Association of GRK5 variant rs10886471 with the therapeutic effect of repaglinide in patients of type 2 diabetes mellitus in Peshawar, Pakistan.

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder with a rising global prevalence. The primary objective of this study was to explore the relationship between the GRK5 variant (rs10886471) and the therapeutic effect of repaglinide in patients of T2DM in Peshawar, Pakistan. A quasi-experimental study was designed. The study group consisted of patients with Type 2 Diabetes Mellitus (T2DM) categorized into responders and non-responders based on their HbA1c level reduction in response to repaglinide treatment. After ethical approval, and consent from the participants, sociodemographic and clinical data was collected from 60 T2DM patients. Blood samples were collected followed by DNA extraction and quantification with UV-Vis Spectroscopy. Genotyping for the GRK5 variant rs10886471 was done using the PCR-based method. Among socio-demographic factors family history and BMI showed significant association (P<0.05) with the therapeutic response to repaglinide. The Statistical analyses, including chi-square tests and logistic regression of GRK5 variant rs10886471 exhibited a significant association with the therapeutic response. Variant allele exhibited significant association (OR: 1.2, p=0.049) with the therapeutic response to repaglinide. The study demonstrated a significant relationship between the GRK5 variant (rs10886471) and the therapeutic response to repaglinide in patients of T2DM of Peshawar, Pakistan.

Unveiling G-protein coupled receptor kinase-5 inhibitors for chronic degenerative diseases: Multilayered prioritization employing explainable machine learning-driven multi-class QSAR, ligand-based pharmacophore and free energy-inspired molecular simulation.

GRK5 holds a pivotal role in cellular signaling pathways, with its overexpression in cardiomyocytes, neuronal cells, and tumor cells strongly associated with various chronic degenerative diseases, which highlights the urgent need for potential inhibitors. In this study, multiclass classification-based QSAR models were developed using diverse machine learning algorithms. These models were built from curated compounds with experimentally derived GRK5 inhibitory activity. Additionally, a pharmacophore model was constructed using active compounds from the dataset. Among the models, the SVM-based approach proved most effective and was initially used to screen DrugBank compounds within the applicability domain. Compounds showing significant GRK5 inhibitory potential underwent evaluation for key pharmacophoric features. Prospective compounds were subjected to molecular docking to assess binding affinity towards GRK5's key active site amino acid residues. Stability at the binding site was analyzed through 200 ns molecular dynamics simulations. MM-GBSA analysis quantified individual free energy components contributing to the total binding energy with respect to binding site residues. Metadynamics analysis, including PCA, FEL, and PDF, provided crucial insights into conformational changes of both apo and holo forms of GRK5 at defined energy states. The study identifies DB02844 (S-Adenosyl-1,8-Diamino-3-Thiooctane) and DB13155 (Esculin) as promising GRK5 inhibitors, warranting further in vitro and in vivo validation studies.

GRK5 promoted renal fibrosis via HDAC5/Smad3 signaling pathway.

Renal fibrosis is a common pathological feature of chronic kidney diseases (CKD), poses a significant burden in the aging population, and is a major cause of end-stage renal disease (ESRD). In this study, we investigated the role of G protein-coupled receptor kinases (GRKs) 5 in the pathogenesis of renal fibrosis. GRK5 is a serine/threonine kinase that regulates G protein-coupled receptor (GPCR) signaling. GRK5 has been shown to play a role in various diseases including cardiac disorders and cancer. However, the role of GRK5 in renal fibrosis remains largely unknown. Our finding revealed that GRK5 was significantly overexpressed in renal fibrosis. Specifically, GRK5 was transferred into the nucleus via its nuclear localization sequence to regulate histone deacetylases (HDAC) 5 expression under renal fibrosis. GRK5 acted as an upstream regulator of HDAC5/Smad3 signaling pathway. HDAC5 regulated and prevented the transcriptional activity of myocyte enhancer factor 2A (MEF2A) to repress the transcription of Smad7 which leading to the activation of Smad3. These findings first revealed that GRK5 may be a potential therapeutic target for the treatment of renal fibrosis. Inhibition of GRK5 activity may be a promising strategy to attenuate the progression of renal fibrosis.

Regulation of G protein-coupled receptor kinase 5 mRNA and protein level in rat brain by addictive drugs / 生理学报

G protein-coupled receptor kinase 5 (GRK5) plays an important role in the regulation of GPCR-transduced signals. Our previous study showed that acute administration of morphine could significantly increase GRK5 mRNA level in the cerebral cortex and hippocampus of the rat brain. The current study investigated the potential effects of acute administration of addictive drugs including morphine, heroine and cocaine on GRK5 mRNA level in the rat brain using in situ hybridization and analyzed the effects of acute and chronic morphine treatments on GRK5 protein level in the rat brain using Western blotting assay. Our results showed that 2 h after the initial morphine (10 mg/kg), cocaine (15 mg/kg) and heroine (1 mg/kg) treatment, the mRNA level of GRK5 in the parietal cortex increased about 110% (P<0.01), 70% (P<0.05) and 100% (P<0.01), respectively. In the temporal cortex, GRK5 mRNA level increased about 90% (P<0.01), 40% (P<0.05) and 80.0% (P<0.01), respectively . In the hippocampus, the mRNA level of GRK5 increased about 60% (P<0.01), 30% (P<0.05) and 80% (P<0.01). However, the mRNA level of GRK5 remained unchanged after acute morphine, cocaine or heroine treatment. In the cerebral cortex of the rat brain, the acute administration of morphine (NS-Mor) increased GRK5 protein level by about 60% while the chronic morphine treatment (Mor-Mor) increased GRK5 protein level even higher [about 130% compared with the control group (chronic saline treatment, NS-NS) group, P<0.01]. In the hippocampus, GRK5 protein level remained unchanged after acute administration of morphine (P>0.1),while the level of GRK5 protein tended to decrease after chronic morphine treatment (P=0.098). In the thalamus, acute morphine treatment caused no change in GRK5 protein level (P>0.1) while after chronic morphine treatment, GRK5 protein level decreased significantly (more than 90%, P<0.01), Taken together, our results indicate that addictive drugs can regulate GRK5 in the rat brain on protein level as well as on mRNA level and suggest that GRK5 may play a role in addiction of psychoactive substances.