Introduction:
Drug resistance remains a formidable challenge in the treatment of various diseases. The action of glucocorticoids is to switch off activated inflammatory genes. The activated glucocorticoid receptors (GR) interact with co-repressor molecules to impair NFκB-associated coactivator activity, reducing histone acetylation, chromatin remodelling. Reduction in histone acetylation occurs via recruitment of histone deacetylase (HDAC) 2 to the activated inflammatory gene complex by activated GR, resulting in efficacious suppression of activated inflammatory genes within the nucleus. AMPK being a master regulator of metabolism can modulate the immune metabolism leading to increased disease activity and resistance.
Methods:
181 steroid sensitive nephrotic syndrome (SSNS), and 95 steroid resistant nephrotic syndrome (SRNS) patients were recruited in the study. mRNA expression was analyzed on peripheral blood mononuclear cells (PBMCs) in SRNS patients (mean age 8.43±3.8 years), SSNS patients (mean age 7.54±3.5 years). PBMCs were treated with 1µM of Theophylline (HDAC2 stimulator) and 0.8µM of Trichostatin A (HDAC2 inhibitor) for a period of 48 hours. qPCR was performed relative gene expression levels were calculated and normalized to the corresponding levels of the housekeeping gene (GAPDH).
Results:
Expression of P-gp (4.79±0.10 v/s 2.13±0.12, p<0.0001) and MRP-1 (3.99 ±0.08 v/s 1.99 ±0.11, p<0.0001) on PBMCs was increased in SRNS as compared to that of SSNS. HDAC2 mRNA levels were significantly decreased in SRNS patients as compared to that of SSNS patients (2.97 ± 0.15 v/s 6.02 ± 0.13, p<0.0001). The bioenergetic profiling increased in SRNS patients (glycolysis 84%, OXPHOS 27%), suggesting a metabolic reprogramming that supports their heightened proliferative and effector functions. AMPK1 gene as well as protein expression was also reduced in SRNS patients as compared to SSNS
Theophylline for a period of 48 hours decreased mRNA levels of P-gp and MRP-1 in PBMCs of SRNS with maximal induction at 1µM (fold change 2.65 and 2.21, *p<0.0001) However HDAC2 mRNA expression increased significantly (fold change5.67, *p<0.0001). In SSNS patients P-gp and MRP-1 mRNA expression decreased at1µM (fold change 1.25, 1.24, *p<0.0001) while the mRNA expression was increased (fold change 6.93, *p<0.0001).
TSA for a period of 48 hours increased mRNA levels of P-gp and MRP-1 in PBMCs of SRNS with maximal induction at 0.8µM (fold change 7.51, 7.31, *p<0.0001) and significantly decreased the level of HDAC2 (fold change1.50, *p<0.0001) similarly in SSNS patients P-gp and MRP-1 mRNA expression increased at 0.8µM (fold change 3.49, 3.35, *p<0.0001) and HDAC2 decreased (fold change2.53, *p<0.0001) at 0.8µM.
Conclusions:
Targeting these pathways could improve treatment outcomes by sensitizing resistant cells to existing therapies, thereby enhancing their efficacy and reducing the likelihood of relapse. Further research is warranted to elucidate the precise mechanisms and therapeutic potential of modulating HDAC2 and AMPK1 in drug-resistant diseases.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.