Inflammation and Oxidative Stress in Diabetic Kidney Disease: The Targets for SGLT2 Inhibitors and GLP-1 Receptor Agonists

Phthalides from the rhizome of Ligusticum chuanxiong Hort. attenuate diabetic nephropathy in mice

ETHNOPHARMACOLOGICAL RELEVANCE

In many famous formulas of traditional Chinese medicine (TCM), the rhizome of Ligusticum chuanxiong (L. chuanxiong) is commonly used as an ingredient for promoting blood circulation and resolving blood stasis to treat diabetic nephropathy. However, its material basis and mechanism of action are still needed to be explored.

AIM OF THE STUDY

The aim of this work is to elucidate the potential effective parts (phthalides) of L. chuanxiong responsible for renal protection and to explore the possible mechanism of renal protection.

MATERIALS AND METHODS

A method based on column chromatography of macroporous resin was established to enrich an effective part (LCE70), and the composition of LCE70 was identified by HPLC-UV and UPLC-MS/MS methods. Mice model was induced by streptozotocin (STZ) to evaluate the protective effect of LCE70 on diabetic nephropathy (DN). In vitro, the suppressive effect of LCE70 on oxidative damage, inflammation and its mechanism were tested using immunoblot analysis, ELISA, etc. Cellular thermal shift assay (CETSA) was adopted to verify the interaction between the phthalides and the key targets involved in renal injury.

RESULTS

LCE70 displayed therapeutic potential against metabolic disorders, renal dysfunction, and fibrosis in a DN model induced by STZ in mice. Furthermore, it markedly reduced oxidative stress of the kidney in DN mice by activating Nrf2 pathway. Z-ligustilide, the main component of LCE70, reacted with Keap1, and thus promoted Nrf2 dissociating from Keap1 to activate Nrf2 pathway.

CONCLUSIONS

LCE70 improved hyperglycemia-induced renal function by enhancing the Nrf2 activation, reducing collagen deposition, and alleviating inflammation and oxidative stress, which suggested its potential as a therapeutic agent for DN.

Type 2 diabetes mellitus pharmacological remission with dapagliflozin plus oral semaglutide

Dapagliflozin, a sodium-glucose co-transporter-2 inhibitor and semaglutide, a glucagon-like peptide 1 receptor agonist, have both demonstrated efficacy in glycemic control, reducing blood pressure, body weight, risk of renal and heart failure in type 2 diabetes mellitus. In this observational, real-world, study we aimed to investigate the efficacy of the combination therapy with those two agents over glycemic control. We thus obtained the data of 1335 patients with type 2 diabetes followed by 11 Diabetes centers in Lombardia, Italy. A group of 443 patients was treated with dapagliflozin alone, the other group of 892 patients was treated with the combination therapy of dapagliflozin plus oral semaglutide. We analyzed changes in glycated hemoglobin from baseline to 6 months of follow-up, as well as changes in fasting glycemia, body weight, body mass index, systolic and diastolic pressure, heart rate, creatinine, estimated glomerular filtration rate and albuminuria. Both groups of patients showed an improvement of glycometabolic control after 6 months of treatment; indeed, the treatment with dapagliflozin plus oral semaglutide showed a reduction of glycated hemoglobin of 1.2% as compared to the 0.5% reduction observed in the dapagliflozin alone group. Significant changes were observed in body mass index, fasting plasmatic glucose, blood pressure, total cholesterol, LDL and albumin to creatinine ratio, with a high rate (55%) of near-normalization of glycated hemoglobin. Our real world data confirmed the potential of the oral combination therapy dapagliflozin with semaglutide in inducing pharmacological remission of type 2 diabetes mellitus.

Current Medical Therapy and Revascularization in Peripheral Artery Disease of the Lower Limbs: Impacts on Subclinical Chronic Inflammation

Peripheral artery disease (PAD), coronary artery disease (CAD), and cerebrovascular disease (CeVD) are characterized by atherosclerosis and inflammation as their underlying mechanisms. This paper aims to conduct a literature review on pharmacotherapy for PAD, specifically focusing on how different drug classes target pro-inflammatory pathways. The goal is to enhance the choice of therapeutic plans by considering their impact on the chronic subclinical inflammation that is associated with PAD development and progression. We conducted a comprehensive review of currently published original articles, narratives, systematic reviews, and meta-analyses. The aim was to explore the relationship between PAD and inflammation and evaluate the influence of current pharmacological and nonpharmacological interventions on the underlying chronic subclinical inflammation. Our findings indicate that the existing treatments have added anti-inflammatory properties that can potentially delay or prevent PAD progression and improve outcomes, independent of their effects on traditional risk factors. Although inflammation-targeted therapy in PAD shows promising potential, its benefits have not been definitively proven yet. However, it is crucial not to overlook the pleiotropic properties of the currently available treatments, as they may provide valuable insights for therapeutic strategies. Further studies focusing on the anti-inflammatory and immunomodulatory effects of these treatments could enhance our understanding of the mechanisms contributing to the residual risk in PAD and pave the way for the development of novel therapies.

Dual amylin and calcitonin receptor agonist treatment reduces biomarkers associated with kidney fibrosis in diabetic rats

Dual amylin and calcitonin receptor agonists (DACRAs) are effective treatments for obesity and type 2 diabetes (T2D). They provide beneficial effects on body weight, glucose control, and insulin action. However, whether DACRAs protect against diabetes-related kidney damage remains unknown. We characterize the potential of long-acting DACRAs (KBP-A, Key Bioscience Peptide-A) as a treatment for T2D-related pathological alterations of the kidney extracellular matrix (ECM) in Zucker diabetic fatty rats (ZDF). We examined levels of endotrophin (profibrotic signaling molecule reflecting collagen type VI formation) and tumstatin (matrikine derived from collagen type IVα3) in serum and evaluated kidney morphology and collagen deposition in the kidneys. We included a study in obese Sprague-Dawley rats to further investigate the impact of KBP-A on ECM biomarkers. In ZDF vehicles, levels of endotrophin and tumstatin increased, suggesting disease progression along with an increase in blood glucose levels. These rats also displayed damage to their kidneys, which was evident from the presence of collagen formation in the medullary region of the kidney. Interestingly, KBP-A treatment attenuated these increases, resulting in significantly lower levels of endotrophin and tumstatin than the vehicle. Levels of endotrophin and tumstatin were unchanged in obese Sprague-Dawley rats, supporting the relation to diabetes-related kidney complications. Furthermore, KBP-A treatment normalized collagen deposition in the kidney while improving glucose control. These studies confirm the beneficial effects of DACRAs on biomarkers associated with kidney fibrosis. Moreover, these antifibrotic effects are likely associated with improved glucose control, highlighting KBP-A as a promising treatment of T2D and its related late complications.NEW & NOTEWORTHY These studies describe the beneficial effects of using a dual amylin and calcitonin receptor agonist (DACRA) for diabetes-related kidney complications. DACRA treatment reduced levels of serological biomarkers associated with kidney fibrosis. These reductions were further reflected by reduced collagen expression in diabetic kidneys. In general, these results validate the use of serological biomarkers while demonstrating the potential effect of DACRAs in treating diabetes-related long-term complications.

Epigenetic roles in clonal hematopoiesis and aging kidney-related chronic kidney disease

Accumulation of somatic hematopoietic stem cell mutations with aging has been revealed by the recent genome-wide analysis. Clonal expansion, known as clonal hematopoiesis of indeterminate potential (CHIP), is a premalignant condition of hematological cancers. It is defined as the absence of definitive morphological evidence of a hematological neoplasm and occurrence of ≥2% of mutant allele fraction in the peripheral blood. In CHIP, the most frequently mutated genes are epigenetic regulators such as DNMT3A, TET2, and ASXL1. CHIP induces inflammation. CHIP is shown to be associated with not only hematological malignancy but also non-malignant disorders such as atherosclerosis, cardiovascular diseases and chronic liver disease. In addition, recent several large clinical trials have shown that CHIP is also the risk factor for developing chronic kidney disease (CKD). In this review article, we proposed novel findings about CHIP and CHIP related kidney disease based on the recent basic and clinical research. The possible mechanism of the kidney injury in CHIP is supposed to be due to the clonal expansion in both myeloid and lymphoid cell lines. In myeloid cell lines, the mutated macrophages increase the inflammatory cytokine level and induce chronic inflammation. It leads to epigenetic downregulation of kidney and macrophage klotho level. In lymphoid cell lines, CHIP might be related to monoclonal gammopathy of renal significance (MGRS). It describes any B cell or plasma cell clonal disorder that does not fulfill the criteria for cancer yet produces a nephrotoxic monoclonal immunoglobulin that leads to kidney injury or disease. MGRS causes M-protein related nephropathy frequently observed among aged CKD patients. It is important to consider the CHIP-related complications such as hematological malignancy, cardiovascular diseases and metabolic disorders in managing the elderly CKD patients. There are no established therapies for CHIP and CHIP-related CKD yet. However, recent studies have supported the development of effective CHIP therapies, such as blocking the expansion of aberrant HSCs and inhibiting chronic inflammation. In addition, drugs targeting the epigenetic regulation of Klotho in the kidney and macrophages might be therapeutic targets of CHIP in the kidney.

The Utilization of Glucagon-like Peptide 1 Agonists and Risk of Following External Eye Diseases in Type 2 Diabetes Mellitus Individuals: A Population-Based Study

The glucagon-like peptide 1 (GLP-1) agonist showed anti-hyperglycemic and anti-inflammatory effects, which may retard the risk of external eye disease. The protective effect of GLP-1 agonist and dry eye disease (DED) was found, while the relationship between GLP-1 agonist and other corneal diseases was not clear. Herein, we aim to evaluate the association between the usage of GLP-1 agonists and the development of the following external eye disease in type 2 diabetes mellitus (T2DM) patients. A retrospective cohort study using the National Health Insurance Research Database (NHIRD) of Taiwan was conducted. The T2DM patients were divided into those with GLP-1 treatment and those without GLP-1 treatment and matched with a 1:2 ratio. The main outcomes were the development of dry eye disease (DED), superficial keratitis, and infectious keratitis. The Cox proportional hazard regression was adopted to produce the adjusted hazard ratio (aHR) with a 95% confidence interval (CI) of external eye diseases between groups. There were 115, 54, and 11 episodes of DED, superficial keratitis, and infectious keratitis in the GLP-1 group. Another 280, 168, and 31 events of DED, superficial keratitis, and infectious keratitis were recorded in the control group. The GLP-1 group demonstrated a significantly lower incidence of DED (aHR: 0.853, 95% CI: 0.668-0.989, p = 0.0356) and superficial keratitis (aHR: 0.670, 95% CI: 0.475-0.945, p = 0.0107) compared to the control group. In the subgroup analyses, the correlation of GLP-1 agonist and DED development was more prominent in patients younger than 60 years old (p = 0.0018). In conclusion, the GLP-1 agonist treatments are significantly associated with a lower incidence of subsequent DED and superficial keratitis, while the relationship was not significant between GLP-1 agonist usage and infectious keratitis.

The relevance of the non-invasive biomarkers lncRNA GAS5/miR-21 ceRNA regulatory network in the early identification of diabetes and diabetic nephropathy

BACKGROUND

To investigate the diagnostic value of serum lncRNA growth arrest-specific transcript 5 (lncRNA GAS5) and microRNA-21 (miR-21) in patients with type 2 diabetes mellitus (T2DM) and diabetic nephropathy (DN), and elucidate their roles in the pathogenesis.

METHODS

A microarray technology was used asses lncRNA GAS5 and miR-21 expression profiles in non-anticoagulant blood from 44 patients including T2DM without DN group (DM), T2DM with DN group (DN), and healthy controls group (N), followed by real-time PCR validation. Logistic regression and receiver operating characteristic (ROC) curves were applied to evaluate the clinical indicators among normal, T2DM, and DN patients.

RESULTS

The serum lncRNA GAS5 expression in T2DM and DN patients was significantly down-regulated compared with the N group, while the expression of miR-21 was significantly up-regulated (all P < 0.05). Fasting blood glucose (FBG) and glycosylated hemoglobin (HbA1c) were negatively correlated with serum lncRNA GAS5, and FBG was independently correlated with serum lncRNA GAS5. Urinary microalbumin, total cholesterol (TC), creatinine (Cr), urea, and systolic blood pressure (SBP) were significantly positively correlated with serum miR-21. Glomerular filtration rate (GFR) and albuminuria (ALB) were negatively correlated with serum miR-21, and ALB was independently correlated with serum miR-21. Serum lncRNA GAS5, miR-21 and lncRNA GAS5/miR-21 showed good diagnostic efficiency as the "diagnostic signature" of T2DM and DN.

CONCLUSION

The lncRNA GAS5/miR-21 diagnostic signature may be a more effective non-invasive biomarker for detecting T2DM. In addition, miR-21 alone may be a more accurate serum biomarker for the early screening of DN patients.

JAK/STAT signaling in diabetic kidney disease

Diabetic kidney disease (DKD) is the most important microvascular complication of diabetes and the leading cause of end-stage renal disease (ESRD) worldwide. The Janus kinase/signal transducer and activator of the transcription (JAK/STAT) signaling pathway, which is out of balance in the context of DKD, acts through a range of metabolism-related cytokines and hormones. JAK/STAT is the primary signaling node in the progression of DKD. The latest research on JAK/STAT signaling helps determine the role of this pathway in the factors associated with DKD progression. These factors include the renin-angiotensin system (RAS), fibrosis, immunity, inflammation, aging, autophagy, and EMT. This review epitomizes the progress in understanding the complicated explanation of the etiologies of DKD and the role of the JAK/STAT pathway in the progression of DKD and discusses whether it can be a potential target for treating DKD. It further summarizes the JAK/STAT inhibitors, natural products, and other drugs that are promising for treating DKD and discusses how these inhibitors can alleviate DKD to explore possible potential drugs that will contribute to formulating effective treatment strategies for DKD in the near future.

Diabetic Nephropathy: Significance of Determining Oxidative Stress and Opportunities for Antioxidant Therapies

Diabetes mellitus (DM) belongs to the category of socially significant diseases with epidemic rates of increases in prevalence. Diabetic nephropathy (DN) is a specific kind of kidney damage that occurs in 40% of patients with DM and is considered a serious complication of DM. Most modern methods for treatments aimed at slowing down the progression of DN have side effects and do not produce unambiguous positive results in the long term. This fact has encouraged researchers to search for additional or alternative treatment methods. Hyperglycemia has a negative effect on renal structures due to a number of factors, including the activation of the polyol and hexosamine glucose metabolism pathways, the activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, the accumulation of advanced glycation end products and increases in the insulin resistance and endothelial dysfunction of tissues. The above mechanisms cause the development of oxidative stress (OS) reactions and mitochondrial dysfunction, which in turn contribute to the development and progression of DN. Modern antioxidant therapies for DN involve various phytochemicals (food antioxidants, resveratrol, curcumin, alpha-lipoic acid preparations, etc.), which are widely used not only for the treatment of diabetes but also other systemic diseases. It has also been suggested that therapeutic approaches that target the source of reactive oxygen species in DN may have certain advantages in terms of nephroprotection from OS. This review describes the significance of studies on OS biomarkers in the pathogenesis of DN and analyzes various approaches to reducing the intensity of OS in the prevention and treatment of DN.

Targeting oxidative stress as a preventive and therapeutic approach for cardiovascular disease

Cardiovascular diseases (CVDs) continue to exert a significant impact on global mortality rates, encompassing conditions like pulmonary arterial hypertension (PAH), atherosclerosis (AS), and myocardial infarction (MI). Oxidative stress (OS) plays a crucial role in the pathogenesis and advancement of CVDs, highlighting its significance as a contributing factor. Maintaining an equilibrium between reactive oxygen species (ROS) and antioxidant systems not only aids in mitigating oxidative stress but also confers protective benefits on cardiac health. Herbal monomers can inhibit OS in CVDs by activating multiple signaling pathways, such as increasing the activity of endogenous antioxidant systems and decreasing the level of ROS expression. Given the actions of herbal monomers to significantly protect the normal function of the heart and reduce the damage caused by OS to the organism. Hence, it is imperative to recognize the significance of herbal monomers as prospective therapeutic interventions for mitigating oxidative damage in CVDs. This paper aims to comprehensively review the origins and mechanisms underlying OS, elucidate the intricate association between CVDs and OS, and explore the therapeutic potential of antioxidant treatment utilizing herbal monomers. Furthermore, particular emphasis will be placed on examining the cardioprotective effects of herbal monomers by evaluating their impact on cardiac signaling pathways subsequent to treatment.

A review of therapeutic impacts of saffron (Crocus sativus L.) and its constituents

Application of herbal medicines in the treatment of diseases is in the center of attention of medical scientific societies. Saffron (Cricus sativus L.) is a medicinal plant belonging to the Iridaceae family with different therapeutic properties. The outcomes of human and animal experiments indicate that therapeutic impacts of saffron and its constituents, crocin, crocetin, and safranal, mainly are mediated via inhibiting the inflammatory reactions and scavenging free radicals. It has been suggested that saffron and crocin extracted from it also up-regulate the expression of sirtuin 1 (SIRT1) and nuclear factor erythroid 2-related factor 2 (Nrf2), down-regulate nuclear factor kappa B (NF-κB) signaling pathway and untimely improve the body organs dysfunction. Inhibition of inducible nitric oxide synthase and cyclooxygenase-2 (COX2) also is attributed to crocin. The current review narrates the therapeutic effects of saffron and its constituents on various body systems through looking for the scientific databases including Web of Science, PubMed, Scopus, and Google Scholar from the beginning of 2010 until the end of 2022.

NAD metabolism modulates inflammation and mitochondria function in diabetic kidney disease

Diabetes mellitus is the leading cause of cardiovascular and renal disease in the United -States. Despite the beneficial interventions available for patients with diabetes, there remains a need for additional therapeutic targets and therapies in diabetic kidney disease (DKD). Inflammation and oxidative stress are increasingly recognized as important causes of renal diseases. Inflammation is closely associated with mitochondrial damage. The molecular connection between inflammation and mitochondrial metabolism remains to be elucidated. Recently, nicotinamide adenine nucleotide (NAD+) metabolism has been found to regulate immune function and inflammation. In the present studies, we tested the hypothesis that enhancing NAD metabolism could prevent inflammation in and progression of DKD. We found that treatment of db/db mice with type 2 diabetes with nicotinamide riboside (NR) prevented several manifestations of kidney dysfunction (i.e., albuminuria, increased urinary kidney injury marker-1 (KIM1) excretion, and pathologic changes). These effects were associated with decreased inflammation, at least in part via inhibiting the activation of the cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) signaling pathway. An antagonist of the serum stimulator of interferon genes (STING) and whole-body STING deletion in diabetic mice showed similar renoprotection. Further analysis found that NR increased SIRT3 activity and improved mitochondrial function, which led to decreased mitochondrial DNA damage, a trigger for mitochondrial DNA leakage which activates the cGAS-STING pathway. Overall, these data show that NR supplementation boosted NAD metabolism to augment mitochondrial function, reducing inflammation and thereby preventing the progression of diabetic kidney disease.

The roles of gut microbiota and its metabolites in diabetic nephropathy

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes, which increases the risk of renal failure and causes a high global disease burden. Due to the lack of sustainable treatment, DN has become the primary cause of end-stage renal disease worldwide. Gut microbiota and its metabolites exert critical regulatory functions in maintaining host health and are associated with many pathogenesis of aging-related chronic diseases. Currently, the theory gut-kidney axis has opened a novel angle to understand the relationship between gut microbiota and multiple kidney diseases. In recent years, accumulating evidence has revealed that the gut microbiota and their metabolites play an essential role in the pathophysiologic processes of DN through the gut-kidney axis. In this review, we summarize the current investigations of gut microbiota and microbial metabolites involvement in the progression of DN, and further discuss the potential gut microbiota-targeted therapeutic approaches for DN.

Expression profiles and potential roles of serum tRNA‑derived fragments in diabetic nephropathy

Diabetic nephropathy (DN) is one of the most important causes of end-stage renal disease and current treatments are ineffective in preventing its progression. Transfer RNA (tRNA)-derived fragments (tRFs), which are small non-coding fragments derived from tRNA precursors or mature tRNAs, have a critical role in various human diseases. The present study aimed to investigate the expression profile and potential functions of tRFs in DN. High-throughput sequencing technology was employed to detect the differential serum levels of tRFs between DN and diabetes mellitus and to validate the reliability of the sequencing results using reverse transcription-quantitative PCR. Ultimately, six differentially expressed (DE) tRFs were identified (P<0.05; |log2fold change| ≥1), including three upregulated (tRF5-GluCTC, tRF5-AlaCGC and tRF5-ValCAC) and three downregulated tRFs (tRF5-GlyCCC, tRF3-GlyGCC and tRF3-IleAAT). Potential functions and regulatory mechanisms of these DE tRFs were further evaluated using an applied bioinformatics-based analysis. Gene ontology analysis revealed that the DE tRFs are mainly enriched in biological processes, including axon guidance, Rad51 paralog (Rad51)B-Rad51C-Rad51D-X-Ray repair cross-complementing 2 complex, nuclear factor of activated T-cells protein binding and fibroblast growth factor-activated receptor activity. Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis indicated that they are associated with axon guidance, neurotrophin signaling, mTOR signaling, AMPK signaling and epidermal growth factor receptor family signaling pathways. In conclusion, the present findings indicated that tRFs were DE in DN and may be involved in the regulation of DN pathology through multiple pathways, thereby providing a new perspective for the study of DN therapeutic targets.

Sodium Glucose Cotransporter-2 Inhibitor Empagliflozin Increases Antioxidative Capacity and Improves Renal Function in Diabetic Rats

INTRODUCTION

There are several pathologic mechanisms involved in diabetic nephropathy, but the role of oxidative stress seems to be one of the most important. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are a relatively new class of antidiabetic drugs that might also have some other effects in addition to lowering glucose. The aim of this study was to evaluate the possible effects of the SGLT2 inhibitor empagliflozin on oxidative stress and renal function in diabetes.

METHODS

Male Wistar rats were randomly divided into four groups: control, control-treated, diabetic, and diabetic-treated (n = 8 per group). Diabetes was induced by a single intraperitoneal dose of streptozotocin (50 mg/kg). The treated animals received empagliflozin for 5 weeks (20 mg/kg/day/po). All groups were sacrificed on the 36th day, and blood and tissue samples were collected. Serum levels of urea, uric acid, creatinine, and glucose levels were determined. The level of malondialdehyde (MDA) and glutathione (GLT), as well as the activity of catalase (CAT) and superoxide dismutase (SOD), was measured in all groups. Data were analyzed using one-way Anova and paired T-tests, and p ≤ 0.05 was considered significant.

RESULTS

Diabetes significantly increased urea (p < 0.001), uric acid (p < 0.001), and creatinine (p < 0.001) in the serum, while the activities of CAT (p < 0.001) and SOD (p < 0.001) were reduced. GLT was also reduced (p < 0.001), and MDA was increased (p < 0.001) in non-treated animals. Treatment with empagliflozin improved renal function, as shown by a reduction in the serum levels of urea (p = 0.03), uric acid (p = 0.03), and creatinine (p < 0.001). Empagliflozin also increased the antioxidant capacity by increasing CAT (p = 0.035) and SOD (p = 0.02) activities and GLT content (p = 0.01) and reduced oxidative damage by lowering MDA (p < 0.001).

CONCLUSIONS

It seems that uncontrolled diabetes induces renal insufficiency by decreasing antioxidant defense mechanisms and inducing oxidative stress. Empagliflozin might have additional benefits in addition to lowering glucose--reversing these processes, improving antioxidative capacity, and improving renal function.

Non-Haemodynamic Mechanisms Underlying Hypertension-Associated Damage in Target Kidney Components

Arterial hypertension (AH) is a global challenge that greatly impacts cardiovascular morbidity and mortality worldwide. AH is a major risk factor for the development and progression of kidney disease. Several antihypertensive treatment options are already available to counteract the progression of kidney disease. Despite the implementation of the clinical use of renin-angiotensin aldosterone system (RAAS) inhibitors, gliflozins, endothelin receptor antagonists, and their combination, the kidney damage associated with AH is far from being resolved. Fortunately, recent studies on the molecular mechanisms of AH-induced kidney damage have identified novel potential therapeutic targets. Several pathophysiologic pathways have been shown to play a key role in AH-induced kidney damage, including inappropriate tissue activation of the RAAS and immunity system, leading to oxidative stress and inflammation. Moreover, the intracellular effects of increased uric acid and cell phenotype transition showed their link with changes in kidney structure in the early phase of AH. Emerging therapies targeting novel disease mechanisms could provide powerful approaches for hypertensive nephropathy management in the future. In this review, we would like to focus on the interactions of pathways linking the molecular consequences of AH to kidney damage, suggesting how old and new therapies could aim to protect the kidney.

Empagliflozin improves renal ischemia-reperfusion injury by reducing inflammation and enhancing mitochondrial fusion through AMPK-OPA1 pathway promotion

BACKGROUND

Renal ischemia-reperfusion injury (IRI) is one reason for renal transplantation failure. Recent studies have shown that mitochondrial dynamics is closely related to IRI, and that inhibition or reversal of mitochondrial division protects organs against IRI. Optic atrophy protein 1 (OPA1), an important factor in mitochondrial fusion, has been shown to be upregulated by sodium-glucose cotransporter 2 inhibitor (SGLT2i). Also, the antiinflammatory effects of SGLT2i have been demonstrated in renal cells. Thus, we hypothesized that empagliflozin could prevent IRI through inhibiting mitochondrial division and reducing inflammation.

METHODS

Using hematoxylin-eosin staining, enzyme linked immunosorbent assay (ELISA), flow cytometry, immunofluorescent staining, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining, real-time PCR, RNA-sequencing, and western blot, we analyzed renal tubular tissue from in vivo and in vitro experiments.

RESULTS

Through animal experiments and sequencing analysis, we first confirmed the protection against IRI and the regulation of mitochondrial dynamics-related factors and inflammatory factors by empagliflozin pretreatment. Then, through hypoxia/reoxygenation (H/R) cellular experiments, we confirmed that empagliflozin could inhibit mitochondrial shortening and division and upregulate OPA1 in human renal tubular epithelial cell line (HK-2) cells. Subsequently, we knocked down OPA1, and mitochondrial division and shortening were observed, which could be alleviated by empagliflozin treatment. Combined with the previous results, we concluded that OPA1 downregulation leads to mitochondrial division and shortening, and empagliflozin can alleviate the condition by upregulating OPA1. We further explored the pathway through which empagliflozin functions. Related studies have shown the activation of AMPK pathway by empagliflozin and the close correlation between the AMPK pathway and OPA1. In our study, we blocked the AMPK pathway, and OPA1 upregulation by empagliflozin was not observed, thus demonstrating the dependence of empagliflozin on the AMPK pathway.

CONCLUSION

The results indicated that empagliflozin could prevent or alleviate renal IRI through antiinflammatory effects and the AMPK-OPA1 pathway. Ischemia-reperfusion injury is an inevitable challenge in organ transplantation. It is necessary to develop a new therapeutic strategy for IRI prevention in addition to refining the transplantation process. In this study, we confirmed the preventive and protective effects of empagliflozin in renal ischemia-reperfusion injury. Based on these findings, empagliflozin is promising to be a preventive agent for renal ischemia-reperfusion injury and can be applied for preemptive administration in kidney transplantation.

Caution may be required in using l-theanine in diabetes mellitus: A study on the rats

BACKGROUND

The study aimed to identify the effects of l-theanine on kidney and heart tissues in diabetic rats. 24 male rats included in the study were divided into 4 groups (n = 6/group): SHAM, LTEA, DM and DM + LTEA. For 28 days, drinking water was given to SHAM and DM, and LTEA (200 mg/kg/day) to LTEA and DM + LTEA groups, intragastrically. DM was induced by 120 mg/kg nicotinamide (NA) + 60 mg/kg streptozotocin (STZ). The levels of cystatin C (CysC) and angiotensin-converting enzyme 2 (ACE2) were determined by ELISA kits, homocysteine, electrolytes and iron by an autoanalyzer, the ratio of oxidized/total reduced glutathione (GSSG/TGSH) by assay kits. The tissues were histopathologically analyzed.

RESULTS

LTEA alleviated histopathological degenerations. However, it decreased significantly serum iron and homocysteine levels (p < 0.05).

CONCLUSION

LTEA did not exhibit significant protective effects on kidney and heart tissues; it may have affected the homocysteine and iron metabolisms in diabetics.

AIF1: Function and Connection with Inflammatory Diseases

Macrophages are a type of immune cell distributed throughout all tissues of an organism. Allograft inflammatory factor 1 (AIF1) is a calcium-binding protein linked to the activation of macrophages. AIF1 is a key intracellular signaling molecule that participates in phagocytosis, membrane ruffling and F-actin polymerization. Moreover, it has several cell type-specific functions. AIF1 plays important roles in the development of several diseases: kidney disease, rheumatoid arthritis, cancer, cardiovascular diseases, metabolic diseases and neurological disorders, and in transplants. In this review, we present a comprehensive review of the known structure, functions and role of AIF1 in inflammatory diseases.

Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors: Harms or Unexpected Benefits?

There is a need for innovative pharmaceutical intervention in light of the increasing prevalence of metabolic disease and cardiovascular disease. The kidneys' sodium-glucose cotransporter 2 inhibitors (SGLT2) receptors are targeted to reduce glucose reabsorption by SGLT2. Patients with type 2 diabetes mellitus (T2DM) benefit the most from reduced blood glucose levels, although this is just one of the numerous physiological consequences. To establish existing understanding and possible advantages and risks for SGLT2 inhibitors in clinical practice, this article will explore the influence of SGLT2 inhibitors on six major organ systems. In addition, this literature review will discuss the benefits and potential drawbacks of SGLT2 inhibitors on various organ systems and their potential application in therapeutic settings.

Protective effects of sitagliptin on methotrexate-induced nephrotoxicity in rats

Methotrexate (MTX), a cytotoxic chemotherapeutic and immunosuppressant agent, is widely used in the treatment of autoimmune diseases and different types of cancers. However, its use has been limited by its life-threatening side effects, including nephrotoxicity and hepatotoxicity. The purpose of this study was to investigate the protective effect of sitagliptin on methotrexate (MTX)-induced nephrotoxicity in rats. Twenty-four rats were divided into four groups: control group, which received the vehicle for 6 days; MTX group, which received a single dose of MTX, followed by five daily doses of vehicle dosing; MTX + sitagliptin group, which received a single dose of MTX 1 h after the first sitagliptin treatment and six daily doses of sitagliptin; and sitagliptin group, which received sitagliptin for 6 days. Both MTX and sitagliptin were given as intraperitoneal injections at a dose of 20 mg/kg body weight. All rats were euthanized on the seventh day of the study. Kidney tissues were harvested and blood samples were collected. Serum levels of blood urea nitrogen (BUN) and creatinine were evaluated. Furthermore, catalase, glutathione peroxidase, superoxide dismutase activities, and malondialdehyde (MDA) levels were determined in kidney tissue. In addition, histopathological analysis was conducted. Histopathological evaluation showed that MTX-induced marked kidney injury. Biochemical analysis revealed a significant increase of BUN and creatinine in the serum of the MTX group. Furthermore, oxidative stress and depressed antioxidant system of the kidney tissues were evident in the MTX group. Sitagliptin did not affect these endpoints when administered alone, but it significantly attenuated the observed MTX-induced effects. These results suggest that sitagliptin exhibits potent anti-oxidant properties against the nephrotoxicity induced by MTX in rats.

Oxidative stress as a culprit in diabetic kidney disease

Diabetic kidney disease (DKD) has become the leading cause of end-stage renal disease (ESRD), and the prevalence of DKD has increased worldwide during recent years. DKD is associated with poor therapeutic outcomes in most patients, but there is limited understanding of its pathogenesis. This review suggests that oxidative stress interacts with many other factors in causing DKD. Highly active mitochondria and NAD(P)H oxidase are major sources of oxidants, and they significantly affect the risk for DKD. Oxidative stress and inflammation may be considered reciprocal causes of DKD, in that each is a cause and an effect of DKD. Reactive oxygen species (ROS) can act as second messengers in various signaling pathways and as regulators of metabolism, activation, proliferation, differentiation, and apoptosis of immune cells. Epigenetic modifications, such as DNA methylation, histone modifications, and non-coding RNAs can modulate oxidative stress. The development of new technologies and identification of new epigenetic mechanisms may provide novel opportunities for the diagnosis and treatment of DKD. Clinical trials demonstrated that novel therapies which reduce oxidative stress can slow the progression of DKD. These therapies include the NRF2 activator bardoxolone methyl, new blood glucose-lowering drugs such as sodium-glucose cotransporter 2 inhibitors, and glucagon-like peptide-1 receptor agonists. Future studies should focus on improving early diagnosis and the development of more effective combination treatments for this multifactorial disease.

Semaglutide inhibits ischemia/reperfusion-induced cardiomyocyte apoptosis through activating PKG/PKCε/ERK1/2 pathway

Apoptosis is a major pathophysiological change following myocardial ischemia/reperfusion (I/R) injury. Glucagon-like peptide 1 (GLP-1) and its receptor GLP-1R are widely expressed in the cardiovascular system and GLP-1/GLP-1R activates the protein kinase G (PKG)-related signaling pathway. Therefore, this study tested whether semaglutide, a new GLP-1 analog, inhibits I/R injury-induced cardiomyocyte apoptosis by activating the PKG/PKCε/ERK1/2 pathway. We induced myocardial I/R injury in rats and hypoxia/reoxygenation (H/R) injury in H9C2 cells and detected the effects of semaglutide, a PKG analog (8-Br-cGMP), and a PKG inhibitor (KT-5823) on the PKG/PKCε/ERK1/2 pathway and cardiomyocyte apoptosis. We found that semaglutide upregulated GLP-1R levels, and both semaglutide and 8-Br-cGMP activated the PKG/PKCε/ERK1/2 pathway, inhibited myocardial infarction (MI), decreased hs-cTNT levels, increased NT-proBNP levels, and suppressed cardiomyocyte apoptosis in I/R rats and H/R H9C2 cells. However, KT-5823 exerted contrasting effects with semaglutide and 8-Br-cGMP, and KT-5823 weakened the cardioprotective effects of semaglutide. In conclusion, semaglutide inhibits I/R injury-induced cardiomyocyte apoptosis by activating the PKG/PKCε/ERK1/2 pathway. The beneficial effect of GLP-1/GLP-1R, involved in the activation of the PKG/PKCε/ERK1/2 pathway, may provide a novel treatment method for myocardial I/R injury.

Gliflozins Have an Anti-Inflammatory Effect on Renal Proximal Tubular Epithelial Cells in a Diabetic and Inflammatory Microenvironment In Vitro

Inflammation is intimately involved in the pathogenesis of diabetic kidney disease. Inhibition of SGLT-2 by a specific class of drugs, gliflozins, has been shown to reduce inflammation and attenuate the progression of diabetic nephropathy, in addition to its main effect of inhibiting renal glucose reabsorption. We used highly purified human renal proximal tubular epithelial cells (PTCs) as an in vitro model to study the cellular response to a diabetic (high glucose) and inflammatory (cytokines) microenvironment and the effect of gliflozins. In this context, we investigated the influence of SGLT-2 inhibition by empa- and dapagliflozin (500 nM) on the expression of pro-inflammatory factors (IL-1β, IL-6, TNF-α, MCP-1, and ICAM-1). The results clearly indicate an anti-inflammatory effect of both gliflozins. Although induced expression of the four cytokines was only slightly attenuated, there was a clear effect on the expression of the adhesion molecule ICAM-1, a master regulator of cellular responses in inflammation and injury resolution. The induced expression of ICAM-1 mRNA was significantly reduced by approximately 13.5% by empagliflozin and also showed an inhibitory trend with dapagliflozin. However, induced ICAM-1 protein expression was significantly inhibited from 24.71 ± 1.0 ng/mL to 18.81 ± 3.9 (empagliflozin) and 19.62 ± 2.1 ng/mL (dapagliflozin). In conclusion, an additional anti-inflammatory effect of empa- and dapagliflozin in therapeutically observed concentrations was demonstrated in primary human PTCs in vitro.

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.

Baicalin Exerts a Protective Effect in Diabetic Nephropathy by Repressing Inflammation and Oxidative Stress Through the SphK1/S1P/NF-κB Signaling Pathway

Background

Inflammation and oxidative stress contribute to the development of diabetic nephropathy (DN). Baicalin (BA) shows renal protection against DN through its anti-inflammatory and anti-oxidant properties. However, the molecular mechanism by which BA exerts the therapeutic effects on DN remains to be investigated.

Methods

The db/db mice and high glucose (HG)-induced HK-2 cells were used as the in vivo and in vitro model of DN, respectively. The effects of BA were assessed by detecting the related blood and urine biochemical parameters, kidney histopathology, inflammatory cytokine production, oxidative stress indicators, and apoptosis. Cell viability and apoptosis were detected by CCK-8 assay and TUNEL assay, respectively. Related protein levels were measured by an immunoblotting method.

Results

In db/db model mice, BA reduced serum glucose concentration, decreased blood lipid levels, ameliorated kidney functions, and decreased histopathological changes in kidney tissues. BA also alleviated oxidative stress and inflammation in db/db mice. In addition, BA blocked the activation of sphingosine kinases type 1/sphingosine 1-phosphate (SphK1/S1P)/NF-κB pathway in db/db mice. In HK-2 cells, BA hindered HG-induced apoptosis, oxidative stress and inflammation, while overexpression of SphK1 or S1P could reverse these effects. BA alleviated HG-induced apoptosis, oxidative stress and inflammation in HK-2 cells through the S1P/NF-κB pathway. Furthermore, BA blocked the NF-κB signaling by diminishing p65 nuclear translocation via the SphK1/S1P pathway.

Conclusion

Our study strongly suggests that BA protects against DN via ameliorating inflammation, oxidative stress and apoptosis through the SphK1/S1P/NF-κB pathway. This study provides a novel insight into the therapeutic effects of BA in DN.

Sodium-Glucose Cotransporter 2 (SGLT2) Inhibitors: Benefits Versus Risk

With the growing burden of metabolic disease, cardiovascular disease, and diabetes mellitus, there is an implication for new pharmacological intervention. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are a class of drugs that work on SGLT2 receptors in the kidneys to decrease glucose reabsorption. Lowering glucose levels mainly aids those with type 2 diabetes (T2DM), but they also have many other effects on the body. This article will investigate the impact of SGLT2i on six relevant organ systems; to establish current knowledge and potential benefits and risk for SGLTi in clinical practice. The medications that inhibit SGLT2 suffix with flozins are known to help decrease hypertension, acute cardiac failure, and bradycardia in the cardiovascular system. Flozins were found to aid with acute pulmonary edema, asthma, bronchitis, and chronic obstructive pulmonary disease (COPD) in the pulmonary system. SGLT2 is also found in the blood-brain barrier (BBB), and as such, SGLT2i can also affect the central nervous system (CNS). They reduced reactive oxygen species (ROS), BBB leakage, microglia burden, and acetylcholinesterase (AChE) levels. In the liver, this class of drugs can also assist with non-alcoholic fatty liver disease (NAFLD), hepatotoxicity, and weight loss. In the pancreas, SGLT2i has been shown to help with primarily diabetes and hyperglycemia. Finally, SGLT2i's are known to aid in decreasing nephrotoxicity and stopping the progression of the glomerular filtration rate (GFR) decrease. New studies have shown that the flozin drugs have been helpful for those who were receiving kidney transplants. Despite the positive effects, there are some concerns about SGLT2i and its notable adverse effects. Flozin drugs are known to cause urinary tract infections (UTIs), dehydration, orthostatic hypotension, postural dizziness, syncope, hypotension, hyperkalemia-induced cardiac arrest, and pancreatitis. This literature review will discuss, in detail, the benefits and risks that SGTL2i have on different organ systems and implicate the role they may play in clinical practice.

Considering the protective effect of exendin-4 against oxidative stress in spiral ganglion neurons

Objectives

The protection of spiral ganglion neurons (SGNs) is crucial for hearing loss. Exendin-4 has been shown to have neuroprotective effects in several neurological disorders. Therefore, this study aimed to investigate the effect of the glucagon-like protein-1 receptor (GLP-1R) agonist exendin-4 on kanamycin-induced injury in mouse SGNs in vitro.

Materials and Methods

In this study, GLP-1R expression in SGNs was verified by immunofluorescence and immunohistochemical staining. In vitro-cultured SGNs and the organ of Corti were exposed to kanamycin with or without exendin-4 treatment. The cell survival rate was measured using the cell counting kit-8 assay, and the damage to auditory nerve fibers (ANF) projecting radially from the SGNs was evaluated using immunofluorescence staining. Reactive oxygen species (ROS) content was determined by flow cytometry, and glutathione peroxidase (GSH-Px) content, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content were determined by spectrophotometry. Protein expression of nuclear factor erythroid-2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) was detected using western blotting.

Results

GLP-1R was expressed in SGNs. Treatment with 1 mM kanamycin for 24 hr induced SGN damage. Exendin-4 (100 nM) had a protective effect against kanamycin-induced SGN cell injury, improved cell survival rate, reduced nerve fiber injury, increased SOD activity and GSH-Px level, and reduced MDA and ROS contents. The Nrf2/HO-1 pathway was activated.

Conclusion

Exendin-4 alleviates oxidative damage and exerts neuroprotective effects in kanamycin-induced SGN injury through the Nrf2/HO-1 signaling pathway. Exendin-4 has the potential to prevent or treat hearing loss due to SGN damage.

Advance in the Correlation between Diabetic Nephropathy and Abnormal Serum Thyroid Hormone Levels in Patients

This study was developed to explore the correlation between diabetic nephropathy (DN) and abnormal serum thyroid hormone (TH) levels in patients, which can provide a reference for disease prevention and control in patients with DN. DN is the most serious complication of diabetes. The mortality rate of diabetic patients with DN is approximately 30 times higher than that of diabetic patients without DN. DN leads to high blood sugar, which causes vascular dysfunction in patients, causes cardiovascular disease, aggravates the disease and disease complexity, and thus increases the mortality of patients. DN patients often have oxidative stress and even fibrosis in severe cases. TH has a potential renal protective effect and can also regulate glucose metabolism and improve abnormal glucose tolerance and insulin resistance. Abnormal serum TH levels increase the risk of DN. Normal thyroid function plays an important role in regulating the physiological functions of the human body. Hormonal disorders promote the development of diabetes mellitus (DM) into DN. The pathogenesis, clinical manifestations, detection, and treatment methods of DN were reviewed in this study. The research progress of the influence of TH on DN was analyzed. This study is conducive to clinical research on DN and provides a reference.

Identification of Oxidative Stress-Related Biomarkers in Diabetic Kidney Disease

BACKGROUND

Diabetic kidney disease (DKD) is a leading cause of end-stage renal disease throughout the world. In kidney disease, oxidative stress has been linked to both antioxidant depletions and increased reactive oxygen species (ROS) production. Thus, the objective of this study was to identify biomarkers related to oxidative stress in DKD.

METHODS

The gene expression profile of the DKD was extracted from the Gene Expression Omnibus (GEO) database. The identification of the differentially expressed genes (DEGs) was performed using the "limma" R package, and weighted gene coexpression network analysis (WGCNA) was used to find the gene modules that were most related to DKD. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed using "Org.Hs.eg.db" R package. The protein-protein interaction (PPI) network was constructed using the STRING database. The hub genes were identified by the Molecular Complex Detection (MCODE) plug-in of Cytoscape software. The diagnostic capacity of hub genes was verified using the receiver operating characteristic (ROC) curve. Correlations between diagnostic genes were analyzed using the "corrplot" package. In addition, the miRNA gene transcription factor (TF) network was used to explain the regulatory mechanism of hub genes in DKD.

RESULTS

DEGs analysis and WGCNA-identified 160 key genes were identified in DKD patients. Among them, nine oxidative stress-related genes were identified as candidate hub genes for DKD. Using the PPI network, five hub genes, NR4A2, DUSP1, FOS, JUN, and PTGS2, were subsequently identified. All the hub genes were downregulated in DKD and had a high diagnostic value of DKD. The regulatory mechanism of hub genes was analyzed from the miRNA gene-TF network.

CONCLUSION

Our study identified NR4A2, DUSP1, FOS, JUN, and PTGS2 as hub genes of DKD. These genes may serve as potential therapeutic targets for DKD patients.

Prognosis and risk factors of chronic kidney disease progression in patients with diabetic kidney disease and non-diabetic kidney disease: a prospective cohort CKD-ROUTE study

Diabetic kidney disease (DKD) is emerging rapidly as the leading cause of chronic kidney disease (CKD) worldwide. In this 3-year prospective, multicenter cohort study, a total of 1138 pre-dialysis CKD patients were recruited. Patients were categorized into two groups according to the etiologies of DKD and non-diabetic kidney disease (NDKD). Propensity score matching was performed to adjust for confounding factors, resulting in 197 patients being assigned to DKD and NDKD groups, respectively. The primary endpoints were 50% estimated glomerular filtration rate (eGFR) decline and initiation of kidney replacement therapy (KRT). The secondary endpoints were all-cause death and the development of cardiovascular disease (CVD) events. We found that DKD patients have a higher risk to develop 50% eGFR decline endpoint (HR:2.30, 95%CI [1.48-3.58], p < 0.001) and KRT endpoint (HR:1.64, 95%CI [1.13-2.37], p < 0.05) than NDKD patients. The 3-year cumulative incidence of 50% eGFR decline and KRT endpoint was significantly higher in DKD patients (26.90% vs.13.71% and 35.03% vs. 22.34%, respectively). The Cox regression analyses showed that the increased systolic blood pressure (SBP), DKD, decreased serum albumin (Alb), and higher CKD stages were risk factors for the 50% eGFR decline endpoint; the increased SBP, DKD, decreased serum Alb, serum creatinine (Scr), higher CKD stages, presence of proteinuria and CVD were risk factors for KRT endpoint; the increased age, decreased hemoglobin (Hb), decreased serum Alb were risk factors for all-cause death endpoint; the increased age, decreased serum Alb were risk factors for CVD events endpoint. Appropriate preventive or therapeutic interventions should be taken to control these predictive factors to delay the development of CKD complications, thereby improving the prognosis and reducing the disease burden of the high-risk populations.

The effect of sodium-glucose cotransporter 2 inhibitors on biomarkers of inflammation: A systematic review and meta-analysis of randomized controlled trials

Aims: Inflammatory biomarkers may play vital roles in the pathophysiology of diabetes and diabetic cardiorenal complications. Sodium-glucose cotransporter-2 (SGLT2) inhibitors have a potential cardiovascular and renal protective effect in type 2 diabetes. The aim of this meta-analysis was to quantify the effects of SGLT2 inhibitors on biomarkers of inflammation in randomized controlled trials (RCTs). Methods: PubMed, Cochrane Library, EMBASE, and Web of Science were searched for eligible RCTs of adults with type 2 diabetes (T2D) with no time limit (updated to 12 October 2022). The biomarkers selected included C-reactive protein (CRP), interleukin-6, tumor necrosis factor-alpha, leptin, adiponectin, ferritin, plasminogen activator inhibitor (PAI)-1, and vascular cell adhesion molecule-1. Data were analyzed using a random-effect model in Review Manager 5.4. Results: Thirty-four studies with 6,261 patients (68.6% male) were eligible for this meta-analysis. The mean age of the participants was 62.57(±11.13) years old, and the median treatment duration length with follow-up was 24 weeks. Generally, the included trials were of good methodological quality. The meta-analysis revealed that ferritin levels were significantly reduced in SGLT2 inhibitor treatment groups versus placebo or standard diabetes therapies (SMD: -1.21; 95% CI: -1.91, -0.52, p < 0.001). The effects of CRP (SMD: 0.25; 95% CI: -0.47, -0.03, p = 0.02) and leptin (SMD: -0.22; 95% CI: -0.43, -0.01, p = 0.04) were reduced, and the effects of adiponectin were improved (SMD: 0.28; 95% CI: 0.15, 0.41, p < 0.001) in placebo-controlled studies. PAI-1 levels were significantly reduced in studies controlled for diabetes therapies (SMD: -0.38; 95% CI: -0.61, -0.15, p = 0.001). Conclusion: This analysis provides strong evidence supporting anti-inflammatory effects of SGLT2 inhibitors in T2D subjects. The mechanisms and possible targets for the inflammation reducing and cardiorenal protective properties of SGLT2 inhibitors remain to be explored.

Aggravated renal fibrosis is positively associated with the activation of HMGB1-TLR2/4 signaling in STZ-induced diabetic mice

Diabetic kidney dysfunction is closely associated with renal fibrosis. Although the suppression of fibrosis is crucial to attenuate kidney damage, the underlying mechanisms remain poorly understood. In this study, renal injury in diabetic mice was induced by the intraperitoneal injection of streptozotocin (100 or 150 mg/kg) for 2 consecutive days. In the model mice, remarkable renal injury was observed, manifested by albuminuria, swelling of kidneys, and histopathological characteristics. The renal fibrosis was obviously displayed with high-intensity staining of fibrin, type IV collagen (Col IV), and fibronectin. The levels of Col IV and transforming growth factor-β1 were significantly increased in diabetic mice kidneys. The aggravated fibrotic process was associated with the overexpression of HMGB1, TLR2/4, and p-NF-κB. Furthermore, a high expression of F4/80 and CD14 indicated that macrophage infiltration was involved in perpetuating inflammation and subsequent fibrosis in the kidneys of diabetic mice. The results demonstrate that the severity of renal fibrosis is positively associated with the activation of HMGB1/TLR2/4 signaling in diabetes.

The Anti-Inflammatory Effect of Novel Antidiabetic Agents

The incidence of type 2 diabetes (T2DM) has been increasing worldwide and remains one of the leading causes of atherosclerotic disease. Several antidiabetic agents have been introduced in trying to regulate glucose control levels with different mechanisms of action. These agents, and sodium-glucose cotransporter-2 inhibitors in particular, have been endorsed by contemporary guidelines in patients with or without T2DM. Their widespread usage during the last three decades has raised awareness in the scientific community concerning their pleiotropic mechanisms of action, including their putative anti-inflammatory effect. In this review, we delve into the anti-inflammatory role and mechanism of the existing antidiabetic agents in the cardiovascular system and their potential use in other chronic sterile inflammatory conditions.

The Role of NF-κB and Bax/Bcl-2/Caspase-3 Signaling Pathways in the Protective Effects of Sacubitril/Valsartan (Entresto) against HFD/STZ-Induced Diabetic Kidney Disease

LCZ696 (valsartan/sacubitril) has the potential to slow the progression of diabetic kidney disease (DKD) according to previous reports. However, the renoprotective mechanism underlying LCZ696 remains unknown. This study aimed to investigate the therapeutic potential and underlying mechanism of LCZ696 in DKD in a type 2 diabetic (T2D) rat model. This model was established in this experiment by feeding a high-fat diet (HFD) for six weeks with a single dose of streptozotocin (STZ, 30 mg/kg body weight). Valsartan or LCZ696 was orally administered to T2D animals for eight weeks. HFD/STZ rats showed hyperglycemia, impaired insulin secretion, significant increases in urea, creatinine, cytokines, nuclear factor kappa B (NF-κB), oxidative stress, caspase-3 activity, glomerular and tubular damage, glomerulsclerosis, Bax and caspese-3 expressions along with a significant decline in IL-10, antioxidant markers, and Bcl-2 expression. The administration of LCZ696 to diabetic rats reduced the serum concentrations of glucose, urea, and creatinine. In addition, ELISA results demonstrated that diabetic rats treated with LCZ696 exhibited a reduction in inflammatory (IL-1β, TNF-α, IL-6) and an increase in anti-inflammatory (IL-10) cytokine levels. In addition, a notable decrease in NF-κB and caspase-3 activity was observed. At the level of renal tissue homogenate, diabetic animals treated with LCZ696 demonstrated clear restorations in GSH content and other antioxidant enzyme levels, in addition to a significant decrease in TBARS levels. In addition, LCZ696 inhibited the expression of the Bax and cleaved caspase-3 proteins and enhanced the expression of the Bcl-2 protein. Improvements in histopathological changes in kidney tissues confirmed and significantly supported these biochemical findings. In summary, LCZ696 alleviated DKD with possible mechanisms including inhibition of inflammation and apoptosis.

The Effect of Allograft Inflammatory Factor-1 on Inflammation, Oxidative Stress, and Autophagy via miR-34a/ATG4B Pathway in Diabetic Kidney Disease

Increasing evidence suggests that disorders of inflammation, oxidative stress, and autophagy contribute to the pathogenesis of diabetic kidney disease (DKD). This study attempted to clarify the effect of allograft inflammatory factor-1 (AIF-1), miR-34a, and ATG4B on inflammation, oxidative stress, and autophagy in DKD both in vitro and in vivo experiments. In vivo, it was found that the levels of AIF-1, miR-34a, oxidative stress, and inflammatory factors were significantly increased in blood and urine samples of DKD patients and mouse models and correlated with the level of urinary protein. In vitro, it was also found that the expressions of AIF-1, miR-34a, ROS, and inflammatory factors were increased, while ATG4B and other autophagy related proteins were decreased in human renal glomerular endothelial cells (HRGECs) cultured with high concentration glucose medium (30 mmol/L). When AIF-1 gene was overexpressed, the levels of miR-34a, ROS, and inflammatory factors were significantly upregulated, and autophagy-related proteins such as ATG4B were downregulated, while downregulation of AIF-1 gene had the opposite effect. In addition, miR-34a inhibited the expression of ATG4B and autophagy-related proteins and increased the levels of ROS and inflammation. Furthermore, the result of luciferase reporter assay suggested that ATG4B was the target gene of miR-34a. When ATG4B gene was overexpressed, the level of autophagy was upregulated, and inflammatory factors were downregulated. Conversely, when ATG4B gene was inhibited, the level of autophagy was downregulated, and inflammatory factors were upregulated. Then, autophagy inducers inhibited the levels of inflammation and ROS, whereas autophagy inhibitors had the opposite function in HRGECs induced by glucose (30 mmol/L). In conclusion, the above data suggested that AIF-1 regulated the levels of inflammation, oxidative stress, and autophagy in HRGECs via miR-34a/ATG4B pathway to contribute to the pathogenesis of diabetic kidney disease.

KITLG Promotes Glomerular Endothelial Cell Injury in Diabetic Nephropathy by an Autocrine Effect

Diabetic nephropathy (DN) is an increasing threat to human health. The impact of hyperglycemia or its metabolites, advanced glycation end-products (AGEs), on glomerular endothelial cells (GECs) and their pathophysiologic mechanisms are not well explored. Our results reveal that AGEs increased the expression and secretion of the KIT ligand (KITLG) in GECs. Both AGEs and KITLG promoted endothelial-to-mesenchymal transition (EndoMT) in GECs and further increased the permeability of GECs through the AKT/extracellular-signal-regulated kinase pathway. Inhibition of KITLG’s effects by imatinib prevented AGE-medicated EndoMT in GECs, supporting the belief that KITLG is a critical factor for GEC injury. We found higher KITLG levels in the GECs and urine of db/db mice compared with db/m mice, and urinary KITLG levels were positively correlated with the urinary albumin-to-creatinine ratio (ACR). Furthermore, type 2 diabetic patients had higher urinary KITLG levels than normal individuals, as well as urinary KITLG levels that were positively correlated with urinary ACR and negatively correlated with the estimated glomerular filtration rate. KITLG plays a pathogenic role in GEC injury in DN and might act as a biomarker of DN progression.

Targeting innate immunity-driven inflammation in CKD and cardiovascular disease

Mortality among patients with chronic kidney disease (CKD) is largely a consequence of cardiovascular disease (CVD) and is a particular concern given the increasing prevalence of CKD. Sterile inflammation triggered by activation of the innate immune system is an important driver of both CKD and associated CVD. Several endogenous mediators, including lipoproteins, crystals such as silica, urate and cholesterol crystals, or compounds released from dying cells interact with pattern recognition receptors expressed on a variety of different cell types, leading to the release of pro-inflammatory cytokines. Disturbed regulation of the haematopoietic system by damage-associated molecular patterns, or as a consequence of clonal haematopoiesis or trained innate immunity, also contributes to the development of inflammation. In observational and genetic association studies, inflammation is linked to the progression of CKD and cardiovascular events. In 2017, the CANTOS trial of canakinumab provided evidence that inhibiting inflammation driven by NLRP3-IL-1-IL-6-mediated signalling significantly reduced cardiovascular event rates in individuals with and without CKD. Other approaches to target innate immune pathways are now under investigation for their ability to reduce cardiovascular events and slow disease progression among patients with atherosclerosis and stage 3 and 4 CKD. This Review summarizes current understanding of the role of inflammation in the pathogenesis of CKD and its associated CVD, and how this knowledge may translate into novel therapeutics.

Oxidative Stress and NRF2/KEAP1/ARE Pathway in Diabetic Kidney Disease (DKD): New Perspectives

Diabetes mellitus (DM) is one of the most debilitating chronic diseases worldwide, with increased prevalence and incidence. In addition to its macrovascular damage, through its microvascular complications, such as Diabetic Kidney Disease (DKD), DM further compounds the quality of life of these patients. Considering DKD is the main cause of end-stage renal disease (ESRD) in developed countries, extensive research is currently investigating the matrix of DKD pathophysiology. Hyperglycemia, inflammation and oxidative stress (OS) are the main mechanisms behind this disease. By generating pro-inflammatory factors (e.g., IL-1,6,18, TNF-α, TGF-β, NF-κB, MCP-1, VCAM-1, ICAM-1) and the activation of diverse pathways (e.g., PKC, ROCK, AGE/RAGE, JAK-STAT), they promote a pro-oxidant state with impairment of the antioxidant system (NRF2/KEAP1/ARE pathway) and, finally, alterations in the renal filtration unit. Hitherto, a wide spectrum of pre-clinical and clinical studies shows the beneficial use of NRF2-inducing strategies, such as NRF2 activators (e.g., Bardoxolone methyl, Curcumin, Sulforaphane and their analogues), and other natural compounds with antioxidant properties in DKD treatment. However, limitations regarding the lack of larger clinical trials, solubility or delivery hamper their implementation for clinical use. Therefore, in this review, we will discuss DKD mechanisms, especially oxidative stress (OS) and NRF2/KEAP1/ARE involvement, while highlighting the potential of therapeutic approaches that target DKD via OS.

The critical role of dysregulated autophagy in the progression of diabetic kidney disease

Diabetic kidney disease (DKD) is one of the major public health problems in society today. It is a renal complication caused by diabetes mellitus with predominantly microangiopathy and is a major cause of end-stage renal disease (ESRD). Autophagy is a metabolic pathway for the intracellular degradation of cytoplasmic products and damaged organelles and plays a vital role in maintaining homeostasis and function of the renal cells. The dysregulation of autophagy in the hyperglycaemic state of diabetes mellitus can lead to the progression of DKD, and the activation or restoration of autophagy through drugs is beneficial to the recovery of renal function. This review summarizes the physiological process of autophagy, illustrates the close link between DKD and autophagy, and discusses the effects of drugs on autophagy and the signaling pathways involved from the perspective of podocytes, renal tubular epithelial cells, and mesangial cells, in the hope that this will be useful for clinical treatment.

Results of a multidisciplinary strategy to improve the management of cardiovascular risk factors after liver transplantation

Although liver transplantation (LT) recipients are at high cardiovascular risk (CVR), the management of CVR factors (CVRF) after LT is far from optimal and needs to be improved. For this reason, we developed a multidisciplinary protocol to standardize the identification, risk stratification, management, and targets of therapy of CVRF during the first post-LT year. The grade of identification and control of CVRF 12 months after LT in the postintervention cohort (LT January 2018-January 2020, n = 150) were compared with a control cohort who underwent LT between July 2015 and December 2016 (n = 100). Before LT, the prevalence of metabolic-associated fatty liver disease as the indication of LT and the presence of obesity were significantly higher in the postintervention cohort, whereas the prevalence of other CVRF and renal dysfunction tended to be higher. Cyclosporine A was used less frequently in the postintervention cohort, whereas everolimus tended to increase. At 12 months after LT, the proportion of patients with measured blood pressure (88% vs. 56%), glycosilated hemoglobin (HbA1c; 96% vs. 72%), and high-density lipoprotein/low-density lipoprotein cholesterol (67% vs. 33%) was higher in the postintervention than in the control cohort (all p < 0.001). Blood pressure (64% vs. 36%, p = 0.02) and HbA1c (85% vs. 70%, p = 0.1) were within target in more individuals with hypertension and diabetes mellitus, respectively, in the postintervention cohort. Median total cholesterol levels were lower in the postintervention (184 mg/dl; interquartile range [IQR], 160-210 mg/dl) than in the control cohort (212 mg/dl; IQR, 186-240 mg/dl; p = 0.02). At 2 years after LT, the incidence of cardiovascular events was 14% in the control cohort and 6% in the postintervention cohort (p = 0.063). In conclusion, a multidisciplinary, multiprofessional strategy can achieve a higher grade of assessment and management of post-LT CVR despite a worsening metabolic profile of LT recipients.

Activated Protein C Ameliorates Tubular Mitochondrial Reactive Oxygen Species and Inflammation in Diabetic Kidney Disease

Diabetic kidney disease (DKD) is an emerging pandemic, paralleling the worldwide increase in obesity and diabetes mellitus. DKD is now the most frequent cause of end-stage renal disease and is associated with an excessive risk of cardiovascular morbidity and mortality. DKD is a consequence of systemic endothelial dysfunction. The endothelial-dependent cytoprotective coagulation protease activated protein C (aPC) ameliorates glomerular damage in DKD, in part by reducing mitochondrial ROS generation in glomerular cells. Whether aPC reduces mitochondrial ROS generation in the tubular compartment remains unknown. Here, we conducted expression profiling of kidneys in diabetic mice (wild-type and mice with increased plasma levels of aPC, APC^high mice). The top induced pathways were related to metabolism and in particular to oxidoreductase activity. In tubular cells, aPC maintained the expression of genes related to the electron transport chain, PGC1-α expression, and mitochondrial mass. These effects were associated with reduced mitochondrial ROS generation. Likewise, NLRP3 inflammasome activation and sterile inflammation, which are known to be linked to excess ROS generation in DKD, were reduced in diabetic APC^high mice. Thus, aPC reduces mitochondrial ROS generation in tubular cells and dampens the associated renal sterile inflammation. These studies support approaches harnessing the cytoprotective effects of aPC in DKD.

Screening and Identification of Hub Genes in the Development of Early Diabetic Kidney Disease Based on Weighted Gene Co-Expression Network Analysis

Objective

The study aimed to screen key genes in early diabetic kidney disease (DKD) and predict their biological functions and signaling pathways using bioinformatics analysis of gene chips interrelated to early DKD in the Gene Expression Omnibus database.

Methods

Gene chip data for early DKD was obtained from the Gene Expression Omnibus expression profile database. We analyzed differentially expressed genes (DEGs) between patients with early DKD and healthy controls using the R language. For the screened DEGs, we predicted the biological functions and relevant signaling pathways by enrichment analysis of Gene Ontology (GO) biological functions and Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways. Using the STRING database and Cytoscape software, we constructed a protein interaction network to screen hub pathogenic genes. Finally, we performed immunohistochemistry on kidney specimens from the Beijing Hospital to verify the above findings.

Results

A total of 267 differential genes were obtained using GSE142025, namely, 176 upregulated and 91 downregulated genes. GO functional annotation enrichment analysis indicated that the DEGs were mainly involved in immune inflammatory response and cytokine effects. KEGG pathway analysis indicated that C-C receptor interactions and the IL-17 signaling pathway are essential for early DKD. We identified FOS, EGR1, ATF3, and JUN as hub sites of protein interactions using a protein-protein interaction network and module analysis. We performed immunohistochemistry (IHC) on five samples of early DKD and three normal samples from the Beijing Hospital to label the proteins. This demonstrated that FOS, EGR1, ATF3, and JUN in the early DKD group were significantly downregulated.

Conclusion

The four hub genes FOS, EGR1, ATF3, and JUN were strongly associated with the infiltration of monocytes, M2 macrophages, and T regulatory cells in early DKD samples. We revealed that the expression of immune response or inflammatory genes was suppressed in early DKD. Meanwhile, the FOS group of low-expression genes showed that the activated biological functions included mRNA methylation, insulin receptor binding, and protein kinase A binding. These genes and pathways may serve as potential targets for treating early DKD.

Emerging Roles of Sodium Glucose Cotransporter 2 (SGLT-2) Inhibitors in Diabetic Cardiovascular Diseases: Focusing on Immunity, Inflammation and Metabolism

Diabetes mellitus (DM) is one of the most fast evolving global issues characterized by hyperglycemia. Patients with diabetes are considered to face with higher risks of adverse cardiovascular events. Those are the main cause of mortality and disability in diabetes patients. There are novel antidiabetic agents that selectively suppress sodium-glucose cotransporter-2 (SGLT-2). They work by reducing proximal tubule glucose reabsorption. Although increasing evidence has shown that SGLT-2 inhibitors can contribute to a series of cardiovascular benefits in diabetic patients, including a reduced incidence of major adverse cardiovascular events and protection of extracardiac organs, the potential mechanisms of SGLT2 inhibitors’ cardiovascular protective effects are still not fully elucidated. Given the important role of inflammation and metabolism in diabetic cardiovascular diseases, this review is intended to rationally compile the multifactorial mechanisms of SGLT-2 inhibitors from the point of immunity, inflammation and metabolism, depicting the fundamental cellular and molecular processing of SGLT-2 inhibitors exerting regulating immunity, inflammation and metabolism. Finally, future directions and perspectives to prevent or delay cardiovascular complications in DM by SGLT-2 inhibitors are presented.

Development and Validation of a Prediction Model for 5-Year Risk of Kidney Dysfunction in Patients with Hypertension and Glucose Metabolism Disorder

Purpose

Patients with hypertension and glucose metabolism disorder (GMD) are at high risk of developing kidney dysfunction (KD). Therefore, we aimed to develop a nomogram for predicting individuals’ 5-year risk of KD in hypertensives with GMD.

Patients and Methods

In total, 1961 hypertensives with GMD were consecutively included. Baseline data were extracted from medical electronic system, and follow-up data were obtained using annual health check-ups or hospital readmission. KD was defined as estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m². Subjects were randomly divided into training and validation sets with a ratio of 7 to 3. Least absolute shrinkage and selection operator method was used to identify potential predictors. Cox proportional hazard model was applied to build a nomogram for predicting KD risk. The discriminative ability, calibration and usefulness of the model were evaluated. The prediction model was verified by internal validation.

Results

During the follow-up of 5351 person-years with a median follow-up of 32 (range: 3–91) months, 130 patients developed KD. Age, sex, ethnicity, hemoglobin A1c, uric acid, and baseline eGFR were identified as significant predictors for incident KD and used for establishing nomogram. The prediction model displayed good discrimination with C-index of 0.770 (95% CI: 0.712–0.828) and 0.763 (95% CI: 0.704–0.823) in training and validation sets, respectively. Calibration curve indicated good agreement between the predicted and actual probabilities. The decision curve analysis demonstrated that the model was clinically useful.

Conclusion

The prediction nomogram, including six common easy-to-obtain factors, shows good performance for predicting 5-year risk of KD in hypertensives with GMD. This quantitative tool could help clinicians, and even primary care providers, recognize potential KD patients early and make strategy for prevention and management.