A novel salviadione derivative, compound 15a, attenuates diabetes-induced renal injury by inhibiting NF-κB-mediated inflammatory responses

A derivative of tanshinone IIA and salviadione, 15a, inhibits inflammation and alleviates DSS-induced colitis in mice by direct binding and inhibition of RIPK2

Inflammatory bowel diseases (IBDs) are chronic inflammatory conditions primarily affecting the gastrointestinal tract. Previous studies established the role of the NF-κB signaling pathway in the development of IBDs, suggesting that anti-inflammatory therapies might offer a viable treatment strategy. Tanshinone IIA and salviadione, both derived from Salviae Miltiorrhizae Radix et Rhizoma, possess anti-inflammatory and anti-oxidative activities. A series of new compounds were synthesized by hybridizing salviadione with tanshinone. Among these compounds, 15a showed beneficial effects in LPS-induced acute lung injury and diabetes-induced renal injury mouse models. The current study explored the therapeutic efficacy of 15a using both acute and chronic colitis models and elucidated the underlying mechanisms. DSS-induced colitis models were established in mice, where acute colitis was treated with compound 15a (5 or 10 mg·kg-1·d-1) for 8 days, while chronic colitis mice received compound 15a (5 or 10 mg·kg-1·d-1, i.g.) during 2.5% DSS administration. The 15a treatment significantly alleviated DSS-induced pathological and inflammatory damages in both acute and chronic colitis mouse models. In mouse intestinal epithelial cell line MODE-K, pretreatment with compound 15a (5 or 10 μM) significantly suppressed LPS + L18-MDP-induced inflammatory responses. The receptor-interacting serine/threonine kinase 2 (RIPK2) was identified as a direct binding target of compound 15a using microarrays and recombinant human proteins. Moreover, 15a could directly bind to and inhibit the phosphorylation of RIPK2, leading to the suppression of the NF-κB and MAPK signaling pathways. Furthermore, LEU153 and VAL32 were identified within the KD domain of RIPK2 as critical amino residues for the binding of 15a. Briefly, the current findings demonstrate that compound 15a holds promise as a therapeutic agent for managing acute and chronic colitis.

Patchouli Alcohol Protects the Heart against Diabetes-Related Cardiomyopathy through the JAK2/STAT3 Signaling Pathway

Diabetic cardiomyopathy (DCM) represents a common pathological state brought about by diabetes mellitus (DM). Patchouli alcohol (PatA) is known for its diverse advantageous effects, notably its anti-inflammatory properties and protective role against metabolic disorders. Despite this, the influence of PatA on DCM remains relatively unexplored. To explore the effect of PatA on diabetes-induced cardiac injury and dysfunction in mice, streptozotocin (STZ) was used to mimic type 1 diabetes in mice. Serological markers and echocardiography show that PatA treatment protects the heart against cardiomyopathy by controlling myocardial fibrosis but not by reducing hyperglycemia in diabetic mice. Discovery Studio 2017 software was used to perform reverse target screening of PatA, and we found that JAK2 may be a potential target of PatA. RNA-seq analysis of heart tissues revealed that PatA activity in the myocardium was primarily associated with the inflammatory fibrosis through the Janus tyrosine kinase 2 (JAK2)/signal transducer and activator of the transcription 3 (STAT3) pathway. In vitro, we also found that PatA alleviates high glucose (HG) + palmitic acid (PA)-induced fibrotic and inflammatory responses via inhibiting the JAK2/STAT3 signaling pathway in H9C2 cells. Our findings illustrate that PatA mitigates the effects of HG + PA- or STZ-induced cardiomyopathy by acting on the JAK2/STAT3 signaling pathway. These insights indicate that PatA could potentially serve as a therapeutic agent for DCM treatment.

Baicalin - 2- ethoxyethyl ester alleviates renal fibrosis by inhibiting PI3K/AKT/NF-κB signaling pathway

With the increasing incidence of chronic kidney disease (CKD), the development of safe and effective anti-renal fibrosis drugs is particularly urgent. Recently, Baicalin has been considered to have a renal protective effect, but its bioavailability is too low. Therefore, we synthesized baicalin-2-ethoxyethyl ester (BAE) by esterification of baicalin. We hope that this experiment will demonstrate the anti-renal fibrosis effect of BAE and explain its molecular mechanism. In this study, the chronic kidney injury model of SD rats was established by 5/6 nephrectomy, and BAE was given for 28 days. The results showed that after BAE treatment, the serum creatinine and urea nitrogen levels decreased significantly, and the pathological changes in kidneys were improved. In addition, RNA-seq analysis showed that the mechanism of BAE in relieving renal fibrosis was related to the ECM receptor, PI3K/AKT signaling pathway, and inflammatory reaction. The western blotting analysis confirmed that BAE could inhibit the expression of α-SMA, TGF-β1, p-PI3K, p-AKT, p-IκBα, and NF-κB p65. We found that BAE can inhibit the inflammatory reaction and promote the degradation of the extracellular matrix by inhibiting the activation of the PI3K/AKT/NF-κB pathway, thus alleviating the symptoms of renal fibrosis in 5/6Nx rats, which revealed BAE was a potential compound to relieve renal fibrosis effect.

Immune responses in diabetic nephropathy: Pathogenic mechanisms and therapeutic target

Diabetic nephropathy (DN) is a chronic, inflammatory disease affecting millions of diabetic patients worldwide. DN is associated with proteinuria and progressive slowing of glomerular filtration, which often leads to end-stage kidney diseases. Due to the complexity of this metabolic disorder and lack of clarity about its pathogenesis, it is often more difficult to diagnose and treat than other kidney diseases. Recent studies have highlighted that the immune system can inadvertently contribute to DN pathogenesis. Cells involved in innate and adaptive immune responses can target the kidney due to increased expression of immune-related localization factors. Immune cells then activate a pro-inflammatory response involving the release of autocrine and paracrine factors, which further amplify inflammation and damage the kidney. Consequently, strategies to treat DN by targeting the immune responses are currently under study. In light of the steady rise in DN incidence, this timely review summarizes the latest findings about the role of the immune system in the pathogenesis of DN and discusses promising preclinical and clinical therapies.