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

Perindopril Dampens Cd-induced Nephrotoxicity by Suppressing Inflammatory Burden, Ang II/Ang 1-7, and Apoptosis Signaling Pathways

Cadmium (Cd) is one of the most abundant toxic heavy metals, and its exposure is linked to serious kidney intoxication, a major health problem. Evidence reported that inflammatory damage is a key factor in Cd renal intoxication. Perindopril (PER) is an angiotensin-converting enzyme inhibitor approved for treating hypertension and other cardiovascular problems. Significantly, RAS activation results in inflammatory damage. Our study aimed to examine the renoprotective effects of PER in Cd-induced nephrotoxicity, the impact of inflammation, and the underlying molecular mechanisms. PER was given at a dose of 1 mg/kg per day. Cd was injected at a dose of 1.2 mg/kg, as a single dose. Treatment with PER led to a significant decrease in serum levels of urea, creatinine, uric acid, and urine albumin/creatinine ratio. PER effectively mitigated inflammation by decreasing MPO, NO, IL-1β, IL-6, and INF-γ levels mediated by downregulating NF-κB expression and suppressing JAK-1 and STAT3 phosphorylation. PER modulates Ang II/Ang 1-7 axis in Cd-intoxicated rats by decreasing Ang II expression and increasing Ang-(1-7) expression. PER inhibits Cd-induced apoptosis by lowering Bax, cytochrome c, and cleaved caspase 3 expressions while increasing Bcl-2 expression. In conclusion, PER dampens Cd-induced kidney intoxication by modulating Ang II/Ang 1-7 axis, suppressing NF-κB, JAK-1/STAT3, and apoptosis signals.

JAK2/STAT3 as a new potential target to manage neurodegenerative diseases: An interactive review

Neurodegenerative diseases (NDDs) are a collection of incapacitating disorders in which neuroinflammation and neuronal apoptosis are major pathological consequences due to oxidative stress. Neuroinflammation manifests in the impacted cerebral areas as a result of pro-inflammatory cytokines stimulating the Janus Kinase2 (JAK2)/Signal Transducers and Activators of Transcription3 (STAT3) pathway via neuronal cells. The pro-inflammatory cytokines bind to their respective receptor in the neuronal cells and allow activation of JAK2. Activated JAK2 phosphorylates tyrosines on the intracellular domains of the receptor which recruit the STAT3 transcription factor. The neuroinflammation issues are exacerbated by the active JAK2/STAT3 signaling pathway in conjunction with additional transcription factors like nuclear factor kappa B (NF-κB), and the mammalian target of rapamycin (mTOR). Neuronal apoptosis is a natural process made worse by persistent neuroinflammation and immunological responses via caspase-3 activation. The dysregulation of micro-RNA (miR) expression has been observed in the consequences of neuroinflammation and neuronal apoptosis. Neuroinflammation and neuronal apoptosis-associated gene amplification may be caused by dysregulated miR-mediated aberrant phosphorylation of JAK2/STAT3 signaling pathway components. Therefore, JAK2/STAT3 is an attractive therapeutic target for NDDs. Numerous synthetic and natural small molecules as JAK2/STAT3 inhibitors have therapeutic advances against a wide range of diseases, and many are now in human clinical studies. This review explored the interactive role of the JAK2/STAT3 signaling system with key pathological factors during the reinforcement of NDDs. Also, the clinical trial data provides reasoning evidence about the possible use of JAK2/STAT3 inhibitors to abate neuroinflammation and neuronal apoptosis in NDDs.

Targeting STAT3 Enzyme for Cancer Treatment

A category of cytoplasmic transcription factors called STATs mediates intracellular signaling, which is frequently generated at receptors on cell surfaces and subsequently sent to the nucleus. STAT3 is a member of a responsible for a variety of human tumor forms, including lymphomas, hematological malignancies, leukemias, multiple myeloma and several solid tumor types. Numerous investigations have demonstrated constitutive STAT3 activation lead to cancer development such as breast, head and neck, lung, colorectal, ovarian, gastric, hepatocellular, and prostate cancers. It's possible to get a hold of the book here. Tumor cells undergo apoptosis when STAT3 activation is suppressed. This review highlights the STAT3 activation and inhibition which can be used for further studies.

The effect of the BK polyomavirus large T antigen on the function and maturity of the CD4+ T cell subsets in kidney transplant recipients

BACKGROUND

In kidney transplant recipients (KTRs) who are immunosuppressed, human BK polyomavirus (BKPyV) infection can be reactivated, resulting in BKPyV-associated nephropathy (BKPyVN). Considering that BKPyV inhibits CD4+ T cell differentiation, we investigated the effect of BKPyV large T antigen (LT-Ag) on the maturation of CD4+ T cell subsets during active BKPyV infection.

METHODS

In this cross-sectional study, we examined the following groups: 1) five KTRs with active viral infection (BKPyV+ KTRs), 2) five KTRs without active viral infection (BKPyV-KTRs), and 3) five healthy controls. We measured the frequency of CD4+ T cells and their different subsets, such as naive T cells, central memory T cells (Tcm), and effector memory T cells (Tem). All these subsets were analyzed by flow cytometry in peripheral blood mononuclear cells (PBMCs) stimulated with the overlapping BKPyV LT-Ag peptide pool. In addition, CD4+ T cell subsets were analyzed by flow cytometry for the presence of CD4, CCR7, CD45RO, CD107a, and granzyme B (GB). In addition, mRNA expression of transcription factors (TFs) such as T-bet, GATA-3, STAT-3, and STAT-6 was examined. The probability of inflammation with perforin protein was examined by SYBR Green real-time PCR.

RESULTS

After stimulation of PBMCs, naive T cells (CD4+CCR7+CD45RO-) (p = 0.9) and CD4+ T cells which release CD107a+ (CD4+CD107a+Geranzyme B-) (p = 0.9) T cells were more abundant in BKPyV+ KTRs than in BKPyV- KTRs. In contrast, central memory T cells (CD4+CCR7+CD45RO+) (p = 0.1) and effector memory T cells (CD4+CCR7-CD45RO+) (p = 0.1) were more abundant in BKPyV- KTRs than in BKPyV+ KTRs. The mRNA expression levels of T-bet, GATA-3, STAT-3, and STAT-6 were significantly higher (p < 0.05) in BKPyV- KTRs than in BKPyV+ KTRs which may be due to a higher differentiation level of CD4+ T cells. Due to inflammation, the mRNA expression level of perforin was higher in BKPyV+ KTRs, than in BKPyV- KTRs, but the difference was not significant (p = 0.175).

CONCLUSIONS

The high number of naive T cells after PBMC stimulation with the LT-Ag peptide pool was observed in BKPyV+ KTRs due to the interaction of LT-Ag with T cells. This means that BKPyV by using its LT-Ag can inhibit the naive T cell differentiation to other T cell subsets like central and effector memory T cells. However, the frequency of CD4+ T cell subsets and the combination of the activities of these cells with the expression profile of the target genes in this study may be efficient in treating and diagnosing BKPyV infections in kidney recipients.

[Therapeutic mechanism of Shenbing Decoction Ⅲ for renal fibrosis in chronic kidney disease: a study with network pharmacology, molecular docking and validation in rats]

OBJECTIVE

To observe the effect of Shenbing Decoction Ⅲ for improving renal function and pathology in rats with 5/6 nephrectomy and analyze its therapeutic mechanism for renal fibrosis in chronic kidney disease using network pharmacology combined with molecular docking.

METHODS

Forty male SD rats were randomized into two groups to receive two-staged 5/6 nephrectomy (n=30) or sham operation (n=10), and 2 weeks after the final operation, serum creatinine level of the rats was measured. The rats with nephrectomy were further randomized into Shenbing Decoction Ⅲ group, losartan group and model group for daily treatment with the corresponding drugs via gavage starting at 1 week after 5/6 nephrectomy. After 16 weeks of treatment, serum creatinine and urea nitrogen levels of the rats were measured, and HE staining and Western blotting were used to examine the changes in renal pathology and fibrosis-related factors. Network pharmacology combined with molecular docking study was performed to explore the therapeutic mechanism Shenbing Decoction Ⅲ against renal fibrosis in chronic kidney disease, and Western blotting was used to verify the expressions of the core targets.

RESULTS

Compared with those in the model group, the rats receiving 5/6 nephrectomy and Shenbing Decoction Ⅲ treatment showed significantly reduced serum creatinine and urea nitrogen levels, lessened renal pathologies, and improvement of the changes in epithelial mesenchymal transition-related proteins. Network pharmacological analysis showed that the main active ingredients of Shenbing Decoction Ⅲ were acacetin, apigenin, eupatilin, quercetin, kaempferol and luteolin, and the key targets included STAT3, SRC, CTNNB1, PIK3R1 and AKT1. Molecular docking study revealed that the active ingredients of Shenbing Decoction Ⅲ had good binding activity to the key targets. Western blotting showed that in rats with 5/6 nephrectomy, treatment with Shenbing Decoction Ⅲ obviously restored the protein expression of STAT3, PI3K, and AKT in renal tissue.

CONCLUSION

Shenbing Decoction Ⅲ can reduce renal injury induced by 5/6 nephrectomy in rats, and its therapeutic effects are mediated possibly by its main pharmacologically active ingredients that alleviate renal fibrosis via modulating multiple targets including STAT3, PIK3R1, and AKT1.

Fibrosis: Types, Effects, Markers, Mechanisms for Disease Progression, and Its Relation with Oxidative Stress, Immunity, and Inflammation

Most chronic inflammatory illnesses include fibrosis as a pathogenic characteristic. Extracellular matrix (ECM) components build up in excess to cause fibrosis or scarring. The fibrotic process finally results in organ malfunction and death if it is severely progressive. Fibrosis affects nearly all tissues of the body. The fibrosis process is associated with chronic inflammation, metabolic homeostasis, and transforming growth factor-β1 (TGF-β1) signaling, where the balance between the oxidant and antioxidant systems appears to be a key modulator in managing these processes. Virtually every organ system, including the lungs, heart, kidney, and liver, can be affected by fibrosis, which is characterized as an excessive accumulation of connective tissue components. Organ malfunction is frequently caused by fibrotic tissue remodeling, which is also frequently linked to high morbidity and mortality. Up to 45% of all fatalities in the industrialized world are caused by fibrosis, which can damage any organ. Long believed to be persistently progressing and irreversible, fibrosis has now been revealed to be a very dynamic process by preclinical models and clinical studies in a variety of organ systems. The pathways from tissue damage to inflammation, fibrosis, and/or malfunction are the main topics of this review. Furthermore, the fibrosis of different organs with their effects was discussed. Finally, we highlight many of the principal mechanisms of fibrosis. These pathways could be considered as promising targets for the development of potential therapies for a variety of important human diseases.

Quercetin inhibits angiotensin II-induced vascular smooth muscle cell proliferation and activation of JAK2/STAT3 pathway: A target based networking pharmacology approach

The rapid growth of vascular smooth muscle cells (VSMCs) represents crucial pathological changes during the development of hypertensive vascular remodeling. Although quercetin exhibits significantly therapeutic effects on antihypertension, the systematic role of quercetin and its exact mode of action in relation to the VSMCs growth and its hypertension-related networking pharmacology is not well-documented. Therefore, the effect of quercetin was investigated using networking pharmacology followed by in vitro strategies to explore its efficacy against angiotensin II (Ang II)-induced cell proliferation. Putative genes of hypertension and quercetin were collected using database mining, and their correlation was investigated. Subsequently, a network of protein-protein interactions was constructed and gene ontology (GO) analysis was performed to identify the role of important genes (including CCND1) and key signaling pathways [including cell proliferation and Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway]. We therefore further investigated the effects of quercetin in Ang II-stimulated VSMCs. This current research revealed that quercetin significantly reduced the cell confluency, cell number, and cell viability, as well as expression of proliferating cell nuclear antigen (PCNA) in Ang II-stimulated VSMCs. Mechanistic study by western blotting confirmed that quercetin treatment attenuated the activation of JAK2 and STAT3 by reducing its phosphorylation in Ang II stimulated VSMCs. Collectively, the current study revealed the inhibitory effects of quercetin on proliferation of Ang II stimulated VSMCs, by inhibiting the activation of JAK2/STAT3 signaling might be one of underlying mechanisms.

Recent Advances in Understanding Nrf2 Agonism and Its Potential Clinical Application to Metabolic and Inflammatory Diseases

Oxidative stress is a major component of cell damage and cell fat, and as such, it occupies a central position in the pathogenesis of metabolic disease. Nuclear factor-erythroid-derived 2-related factor 2 (Nrf2), a key transcription factor that coordinates expression of genes encoding antioxidant and detoxifying enzymes, is regulated primarily by Kelch-like ECH-associated protein 1 (Keap1). However, involvement of the Keap1–Nrf2 pathway in tissue and organism homeostasis goes far beyond protection from cellular stress. In this review, we focus on evidence for Nrf2 pathway dysfunction during development of several metabolic/inflammatory disorders, including diabetes and diabetic complications, obesity, inflammatory bowel disease, and autoimmune diseases. We also review the beneficial role of current molecular Nrf2 agonists and summarize their use in ongoing clinical trials. We conclude that Nrf2 is a promising target for regulation of numerous diseases associated with oxidative stress and inflammation. However, more studies are needed to explore the role of Nrf2 in the pathogenesis of metabolic/inflammatory diseases and to review safety implications before therapeutic use in clinical practice.

Drug Repurposing in Rare Diseases: An Integrative Study of Drug Screening and Transcriptomic Analysis in Nephropathic Cystinosis

Diagnosis and cure for rare diseases represent a great challenge for the scientific community who often comes up against the complexity and heterogeneity of clinical picture associated to a high cost and time-consuming drug development processes. Here we show a drug repurposing strategy applied to nephropathic cystinosis, a rare inherited disorder belonging to the lysosomal storage diseases. This approach consists in combining mechanism-based and cell-based screenings, coupled with an affordable computational analysis, which could result very useful to predict therapeutic responses at both molecular and system levels. Then, we identified potential drugs and metabolic pathways relevant for the pathophysiology of nephropathic cystinosis by comparing gene-expression signature of drugs that share common mechanisms of action or that involve similar pathways with the disease gene-expression signature achieved with RNA-seq.