Nazir, S. | bioRxiv Science

bioRxiv2021

Reversal of the renal hyperglycemic memory by targeting sustained tubular p21 expression

A major therapeutic obstacle in diabetes mellitus is the metabolic or hyperglycemic memory: the persistence of impaired organ function despite improvement of blood glucose. Therapies reversing the hyperglycemic memory and thus improving already established organ-dysfunction are lacking, but urgently needed considering the increasing prevalence of diabetes mellitus worldwide. Here we show that glucose-mediated changes in gene expression largely persist in diabetic kidney disease (DKD) despite reversing hyperglycemia. The senescence-associated cyclin-dependent kinase inhibitor p21 (Cdkn1a) was the top hit among genes persistently induced by hyperglycemia and was associated with sustained induction of the p53-p21 pathway. Persistent p21 induction was confirmed in various animal models, in several independent human samples and in in vitro models. Tubular p21 expression and urinary p21-levels were associated with DKD severity and remained elevated despite improved blood glucose levels in humans, suggesting that p21 may be a biomarker indicating persistent ("memorized") kidney damage. Glucose-mediated p21 induction and tubular senescence were enhanced in mice with reduced levels of the disease resolving protease activated protein C (aPC). Mechanistically, glucose-induced and sustained tubular p21 expression is linked with demethylation of its promoter and reduced DNMT1 expression. aPC reverses already established p21 expression independent of its anticoagulant function through receptor signaling. Accordingly, new pharmacological approaches specifically mimicking aPC signaling (3K3A-aPC, parmodulin-2) enabled the reversal of glucose-mediated sustained tubular p21 expression, tubular senescence, and DKD. Thus, p21-dependent tubular senescence contributes to the hyperglycemic memory but can be therapeutically targeted. Single sentence summaryaPC signaling targets persistent p21 expression and tubular senescence and reverses the hyperglycemic memory in diabetic kidney disease.

molecular biology↗

bioRxiv2020

Forensic features and genetic legacy of the Baloch population of Pakistan and the Hazara population across Durand-line revealed by Y chromosomal STRs

Hazara population across Durand-line has experienced extensive interaction with Central Asian and East Asian populations. Hazara individuals have typical Mongolian facial appearances and they called themselves descendants of Genghis Khans army. The people who speak the Balochi language are called Baloch. Previously, a worldwide analysis of Y-chromosomal haplotype diversity for rapidly mutating (RM) Y-STRs and with PowerPlex Y23 System (Promega Corporation Madison, USA) kit was created with collaborative efforts, but Baloch and Hazara population from Pakistan and Hazara population from Afghanistan were missing. A limited data with limited number of markers and samples is available which poorly define these populations. So, in the current study, Yfiler Plus PCR Amplification Kit loci were examined in 260 unrelated Hazara individuals from Afghanistan, 153 Hazara individuals, and 111 Balochi individuals from Baluchistan Pakistan. For the Hazara population from Afghanistan and Pakistan overall, 380 different haplotypes were observed on these 27 Y-STR loci, gene diversities ranged from 0.51288 (DYS389I) to 0.9257 (DYF387S1) and haplotype diversity was 0.9992 +/- 0.0004. For the Baloch population, every individual was unique at 27 Y-STR loci, gene diversity ranged from 0.5718 (DYS460) to 0.9371(DYF387S1). Twelve haplotypes shared between 178 individuals while only two haplotypes among these twelve were shared between 87 individuals in Hazara populations. Rst and Fst pairwise genetic distance analyses, multidimensional scaling (MDS) plot, Neighbor-joining (NJ) tree, linear discriminatory analysis (LDA), and median-joining network (MJNs) were performed, which shed light on the history of Hazara and Baloch populations. Interestingly null alleles were observed at DYS448 with specific mutation patterns in Hazara populations. The results of our study showed that the Yfiler Plus PCR Amplification Kit marker set provided substantially stronger discriminatory power in the Baloch population of Pakistan and the Hazara population across the Durand-line.

evolutionary biology↗