Project description:Rats (Wag/Rij, females) were chronically treated with Losartan (20mg/d), an angiotensin II-receptor blocker during 9 months. Gene expression profiling was performed on aortic media to understand the long-term effect of this molecule on the cardiovascular system.
Project description:Rats (Wag/Rij, females) were chronically treated with Losartan (20mg/d), an angiotensin II-receptor blocker during 9 months. Gene expression profiling was performed on aortic media to understand the long-term effect of this molecule on the cardiovascular system. Two-conditions experiment, Ctrl vs Losartan-treated animals. Biological replicates: 5 control replicates, 5 Losrtan-treated animals. All the RNA samples were pooled to provide a reference RNA for a two-color experiment.
Project description:COVID-19 associated acute kidney injury (COVID-AKI) is a common complication of SARS-CoV-2 infection in hospitalized patients. It is unclear how susceptible human kidneys are to direct SARS-CoV-2 infection and whether pharmacologic manipulation of the renin-angiotensin II signaling (RAS) pathway modulates this susceptibility. Using induced pluripotent stem cell derived kidney organoids, SARS-CoV-1, SARS-CoV-2 and MERS-CoV tropism, defined by the paired expression of a host receptor (ACE2, NRP1 or DPP4) and protease (TMPRSS2, TMPRSS4, FURIN, CTSB or CTSL), was identified primarily amongst proximal tubule cells. Losartan, an angiotensin II receptor blocker being tested in COVID-19 patients, inhibited angiotensin II mediated internalization of ACE2, upregulated interferon stimulated genes (IFITM1 and BST2) known to restrict viral entry, and attenuated the infection of proximal tubule cells by SARS-CoV-2. Our work highlights the susceptibility of proximal tubule cells to SARS-CoV-2 and reveals a putative protective role for RAS inhibitors during SARS-CoV-2 infection.
Project description:Immune checkpoint blockers (ICBs) have failed in all Phase III glioblastoma trials. Here, we found that ICBs induce cerebral edema in some patients and mice with glioblastoma. Through single-cell RNA sequencing, intravital imaging, and T cell blocking studies in mice, we demonstrated that this edema results from an inflammatory response following anti-PD1 antibody treatment that disrupts the blood-tumor-barrier. Used in lieu of immunosuppressive corticosteroids, the angiotensin receptor blocker losartan prevented this ICB-induced edema and reprogrammed the tumor microenvironment, curing 20% of mice which increased to 40% in combination with standard of care treatment. Using a bihemispheric tumor model, we identified a “hot” tumor immune signature prior to losartan+anti-PD1 therapy that predicted long-term survival. Our findings provide the rationale and associated biomarkers to test losartan with ICBs in glioblastoma patients.
Project description:To improve our limited understanding of the pathogenesis of thoracic aortic aneurysm (TAA) leading to acute aortic dissection, we used single-cell RNA sequencing to profile disease-relevant transcriptomic changes of aortic cell populations in a well-characterized mouse model of the most commonly diagnosed form of Marfan syndrome (MFS). As result,MFSmod were identified only in the aorta of Fbn1mgR/mgR mice. In situ hybridizations of diagnostic transcripts located MFSmod cells to the intima of Fbn1mgR/mgR aortas. Consistent with angiotensin II type I receptor (At1r) contribution to TAA development, MFSmod cells were absent in the aorta of Fbn1mgR/mgR mice treated with the At1r antagonist losartan. Altogether, our findings indicate that a discrete dynamic alteration of aortic cell identity is associated with dissecting TAA in MFS mice and increased risk of aortic dissection in MFS patients.
Project description:We undertook a transcriptome-wide discovery approach to provide information on the involved gene regulatory responses to change in fetal cardiac mass in response to chronic infusion of angiotensin II or losartan. One of each of 8 twin fetus pairs was infused with either angiotensin II or losartan daily for five days in utero. A portion of the left ventricular free wall of treatment and control fetuses was excised, homogenized in a reagent, and then total RNA was then isolated and assayed on the agilent microarray
Project description:We undertook a transcriptome-wide discovery approach to provide information on the involved gene regulatory responses to change in fetal cardiac mass in response to chronic infusion of angiotensin II or losartan.
