC-δ membrane translocation and the level of interaction between NOX subunit (p47^phox) and PKC-δ via coimmunoprecipitation. As hypothesized, treatment with C+P therapy decreased levels of neurologic damage. ROS production, NOX subunit expression, NOX activity, and p-PKC-δ/PKC-δ were all significantly decreased in subjects treated with C+P. C+P decreased membrane translocation of PKC-δ and lowered the level of interaction between p47^phox and PKC-δ. This study suggests that C+P induces neuroprotective effects in ischemic stroke through inhibiting oxidative stress. Our findings also indicate that PKC-δ, NOX, and MnSOD are vital regulators of oxidative processes, suggesting that C+P may serve as an antioxidant.

Natural COA water inhibits mitochondrial ROS-mediated apoptosis through Plk3 downregulation under STZ diabetic stress in pancreatic β-cell lines

Diabetes from pancreatic β cell death and insulin resistance is a serious metabolic disease in the world. Although the overproduction of mitochondrial reactive oxygen species (ROS) plays an important role in the pathogenesis of diabetes, its specific molecular mechanism remains unclear. Here, we show that the natural Charisma of Aqua (COA) water plays a role in Streptozotocin (STZ) diabetic stress-induced cell death inhibition. STZ induces mitochondrial ROS by increasing Polo-like kinase 3 (Plk3), a major mitotic regulator, in both Beta TC-6 and Beta TC-tet mouse islet cells and leads to apoptosis. Overexpression of Plk3 regulates an increase in mitochondrial ROS as well as cell death, also these events were inhibited by Plk3 gene knockdown in STZ diabetic stimulated-Beta TC-6 cells. Interestingly, we found that natural COA water blocks mitochondrial ROS generation through the reduction of Plk3 and prevents apoptosis in STZ-treated beta cells. Furthermore, using the 3D organoid (ex vivo) system, we confirmed that the insulin secretion of the supernatant medium under STZ treated pancreatic β-cells is protected by the natural COA water. These findings demonstrate that the natural water COA has a beneficial role in maintaining β cell function through the inhibition of mitochondrial ROS-mediated cell death, and it might be introduced as a potential insulin stabilizer.

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Pancreatic β cell is stabilized through natural COA water in STZ-induced diabetes.

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Mitochondrial membrane potential (ΔΨm) is controlled by natural COA water.

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Plk3 expression under STZ treatment is negatively regulated by natural COA water.

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Insulin secretion is stabilized by natural COA water under STZ treatment in ex vivo (3D organoid) model.

Modulation of Reactive Oxygen Species Homeostasis as a Pleiotropic Effect of Commonly Used Drugs

Age-associated diseases represent a growing burden for global health systems in our aging society. Consequently, we urgently need innovative strategies to counteract these pathological disturbances. Overwhelming generation of reactive oxygen species (ROS) is associated with age-related damage, leading to cellular dysfunction and, ultimately, diseases. However, low-dose ROS act as crucial signaling molecules and inducers of a vaccination-like response to boost antioxidant defense mechanisms, known as mitohormesis. Consequently, modulation of ROS homeostasis by nutrition, exercise, or pharmacological interventions is critical in aging. Numerous nutrients and approved drugs exhibit pleiotropic effects on ROS homeostasis. In the current review, we provide an overview of drugs affecting ROS generation and ROS detoxification and evaluate the potential of these effects to counteract the development and progression of age-related diseases. In case of inflammation-related dysfunctions, cardiovascular- and neurodegenerative diseases, it might be essential to strengthen antioxidant defense mechanisms in advance by low ROS level rises to boost the individual ROS defense mechanisms. In contrast, induction of overwhelming ROS production might be helpful to fight pathogens and kill cancer cells. While we outline the potential of ROS manipulation to counteract age-related dysfunction and diseases, we also raise the question about the proper intervention time and dosage.

Resistance Exercise Training Improves Metabolic and Inflammatory Control in Adipose and Muscle Tissues in Mice Fed a High-Fat Diet

This study investigates whether ladder climbing (LC), as a model of resistance exercise, can reverse whole-body and skeletal muscle deleterious metabolic and inflammatory effects of high-fat (HF) diet-induced obesity in mice. To accomplish this, Swiss mice were fed for 17 weeks either standard chow (SC) or an HF diet and then randomly assigned to remain sedentary or to undergo 8 weeks of LC training with progressive increases in resistance weight. Prior to beginning the exercise intervention, HF-fed animals displayed a 47% increase in body weight (BW) and impaired ability to clear blood glucose during an insulin tolerance test (ITT) when compared to SC animals. However, 8 weeks of LC significantly reduced BW, adipocyte size, as well as glycemia under fasting and during the ITT in HF-fed rats. LC also increased the phosphorylation of Akt_Ser473 and AMPK_Thr172 and reduced tumor necrosis factor-alpha (TNF-α) and interleukin 1 beta (IL1-β) contents in the quadriceps muscles of HF-fed mice. Additionally, LC reduced the gene expression of inflammatory markers and attenuated HF-diet-induced NADPH oxidase subunit gp91phox in skeletal muscles. LC training was effective in reducing adiposity and the content of inflammatory mediators in skeletal muscle and improved whole-body glycemic control in mice fed an HF diet.

Curcumin, Polydatin and Quercetin Synergistic Activity Protects from High-Glucose-Induced Inflammation and Oxidative Stress

Chronic hyperglycemia, the diagnostic biomarker of Type 2 Diabetes Mellitus (T2DM), is a condition that fosters oxidative stress and proinflammatory signals, both involved in the promotion of cellular senescence. Senescent cells acquire a proinflammatory secretory phenotype, called SASP, exacerbating and perpetuating the detrimental effects of hyperglycemia. Bioactive compounds can exert antioxidant and anti-inflammatory properties. However, the synergistic anti-inflammatory and antioxidant effects of the most extensively investigated natural compounds have not been confirmed yet in senescent cells and in hyperglycemic conditions. Here, we exposed young and replicative senescent HUVEC (yHUVEC and sHUVEC) to a high-glucose (HG) condition (45 mM) and treated them with Polydatin (POL), Curcumin (CUR) and Quercetin (QRC), alone or in combination (MIX), to mirror the anti-inflammatory component OxiDef^TM contained in the novel nutraceutical Glicefen^TM (Mivell, Italy). In both yHUVEC and sHUVEC, the MIX significantly decreased the expression levels of inflammatory markers, such as MCP-1, IL-1β and IL-8, and ROS production. Importantly, in sHUVEC, a synergistic effect of the MIX was observed, suggesting its senomorphic activity. Moreover, the MIX was able to reduce the expression level of RAGE, a receptor involved in the activation of proinflammatory signaling. Overall, our data suggest that the consumption of nutraceuticals containing different natural compounds could be an adjuvant supplement to counteract proinflammatory and pro-oxidative signals induced by both hyperglycemic and senescence conditions.

S-Acetyl-Glutathione Attenuates Carbon Tetrachloride-Induced Liver Injury by Modulating Oxidative Imbalance and Inflammation

Liver fibrosis, depending on the stage of the disease, could lead to organ dysfunction and cirrhosis, and no effective treatment is actually available. Emergent proof supports a link between oxidative stress, liver fibrogenesis and mitochondrial dysfunction as molecular bases of the pathology. A valid approach to protect against the disease would be to replenish the endogenous antioxidants; thus, we investigated the protective mechanisms of the S-acetyl-glutathione (SAG), a glutathione (GSH) prodrug. Preliminary in vitro analyses were conducted on primary hepatic cells. SAG pre-treatment significantly protected against cytotoxicity induced by CCl4. Additionally, CCl4 induced a marked increase in AST and ALT levels, whereas SAG significantly reduced these levels, reaching values found in the control group. For the in vivo analyses, mice were administered twice a week with eight consecutive intraperitoneal injections of 1 mL/kg CCl4 (diluted at 1:10 in olive oil) to induce oxidative imbalance and liver inflammation. SAG (30 mg/kg) was administered orally for 8 weeks. SAG significantly restored SOD activity, GSH levels and GPx activity, while it strongly reduced GSSG levels, lipid peroxidation and H₂O₂ and ROS levels in the liver. Additionally, CCl4 induced a decrease in anti-oxidants, including Nrf2, HO-1 and NQO-1, which were restored by treatment with SAG. The increased oxidative stress characteristic on liver disfunction causes the impairment of mitophagy and accumulation of dysfunctional and damaged mitochondria. Our results showed the protective effect of SAG administration in restoring mitophagy, as shown by the increased PINK1 and Parkin expressions in livers exposed to CCl4 intoxication. Thus, the SAG administration showed anti-inflammatory effects decreasing pro-inflammatory cytokines TNF-α, IL-6, MCP-1 and IL-1β in both serum and liver, and suppressing the TLR4/NFkB pathway. SAG attenuated reduced fibrosis, collagen deposition, hepatocellular damage and organ dysfunction. In conclusion, our results suggest that SAG administration protects the liver from CCl4 intoxication by restoring the oxidative balance, ameliorating the impairment of mitophagy and leading to reduced inflammation.

Inhibitory Potential of Shen-Shuai-Ling Formulation on Renal Interstitial Fibrosis via Upregulation of PLZF

Background

Renal interstitial fibrosis (RIF) is an important cause of kidney disease, which seriously affects people's health. As a traditional Chinese medicine, Shen-Shuai-Ling Formulation (SSLF) has obvious kidney function. However, the therapeutic effect of SSLF on RIF and its molecular mechanism are still unclear.

Methods

First, the potential targets and pathways of SSLF for RIF were predicted by network pharmacology, and then, the binding of luteolin and target protein to SSLF was verified by molecular docking and Co-IP experiments. Finally, the effects of SSLF and luteolin on PLZF and (Pro) renin receptor (PRR) were verified by western blot and qPCR experiments. Angiotensin (Ang)-1, Ang-2, and transforming growth factor-β (TGF-β) were the indexes of renal interstitial fibrosis.

Results

Through the drug-active component-target network diagram, we found that luteolin has the most connections, and promyelocytic leukemia zinc finger (PLZF) is the target protein. GO analysis and KEGG pathway analysis of targets were performed using Cytoscape ClueGO. Molecular docking experiments and Co-IP are used to prove that luteolin and PLZF can be combined. Western blot and qPCR results showed that both SSLF and luteolin significantly upregulated the expression of PLZF and decreased the levels of PRR, Ang-1, Ang-2, and TGF-β. The overexpression of PLZF decreased the expression of PRR, the knockdown of PLZF increased the expression of PRR, and the overexpression of PRR decreased the expression of Ang-1, Ang-2, and TGF-β.

Conclusions

SSLF inhibits PRR and renal interstitial fibers by the upregulation of PLZF levels.

Targeting the ASMase/S1P pathway protects from sortilin-evoked vascular damage in hypertension

Sortilin has been positively correlated with vascular disorders in humans. No study has yet evaluated the possible direct effect of sortilin on vascular function. We used pharmacological and genetic approaches coupled with study of murine and human samples to unravel the mechanisms recruited by sortilin in the vascular system. Sortilin induced endothelial dysfunction of mesenteric arteries through NADPH oxidase 2 (NOX2) isoform activation, dysfunction that was prevented by knockdown of acid sphingomyelinase (ASMase) or sphingosine kinase 1. In vivo, recombinant sortilin administration induced arterial hypertension in WT mice. In contrast, genetic deletion of sphingosine-1-phosphate receptor 3 (S1P3) and gp91phox/NOX2 resulted in preservation of endothelial function and blood pressure homeostasis after 14 days of systemic sortilin administration. Translating these research findings into the clinical setting, we detected elevated sortilin levels in hypertensive patients with endothelial dysfunction. Furthermore, in a population-based cohort of 270 subjects, we showed increased plasma ASMase activity and increased plasma levels of sortilin, S1P, and soluble NOX2-derived peptide (sNOX2-dp) in hypertensive subjects, and the increase was more pronounced in hypertensive subjects with uncontrolled blood pressure. Our studies reveal what we believe is a previously unrecognized role of sortilin in the impairment of vascular function and in blood pressure homeostasis and suggest the potential of sortilin and its mediators as biomarkers for the prediction of vascular dysfunction and high blood pressure.

EW-7197 Attenuates the Progression of Diabetic Nephropathy in db/db Mice through Suppression of Fibrogenesis and Inflammation

BACKGROUND

Diabetic nephropathy (DN) is characterized by albuminuria and accumulation of extracellular matrix (ECM) in kidney. Transforming growth factor-β (TGF-β) plays a central role in promoting ECM accumulation. We aimed to examine the effects of EW-7197, an inhibitor of TGF-β type 1 receptor kinase (ALK5), in retarding the progression of DN, both in vivo, using a diabetic mouse model (db/db mice), and in vitro, in podocytes and mesangial cells.

METHODS

In vivo study: 8-week-old db/db mice were orally administered EW-7197 at a dose of 5 or 20 mg/kg/day for 10 weeks. Metabolic parameters and renal function were monitored. Glomerular histomorphology and renal protein expression were evaluated by histochemical staining and Western blot analyses, respectively. In vitro study: DN was induced by high glucose (30 mM) in podocytes and TGF-β (2 ng/mL) in mesangial cells. Cells were treated with EW-7197 (500 nM) for 24 hours and the mechanism associated with the attenuation of DN was investigated.

RESULTS

Enhanced albuminuria and glomerular morphohistological changes were observed in db/db compared to that of the nondiabetic (db/m) mice. These alterations were associated with the activation of the TGF-β signaling pathway. Treatment with EW-7197 significantly inhibited TGF-β signaling, inflammation, apoptosis, reactive oxygen species, and endoplasmic reticulum stress in diabetic mice and renal cells.

CONCLUSION

EW-7197 exhibits renoprotective effect in DN. EW-7197 alleviates renal fibrosis and inflammation in diabetes by inhibiting downstream TGF-β signaling, thereby retarding the progression of DN. Our study supports EW-7197 as a therapeutically beneficial compound to treat DN.

Mechanistic Insight into Oxidative Stress-Triggered Signaling Pathways and Type 2 Diabetes

Oxidative stress (OS) is a metabolic dysfunction mediated by the imbalance between the biochemical processes leading to elevated production of reactive oxygen species (ROS) and the antioxidant defense system of the body. It has a ubiquitous role in the development of numerous noncommunicable maladies including cardiovascular diseases, cancers, neurodegenerative diseases, aging and respiratory diseases. Diseases associated with metabolic dysfunction may be influenced by changes in the redox balance. Lately, there has been increasing awareness and evidence that diabetes mellitus (DM), particularly type 2 diabetes, is significantly modulated by oxidative stress. DM is a state of impaired metabolism characterized by hyperglycemia, resulting from defects in insulin secretion or action, or both. ROS such as hydrogen peroxide and the superoxide anion introduce chemical changes virtually in all cellular components, causing deleterious effects on the islets of β-cells, in turn affecting insulin production. Under hyperglycemic conditions, various signaling pathways such as nuclear factor-κβ (NF-κβ) and protein kinase C (PKC) are also activated by ROS. All of these can be linked to a hindrance in insulin signaling pathways, leading to insulin resistance. Hyperglycemia-induced oxidative stress plays a substantial role in complications including diabetic nephropathy. DM patients are more prone to microvascular as well as atherosclerotic macrovascular diseases. This systemic disease affects most countries around the world, owing to population explosion, aging, urbanization, obesity, lifestyle, etc. However, some modulators, with their free radical scavenging properties, can play a prospective role in overcoming the debilitating effects of OS. This review is a modest approach to summarizing the basics and interlinkages of oxidative stress, its modulators and diabetes mellitus. It may add to the understanding of and insight into the pathophysiology of diabetes and the crucial role of antioxidants to weaken the complications and morbidity resulting from this chronic disease.

Skeletal Muscle Microvascular Dysfunction in Obesity-Related Insulin Resistance: Pathophysiological Mechanisms and Therapeutic Perspectives

Obesity is a worrisomely escalating public health problem globally and one of the leading causes of morbidity and mortality from noncommunicable disease. The epidemiological link between obesity and a broad spectrum of cardiometabolic disorders has been well documented; however, the underlying pathophysiological mechanisms are only partially understood, and effective treatment options remain scarce. Given its critical role in glucose metabolism, skeletal muscle has increasingly become a focus of attention in understanding the mechanisms of impaired insulin function in obesity and the associated metabolic sequelae. We examined the current evidence on the relationship between microvascular dysfunction and insulin resistance in obesity. A growing body of evidence suggest an intimate and reciprocal relationship between skeletal muscle microvascular and glucometabolic physiology. The obesity phenotype is characterized by structural and functional changes in the skeletal muscle microcirculation which contribute to insulin dysfunction and disturbed glucose homeostasis. Several interconnected etiologic molecular mechanisms have been suggested, including endothelial dysfunction by several factors, extracellular matrix remodelling, and induction of oxidative stress and the immunoinflammatory phenotype. We further correlated currently available pharmacological agents that have deductive therapeutic relevance to the explored pathophysiological mechanisms, highlighting a potential clinical perspective in obesity treatment.

The Atrophic Effect of 1,25(OH)2 Vitamin D3 (Calcitriol) on C2C12 Myotubes Depends on Oxidative Stress

Dysfunctional mitochondrial metabolism has been linked to skeletal muscle loss in several physio-pathological states. Although it has been reported that vitamin D (VD) supports cellular redox homeostasis by maintaining normal mitochondrial functions, and VD deficiency often occurs in conditions associated with skeletal muscle loss, the efficacy of VD supplementation to overcome muscle wasting is debated. Investigations on the direct effects of VD metabolites on skeletal muscle using C2C12 myotubes have revealed an unexpected pro-atrophic activity of calcitriol (1,25VD), while its upstream metabolites cholecalciferol (VD3) and calcidiol (25VD) have anti-atrophic effects. Here, we investigated if the atrophic effects of 1,25VD on myotubes depend on its activity on mitochondrial metabolism. The impact of 1,25VD and its upstream metabolites VD3 and 25VD on mitochondria dynamics and the activity of C2C12 myotubes was evaluated by measuring mitochondrial content, architecture, metabolism, and reactive oxygen species (ROS) production. We found that 1,25VD induces atrophy through protein kinase C (PKC)-mediated ROS production, mainly of extramitochondrial origin. Consistent with this, cotreatment with the antioxidant N-acetylcysteine (NAC), but not with the mitochondria-specific antioxidant mitoTEMPO, was sufficient to blunt the atrophic activity of 1,25VD. In contrast, VD3 and 25VD have antioxidant properties, suggesting that the efficacy of VD supplementation might result from the balance between atrophic pro-oxidant (1,25VD) and protective antioxidant (VD3 and 25VD) metabolites.

A review on network pharmacology based phytotherapy in treating diabetes- An environmental perspective

Diabetes has become common lifestyle disorder associated with obesity and cardiovascular diseases. Environmental factors like physical inactivity, polluted surroundings and unhealthy dieting also plays a vital role in diabetes pathogenesis. As the current anti-diabetic drugs possess unprecedented side effects, traditional herbal medicine can be used an alternative therapy. The paramount challenge with the herbal formulation usage is the lack of standardized procedure, entangled with little knowledge on drug safety and mechanism of drug action. Heavy metal contamination is a major environmental hazard where plants tend to accumulate toxic metals like nickel, chromium and lead through industrial and agricultural activities. It becomes inappropriate to use these plants for phytotherapy as it may affect the human health on long term consumption. This review discuss about the environmental risk factors related to diabetes and better implication of medicinal plants in anti-diabetic therapy using network pharmacology. It is an in silico analytical tool that helps to unravel the multi-targeted action of herbal formulations rich in secondary metabolites. Also, a special focus is attempted to pool the databases regarding the medicinal plants for diabetes and associated diseases, their bioactive compounds, possible diabetic targets, drug-target interaction and toxicology reports that may open an aisle in safer, effective and toxicity-free drug discovery.

Coronary Large Conductance Ca2+-Activated K+ Channel Dysfunction in Diabetes Mellitus

Diabetes mellitus (DM) is an independent risk of macrovascular and microvascular complications, while cardiovascular diseases remain a leading cause of death in both men and women with diabetes. Large conductance Ca2+-activated K+ (BK) channels are abundantly expressed in arteries and are the key ionic determinant of vascular tone and organ perfusion. It is well established that the downregulation of vascular BK channel function with reduced BK channel protein expression and altered intrinsic BK channel biophysical properties is associated with diabetic vasculopathy. Recent efforts also showed that diabetes-associated changes in signaling pathways and transcriptional factors contribute to the downregulation of BK channel expression. This manuscript will review our current understandings on the molecular, physiological, and biophysical mechanisms that underlie coronary BK channelopathy in diabetes mellitus.

The nexus between redox state and intermediary metabolism

Reactive oxygen species (ROS) are not just a by-product of cellular metabolic processes but act as signalling molecules that regulate both physiological and pathophysiological processes. A close connection exists in cells between redox homeostasis and cellular metabolism. In this review, we describe how intracellular redox state and glycolytic intermediary metabolism are closely coupled. On the one hand, ROS signalling can control glycolytic intermediary metabolism by direct regulation of the activity of key metabolic enzymes and indirect regulation via redox-sensitive transcription factors. On the other hand, metabolic adaptation and reprogramming in response to physiological or pathological stimuli regulate intracellular redox balance, through mechanisms such as the generation of reducing equivalents. We also discuss the impact of these intermediary metabolism-redox circuits in physiological and disease settings across different tissues. A better understanding of the mechanisms regulating these intermediary metabolism-redox circuits will be crucial to the development of novel therapeutic strategies.

Diabetes and Heart Failure: Multi-Omics Approaches

Diabetes and heart failure, as important global issues, cause substantial expenses to countries and medical systems because of the morbidity and mortality rates. Most people with diabetes suffer from type 2 diabetes, which has an amplifying effect on the prevalence and severity of many health problems such as stroke, neuropathy, retinopathy, kidney injuries, and cardiovascular disease. Type 2 diabetes is one of the cornerstones of heart failure, another health epidemic, with 44% prevalence. Therefore, finding and targeting specific molecular and cellular pathways involved in the pathophysiology of each disease, either in diagnosis or treatment, will be beneficial. For diabetic cardiomyopathy, there are several mechanisms through which clinical heart failure is developed; oxidative stress with mediation of reactive oxygen species (ROS), reduced myocardial perfusion due to endothelial dysfunction, autonomic dysfunction, and metabolic changes, such as impaired glucose levels caused by insulin resistance, are the four main mechanisms. In the field of oxidative stress, advanced glycation end products (AGEs), protein kinase C (PKC), and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) are the key mediators that new omics-driven methods can target. Besides, diabetes can affect myocardial function by impairing calcium (Ca) homeostasis, the mechanism in which reduced protein phosphatase 1 (PP1), sarcoplasmic/endoplasmic reticulum Ca2+ ATPase 2a (SERCA2a), and phosphorylated SERCA2a expressions are the main effectors. This article reviewed the recent omics-driven discoveries in the diagnosis and treatment of type 2 diabetes and heart failure with focus on the common molecular mechanisms.

Nutrient regulation of inflammatory signalling in obesity and vascular disease

Despite obesity and diabetes markedly increasing the risk of developing cardiovascular diseases, the molecular and cellular mechanisms that underlie this association remain poorly characterised. In the last 20 years it has become apparent that chronic, low-grade inflammation in obese adipose tissue may contribute to the risk of developing insulin resistance and type 2 diabetes. Furthermore, increased vascular pro-inflammatory signalling is a key event in the development of cardiovascular diseases. Overnutrition exacerbates pro-inflammatory signalling in vascular and adipose tissues, with several mechanisms proposed to mediate this. In this article, we review the molecular and cellular mechanisms by which nutrients are proposed to regulate pro-inflammatory signalling in adipose and vascular tissues. In addition, we examine the potential therapeutic opportunities that these mechanisms provide for suppression of inappropriate inflammation in obesity and vascular disease.

Malondialdehyde concentrations in obsessive-compulsive disorder: a systematic review and meta-analysis

BACKGROUND

This meta-analysis aimed to investigate serum and plasma malondialdehyde (MDA) levels in patients with obsessive-compulsive disorder (OCD) in comparison to healthy controls.

METHODS

Following the PRISMA protocol, we searched for the relevant studies through the databases of Scopus, PubMed, Google Scholar, and web of science until September 2019 with no time restriction. Overall, nine studies were included in the current meta-analysis. Data were pooled using a random-effects model; in addition, standard mean difference (SMD) and/or weight mean difference (WMD) was calculated. Cochran's Q test and I-square (I2) statistics were used to evaluate between-study heterogeneity. The Newcastle-Ottawa scale (NOS) was used to evaluate the quality of the included studies. Statistical analyses were done using the STATA version 14.

RESULTS

Our systematic review included nine case-control studies (including 367 cases and 337 controls). Pooling findings from these studies showed a significantly higher MDA level in OCD patient compared to control groups (SMD = 1.62; 95% CI [0.53, 2.72]; I2 = 96.9%; Pheterogeneity (Ph) < 0.001). This finding remained unchanged among studies which reported MDA in the same unit (WMD = 1.93; 95% CI [0.27, 3.59]; I2 = 99.2%; Ph < 0.001). Subgroup analysis by the study location and sample size revealed findings that were also significant.

CONCLUSION

We found that MDA levels are higher in OCD patients than healthy controls. This finding highlights the importance of inflammatory responses in OCD patients that should be considered for future investigations. Further studies are recommended to expand current knowledge on this issue.