Mitiglinide Calcium Hydrate

Deletion of IG20 (also known as MADD), which can encode multiple isoforms, causes diabetes in mice by impairing glucose-stimulated insulin secretion. To evaluate the role of IG20 in mediating the therapeutic potential of glinide-class insulin secretagogues, we tested their effects in Ig20/Madd-knockout (KMA1ko) mice. Glucose tolerance tests revealed that repaglinide, mitiglinide, and nateglinide failed to lower blood glucose levels or enhance insulin secretion in KMA1ko mice, suggesting that IG20 deficiency significantly diminishes the therapeutic efficacy of glinides. The functional relevance of at least 6 IG20 isoforms remains to be defined. Interestingly, among the six IG20 splicing isoforms re-expressed in IG20-deficient Min6 cells, only KIAA0358 was capable of restoring glucose-stimulated insulin secretion. Notably, KIAA0358 re-expression also rescued repaglinide-induced insulin secretion in vivo. Further transmission electron microscopy and total internal reflection fluorescence microscopy analyses showed that KIAA0358 significantly promoted insulin granule transport and docking impaired by IG20 knockout. Furthermore, guanine nucleotide exchange assay and GST pull-down demonstrated that KIAA0358 functions as a Rab GEF to convert Rab3A and Rab27A from the GDP-bound to the active GTP-bound state, thereby restoring their interactions with the downstream effector proteins Rim2α and Slac-2a that were impaired by IG20 deficiency. Therefore, by regulating the activation states of Rab3A and Rab27A, KIAA0358 mediated the transport and docking of insulin granules to the plasma membrane. This study also highlights that the genes encoding non-drug target proteins can influence drug efficacy and provides a novel conceptual foundation for precision medicine strategies aimed at reducing drug resistance and enhancing the clinical efficacy of glinides.

Osteoarthritis (OA), a leading cause of joint dysfunction, is characterized by progressive cartilage degradation linked to chondrocyte pyroptosis, yet disease-modifying therapies remain elusive. In this study, we conducted the first systematic drug repurposing screen in chondrocytes, aiming at identifying drugs that may suppress pyroptosis and verifying the therapeutic effects on OA.

Mitiglinide's effects on chondrocyte viability were quantified via CCK-8 assays and live/dead staining. Pyroptosis inhibition, extracellular matrix (ECM) homeostasis, and NF-κB activation were measured by western blot and immunofluorescence. Network pharmacology analysis and molecular docking were applied to predict the interacting protein of mitiglinide, while Nrf2 was knocked down by siRNAs to confirm its role in mitiglinide regulated pyroptosis and ECM. In vivo, destabilization of the medial meniscus (DMM) model -induced OA mice received mitiglinide for 8 weeks, with efficacy evaluated through X-ray, OARSI-graded histopathology, immunohistochemistry, Hematoxylin-Eosin and Safranin O-Fast green staining.

Through high-throughput screening (HTS) of 1,228 FDA-approved drugs, we identified a list of pyroptosis inhibitors, and mitiglinide was suggested as one of the most potent pyroptosis inhibitors in chondrocyte. Mechanistic studies demonstrated that mitiglinide may directly target Nrf2 and suppress its downstream NF-κB-driven NLRP3 inflammasome activation; it may also promote ECM homeostasis in chondrocytes. In vivo study showed that mitiglinide may effectively attenuate OA pathology in mice.

Mitiglinide, identified via FDA-drug-library screening, alleviates OA progression by suppressing NLRP3 inflammasome activation and ECM degradation via activation of the Nrf2/HO-1 signaling pathway. This positions mitiglinide as a repurposed disease-modifying OA drug candidate.