Cyclerion (United States)

Lower-limb peripheral artery disease (PAD) is one of the major complications of diabetes mellitus. PAD is associated with poor limb and cardiovascular prognoses, along with a dramatic decrease in life expectancy. Despite major medical advances in the treatment of diabetes, a substantial therapeutic gap remains in the PAD population. Praliciguat is an orally available soluble guanylate cyclase (sGC) stimulator that has been reported both pre-clinically and in early-stage clinical trials to have favorable effects in metabolic and hemodynamic outcomes, suggesting that it may have a potential beneficial effect in PAD. We then evaluated the effect of praliciguat on hind limb ischemia (HLI) recovery in leptin receptor-deficient (Lepr db/db ). 28 days after surgery. Ischemic foot perfusion and function parameters were better in praliciguat-treated mice than in vehicle controls. Improved ischemic foot perfusion was not associated with either improved traditional cardiovascular risk factors (i.e., weight, glycemia) or increased angiogenesis. However, treatment with praliciguat significantly increased arteriole diameter, decreased ICAM1 expression, and prevented the accumulation of oxidative pro-angiogenic and pro-inflammatory muscle fibers. While investigating the mechanism underlying the beneficial effects of praliciguat therapy, we found that praliciguat significantly downregulates Cxcl12 mRNA expression in cultured myoblasts which in turn may decrease ICAM1 mRNA expression in endothelial cells. Conclusion: Our results demonstrated that praliciguat promotes blood flow recovery in the ischemic muscle of mice with type 2 diabetes, at least in part by increasing arteriole diameter and by downregulating ICAM1 expression.

Aim Dysfunction of nitric oxide (NO) – soluble guanylate cyclase (sGC) – cyclic guanosine monophosphate (cGMP) signalling is implicated in the pathophysiology of cognitive impairment and dementia. Zagociguat is a central nervous system-(CNS-) penetrant sGC stimulator designed to amplify NO-cGMP signalling in the CNS. This article reports on a phase 1b study evaluating the safety and pharmacodynamic effects of zagociguat. Methods In this randomized crossover study, 24 healthy participants ≥65 years of age were planned to receive 15 mg zagociguat or placebo once daily for two 15-day periods separated by a 27-day washout. Adverse events, vital signs, electrocardiograms, and laboratory tests to assess safety. Pharmacokinetics of zagociguat were evaluated in blood and CSF. Pharmacodynamic assessments included evaluation of cerebral blood flow, CNS tests, pharmaco-electroencephalography, passive leg movement, and biomarkers in blood, cerebrospinal fluid, and brain. Results Twenty-four participants were enrolled and 12 participants completed both treatment periods, while 12 participants completed only one treatment period. Zagociguat was well tolerated and penetrated the blood-brain barrier. Zagociguat induced modest decreases in blood pressure. No consistent effects of zagociguat on other pharmacodynamic parameters were detected. Conclusion Zagociguat was well tolerated and induced modest systemic blood pressure reductions consistent with other sGC stimulators. No clear pharmacodynamic effects of zagociguat were detected, perhaps due to optimal CNS function in healthy participants. Studies in participants with proven reduced cerebral blood flow or CNS function may be an avenue for further evaluation of the compound.

Lower-limb peripheral artery disease is one of the major complications of diabetes. Peripheral artery disease is associated with poor limb and cardiovascular prognoses, along with a dramatic decrease in life expectancy. Despite major medical advances in the treatment of diabetes, a substantial therapeutic gap remains in the peripheral artery disease population. Praliciguat is an orally available sGC (soluble guanylate cyclase) stimulator that has been reported both preclinically and in early stage clinical trials to have favorable effects in metabolic and hemodynamic outcomes, suggesting that it may have a potential beneficial effect in peripheral artery disease. We evaluated the effect of praliciguat on hind limb ischemia recovery in a mouse model of type 2 diabetes. Hind limb ischemia was induced in leptin receptor-deficient (Leprdb/db) mice by ligation and excision of the left femoral artery. Praliciguat (10 mg/kg/day) was administered in the diet starting 3 days before surgery. Twenty-eight days after surgery, ischemic foot perfusion and function parameters were better in praliciguat-treated mice than in vehicle controls. Improved ischemic foot perfusion was not associated with either improved traditional cardiovascular risk factors (ie, weight, glycemia) or increased angiogenesis. However, treatment with praliciguat significantly increased arteriole diameter, decreased ICAM1 (intercellular adhesion molecule 1) expression, and prevented the accumulation of oxidative proangiogenic and proinflammatory muscle fibers. While investigating the mechanism underlying the beneficial effects of praliciguat therapy, we found that praliciguat significantly downregulated Myh2 and Cxcl12 mRNA expression in cultured myoblasts and that conditioned medium form praliciguat-treated myoblast decreased ICAM1 mRNA expression in endothelial cells. These results suggest that praliciguat therapy may decrease ICAM1 expression in endothelial cells by downregulating Cxcl12 in myocytes. Our results demonstrated that praliciguat promotes blood flow recovery in the ischemic muscle of mice with type 2 diabetes, at least in part by increasing arteriole diameter and by downregulating ICAM1 expression.

Advanced age, underlying cardiovascular disease (including hypertension), and obesity are associated with a higher risk of progression to severe hypoxemia, acute respiratory distress syndrome (ARDS), and death in COVID-19-infected patients. African Americans have a higher degree of COVID-19 mortality. The incidence of salt-sensitive hypertension is higher in older individuals and African Americans. Lower circulating levels of natriuretic peptides, key regulators of vascular tone and kidney function, have been associated with salt-sensitive hypertension and obesity. Evidence has accumulated that ANP administered to pulmonary endothelial cells, isolated lungs, and patients suffering from ARDS reduces endothelial damage and preserves the endothelial barrier, thereby reducing pulmonary edema and inflammation. Epidemiologic and pharmacologic data suggest that deficiencies in the natriuretic peptide hormone system may contribute to the development of severe lung pathology in COVID-19 patients, and treatments that augment natriuretic peptide signaling may have potential to limit progression to ARDS.

The pharmacokinetics (PK), metabolism, excretion, mass balance, and tissue distribution of [14C]praliciguat were evaluated following oral administration of a 3‐mg/kg dose in Sprague‐Dawley rats and in a quantitative whole‐body autoradiography (QWBA) study conducted in male Long‐Evans rats. Plasma Tmax was 1 hour and the t1/2 of total plasma radioactivity was 23.7 hours. Unchanged praliciguat accounted for 87.4%, and a minor metabolite (N‐dealkylated‐praliciguat) accounted for 7.6% of the total radioactivity in plasma through 48 hours (AUC0‐48). Tissues with the highest exposure ratios relative to plasma were liver, intestines, adrenal gland, and adipose, and those with the lowest values were seminal vesicle, blood, CNS tissues, lens of the eye, and bone. Most of the [14C]praliciguat‐derived radioactivity was excreted within 48 hours after oral administration. Mean cumulative recovery of the administered radioactivity in urine and feces over 168 hours was 3.7% and 95.7%, respectively. Unchanged praliciguat was not quantifiable in urine or bile of cannulated rats; however, based on the total radioactivity in these fluids, a minimum of approximately 82% of the orally administered dose was absorbed. [14C]Praliciguat was metabolized via oxidative and glucuronidation pathways and the most abundant metabolites recovered in bile were praliciguat‐glucuronide and hydroxy‐praliciguat‐glucuronide. These results indicate that praliciguat had rapid absorption, high bioavailability, extensive tissue distribution, and elimination primarily via hepatic metabolism.