Citations

BACKGROUND: Atrial natriuretic peptide (ANP) and glucagon-like peptide-1 (GLP-1) are endogenous hormones known for roles in cardiovascular regulation and metabolic homeostasis. ANP mediates its actions via the GC-A receptor, while GLP-1 via the GLP-1 receptor (GLP-1R). Both peptides may stimulate insulin secretion from pancreatic beta cells and augment lipid metabolism in adipocytes, yet potential synergistic effects remain unexplored. To optimize ANP activation of GC-A, we developed a novel 15 amino acid miniaturized GC-A activating peptide CRRL555. CRRL555 possesses greater GC-A binding and activating properties than ANP. AIMS: We investigated the metabolic properties of CRRL555/GC-A and its interaction with GLP-1/GLP-1R in vitro. METHODS: Rat pancreatic beta cells (INS-1) were stimulated with high glucose (20mM) and treated with GLP-1 or CRRL555 (10 -10 -10 -6 M) and together for 1 hr. Supernatant was collected and insulin was measured by ELISA. Human visceral adipocytes were differentiated for 10 days and then treated with GLP-1 or CRRL555 (10 -10 -10 -6 M) or together for 6 hrs. Supernatant was collected and glycerol and free fatty acid (NEFA), indicators of lipolysis, were measured. RESULTS: CRRL555 (p<0.05) and GLP-1 (p<0.05), dose dependently, stimulated insulin secretion in INS-1 cells in the presence of high glucose. Importantly, CRRL555 combined with GLP-1, resulted in a greater enhancement (p<0.05) of insulin secretion compared to either peptide alone. While high dose CRRL555 and GLP-1 (10 -6 M) stimulated lipolysis in visceral adipocytes with increases in glycerol and NEFA, only CRRL555 at low dose (10 -10 M), and not low dose GLP-1 (10 -10 M), stimulated glycerol and NEFA production (p<0.05). When low dose GLP-1 (10 -10 M) was added to low dose CRRL555(10 -10 M), lipolysis was like CRRL555 alone. CONCLUSION: We report a novel synergy in insulin release from beta cells with combined stimulation of the potent and miniaturized GC-A designer peptide CRRL555 with GLP-1. CRRL555 possesses greater lipolytic properties compared to GLP-1 in visceral adipocytes at low doses advancing novel metabolic actions of CRRL555 alone or combined with GLP-1R activation. These in vitro studies of dual receptor activation of GC-A and GLP-1R highlight the therapeutic potential of combining CRRL555 with GLP-1-based therapies for the treatment of cardiometabolic diseases, thus supporting studies of dual GC-A/GLP-1R activation in experimental cardiometabolic disease states.

Abstract Background/Introduction MANP is a novel atrial natriuretic peptide (ANP) analog bioengineered as a particulate guanylyl cyclase A receptor (GC-A) activator with superior receptor binding, resistance to neprilysin degradation, natriuretic, aldosterone suppressing and blood pressure (BP) lowering properties than native ANP. MANP is now under clinical development for resistant hypertension (RH). The rationale for its design was the fundamental role of the ANP/GC-A system in BP homeostasis through which GC-A activation with MANP leads to BP reduction through renal, vascular, and hormonal mechanisms mediated by the second messenger cGMP. Purpose We investigated the safety, tolerability, cGMP activation and BP reductions of MANP compared to placebo in subjects with RH. Methods We performed a double-blind, placebo controlled randomized trial in 36 RH patients comprised of approximately 50% non-African Americans (NAA) and 50% AA. MANP was administered in 6 cohorts receiving ascending subcutaneous (SQ) doses of MANP once daily from 3 ug/kg to a maximal dose of 7 ug/kg or placebo for 5 days and then followed for 21 days after dosing. Endpoints included safety, cGMP activation and changes in systolic BP (SBP), aldosterone (Aldo) levels and glomerular filtration rate (GFR). Results MANP was safe and well tolerated. One patient in the 7 ug/kg cohort was discontinued due to symptomatic hypotension. Compared to baseline, plasma cGMP increased in all MANP groups on Day 1 and Day 5 with no change in the placebo group. The maximal SBP reduction in the MANP group on Days 1 (D1) and 5 (D5) was -17.5 (D1) and -16 mmHg (D5) with 3 ug/kg (lowest dose) and -39.5 (D1) and -36.3 mmHg (D5) with 7 ug/kg (highest dose); Changes in the Placebo group were -6.3 (D1) and -16.7 mmHg (D5). Notably, the SBP reductions in AA were greater than NAA in the 4 and 7 ug/kg cohorts. After the 1-hour timepoint on both the first and fifth days, Aldo and percentage of Aldo reduction generally remained suppressed compared to baseline. Twenty-one days after MANP dosing, SBP remained lower in three groups receiving SQ MANP (4, 4.5 and 7 ug/kg) compared to placebo in association with a preservation of GFR. There were no reported drug related serious adverse events. Conclusions This clinical trial demonstrates that once a day SQ administration of MANP in RH subjects activates cGMP, without attenuation over 5 days, and reduces SBP and preserves GFR. At higher doses of MANP, SBP reductions were greater in AA compared to NAA. MANP also demonstrated Aldo inhibiting actions compared to placebo. Importantly, MANP was overall safe and well-tolerated. Our findings support the continued clinical development of MANP as a novel GC-A activating peptide for the treatment of RH.

Abstract Introduction/Objective Infections of prosthetic joints cause significant morbidity and often result in removal of the infected joint. In many cases, an infectious etiology can be difficult to definitively identify. As a result, providers suspecting prosthetic joint infections (PJI) often place large order sets of microbiology tests, including fungal and mycobacterial cultures. Fungal and mycobacterial cultures are labor-intensive for the laboratory taking up to 28 days and 42 days, respectively, to complete. As a potential area for a diagnostic stewardship intervention, we wanted to evaluate how often a fungal or mycobacterial culture produced actionable information in cases of suspected PJI. Methods/Case Report Data reports were retrieved from both the Electronic Health Record (EHR) and the Laboratory Information System (LIS) from May 2022 to May 2023. As sources submitted by the provider often do not specify that the joint is prosthetic, data from LIS was evaluated to identify microbiology culture test sets ordered on joint sources, while data from EHR was examined to isolate patients with implanted joints. Using Microsoft Excel, data from both systems was compared in order to match microbiology culture test sets to the known implanted joints. LIS data from implanted joint sources was assessed to record negative (no growth) and positive (growth) cultures, and to register all organisms isolated. Results (if a Case Study enter NA) Of 794 order sets for cultures collected from prosthetic joint sources, 430 included requests for fungal culture and 79 included requests for mycobacterial culture. Of these 79 requests for mycobacterial culture, 0 organisms were isolated (0%). Of these 430 requests for fungal culture, 7 grew yeast (1.6%) and 7 out of 7 (100%) of these yeasts were also isolated on general (aerobic bacterial) culture. No molds were isolated. Conclusion Discontinuing the routine practice of ordering fungal and mycobacterial culture for prosthetic joint sources would have no negative impact on patient care but would reduce unnecessary work in the microbiology laboratory and potentially avoid additional costs to the patient. Education to the orthopedic provider group as well as best practice alerts in the EHR will be pursued, based on the findings from this study, in order to reduce unnecessary culture orders.

AbstractIntroductionPrior consensus meetings have addressed the relationship between phosphodiesterase type 5 (PDE5) inhibition and cardiac health. Given significant accumulation of new data in the past decade, a fourth consensus conference on this topic was convened in Pasadena, California, on March 10 and 11, 2023.ObjectivesOur meeting aimed to update existing knowledge, assess current guidelines, and make recommendations for future research and practice in this area.MethodsAn expert panel reviewed existing research and clinical practice guidelines.ResultsKey findings and clinical recommendations are the following: First, erectile dysfunction (ED) is a risk marker and enhancer for cardiovascular (CV) disease. For men with ED and intermediate levels of CV risk, coronary artery calcium (CAC) computed tomography should be considered in addition to previous management algorithms. Second, sexual activity is generally safe for men with ED, although stress testing should still be considered for men with reduced exercise tolerance or ischemia. Third, the safety of PDE5 inhibitor use with concomitant medications was reviewed in depth, particularly concomitant use with nitrates or alpha-blockers. With rare exceptions, PDE5 inhibitors can be safely used in men being treated for hypertension, lower urinary tract symptoms and other common male disorders. Fourth, for men unresponsive to oral therapy or with absolute contraindications for PDE5 inhibitor administration, multiple treatment options can be selected. These were reviewed in depth with clinical recommendations. Fifth, evidence from retrospective studies points strongly toward cardioprotective effects of chronic PDE5-inhibitor use in men. Decreased rates of adverse cardiac outcomes in men taking PDE-5 inhibitors has been consistently reported from multiple studies. Sixth, recommendations were made regarding over-the-counter access and potential risks of dietary supplement adulteration. Seventh, although limited data exist in women, PDE5 inhibitors are generally safe and are being tested for use in multiple new indications.ConclusionStudies support the overall cardiovascular safety of the PDE5 inhibitors. New indications and applications were reviewed in depth.

Abstract Myocardial fibrosis is a pathological hallmark of cardiovascular disease (CVD), and excessive fibrosis can lead to new-onset heart failure and increased mortality. Currently, pharmacological therapies for myocardial fibrosis are limited, highlighting the need for novel therapeutic approaches. The particulate guanylyl cyclase B (GC-B) receptor possesses beneficial antifibrotic actions through the binding of its natural ligand C-type natriuretic peptide (CNP) and the generation of the intracellular second messenger, cyclic guanosine 3′,5′-monophosphate (cGMP). These actions include the suppression of fibroblast proliferation and reduction in collagen synthesis. With its abundant expression on fibroblasts, the GC-B receptor has emerged as a key molecular target for innovative CVD therapeutics. However, small molecules that can bind and potentiate the GC-B/cGMP pathway have yet to be discovered. From a cell-based high-throughput screening initiative of the NIH Molecular Libraries Small Molecule Repository and hit-to-lead evolution based on a series of structure–activity relationships, we report the successful discovery of MCUF-42, a GC-B-targeted small molecule that acts as a positive allosteric modulator (PAM). Studies herein support MCUF-42's ability to enhance the binding affinity between GC-B and CNP. Moreover, MCUF-42 potentiated cGMP levels induced by CNP in human cardiac fibroblasts (HCFs) and notably also enhanced the inhibitory effect of CNP on HCF proliferation. Together, our findings highlight that MCUF-42 is a small molecule that can modulate the GC-B/cGMP signaling pathway, potentially enhancing the antifibrotic actions of CNP. Thus, these data underscore the continued development of GC-B small molecule PAMs as a novel therapeutic strategy for targeting cardiac fibrosis and CVD.

Regular, long-term aspirin use may act synergistically with genetic variants, particularly those in mechanistically relevant pathways, to confer a protective effect on colorectal cancer (CRC) risk. We leveraged pooled data from 52 clinical trial, cohort, and case-control studies that included 30,806 CRC cases and 41,861 controls of European ancestry to conduct a genome-wide interaction scan between regular aspirin/nonsteroidal anti-inflammatory drug (NSAID) use and imputed genetic variants. After adjusting for multiple comparisons, we identified statistically significant interactions between regular aspirin/NSAID use and variants in 6q24.1 (top hit rs72833769 ), which has evidence of influencing expression of TBC1D7 (a subunit of the TSC1-TSC2 complex, a key regulator of MTOR activity), and variants in 5p13.1 (top hit rs350047 ), which is associated with expression of PTGER4 (codes a cell surface receptor directly involved in the mode of action of aspirin). Genetic variants with functional impact may modulate the chemopreventive effect of regular aspirin use, and our study identifies putative previously unidentified targets for additional mechanistic interrogation.

Introduction: Aldosterone (Aldo) increases sodium and water reabsorption and mediates inflammatory processes. Its relationship to co-morbidities has not been well defined in the general population. Hypothesis: We addressed the hypothesis that plasma aldosterone concentration (PAC) is associated with metabolic and cardiorenal diseases in the general community. Methods: We determined PAC in a general community-based cohort from Olmsted County, MN (n=1,674), and defined correlations with cardiorenal, metabolic diseases and myocardial function and structure. Results: PAC was detected in all subjects and ranged from 2.5 to 91 ng/dl (mean value 6.7 ng/dl, +/- SD 6.6). Multivariate analysis adjusted for age, gender, BMI, ANP and BNP showed highly significant correlations between PAC and hypertension (HTN) (p<.0001, OR=2.28, CI:1.91-2.71), atrial fibrillation (p<.01), chronic kidney disease (CKD) (p<.0001, OR=1.64, CI:1.33-2.02), central obesity (p<.0001, OR=1.61, CI:1.27-2.05), hypertriglyceridemia (p<.003), prevalence of metabolic syndrome (MetS) (p<.0007, OR=1.40, CI=1.15-1.71), obesity (p<.0001, OR=1.48, CI:1.27-1.73), and concentric left ventricular hypertrophy (cLVH) (p=.01). Recognizing that ANP and BNP are known inhibitors of Aldo, we defined the relationship between these cardiac hormones (NTpro-ANP and NT-proBNP) and PAC and observed highly significant inverse relationships with NTpro-ANP (p=0.0009), NTpro-BNP (p=0.0003) in the general population. Conclusions: In conclusion, in the general community, PAC is strongly correlated with renal, metabolic and cardiovascular diseases as well as cardiac remodeling. Specifically, increasing PAC is strongly associated with HTN, CKD, obesity, MetS, cLVH, and lower levels of natriuretic peptides. Our data suggest a key role of Aldo as a possible biomarker and/or mediator of human cardiorenal and metabolic diseases even in the general adult population, prior to overt disease. This study also supports a possible counter regulatory relationship between cardiac natriuretic peptides and PAC. Further studies are warranted to evaluate possible therapeutic interventions targeting Aldo as a strategy to delay disease progression.