Analysis of renal protective effects of ARB and SGLT2i at single cell level.

Angiotensin receptor blockade (ARB) and sodium-glucose co-transporter 2 inhibitor (SGLT2i) have been used as the standard therapy for patients with diabetic kidney disease (DKD). However, how these two drugs possess additive renal protective effects remains unclear. Here, we conducted single cell RNA-sequencing to profile the kidney cell transcriptome of db/db mice treated with vehicle, ARB, SGLT2i, or both drugs and db/m mice. We identified 10 distinct clusters of kidney cells with predominant proximal tubular (PT) cells. We found that ARB has more anti-inflammatory and anti-fibrosis effects while SGLT2i affects more mitochondrial function. We also identified a new PT subcluster which was increased in DKD but reversed by treatments.This new subcluster was also confirmed by Immunostaining of mouse and human kidneys with DKD. Together, our study reveal kidney cell-specific gene signatures in response to ARB and SGLT2i and also identified a new PT subcluster which provides new insight into DKD. Male db/db mice (BKS.Cg-Dock7m+/+Leprdb/Nju) were purchased from the Model Animal Research Center of Nanjing University. Male lean controls db/m mice were purchased from The Jackson Laboratory. We used only male mice here because these mice develop DKD more consistently than female mice. Mice were housed in a specific pathogen-free facility with free access to food and water and a 12:12h night-day cycle. Male db/db mice develop DKD defined by development of albuminuria at 10 weeks of age. The db/db mice were randomly assigned to four groups as follow: treated vehicle control (phosphate-buffered saline, PBS) (n = 8), treated with 3mg/kg/day of dapagliflozin (n = 8), treated with 20mg/kg/day of irbesartan (n = 8), and combination therapy with both dapagliflozin and irbesartan (n = 8). Vehicle and drugs were administra- ted daily by oral gavage for 8 weeks and all mice were sacrificed at age of 18 weeks. All animal studies were performed in accordance with the protocol approved by the Animal Care Committee at the Chongqing Medicine University. BW and fasting BG levels were monitored weekly by glucometer readings. Urine samples were collected weekly.