Advanced glycation end products induce the apoptosis of and inflammation in mouse podocytes through CXCL9-mediated JAK2/STAT3 pathway activation

CXCL5 inhibition improves kidney function by protecting renal tubular epithelial cells in diabetic kidney disease

Inflammation is one of exacerbating factors of diabetic kidney disease (DKD). Upregulated CXCL5 is found in clinical and experimental diabetes studies. This study aimed to investigate the impact and mechanism of CXCL5 on DKD. DKD patients with different levels of urine albumin-to-creatinine ratio were enrolled. Leprdb/db mice and CXCL5-knockout diabetic mice were used as mouse models for DKD. Human renal tubular epithelial cells were used for in vitro experiments. Circulating CXCL5 were increased in DKD patients compared to the non-DKD subjects. CXCL5 inhibition through CXCL5-neutralizing antibodies or genetic knockout improved kidney function and ameliorated tubular injury and renal fibrosis. In high-glucose-stimulated tubular epithelial cells, administration of CXCL5-neutralizing antibodies or siRNA resulted in reduced phospho-JNK/c-JUN/p65 and the downstream inflammatory, fibrotic, and apoptotic protein expressions. Administration of CXCR2 and JNK inhibitors impeded the CXCL5-induced tubular epithelial cell damages. In conclusion, these findings indicated that anti-CXCL5 strategies may be potential treatments for DKD.

Peperomia pellucida (L.) Kunth suppresses glycation-induced inflammatory response in human retinal pigment epithelial cell line ARPE-19 via JAK-STAT3 signaling

The formation of advanced glycation end product (AGE) is a risk factor for diabetic retinopathy. Since the current treatment for diabetic retinopathy is accompanied by side effects, preliminary findings have suggested Peperomia pellucida (L.) Kunth as a potential alternative therapeutic option for diabetic retinopathy. This study aimed to elucidate the anti-inflammatory mechanism of P. pellucida in the AGE-stimulated human retinal pigment epithelial cell line ARPE-19. Phytochemical analysis revealed phenylpronanoids, terpenes, and fatty acids in P. pellucida. Through in vitro cell viability assay, the P. pellucida methanolic extract (IC50 = 8.70 mg/mL) and ethyl acetate fraction (IC50 = 7.34 mg/mL) were considered as non toxic for ARPE-19. AGE induced an inflammatory response in ARPE-19 by upregulating the gene (2.4-5.8-fold) and protein (1.4-2.3-fold) expression of signal transducer and activator of transcription 3 (STAT3), interleukin-8 (IL-8), monocyte chemoattractant protein-1, matrix metalloproteinase 2, and vascular endothelial growth factor. At 1.5 mg/mL, P. pellucida methanolic extract suppressed IL-8 expression (p < 0.05), implying its anti-inflammatory action at the early inflammatory stage through the Janus kinase (JAK)-STAT3 pathway. The methanolic extract also restored the ARPE-19 viability under AGE-induced inflammatory stress. The downregulation of inflammatory biomarkers along the JAK-STAT3 pathway suggested P. pellucida as a promising anti-inflammatory source for diabetic retinopathy.

Podocyte programmed cell death in diabetic kidney disease: Molecular mechanisms and therapeutic prospects

Diabetic kidney disease (DKD) is the primary cause of chronic kidney and end-stage renal disease. Glomerular podocyte loss and death are pathological hallmarks of DKD, and programmed cell death (PCD) in podocytes is crucial in DKD progression. PCD involves apoptosis, autophagy, ferroptosis, pyroptosis, and necroptosis. During DKD, PCD in podocytes is severely impacted and primarily characterized by accelerated podocyte apoptosis and suppressed autophagy. These changes lead to a gradual decrease in podocyte numbers, impairing the glomerular filtration barrier function and accelerating DKD progression. However, research on the interactions between the different types of PCD in podocytes is lacking. This review focuses on the novel roles and mechanisms of PCD in the podocytes of patients with DKD. Additionally, we summarize clinical drugs capable of regulating podocyte PCD, present challenges and prospects faced in developing drugs related to podocyte PCD and suggest that future research should further explore the detailed mechanisms of podocyte PCD and interactions among different types of PCD.

Oxidative Stress: A Culprit in the Progression of Diabetic Kidney Disease

Diabetic kidney disease (DKD) is the principal culprit behind chronic kidney disease (CKD), ultimately developing end-stage renal disease (ESRD) and necessitating costly dialysis or kidney transplantation. The limited therapeutic efficiency among individuals with DKD is a result of our finite understanding of its pathogenesis. DKD is the result of complex interactions between various factors. Oxidative stress is a fundamental factor that can establish a link between hyperglycemia and the vascular complications frequently encountered in diabetes, particularly DKD. It is crucial to recognize the essential and integral role of oxidative stress in the development of diabetic vascular complications, particularly DKD. Hyperglycemia is the primary culprit that can trigger an upsurge in the production of reactive oxygen species (ROS), ultimately sparking oxidative stress. The main endogenous sources of ROS include mitochondrial ROS production, NADPH oxidases (Nox), uncoupled endothelial nitric oxide synthase (eNOS), xanthine oxidase (XO), cytochrome P450 (CYP450), and lipoxygenase. Under persistent high glucose levels, immune cells, the complement system, advanced glycation end products (AGEs), protein kinase C (PKC), polyol pathway, and the hexosamine pathway are activated. Consequently, the oxidant-antioxidant balance within the body is disrupted, which triggers a series of reactions in various downstream pathways, including phosphoinositide 3-kinase/protein kinase B (PI3K/Akt), transforming growth factor beta/p38-mitogen-activated protein kinase (TGF-β/p38-MAPK), nuclear factor kappa B (NF-κB), adenosine monophosphate-activated protein kinase (AMPK), and the Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling. The disease might persist even if strict glucose control is achieved, which can be attributed to epigenetic modifications. The treatment of DKD remains an unresolved issue. Therefore, reducing ROS is an intriguing therapeutic target. The clinical trials have shown that bardoxolone methyl, a nuclear factor erythroid 2-related factor 2 (Nrf2) activator, blood glucose-lowering drugs, such as sodium-glucose cotransporter 2 inhibitors, and glucagon-like peptide-1 receptor agonists can effectively slow down the progression of DKD by reducing oxidative stress. Other antioxidants, including vitamins, lipoic acid, Nox inhibitors, epigenetic regulators, and complement inhibitors, present a promising therapeutic option for the treatment of DKD. In this review, we conduct a thorough assessment of both preclinical studies and current findings from clinical studies that focus on targeted interventions aimed at manipulating these pathways. We aim to provide a comprehensive overview of the current state of research in this area and identify key areas for future exploration.

Inflammation in diabetes complications: molecular mechanisms and therapeutic interventions

At present, diabetes mellitus (DM) has been one of the most endangering healthy diseases. Current therapies contain controlling high blood sugar, reducing risk factors like obesity, hypertension, and so on; however, DM patients inevitably and eventually progress into different types of diabetes complications, resulting in poor quality of life. Unfortunately, the clear etiology and pathogenesis of diabetes complications have not been elucidated owing to intricate whole-body systems. The immune system was responsible to regulate homeostasis by triggering or resolving inflammatory response, indicating it may be necessary to diabetes complications. In fact, previous studies have been shown inflammation plays multifunctional roles in the pathogenesis of diabetes complications and is attracting attention to be the meaningful therapeutic strategy. To this end, this review systematically concluded the current studies over the relationships of susceptible diabetes complications (e.g., diabetic cardiomyopathy, diabetic retinopathy, diabetic peripheral neuropathy, and diabetic nephropathy) and inflammation, ranging from immune cell response, cytokines interaction to pathomechanism of organ injury. Besides, we also summarized various therapeutic strategies to improve diabetes complications by target inflammation from special remedies to conventional lifestyle changes. This review will offer a panoramic insight into the mechanisms of diabetes complications from an inflammatory perspective and also discuss contemporary clinical interventions.

Identification of Potential Blood-Based Biomarkers for Frailty by Using an Integrative Approach

INTRODUCTION

Although frailty is a geriatric syndrome that is associated with disability, hospitalization, and mortality, it can be reversible and preventable with the appropriate interventions. Additionally, as the current diagnostic criteria for frailty include only physical, psychological, cognitive, and social measurements, there is a need for promising blood-based molecular biomarkers to aid in the diagnosis of frailty.

METHODS

To identify candidate blood-based biomarkers that can enhance current diagnosis of frailty, we conducted a comprehensive analysis of clinical data, messenger RNA-sequencing (RNA-seq), and aging-related factors using a total of 104 older adults aged 65-90 years (61 frail subjects and 43 robust subjects) in a cross-sectional case-control study.

RESULTS

We identified two candidate biomarkers of frailty from the clinical data analysis, nine from the RNA-seq analysis, and six from the aging-related factors analysis. By using combinations of the candidate biomarkers and clinical information, we constructed risk prediction models. The best models used combinations that included skeletal muscle mass index measured by dual-energy X-ray absorptiometry (adjusted p = 0.026), GDF15 (adjusted p = 1.46E-03), adiponectin (adjusted p = 0.012), CXCL9 (adjusted p = 0.011), or apelin (adjusted p = 0.020) as the biomarker. These models achieved a high area under the curve of 0.95 in an independent validation cohort (95% confidence interval: 0.79-0.97). Our risk prediction models showed significantly higher areas under the curve than did models constructed using only basic clinical information (Welch's t test p < 0.001).

CONCLUSION

All five biomarkers showed statistically significant correlations with components of the frailty diagnostic criteria. We discovered several potential biomarkers for the diagnosis of frailty. Further refinement may lead to their future clinical use.

FTO-mediated m6A modification of serum amyloid A2 mRNA promotes podocyte injury and inflammation by activating the NF-κB signaling pathway

Diabetic kidney disease (DKD) is one of the severe complications of diabetes mellitus, yet there is no effective treatment. Exploring the development of DKD is essential to treatment. Podocyte injury and inflammation are closely related to the development of DKD. However, the mechanism of podocyte injury and progression in DKD remains largely unclear. Here, we observed that FTO expression was significantly upregulated in high glucose-induced podocytes and that overexpression of FTO promoted podocyte injury and inflammation. By performing RNA-seq and MeRIP-seq with control podocytes and high glucose-induced podocytes with or without FTO knockdown, we revealed that serum amyloid A2 (SAA2) is a target of FTO-mediated m6A modification. Knockdown of FTO markedly increased SAA2 mRNA m6A modification and decreased SAA2 mRNA expression. Mechanistically, we demonstrated that SAA2 might participate in podocyte injury and inflammation through activation of the NF-κB signaling pathway. Furthermore, by generating podocyte-specific adeno-associated virus 9 (AAV9) to knockdown SAA2 in mice, we discovered that the depletion of SAA2 significantly restored podocyte injury and inflammation. Together, our results suggested that upregulation of SAA2 promoted podocyte injury through m6A-dependent regulation, thus suggesting that SAA2 may be a therapeutic target for diabetic kidney disease.

Role of the CCL20/CCR6 axis in tubular epithelial cell injury: Kidney-specific translational insights from acute kidney injury to chronic kidney disease

This study investigated the role of the axis involving chemokine receptor 6 (CCR6) and its ligand chemokine (C-C motif) ligand 20 (CCL20) in acute kidney disease (AKD) using an ischemia-reperfusion injury (IRI) model. The model was established by clamping the unilateral renal artery pedicle of C57BL/6 mice for 30 min, followed by evaluation of CCL20/CCR6 expression at 4 weeks post-IRI. In vitro studies were conducted to examine the effects of hypoxia and H2 O2 -induced oxidative stress on CCL20/CCR6 expression in kidney tissues of patients with AKD and chronic kidney disease (CKD). Tubular epithelial cell apoptosis was more severe in C57BL/6 mice than in CCL20 antibody-treated mice, and CCR6, NGAL mRNA, and IL-8 levels were higher under hypoxic conditions. CCL20 blockade ameliorated apoptotic damage in a dose-dependent manner under hypoxia and reactive oxygen species injury. CCR6 expression in IRI mice indicated that the disease severity was similar to that in patients with the AKD phenotype. Morphometry of CCL20/CCR6 expression revealed a higher likelihood of CCR6+ cell presence in CKD stage 3 patients than in stage 1-2 patients. Kidney tissues of patients with CKD frequently contained CCL20+ cells, which were positively correlated with interstitial inflammation. CCL20/CCR6 levels were increased in fibrotic kidneys at 4 and 8 weeks after 5/6 nephrectomy. These findings suggest that modulating the CCL20/CCR6 pathway is a potential therapeutic strategy for managing the progression of AKD to CKD.

Kidney Fibrosis and Oxidative Stress: From Molecular Pathways to New Pharmacological Opportunities

Kidney fibrosis, diffused into the interstitium, vessels, and glomerulus, is the main pathologic feature associated with loss of renal function and chronic kidney disease (CKD). Fibrosis may be triggered in kidney diseases by different genetic and molecular insults. However, several studies have shown that fibrosis can be linked to oxidative stress and mitochondrial dysfunction in CKD. In this review, we will focus on three pathways that link oxidative stress and kidney fibrosis, namely: (i) hyperglycemia and mitochondrial energy imbalance, (ii) the mineralocorticoid signaling pathway, and (iii) the hypoxia-inducible factor (HIF) pathway. We selected these pathways because they are targeted by available medications capable of reducing kidney fibrosis, such as sodium-glucose cotransporter-2 (SGLT2) inhibitors, non-steroidal mineralocorticoid receptor antagonists (MRAs), and HIF-1alpha-prolyl hydroxylase inhibitors. These drugs have shown a reduction in oxidative stress in the kidney and a reduced collagen deposition across different CKD subtypes. However, there is still a long and winding road to a clear understanding of the anti-fibrotic effects of these compounds in humans, due to the inherent practical and ethical difficulties in obtaining sequential kidney biopsies and the lack of specific fibrosis biomarkers measurable in easily accessible matrices like urine. In this narrative review, we will describe these three pathways, their interconnections, and their link to and activity in oxidative stress and kidney fibrosis.

Advances in oxidative stress in pathogenesis of diabetic kidney disease and efficacy of TCM intervention

Diabetic kidney disease (DKD) is a common complication of diabetes and has become the leading cause of end-stage kidney disease. The pathogenesis of DKD is complicated, and oxidative stress is considered as a core of DKD onset. High glucose can lead to increased production of reactive oxygen species (ROS) via the polyol, PKC, AGE/RAGE and hexosamine pathways, resulting in enhanced oxidative stress response. In this way, pathways such as PI3K/Akt, TGF-β1/p38-MAPK and NF-κB are activated, inducing endothelial cell apoptosis, inflammation, autophagy and fibrosis that cause histologic and functional abnormalities of the kidney and finally result in kidney injury. Presently, the treatment for DKD remains an unresolved issue. Traditional Chinese medicine (TCM) has unique advantages for DKD prevention and treatment attributed to its multi-target, multi-component, and multi-pathway characteristics. Numerous studies have proved that Chinese herbs (e.g., Golden Thread, Kudzuvine Root, Tripterygium glycosides, and Ginseng) and patent medicines (e.g., Shenshuaining Tablet, Compound Rhizoma Coptidis Capsule, and Zishen Tongluo Granule) are effective for DKD treatment. The present review described the role of oxidative stress in DKD pathogenesis and the effect of TCM intervention for DKD prevention and treatment, in an attempt to provide evidence for clinical practice.

Advanced Glycation End Products-Induced Activation of Keratinocytes: A Mechanism Underlying Cutaneous Immune Response in Psoriasis

Psoriasis is a common inflammatory skin disease, in which epidermal keratinocytes play a vital role in its pathogenesis by acting both as the responder and as the accelerator to the cutaneous psoriatic immune response. Advanced glycation end products (AGEs) are a class of proinflammatory metabolites that are commonly accumulating in cardiometabolic disorders. Recent studies have also observed the increased level of AGEs in the serum and skin of psoriasis patients, but the role of AGEs in psoriatic inflammation has not been well investigated. In the present study, we initially detected abnormal accumulation of AGEs in epidermal keratinocytes of psoriatic lesions collected from psoriasis patients. Furthermore, AGEs promoted the proliferation of keratinocytes via upregulated Keratin 17 (K17)-mediated p27KIP1 inhibition followed by accelerated cell cycle progression. More importantly, AGEs facilitated the production of interleukin-36 alpha (IL-36α) in keratinocytes, which could enhance T helper 17 (Th17) immune response. In addition, the induction of both K17 and IL-36α by AGEs in keratinocytes was dependent on the activation of signal transducer and activator of transcription 1/3 (STAT1/3) signaling pathways. At last, the effects of AGEs on keratinocytes were mediated by the receptor for AGEs (RAGE). Taken together, these findings support that AGEs potentiate the innate immune function of keratinocytes, which contributes to the formation of psoriatic inflammation. Our study implicates AGEs as a potential pathogenic link between psoriasis and cardiometabolic comorbidities.

Advanced polymer hydrogels that promote diabetic ulcer healing: mechanisms, classifications, and medical applications

Diabetic ulcers (DUs) are one of the most serious complications of diabetes mellitus. The application of a functional dressing is a crucial step in DU treatment and is associated with the patient's recovery and prognosis. However, traditional dressings with a simple structure and a single function cannot meet clinical requirements. Therefore, researchers have turned their attention to advanced polymer dressings and hydrogels to solve the therapeutic bottleneck of DU treatment. Hydrogels are a class of gels with a three-dimensional network structure that have good moisturizing properties and permeability and promote autolytic debridement and material exchange. Moreover, hydrogels mimic the natural environment of the extracellular matrix, providing suitable surroundings for cell proliferation. Thus, hydrogels with different mechanical strengths and biological properties have been extensively explored as DU dressing platforms. In this review, we define different types of hydrogels and elaborate the mechanisms by which they repair DUs. Moreover, we summarize the pathological process of DUs and review various additives used for their treatment. Finally, we examine the limitations and obstacles that exist in the development of the clinically relevant applications of these appealing technologies. This review defines different types of hydrogels and carefully elaborate the mechanisms by which they repair diabetic ulcers (DUs), summarizes the pathological process of DUs, and reviews various bioactivators used for their treatment.

Transcriptomic and Functional Evidence That miRNA193a-3p Inhibits Lymphatic Endothelial Cell (LEC) and LEC + MCF-7 Spheroid Growth Directly and by Altering MCF-7 Secretome

MicroRNA 193a-3p (miR193a-3p) is a short non-coding RNA with tumor suppressor properties. Breast cancer (BC) progression is governed by active interaction between breast cancer cells, vascular (V)/lymphatic (L) endothelial cells (ECs), and BC secretome. We have recently shown that miR193a-3p, a tumor suppressor miRNA, inhibits MCF-7 BC cell-driven growth of VECs via direct antimitogenic actions and alters MCF-7 secretome. Since LEC-BC cross-talk plays a key role in BC progression, we investigated the effects of miR193a-3p on MCF-7 secretome and estradiol-mediated growth effects in LECs and LEC + MCF-7 spheroids, and delineated the underlying mechanisms. Transfection of LECs with miR193a-3p, as well as secretome from MCF-7 transfected cells, inhibited LEC growth, and these effects were mimicked in LEC + MCF-7 spheroids. Moreover, miR193a-3p inhibited ERK1/2 and Akt phosphorylation in LECs and LEC + MCF-7 spheroids, which are importantly involved in promoting cancer development and metastasis. Treatment of LECs and LEC + MCF-7 spheroids with estradiol (E2)-induced growth, as well as ERK1/2 and Akt phosphorylation, and was abrogated by miR193a-3p and secretome from MCF-7 transfected cells. Gene expression analysis (GEA) in LEC + MCF-7 spheroids transfected with miR193a-3p showed significant upregulation of 54 genes and downregulation of 73 genes. Pathway enrichment analysis of regulated genes showed significant modulation of several pathways, including interferon, interleukin/cytokine-mediated signaling, innate immune system, ERK1/2 cascade, apoptosis, and estrogen receptor signaling. Transcriptomic analysis showed downregulation in interferon and anti-apoptotic and pro-growth molecules, such as IFI6, IFIT1, OSA1/2, IFITM1, HLA-A/B, PSMB8/9, and PARP9, which are known to regulate BC progression. The cytokine proteome array of miR193a-3p transfected MCF secretome and confirmed the upregulation of several growth inhibitory cytokines, including IFNγ, Il-1a, IL-1ra, IL-32, IL-33, IL-24, IL-27, cystatin, C-reactive protein, Fas ligand, MIG, and sTIM3. Moreover, miR193a-3p alters factors in MCF-7 secretome, which represses ERK1/2 and Akt phosphorylation, induces pro-apoptotic protein and apoptosis in LECs, and downregulates interferon-associated proteins known to promote cancer growth and metastasis. In conclusion, miR193a-3p can potentially modify the tumor microenvironment by altering pro-growth BC secretome and inhibiting LEC growth, and may represent a therapeutic molecule to target breast tumors/cancer.

T cells and their products in diabetic kidney disease

Diabetic kidney disease (DKD) is the most common cause of end-stage renal disease and has gradually become a public health problem worldwide. DKD is increasingly recognized as a comprehensive inflammatory disease that is largely regulated by T cells. Given the pivotal role of T cells and T cells-producing cytokines in DKD, we summarized recent advances concerning T cells in the progression of type 2 diabetic nephropathy and provided a novel perspective of immune-related factors in diabetes. Specific emphasis is placed on the classification of T cells, process of T cell recruitment, function of T cells in the development of diabetic kidney damage, and potential treatments and therapeutic strategies involving T cells.

Exploring the mechanisms underlying the therapeutic effect of the drug pair Rhubarb-Coptis in diabetic nephropathy using network pharmacology and molecular docking analysis

Background

To use network pharmacology to explore the mechanism of the drug pair Rhubarb-Coptis in the treatment of diabetic nephropathy (DN).

Methods

The Traditional Chinese Medicine Systems Pharmacology (TCMSP) database was used to screen active ingredients of drug pair Rhubarb-Coptis. Targets were obtained using the TCMSP and SwissTargetPrediction databases. DN disease targets were extracted from the Online Mendelian Inheritance in Man (OMIM), GeneCards, and Therapeutic Target database (TTD) databases. A "drug-compound-target" network and protein-protein interaction (PPI) network were constructed and analyzed through the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database and Cytoscape software. Gene Ontology (GO) functional and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed in the Database for Annotation, Visualization, and Integrated Discovery (DAVID) database. Molecular docking was performed using AutoDock Vina and PyMOL software.

Results

A total of 30 active components and 609 targets of Rhubarb-Coptis were screened out, and 98 common targets of DN and Rhubarb-Coptis were obtained. Quercetin, berberine, epiruberine, epautin, and moupinamide were the main active components in the treatment of DN. The STAT3, CTNNB1, PIK3R1, PIK3CA, and TP53 genes were identified as the potential 5 key targets. The GO enrichment analysis showed that these 5 key targets mainly involved in inflammation, oxidative stress, and apoptosis. KEGG enrichment analysis showed that the pathways were mainly enriched in the AGE-RAGE and HIF-1 signaling pathways. Molecular docking revealed that the 5 key targets could combine well with their corresponding active compounds.

Conclusions

This study expounds the therapeutic effect of Rhubarb-Coptis on DN from a holistic perspective, and provides a valuable basis for clinical application and academic research.

Mechanisms of podocyte injury and implications for diabetic nephropathy

Albuminuria is the hallmark of both primary and secondary proteinuric glomerulopathies, including focal segmental glomerulosclerosis (FSGS), obesity-related nephropathy, and diabetic nephropathy (DN). Moreover, albuminuria is an important feature of all chronic kidney diseases (CKDs). Podocytes play a key role in maintaining the permselectivity of the glomerular filtration barrier (GFB) and injury of the podocyte, leading to foot process (FP) effacement and podocyte loss, the unifying underlying mechanism of proteinuric glomerulopathies. The metabolic insult of hyperglycemia is of paramount importance in the pathogenesis of DN, while insults leading to podocyte damage are poorly defined in other proteinuric glomerulopathies. However, shared mechanisms of podocyte damage have been identified. Herein, we will review the role of haemodynamic and oxidative stress, inflammation, lipotoxicity, endocannabinoid (EC) hypertone, and both mitochondrial and autophagic dysfunction in the pathogenesis of the podocyte damage, focussing particularly on their role in the pathogenesis of DN. Gaining a better insight into the mechanisms of podocyte injury may provide novel targets for treatment. Moreover, novel strategies for boosting podocyte repair may open the way to podocyte regenerative medicine.

Modes of podocyte death in diabetic kidney disease: an update

Diabetic kidney disease (DKD) accounts for a large proportion of end-stage renal diseases that require renal replacement therapies including dialysis and transplantation. Therefore, it is critical to understand the occurrence and development of DKD. Podocytes are mainly injured during the development of DKD, ultimately leading to their extensive death and loss. In turn, the injury and death of glomerular podocytes are also the main culprits of DKD. This review introduces the characteristics of podocytes and summarizes the modes of their death in DKD, including apoptosis, autophagy, mitotic catastrophe (MC), anoikis, necroptosis, and pyroptosis. Apoptosis is characterized by nuclear condensation and the formation of apoptotic bodies, and it exerts a different effect from autophagy in mediating DKD-induced podocyte loss. MC mediates a faulty mitotic process while anoikis separates podocytes from the basement membrane. Moreover, pyroptosis activates inflammatory factors to aggravate podocyte injuries whilst necroptosis drives signaling cascades, such as receptor-interacting protein kinases 1 and 3 and mixed lineage kinase domain-like, ultimately promoting the death of podocytes. In conclusion, a thorough knowledge of the modes of podocyte death in DKD can help us understand the development of DKD and lay the foundation for strategies in DKD disease therapy.

Limonin ameliorates acute pancreatitis by suppressing JAK2/STAT3 signaling pathway

Acute pancreatitis (AP) is one of the most common acute abdomen of digestive system and has the characteristics of dangerous condition and rapid development. Limonin has been confirmed to hold anti-inflammatory and antioxidant effects in various diseases. However, its potential beneficial effect on AP and the concrete mechanisms have never been revealed. Here, two mouse models were used to investigate the protective effects of limonin on AP, the caerulein-induced mild acute pancreatitis (MAP) model and L-arginine-induced severe AP (SAP) model. Firstly, it was found that limonin administration attenuated lipase and serum amylase levels and ameliorated the histopathological manifestations of pancreatic tissue in a dose-dependent manner. Additionally, the amelioration of AP by limonin was associated with reduced levels of inflammation initiators (IL-6, IL-1β, CCL2, and TNF-α). Mechanistically, we found that limonin suppressed the Janus Activating Kinase 2 (JAK2)/Signal Transducer and Activator of Transcription 3 (STAT3) signaling pathway, as evident by the decreased levels of JAK2 and p-STAT3. And activation of JAK2 using JAK2 activator rescued the protective effects of limonin on AP. Thus, our results demonstrate that limonin can ameliorate AP in two mice models via suppressing JAK2/STAT3 signaling pathway.

Profilin-1 is involved in macroangiopathy induced by advanced glycation end products via vascular remodeling and inflammation

BACKGROUND

The accumulation of advanced glycation end products (AGEs) have been implicated in the development and progression of diabetic vasculopathy. However, the role of profilin-1 as a multifunctional actin-binding protein in AGEs-induced atherosclerosis (AS) is largely unknown.

AIM

To explore the potential role of profilin-1 in the pathogenesis of AS induced by AGEs, particularly in relation to the Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) signaling pathway.

METHODS

Eighty-nine individuals undergoing coronary angiography were enrolled in the study. Plasma cytokine levels were detected using ELISA kits. Rat aortic vascular smooth muscle cells (RASMCs) were incubated with different compounds for different times. Cell proliferation was determined by performing the MTT assay and EdU staining. An AGEs-induced vascular remodeling model was established in rats and histological and immunohistochemical analyses were performed. The mRNA and protein levels were detected using real-time PCR and Western blot analysis, respectively. In vivo, shRNA transfection was performed to verify the role of profilin-1 in AGEs-induced proatherogenic mediator release and aortic remodeling. Statistical analyses were performed using SPSS 22.0 software.

RESULTS

Compared with the control group, plasma levels of profilin-1 and receptor for AGEs (RAGE) were significantly increased in patients with coronary artery disease, especially in those complicated with diabetes mellitus (P < 0.01). The levels of profilin-1 were positively correlated with the levels of RAGE (P < 0.01); additionally, the levels of both molecules were positively associated with the degree of coronary artery stenosis (P < 0.01). In vivo, tail vein injections of AGEs induced the release of proatherogenic mediators, such as asymmetric dimethylarginine, intercellular adhesion molecule-1, and the N-terminus of procollagen III peptide, concomitant with apparent aortic morphological changes and significantly upregulated expression of the profilin-1 mRNA and protein in the thoracic aorta (P < 0.05 or P < 0.01). Downregulation of profilin-1 expression with an shRNA significantly attenuated AGEs-induced proatherogenic mediator release (P < 0.05) and aortic remodeling. In vitro, incubation of vascular smooth muscle cells (VSMCs) with AGEs significantly promoted cell proliferation and upregulated the expression of the profilin-1 mRNA and protein (P < 0.05). AGEs (200 μg/mL, 24 h) significantly upregulated the expression of the STAT3 mRNA and protein and JAK2 protein, which was blocked by a JAK2 inhibitor (T3042-1) and/or STAT3 inhibitor (T6308-1) (P < 0.05). In addition, pretreatment with T3042-1 or T6308-1 significantly inhibited AGEs-induced RASMC proliferation (P < 0.05).

CONCLUSION

AGEs induce proatherogenic events such as VSMC proliferation, proatherogenic mediator release, and vascular remodeling, changes that can be attenuated by silencing profilin-1 expression. These results suggest a crucial role for profilin-1 in AGEs-induced vasculopathy.

Targeting Canonical and Non-Canonical STAT Signaling Pathways in Renal Diseases

Signal transducer and activator of transcription (STAT) plays an essential role in the inflammatory reaction and immune response of numerous renal diseases. STATs can transmit the signals of cytokines, chemokines, and growth factors from the cell membrane to the nucleus. In the canonical STAT signaling pathways, upon binding with their cognate receptors, cytokines lead to a caspase of Janus kinases (JAKs) and STATs tyrosine phosphorylation and activation. Besides receptor-associated tyrosine kinases JAKs, receptors with intrinsic tyrosine kinase activities, G-protein coupled receptors, and non-receptor tyrosine kinases can also activate STATs through tyrosine phosphorylation or, alternatively, other post-translational modifications. Activated STATs translocate into the nucleus and mediate the transcription of specific genes, thus mediating the progression of various renal diseases. Non-canonical STAT pathways consist of preassembled receptor complexes, preformed STAT dimers, unphosphorylated STATs (U-STATs), and non-canonical functions including mitochondria modulation, microtubule regulation and heterochromatin stabilization. Most studies targeting STAT signaling pathways have focused on canonical pathways, but research extending into non-canonical STAT pathways would provide novel strategies for treating renal diseases. In this review, we will introduce both canonical and non-canonical STAT pathways and their roles in a variety of renal diseases.

The progress of chemokines and chemokine receptors in autism spectrum disorders

Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders and the main symptoms of ASD are impairments in social communication and abnormal behavioral patterns. Studies have shown that immune dysfunction and neuroinflammation play a key role in ASD patients and experimental models. Chemokines are groups of small proteins that regulate cell migration and mediate inflammation responses via binding to chemokine receptors. Thus, chemokines/chemokine receptors may be involved in neurodevelopmental disorders and associated with ASD. In this review, we summarize the research progress of chemokine aberrations in ASD and also review the recent progress of clinical treatment of ASD and pharmacological research related to chemokines/chemokine receptors. This review highlights the possible connection between chemokines/chemokine receptors and ASD, and provides novel potential targets for drug discovery of ASD.

Renoprotective Effect of the Recombinant Anti-IL-6R Fusion Proteins by Inhibiting JAK2/STAT3 Signaling Pathway in Diabetic Nephropathy

Diabetic nephropathy the main reason for end stage renal disease is a common microvascular complication in patients with type 1 and type 2 diabetes. The interleukin-6 (IL-6), acting as a pleiotropic cytokine, play key roles in main autoimmune disorders. The recombinant anti-IL-6R fusion proteins (VHH-0031) constructed and obtained in our lab is a dual target-directed single domain-based fusion protein against the interleukin-6 receptor. This study aims to explore the renoprotective effect of VHH-0031 in diabetic nephropathy. VHH-0031 treatment alleviated renal inflammation, morphologic injury and renal insufficiency in both Goto-Kakizaki rats and STZ-induced Sprague Dawley rats. These renoprotective effects of VHH-0031 are associated with alleviating inflammation and suppression of the JAK2/STAT3 signaling pathway. The mesangial cells treated with VHH-0031 exhibited anti-proliferation, anti-inflammation and inactivation of JAK2/STAT3 pathway under high glucose condition. In conclusion, this study demonstrates that VHH-0031 exhibited a potent protective effect in kidney of diabetic rats and its mechanism may be concerned with the inhibition of the IL-6R/JAK2/STAT3 pathway of glomerular mesangial cells.

The cardiovascular complications of diabetes: a striking link through protein glycation

Diabetes mellitus is a predominant cause of mortality and morbidity worldwide. One of its serious health problems is cardiovascular complications. Advanced glycation end products (AGEs) are a group of heterogeneous toxic oxidant compounds that are formed after a non-enzymatic reaction between monosaccharides and free amino groups of proteins, compound lipids, and nucleic acids. AGE interacts with various types of cells through a receptor for AGE (RAGE). The interaction between AGE and RAGE is responsible for a cascade of inflammation, oxidative stress, and disruption of calcium homeostasis in cardiac cells of diabetic patients. There is striking evidence that the AGE/RAGE axis with its consequences on inflammation and oxidative stress plays a major role in the development of cardiovascular complications. Therefore, considering AGE as a therapeutic target with foreseeable results would be a wise direction for future research. Interestingly, several studies on nutraceutical, pharmaceutical, and natural products have begun to reveal promising therapeutic results, and this could lead to better health outcomes for many diabetic patients worldwide. This article discusses the current literature addressing the connection between protein glycation and diabetes cardiovascular complications and suggests future avenues of research.

Do novel treatment strategies enhance T cell-mediated Immunity: Opportunities and challenges in pancreatic cancer immunotherapy

Although immunotherapy is successful when included as component of treatment strategies for advanced cancers, data are insufficient for evaluating its efficacy for treating patients with pancreatic cancer (PC). PC is remarkably resistant to current immunotherapies because of its strongly immunosuppressive tumor microenvironment comprising immunosuppressive cells such as myeloid-derived suppressor cells and regulatory T cells, which limit the efficacy of T cell infiltration. Thus, the ability to achieve robust and durable intrinsic T cell efficacy may represent the key for improving patients' outcomes. Recent studies show that the efficacy of immunotherapy for treating PC will be significantly improved when combined with novel treatment strategies. This review summarizes the latest research in this rapidly progressing area and provides an overview of how current therapies enhance T cell-mediated immunotherapies that employ immune checkpoint inhibitors, cytokines, cell receptor modulators, tumor microenvironment regulators, vaccines, and gene-targeted immunotherapies. We highlight novel discoveries, which promise to guide future management of PC, and clinical trials aimed to increase the overall survival rate of patients with PC.

Autoimmune thyroid disease and type 1 diabetes mellitus: same pathogenesis; new perspective?

Autoimmune thyroid disease (AITD) and type 1 diabetes mellitus (T1DM) are two common autoimmune diseases that can occur concomitantly. In general, patients with diabetes have a high risk of AITD. It has been proposed that a complex genetic basis together with multiple nongenetic factors make a variable contribution to the pathogenesis of T1DM and AITD. In this paper, we summarize current knowledge in the field regarding potential pathogenic factors of T1DM and AITD, including human leukocyte antigen, autoimmune regulator, lymphoid protein tyrosine phosphatase, forkhead box protein P3, cytotoxic T lymphocyte-associated antigen, infection, vitamin D deficiency, and chemokine (C-X-C motif) ligand. These findings offer an insight into future immunotherapy for autoimmune diseases.

CCL18-NIR1 promotes oral cancer cell growth and metastasis by activating the JAK2/STAT3 signaling pathway

BACKGROUND

Chemokine (C-C motif) ligand 18 (CCL18) affects the malignant progression of varying cancers by activating chemokine receptors. Our previous work has shown that CCL18 promotes hyperplasia and invasiveness of oral cancer cells; however, the cognate receptors of CCL18 involved in the pathogenesis of oral squamous cell carcinoma (OSCC) have not yet been identified. This study aimed to investigate the molecular mechanisms which underlie promotive effects of CCL18 on OSCC progression by binding to functional receptors.

METHODS

The expression of CCL18 receptor-NIR1 in OSCC was determined by conducting western blot, immunofluorescence, and immunocytochemistry assays. Chi square test was applied to analyze the relationship between expression levels of NIR1 and clinicopathological variables. Recombinant CCL18 (rCCL18), receptor siRNA and JAK specific inhibitor (AG490) were used in experiments investigating the effects of the CCL18-NIR1 axis on growth of cancer cells (i.e., proliferation, and metastasis), epithelial-mesenchymal transition (EMT) and the activation of the JAK2/STAT3 signaling pathway.

RESULTS

NIR1 as functional receptor of CCL18 in OSCC, was found to be significantly upregulated in OSCC and positively related to the TNM stage of OSCC patients. rCCL18 induced the phenotypical alterations in oral cancer cells including cell growth, metastasis and EMT. The JAK2/STAT3 signaling pathway was confirmed to be a downstream pathway mediating the effects of CCL18 in OSCC. AG490 and knockdown of NIR1 could block the effects of rCCL18-induced OSCC.

CONCLUSION

CCL18 can promote the progression of OSCC by binding NIR1, and the CCL18-NIR1 axis can activate JAK2/STAT3 signaling pathway. The identification of the mechanisms underlying CCL18-mediated promotion of OSCC progression could highlight potential therapeutic targets for treating oral cancer.

The Role of Chemokines and Chemokine Receptors in Diabetic Nephropathy

Kidney function decline is one of the complications of diabetes mellitus and may be indicated as diabetic nephropathy (DN). DN is a chronic inflammatory disease featuring proteinuria and a decreasing glomerular filtration rate. Despite several therapeutic options being currently available, DN is still the major cause of end-stage renal disease. Accordingly, widespread innovation is needed to improve outcomes in patients with DN. Chemokines and their receptors are critically involved in the inflammatory progression in the development of DN. Although recent studies have shown multiple pathways related to the chemokine system, the specific and direct effects of chemokines and their receptors remain unclear. In this review, we provide an overview of the potential role and mechanism of chemokine systems in DN proposed in recent years. Chemokine system-related mechanisms may provide potential therapeutic targets in DN.

Aerobic Endurance Exercise Ameliorates Renal Vascular Sclerosis in Aged Mice by Regulating PI3K/AKT/mTOR Signaling Pathway

Renal vascular sclerosis caused by aging plays an important role in the occurrence and development of chronic kidney disease. Clinical studies have confirmed that endurance exercise is able to delay the aging of skeletal muscle and brain tissue. However, to date, few studies have assessed whether endurance exercise is able to improve the occurrence of renal vascular sclerosis caused by natural aging and its related mechanisms. In this study, we investigated the protective effect of aerobic endurance exercise on renal vascular sclerosis in aged mice and its effect on the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway. The results suggested that aerobic endurance exercise preserved kidney morphology and renal function. Glomerular basement membrane thickness was evidently increased, podocyte foot processes were effaced in aged mice, and aerobic endurance exercise significantly ameliorated the overall lesion range. The protein expression of vascular endothelial growth factor (VEGF) and JG12 was lower in the senile control group (OC group). The protein expression of VEGF and JG12 was significantly increased after aerobic endurance exercise. Furthermore, aerobic endurance exercise resulted in downregulation of Bax, Caspase 3, IL-6, and senescent cells and upregulation of Bcl-2. The upregulation of PI3K and its downstream signal molecules AKT and mTOR after aerobic endurance exercise was further observed. Our observations indicated that aerobic endurance exercise may inhibit renal vascular sclerosis in aged mice by regulating the PI3K/AKT/mTOR signaling pathway.

CXCL9 chemokine promotes the progression of human pancreatic adenocarcinoma through STAT3-dependent cytotoxic T lymphocyte suppression

Chemokines play essential roles in the progression of various human cancers; however, the expression and role of CXC chemokines in pancreatic adenocarcinoma (PAAD) have not yet been identified. The aim of this study is to identify the expression patterns, clinical significance and mechanisms of CXC chemokines in regulating tumour microenvironment of PAAD. Three CXC chemokines, including CXCL5, CXCL9, and CXCL10, were significantly overexpressed in PAAD tissues, which were correlated with the poor survival of the patients. CXCL9/10 was associated with change of immune cell pattern in the tumour microenvironment, and supplementation of CXCL9 in the orthotopic murine PAAD model promoted tumour progression. In particular, CXCL9 reduced the CD8+ cytotoxic T lymphocytes in the tumour microenvironment of PAAD, which could be attributed to the reduced CD8+ T cell proliferation, activation, and secretion of anti-tumour cytokines. In vitro treatment of CXCL9 directly led to the suppression of the proliferation, activation, and secretion of anti-tumour cytokines of isolated CD8+ T cells. Inhibition of STAT3 recovered the CXCL9-inhibited proliferation, activation, and secretion of anti-tumour cytokines of CD8+ T cells. Our study indicates CXCL9 as a potential target of immunotherapy in PAAD treatment by regulating the CD8+ T lymphocytes in the tumour microenvironment.

Bioinformatics analysis of hepatic gene expression profiles in type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is characterized by hyperglycemia. The liver has a critical role in regulating glucose homeostasis. The present study aimed to analyze hepatic gene expression profiles and to identify the key genes and pathways involved in T2DM. Gene expression profiles of 10 patients with T2DM and 7 subjects with normal glucose tolerance were downloaded from the Gene Expression Omnibus database. Subsequently, differentially expressed genes (DEGs) were identified and functional enrichment analysis was performed. In addition, a protein-protein interaction network was built and hub genes were identified. In total, 1,320 DEGs were identified, including 698 up- and 622 downregulated genes, and these were mainly enriched in positive regulation of transcription from RNA polymerase II promoter, cell adhesion, inflammatory response, positive regulation of apoptotic process, signal transduction and the Tolllike receptor signaling pathway. A total of 8 hub genes (G-protein subunit gamma transducin 2, ubiquitinconjugating enzyme E2 D1, glutamate metabotropic receptor 1, G-protein signaling modulator 1, C-X-C motif chemokine ligand 9, neurotensin, purinergic receptor P2Y1 and ring finger protein 41) were screened from the network. The present study may contribute to the elucidation of the hepatic pathology of T2DM.

Zafirlukast, a Cysteinyl Leukotriene Receptor 1 Antagonist, Reduces the Effect of Advanced Glycation End-Products in Rat Renal Mesangial Cells In Vitro

Background

Zafirlukast is an antagonist of cysteinyl leukotriene receptor 1 (CysLTR1). Advanced glycation end-products (AGEs) are formed by the glycation of lipids and proteins in hyperglycemia, including diabetes mellitus. Zafirlukast has not previously been studied in diabetic nephropathy. This study aimed to investigate the effects of zafirlukast on rat renal mesangial cells cultured with AGEs in vitro.

Material/Methods

Mesangial cells were cultured in AGEs (0, 20, 50, 100 μg/ml), and with AGEs (100 μg/ml) and zafirlukast (2.5 μm, 5 μm, and 100 μm). An enzyme-linked immunoassay (ELISA) was used to measure the levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and monocyte chemoattractant protein-1 (MCP-1). Reactive oxygen species (ROS) were assessed by intracellular fluorescence measurement of 2′-7′-dichlorodihydrofluorescein diacetate (DCFH-DA), and detection kits were used to measure malondialdehyde (MDA), lactate dehydrogenase (LDH), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD). Cell apoptosis was assessed by flow cytometry, and Western blot was used to measure protein levels.

Results

In mesangial cells cultured with AGEs, markers of inflammation, oxidative stress, and apoptosis and levels of CysLTR1 increased, and these effects were reduced by zafirlukast in a dose-dependent manner. The effects of zafirlukast as a CysLTR1 antagonist protected mesangial cells from the effects of AGE in vitro.

Conclusions

Zafirlukast, a CysLTR1 antagonist, reduced the levels of inflammatory cytokines, markers of oxidative stress, and cell apoptosis induced by AGE in mesangial cells in a dose-dependent way. Future in vivo studies are needed to investigate the potential role for zafirlukast in models of diabetic nephropathy.

CXCL9 regulates acetaminophen-induced liver injury via CXCR3

Drug-induced liver injury has become a serious public health problem. Although the mechanism of acetaminophen (APAP)-induced liver injury has been studied for decades it has not been fully elucidated. In-depth study into the mechanisms underlying APAP-induced liver injury may provide useful information for more effective prevention and treatment. In the present study, the role of C-X-C motif chemokine ligand-9 (CXCL9) in APAP-induced liver injury was investigated thus providing a novel direction for the prevention and treatment of drug hepatitis. A total of 20 fasting male patients ingested APAP tablets at Nanjing First Hospital. In addition, wild type (WT) mice were treated with 250 mg/kg APAP or isodose PBS for 1, 3, 6 and 12 h, respectively. Results from reverse-transcription-quantitative polymerase chain reaction analyses demonstrated that CXCL9 mRNA levels were increased in the blood of patients who took APAP in a fasting state and in the livers of APAP-treated WT mice, compared with their respective controls. Hepatocyte apoptosis in the liver tissue of APAP-treated mice decreased following administration of a CXCL9 neutralizing antibody. Caspase-3, caspase-8 and phosphorylated-AKT (S437) were activated in primary hepatocytes isolated from WT mice following CXCL9 treatment. However, no significant differences in expression of caspase-3, caspase-8 and p-AKT (S437) were detected in hepatocytes isolated from C-X-C motif chemokine receptor 3 (CXCR3)^−/− mice following CXCL9 treatment. After CXCL9 administration, WT mice exhibited higher serum levels of aspartate transaminase and increased caspase-3 and caspase-8 activity in liver tissue compared with controls. The same trends were not observed in CXCR3^−/− mice. In conclusion, CXCL9 regulated APAP-induced liver injury through stimulation of hepatocyte apoptosis via binding to CXCR3. These findings provide a novel prevention and treatment strategy for DILI.

Advanced Glycation End Products in Chinese Medicine Mediated Aging Diseases: A Review

Aging has become a worldwide problem. During this process, the incidence of related diseases such as diabetes and atherosclerosis increases dramatically. Studies within the most recent two decades suggest a pivotal role of Advanced Glycation End Products (AGEs) in the aging process. This review aims to systemically summarize the effects and potential mechanism of Chinese Medicines on inhibiting AGEs-related aging diseases.

One Actor, Many Roles: Histopathologies Associated With APOL1 Genetic Variants

Genetic variants in APOL1, encoding apolipoprotein L1, are major drivers of glomerular disease in peoples of sub-Saharan African descent. APOL1-associated primary glomerular diseases include focal segmental glomerulosclerosis, human immunodeficiency virus-associated nephropathies, and arterionephrosclerosis. Other conditions where APOL1 variants affect outcomes include membranous nephropathy, lupus nephritis, diabetic nephropathy, preeclampsia, and kidney transplant. In focal segmental glomerulosclerosis, APOL1 variants are associated with upregulation of RNA encoding chemokine C-X-C motif receptor 3 ligands and ubiquitin D; the significance of these findings remains unclear but may provide valuable insight into disease mechanisms.

Involvement of STAT3 Signaling in High Glucose-Induced Epithelial Mesenchymal Transition in Human Peritoneal Mesothelial Cell Line HMrSV5

Background/Aims: Peritoneal fibrosis (PF) is a common complication in patients receiving long-term peritoneal dialysis, which results in damage to peritoneal functions. Epithelial-mesenchymal transition (EMT) is a key step in the early pathogenesis of PF. Increasing evidence has shown that signal transducer and activator of transcription 3 (STAT3) signaling pathway is involved in EMT and tissue fibrosis by interacting with distinct EMT-inducing molecules, including transforming growth factor (TGF)-β and advanced glycation end products (AGEs). This study investigated the involvement of STAT3 in the PF process. Methods: We used high glucose-treated human peritoneal mesothelial cell line HMrSV5 as an in vitro model to expose the peritoneal mesothelial cells to high-glucose dialysate. Expression of EMT markers was detected by qRT-PCR. Accumulation of methylglyoxal (MGO) and AGEs in the culture supernatant were measured by enzyme-linked immunosorbent assay. Phosphorylation of STAT3 was assessed by Western blot. Results: Results showed that high glucose upregulated TGF-β, increased the productions of MGO and AGEs, and induced EMT in HMrSV5 cells. High glucose also activated the STAT3 pathway. STAT3 inhibitor reduced the high glucose-induced EMT, via reducing TGF-β expression and repressing the accumulation of MGO and AGEs. Conclusion: Our results revealed a critical role for STAT3 signaling in high glucose-induced EMT in HMrSV5 cells, and suggested that inhibition of STAT3 might be a treatment for high glucose-induced fibrogenesis in PF.

Targeting STAT3 signaling in kidney disease

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway is a multifaceted transduction system that regulates cellular responses to incoming signaling ligands. STAT3 is a central member of the JAK/STAT signaling cascade and has long been recognized for its increased transcriptional activity in cancers and autoimmune disorders but has only recently been in the spotlight for its role in the progression of kidney disease. Although genetic knockout and manipulation studies have demonstrated the salutary benefits of inhibiting STAT3 activity in several kidney disease models, pharmacological inhibition has yet to make it to the clinical forefront. In recent years, significant effort has been aimed at suppressing STAT3 activation for treatment of cancers, which has led to the development of a wide variety of STAT3 inhibitors, but only a handful have been tested in kidney disease models. Here, we review the detrimental role of dysregulated STAT3 activation in a variety of kidney diseases and the current progress in the treatment of kidney diseases with pharmacological inhibition of STAT3 activity.

Nobiletin suppresses high-glucose-induced inflammation and ECM accumulation in human mesangial cells through STAT3/NF-κB pathway

Diabetic nephropathy (DN) is a complication of chronic diabetes and the main cause of end-stage renal disease all over the world. Inflammation and extracellular matrix (ECM) accumulation play important roles in the pathogenesis of DN. Evidence suggested that nobiletin acts anti-inflammatory role and plays a critical role in diabetes; however, its role in DN remains unclear. In the current study, we promulgated the nobiletin involved in high-glucose-induced glomerular mesangial cell inflammation and ECM accumulation. Nobiletin treatment significantly abrogated high-glucose-induced glomerular mesangial cell proliferation. Nobiletin treatment markedly suppressed inflammation cytokine secretion, including interleukin (IL)-1β, IL-6, tumor necrosis factor α, and monocyte chemoattractant protein 1 in high-glucose-induced glomerular mesangial cell. Also, exposed nobiletin to high-glucose-induced glomerular mesangial cell considerably reduced ECM accumulation through inhibited ECM-associated protein type 4 collagen and fibronectin expression. Furthermore, nobiletin treatment abolished nuclear factor κB (NF-κB) pathway activation through signal transducer and activator of transcription 3 (STAT3) inhibition. Overexpression STAT3 reversed the effects of nobiletin on high-glucose-induced glomerular mesangial cell proliferation, inflammation, ECM accumulation, and NF-κB pathway activation. Hence, our results suggest that nobiletin play roles in high-glucose-induced glomerular mesangial cells through inhibiting inflammation and ECM accumulation, and the STAT3/NF-κB pathway was involved in the function of nobiletin.

miR-375 prevents nasal mucosa cells from apoptosis and ameliorates allergic rhinitis via inhibiting JAK2/STAT3 pathway

This study aims to explore the roles, and related mechanisms of miR-375 in nasal mucosa cells apoptosis and allergic rhinitis. Here, miR-375 was found to be decreased in the epithelia of nasal mucosa of allergic rhinitis mice and TNF-α-stimulated nasal mucosa cells, while JAK2 expression exhibited an opposite effect. Mechanistically, miR-375/JAK2 regulatory axis was identified in nasal mucosa cells via luciferase reporter, qRT-PCR, western blot and RNA immune co-precipitation (RIP) assays. Pre- or post-injection of miR-375 agomir following ovalbumin (OVA) treatment attenuated OVA-induced allergic rhinitis, characterized as the downregulation of IL-6 and TNF-α secretion, and upregulation of IL-10 secretion, these effects were attenuated by infection with JAK2 adenovirus through nasal cavity inhalation. Additionally, overexpression of miR-375 reversed TNF-α-mediated nasal mucosa cells apoptosis, which was attenuated by JAK2 overexpression. Therefore, our results indicate that miR-375 prevents nasal mucosa cells from apoptosis and ameliorates allergic rhinitis via inhibiting JAK2/STAT3 pathway.

Trans-resveratrol mitigates type 1 diabetes-induced oxidative DNA damage and accumulation of advanced glycation end products in glomeruli and tubules of rat kidneys

Hyperglycemia induces the formation of advanced glycation end products (AGEs) and their receptors (RAGEs), which alter several intracellular signaling mechanisms leading to the onset and progression of diabetic nephropathy. The present study focused on, i) modulatory effects of trans-resveratrol (3,5,4'-trihydroxy-trans-stilbene) on structural changes, AGE (N^Ɛ-carboxymethyl-lysine), RAGE, oxidative stress and DNA damage, and apoptosis, and ii) localization of fibrotic changes, AGE, RAGE, 8-oxo-dG and 4-hydroxynonenal (4-HNE) in diabetic rat kidneys. Resveratrol (5mg/kg; po, administered during last 45days of 90-day-long hyperglycemic period) administration to streptozotocin-induced type 1 diabetic male Wistar rats reduced renal hypertrophy and structural changes (tubular atrophy, mesangial expansion or shrinkage, diffuse glomerulonephritis, and fibrosis), AGE accumulation, oxidative stress and DNA damage (8-oxo-dG), 4-HNE, caspase-3, and cleaved-caspase-3, but not the RAGE expression. The AGE accumulated in the mesangium, vascular endothelium, and proximal convoluted tubules and less intensely in distal convoluted tubules of diabetic rat kidneys. The RAGE expression increased in the convoluted tubules and collecting ducts of diabetic rat kidneys, but not in the mesangium. Diabetes increased the expression of 8-oxo-dG in nuclei and cytoplasm of renal cells, and 4-HNE in glomeruli, convoluted tubules, the loops of Henle and collecting ducts. Hyperglycemia-induced AGE-RAGE axis and oxidative stress in turn induced apoptosis in diabetic kidneys. Resveratrol mitigated all diabetic effects except the RAGE expression. In conclusion, Resveratrol significantly alleviates diabetes-induced glycation, oxidative damage, and apoptosis to inhibit the progression of diabetic nephropathy. Resveratrol supplementation may be useful to hinder the onset and progression of diabetic kidney diseases.