Addition of adipose tissue-derived mesenchymal stem cells improves empagliflozin therapy for alleviating hyperglycemia--induced neuropathy

Background: We examined the impact of adipose-derived mesenchymal stem cell (ADMSC)-facilitated em-pagliflozin (EMPA) therapy for alleviating hyperglycemic induced neuropathy [i.e., diabetic neuropathy (DN)]. Methods: Study constituted N2a cell culture and rats to be classified into groups 1 (sham-operated-control)/2 (DN)/3 (DN + empagliflozin/20 mg/kg/daily orally for 6 weeks since post-day-7 DN induction)/4 (DN + ADMSCs/1.2 x 10(6) cells by vein transfusion at time intervals of 1/3/5 weeks after DN induction)/5 (DN + empagliflozin + ADMSCs) and sacrificed by day-42 after DN induction. Results: In vitro results showed that, compared to N2a cells, the cellular levels of senescence/DNA-damage and protein expressions of oxidative-stress (OS), apoptotic, autophagic and inflammatory biomarkers were significantly higher in N2a + glucose (25 mM) but were significantly reversed in N2a + glucose + ADMSCs, whereas the cellular levels of mitochondrial cytochrome C and protein levels of anti-oxidants displayed an opposite pattern of OS (all P<0.001). The above-mentioned parameters (i.e., OS/apoptosis/fibrosis/autophagy/ DNA-damage) were lowest in N2a cells, highest in N2a + glucose and significantly higher in N2a + glucose + EMPA (50 mu M) than in N2a + glucose + EMPA (150 mu M) (all P<0.001). By days 7/14/21/28/35/42 after DN induction, the values of thermal paw-withdrawal-latency (TPWL)/mechanical-paw-withdrawal-threshold were highest in group 1 and significantly progressively increased from groups 2/4/3/5 (all P<0.0001). The cellular levels of unmyelinated C-and myelinated A-delta fibers, and protein levels of OS/apoptotic/DNA-damaged/fibrotic/autophagic/inflammatory/ pain-facilitated/voltage-gated sodium channel biomarkers in L4-L5 levels of dorsal-root-ganglia exhibited an contradictory manner of TPWL among the groups (all P<0.0001). Conclusions: Combination of EMPA and ADMSC therapy was superior to either alone for improving outcomes of DN.