An outbreak of pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that started in Wuhan, China, at the end of 2019 has become a global pandemic. Both SARS-CoV-2 and SARS-CoV enter host cells via the angiotensin-converting enzyme 2 (ACE2) receptor, which is expressed in various human organs. We have reviewed previously published studies on SARS and recent studies on SARS-CoV-2 infection, named coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO), confirming that many other organs besides the lungs are vulnerable to the virus. ACE2 catalyzes angiotensin II conversion to angiotensin-(1–7), and the ACE2/angiotensin-(1–7)/MAS axis counteracts the negative effects of the renin-angiotensin system (RAS), which plays important roles in maintaining the physiological and pathophysiological balance of the body. In addition to the direct viral effects and inflammatory and immune factors associated with COVID-19 pathogenesis, ACE2 downregulation and the imbalance between the RAS and ACE2/angiotensin-(1–7)/MAS after infection may also contribute to multiple organ injury in COVID-19. The SARS-CoV-2 spike glycoprotein, which binds to ACE2, is a potential target for developing specific drugs, antibodies, and vaccines. Restoring the balance between the RAS and ACE2/angiotensin-(1–7)/MAS may help attenuate organ injuries. Graphical abstract SARS-CoV-2 enters lung cells via the ACE2 receptor. The cell-free and macrophage-phagocytosed virus can spread to other organs and infect ACE2-expressing cells at local sites, causing multi-organ injury.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis in some but not all breast cancer cell lines. Breast cancers can be divided into those which express the estrogen (ER) and progesterone (PR) receptors, those with HER-2 amplification, and those without expression of ER, PR, or HER-2 amplification (referred to as basal or triple-negative breast cancer). We tested a panel of 20 breast cancer cell lines representing the different types of breast cancer to evaluate if the molecular phenotype of the breast cancer cells determined their response to TRAIL. The most striking finding was that eight of eleven triple-negative cell lines are sensitive to TRAIL-mediated apoptosis. The eight TRAIL-sensitive triple-negative cell lines have a mesenchymal phenotype while the three TRAIL-resistant triple-negative cell lines have an epithelial phenotype. Two of five cell lines with HER-2 amplification were sensitive to TRAIL and none of the five ER positive cell lines were sensitive. RNAi-mediated knockdown of TRAIL receptor expression demonstrated that TRAIL Receptor 2 (TRAIL-R2) mediates the effects of TRAIL, even when both TRAIL-R1 and TRAIL-R2 are expressed. Finally, inhibition of EGFR, expressed in both TRAIL-sensitive and TRAIL-resistant

ABSTRACT:Transporter gene knockout rats are practically advantageous over murine models for pharmacokinetic and excretion studies, but their phenotypic characterization is lacking. At present, relevant aspects of pharmacokinetics, metabolism, distribution, and excretion of transporter probes [P-glycoprotein (P-gp): loperamide and paclitaxel; breast cancer resistance protein (Bcrp): sulfasalazine; and multidrug resistance-associated protein 2 (Mrp2): carboxydichlorofluorescein] were studied systematically across SAGE P-gp, Bcrp, and Mrp2 knockout rats. In Mdr1a knockout rats, loperamide and paclitaxel oral bioavailability was 2-and 4-fold increased, respectively, whereas clearance was significantly reduced (40-42%), consistent with the expected 10-to 20-fold reduction in paclitaxel excretion. N-Desmethyl-loperamide pharmacokinetics were not altered in any of the three knockouts after oral loperamide. In rats lacking P-gp, paclitaxel brain partitioning was significantly increased (4-fold). This finding is consistent with observations of loperamide central nervous system opioid pharmacology in Mdr1a knockout rats. Sulfasalazine oral bioavailability was markedly increased 21-fold in Bcrp knockouts and, as expected, was also 2-to 3-fold higher in P-gp and Mrp2 knockout rats. The sulfapyridine metabolite/parent ratio was decreased 10-fold in rats lacking Bcrp after oral, but not intravenous, sulfasalazine administration. Carboxydichlorofluorescein biliary excretion was obliterated in Mrp2 knockout rats, resulting in 25% decreased systemic clearance and 35% increased half-life. In contrast, carboxydichlorofluorescein renal clearance was not impaired in the absence of Mrp2, Bcrp, or P-gp. In conclusion, SAGE Mdr1a, Bcrp, and Mrp2 knockout rats generally demonstrated the expected phenotypes with respect to alterations in pharmacokinetics of relevant probe substrates; therefore, these knockout rats can be used as an alternative to murine models whenever a larger species is practically advantageous or more relevant to the drug discovery/development program.

Summary Background Mortality within the first 6 months after initiating antiretroviral therapy (ART) is common in resource-limited settings and is often due to tuberculosis (TB) among patients with advanced HIV disease. Isoniazid preventive therapy (IPT) is recommended in HIV-infected adults, but sub-clinical TB can be difficult to diagnose. We hypothesized that empiric TB treatment would reduce early mortality compared to IPT in high-burden settings. Methods We conducted a multi-country randomized clinical trial comparing empiric TB therapy (Empiric) vs. isoniazid preventive therapy (IPT) in HIV-infected outpatients initiating ART with CD4 counts <50 cells/mm3. Individuals were screened for TB using a symptom screen, locally available diagnostics, and the GeneXpert MTB/RIF assay when available. The primary endpoint was survival (death or unknown status) at 24 weeks post randomization. Kaplan Meier estimates of the endpoint rates across arms were compared by the z-test. Registered at ClinicalTrials.gov (NCT01380080). Findings From October 31, 2011 until June 9, 2014, we randomized 850 participants (424 in Empiric arm and 426 in IPT arm); the median CD4 count at baseline was 18 cells/mm3 (IQR: 9, 32). At week 24, each arm had 22 primary endpoints, for rates of 5.2% in each arm (95% CI: 3.5% to 7.8% for Empiric and 3.4% to 7.8% for IPT; absolute risk difference of -0.06% (95% CI: −3.05% to 2.94%). Grade 3 or 4 signs or symptoms occurred in 50 (12%) in the Empiric arm and 46 (11%) in the IPT arm. Grade 3 or 4 laboratory abnormalities occurred in 99 (23%) in the Empiric arm and 97 (23%) in the IPT arm. Incident TB was more common in the Empiric arm (31 vs. 18 events, p=0.01). Interpretation Empiric TB therapy did not reduce mortality at 24 weeks in outpatient adults initiating ART with advanced HIV disease. The low mortality rate of the trial supports implementation of systematic TB screening and IPT in outpatients with advanced HIV disease.