Potential of Endogenous Oxytocin in Endocrine Treatment and Prevention of COVID-19.

Coronavirus disease 2019 or COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a significant threat to the health of human beings. While wearing mask, maintaining social distance and performing self-quarantine can reduce virus spreading passively, vaccination actively enhances immune defense against COVID-19. However, mutations of SARS-CoV-2 and presence of asymptomatic carriers frustrate the effort of completely conquering COVID-19. A strategy that can reduce the susceptibility and thus prevent COVID-19 while blocking viral invasion and pathogenesis independent of viral antigen stability is highly desirable. In the pathogenesis of COVID-19, endocrine disorders have been implicated. Correspondingly, many hormones have been identified to possess therapeutic potential of treating COVID-19, such as estrogen, melatonin, corticosteroids, thyroid hormone and oxytocin. Among them, oxytocin has the potential of both treatment and prevention of COVID-19. This is based on oxytocin promotion of immune-metabolic homeostasis, suppression of inflammation and pre-existing comorbidities, acceleration of damage repair, and reduction of individuals' susceptibility to pathogen infection. Oxytocin may specifically inactivate SARS-COV-2 spike protein and block viral entry into cells via angiotensin-converting enzyme 2 by suppressing serine protease and increasing interferon levels and number of T-lymphocytes. In addition, oxytocin can promote parasympathetic outflow and the secretion of body fluids that could dilute and even inactivate SARS-CoV-2 on the surface of cornea, oral cavity and gastrointestinal tract. What we need to do now is clinical trials. Such trials should fully balance the advantages and disadvantages of oxytocin application, consider the time- and dose-dependency of oxytocin effects, optimize the dosage form and administration approach, combine oxytocin with inhibitors of SARS-CoV-2 replication, apply specific passive immunization, and timely utilize efficient vaccines. Meanwhile, blocking COVID-19 transmission chain and developing other efficient anti-SARS-CoV-2 drugs are also important. In addition, relative to the complex issues with drug applications over a long term, oxytocin can be mobilized through many physiological stimuli, and thus used as a general prevention measure. In this review, we explore the potential of oxytocin for treatment and prevention of COVID-19 and perhaps other similar pathogens.

Neural Functions of Hypothalamic Oxytocin and its Regulation.

Oxytocin (OT), a nonapeptide, has a variety of functions. Despite extensive studies on OT over past decades, our understanding of its neural functions and their regulation remains incomplete. OT is mainly produced in OT neurons in the supraoptic nucleus (SON), paraventricular nucleus (PVN) and accessory nuclei between the SON and PVN. OT exerts neuromodulatory effects in the brain and spinal cord. While magnocellular OT neurons in the SON and PVN mainly innervate the pituitary and forebrain regions, and parvocellular OT neurons in the PVN innervate brainstem and spinal cord, the two sets of OT neurons have close interactions histologically and functionally. OT expression occurs at early life to promote mental and physical development, while its subsequent decrease in expression in later life stage accompanies aging and diseases. Adaptive changes in this OT system, however, take place under different conditions and upon the maturation of OT release machinery. OT can modulate social recognition and behaviors, learning and memory, emotion, reward, and other higher brain functions. OT also regulates eating and drinking, sleep and wakefulness, nociception and analgesia, sexual behavior, parturition, lactation and other instinctive behaviors. OT regulates the autonomic nervous system, and somatic and specialized senses. Notably, OT can have different modulatory effects on the same function under different conditions. Such divergence may derive from different neural connections, OT receptor gene dimorphism and methylation, and complex interactions with other hormones. In this review, brain functions of OT and their underlying neural mechanisms as well as the perspectives of their clinical usage are presented.

Implementation of Cholesterol-Lowering Therapy to Reduce Cardiovascular Risk in Persons Living with HIV.

The widespread availability of highly effective antiretroviral therapies has reduced mortality from opportunistic infections in persons living with HIV (PLHIV), resulting in an increase in atherosclerotic cardiovascular disease (ASCVD) and other chronic illnesses (Samji et al. 2013). Although there has been a decline in morbidity and mortality from ASCVD in the past several decades, contemporary studies continue to report higher rates of cardiovascular events (Rosenson et al. 2020). HIV has been identified as a risk enhancer for ASCVD by multiple professional guideline writing committees (Grundy Scott et al. 2019, Mach et al. 2020); however, the utilization of cholesterol-lowering therapies in PLHIV remains low (Rosenson et al. 2018). Moreover, the use of statin therapy in PLHIV is complicated by drug-drug interactions that may either elevate or lower the blood statin concentrations resulting in increased toxicity or reduced efficacy respectively. Other comorbidities commonly associated with HIV present other challenges for the use of cholesterol-lowering therapies. This review will summarize the data on lipoprotein-associated ASCVD risk in PLHIV and discuss the challenges with effective treatment. Finally, we present a clinical algorithm to optimize cardiovascular risk reduction in this high-risk population.

Regional Strain Pattern and Correlation with Cardiac Magnetic Resonance Imaging in Fabry Disease.

BACKGROUND: Cardiovascular disease is the most common cause of death among Fabry disease patients, who carry significantly increased risk for heart failure and sudden cardiac death. Echocardiographic strain imaging and cardiac MRI are important clinical tools for early detection of cardiomyopathy before onset of systolic or diastolic dysfunction. However, studies on these imaging modalities are limited among Fabry patients. AIM AND OBJECTIVE: To evaluate echocardiographic strain pattern and correlation with cardiac MRI in Fabry disease. MATERIALS AND METHODS: We performed a detailed analysis of global longitudinal strain and correlation with cardiac MRI finding in 9 patients diagnosed with Fabry disease. RESULTS: Despite normal left ventricular ejection fraction, basal and mid inferior segments are more likely to demonstrate strain abnormalities compared to other regions. Additionally, increased interventricular septal and left ventricular posterior wall thickness are correlated with greater strain abnormalities. Finally, MRI evidence of fibrosis and infiltration are detected among most patients with strain abnormalities, but in some cases, strain imaging were able to detect early evidence of cardiomyopathy even before MRI was fully able to detect the change. Basal and mid inferoseptal segment strain abnormalities are early signs of developing cardiomyopathy among patients with Fabry disease. CONCLUSION: Though cardiac MRIs are critical tools for detection of myocardial infiltration and scarring, these findings may not always be detectable in early phases of the disease. Multiple imaging modalities maybe considered in monitoring and evaluation of cardiomyopathy in Fabry disease.

Characteristics of VCP mutation-associated cardiomyopathy.

VCP associated inclusion body myopathy, Paget's disease of bone, and Frontotemporal Dementia (IBMPFD, VCP disease, or multisystem proteinopathy type 1 (MSP1)) is an autosomal dominant disease caused by missense mutations in the VCP gene, which plays a crucial role in ubiquitin-proteasome dependent degradation of cytosolic proteins. Those diagnosed with the disorder often suffer from cardiovascular complications in the advanced stages. We conducted an observational cross-section study to investigate echocardiographic features of asymptomatic carriers and those affected by the disease to determine the differences and potential early features of the VCP-associated cardiomyopathy. The study cohort constituted of 32 patients with VCP mutations including 23 affected individuals diagnosed with myopathy +/- Paget disease of bone, and 9 asymptomatic carriers. Among the affected individuals, 95.7% had myopathy, 43.5% had Paget's disease of bone, and none had frontotemporal dementia, and the carriers were asymptomatic. Not surprisingly the carriers were younger (mean age 38.4 ±â€¯3.8 years), than the affected cohort (mean age 50.6 ±â€¯9.1 years; p < 0.001). There was a 43.5% prevalence of diastolic dysfunction on echocardiogram among patients who were symptomatic from VCP disease, whereas none of the two asymptomatic carriers manifested diastolic dysfunction (p = 0.017). Among the 5 affected individuals who had consequential echocardiograms 2-3 years apart, three affected individuals developed diastolic dysfunction, and two already had diastolic dysfunction on the initial study. The two carriers did not develop diastolic function changes. This present study represents the largest series of echocardiograms performed in patients and asymptomatic carriers with VCP myopathy, and will pave the way for future, large-scale studies that may include other imaging modalities such as cardiac MRI and strain evaluation in patients at all stages of the disease.

Pericardial Effusion After Renal Transplantation: Timing and Clinical Characteristics.

BACKGROUND: Pericardial effusion and tamponade have been recognized as potentially serious complications in patients who have undergone renal transplantation. Our study aims to analyze the association between sirolimus and the development of pericardial effusion in renal transplant recipients. METHODS: This is a single-center retrospective study of 585 consecutive patients who underwent renal transplantation between 2005 and 2016. The study included 82 patients (14%) who developed new pericardial effusion after transplantation. Baseline demographics, medical comorbidities, medication use, echocardiographic parameters, and time to occurrence of effusion were assessed. Patients were divided into 2 groups based on timing of effusion development: early onset, ≤4 years after transplantation (51%); and late onset, >4 years after transplantation (49%). We examined the likelihood of immunosuppressant use and timing of effusion development using univariate and multivariate logistic regression analysis. RESULTS: The mean age of the cohort was 55.1 ± 11.5 years, 58.5% were men, 81.7% were white, and mean time from transplantation to the development of effusion was 4 ± 3.1 years. There were no significant differences between the early and late effusion groups in the demographic characteristics and medical comorbidities. However, sirolimus therapy was more common in the late effusion group. Furthermore, after adjusting for comorbidities, sirolimus use was associated with greater risk for developing late-onset effusion, adjusted odds ratio of 3.58 (95% confidence interval 1.25-10.20, P = .017). CONCLUSION: Pericardial effusion is prevalent in renal transplant recipients. In our cohort, treatment with sirolimus was associated with late-onset pericardial effusion. Awareness of pericardial disease in this population is important, and further studies are needed to identify predisposing factors.

Sex Differences Remain Under-Reported in Cardiovascular Publications.

Background: For the past two decades, there has been increased interest from medical journals and calls to action from various organizations such as the National Institutes of Health to study sex differences in cardiovascular (CV) disease. It is unknown whether this emphasis has translated to a growth in publications addressing sex differences in CV disease. Materials and Methods: We performed a bibliometric analysis of all CV publications from 2006 to 2015. The National Library of Medicine's PubMed database was searched for articles containing the phrases "cardiac," "cardiovascular" or "cardiology," in the first author affiliation field. This was followed by a subsequent search for publications containing any of the following phrases in the title and/or abstract: "woman," "women," "female," "females," "gender," or "sex." The presence of such terms defined the publication as sex-specific. Trends over time were analyzed for specified subgroups, including publication category and funding source. Results: A total of 189,543 CV publications were identified, out of which there were 24,615 (12.99%) sex-specific publications. For the 10-year period, there were no significant changes in the relative proportion of sex-specific publications. When specific publication categories were analyzed, there were significant proportional increase of sex-specific publications in general articles category, but not for reviews, clinical trials, meta-analysis, or letters. Conclusion: Despite calls for greater attention, only a small fraction of publications for the past decade have reported on sex differences. There was no significant proportional growth of sex-specific publications for a recent 10-year period, except for the general research articles.

Cardiovascular protective properties of oxytocin against COVID-19.

SARS-CoV-2 infection or COVID-19 has become a worldwide pandemic; however, effective treatment for COVID-19 remains to be established. Along with acute respiratory distress syndrome (ARDS), new and old cardiovascular injuries are important causes of significant morbidity and mortality in COVID-19. Exploring new approaches managing cardiovascular complications is essential in controlling the disease progression and preventing long-term complications. Oxytocin (OXT), an immune-regulating neuropeptide, has recently emerged as a strong candidate for treatment and prevention of COVID-19 pandemic. OXT carries special functions in immunologic defense, homeostasis and surveillance. It suppresses neutrophil infiltration and inflammatory cytokine release, activates T-lymphocytes, and antagonizes negative effects of angiotensin II and other key pathological events of COVID-19. Additionally, OXT can promote γ-interferon expression to inhibit cathepsin L and increases superoxide dismutase expression to reduce heparin and heparan sulphate fragmentation. Through these mechanisms, OXT can block viral invasion, suppress cytokine storm, reverse lymphocytopenia, and prevent progression to ARDS and multiple organ failures. Importantly, besides prevention of metabolic disorders associated with atherosclerosis and diabetes mellitus, OXT can protect the heart and vasculature through suppressing hypertension and brain-heart syndrome, and promoting regeneration of injured cardiomyocytes. Unlike other therapeutic agents, exogenous OXT can be used safely without the side-effects seen in remdesivir and corticosteroid. Importantly, OXT can be mobilized endogenously to prevent pathogenesis of COVID-19. This article summarizes our current understandings of cardiovascular pathogenesis caused by COVID-19, explores the protective potentials of OXT against COVID-19-associated cardiovascular diseases, and discusses challenges in applying OXT in treatment and prevention of COVID-19. CHEMICAL COMPOUNDS: Angiotensin-converting enzyme 2 (ACE2); atrial natriuretic peptide (ANP); cathepsin L; heparan sulphate proteoglycans (HSPGs); interferon; interleukin; oxytocin; superoxide dismutase; transmembrane serine protease isoform 2 (TMPRSS2).

Astroglial Regulation of Magnocellular Neuroendocrine Cell Activities in the Supraoptic Nucleus.

Studies on the interactions between astrocytes and neurons in the hypothalamo-neurohypophysial system have significantly facilitated our understanding of the regulation of neural activities. This has been exemplified in the interactions between astrocytes and magnocellular neuroendocrine cells (MNCs) in the supraoptic nucleus (SON), specifically during osmotic stimulation and lactation. In response to changes in neurochemical environment in the SON, astrocytic morphology and functions change significantly, which further modulates MNC activity and the secretion of vasopressin and oxytocin. In osmotic regulation, short-term dehydration or water overload causes transient retraction or expansion of astrocytic processes, which increases or decreases the activity of SON neurons, respectively. Prolonged osmotic stimulation causes adaptive change in astrocytic plasticity in the SON, which allows osmosensory neurons to reserve osmosensitivity at new levels. During lactation, changes in neurochemical environment cause retraction of astrocytic processes around oxytocin neurons, which increases MNC's ability to secrete oxytocin. During suckling by a baby/pup, astrocytic processes in the mother/dams exhibit alternative retraction and expansion around oxytocin neurons, which mirrors intermittently synchronized activation of oxytocin neurons and the post-excitation inhibition, respectively. The morphological and functional plasticities of astrocytes depend on a series of cellular events involving glial fibrillary acidic protein, aquaporin 4, volume regulated anion channels, transporters and other astrocytic functional molecules. This review further explores mechanisms underlying astroglial regulation of the neuroendocrine neuronal activities in acute processes based on the knowledge from studies on the SON.

Therapeutic Potential of Oxytocin in Atherosclerotic Cardiovascular Disease: Mechanisms and Signaling Pathways.

Coronary artery disease (CAD) is a major cardiovascular disease responsible for high morbidity and mortality worldwide. The major pathophysiological basis of CAD is atherosclerosis in association with varieties of immunometabolic disorders that can suppress oxytocin (OT) receptor (OTR) signaling in the cardiovascular system (CVS). By contrast, OT not only maintains cardiovascular integrity but also has the potential to suppress and even reverse atherosclerotic alterations and CAD. These protective effects of OT are associated with its protection of the heart and blood vessels from immunometabolic injuries and the resultant inflammation and apoptosis through both peripheral and central approaches. As a result, OT can decelerate the progression of atherosclerosis and facilitate the recovery of CVS from these injuries. At the cellular level, the protective effect of OT on CVS involves a broad array of OTR signaling events. These signals mainly belong to the reperfusion injury salvage kinase pathway that is composed of phosphatidylinositol 3-kinase-Akt-endothelial nitric oxide synthase cascades and extracellular signal-regulated protein kinase 1/2. Additionally, AMP-activated protein kinase, Ca2+/calmodulin-dependent protein kinase signaling and many others are also implicated in OTR signaling in the CVS protection. These signaling events interact coordinately at many levels to suppress the production of inflammatory cytokines and the activation of apoptotic pathways. A particular target of these signaling events is endoplasmic reticulum (ER) stress and mitochondrial oxidative stress that interact through mitochondria-associated ER membrane. In contrast to these protective effects and machineries, rare but serious cardiovascular disturbances were also reported in labor induction and animal studies including hypotension, reflexive tachycardia, coronary spasm or thrombosis and allergy. Here, we review our current understanding of the protective effect of OT against varieties of atherosclerotic etiologies as well as the approaches and underlying mechanisms of these effects. Moreover, potential cardiovascular disturbances following OT application are also discussed to avoid unwanted effects in clinical trials of OT usages.

Role of Connexin 36 in Autoregulation of Oxytocin Neuronal Activity in Rat Supraoptic Nucleus.

In the supraoptic nucleus (SON), the incidence of dye coupling among oxytocin (OT) neurons increases significantly in nursing mothers. However, the type(s) of connexin (Cx) involved is(are) unknown. In this study, we specifically investigated whether Cx36 plays a functional role in the coupling between OT neurons in the SON of lactating rats. In this brain region, Cx36 was mainly coimmunostained with vasopressin neurons in virgin female rats, whereas in lactating rats, Cx36 was primarily colocalized with OT neurons. In brain slices from lactating rats, application of quinine (0.1 mM), a selective blocker of Cx36, significantly reduced dye coupling among OT neurons as well as the discharge/firing frequency of spikes/action potentials and their amplitude, and transiently depolarized the membrane potential of OT neurons in whole-cell patch-clamp recordings. However, quinine significantly reduced the amplitude, but not frequency, of inhibitory postsynaptic currents in OT neurons; the duration of excitatory postsynaptic currents was reduced but not their frequency and amplitude. Furthermore, the excitatory effect of OT (1 pM) on OT neurons was significantly weakened and delayed by quinine, and burst firing was absent in the presence of this inhibitor. Lastly, Western blotting analysis revealed that the presence of combined, but not alone, quinine and OT significantly reduced the amount of Cx36 in the SON. Thus, Cx36-mediated junctional communication plays a crucial role in autoregulatory control of OT neuronal activity, likely by acting at the postsynaptic sites. The level of Cx36 is modulated by its own activity and the presence of OT.

Colon cancer laterality is associated with atherosclerosis and coronary artery disease.

BACKGROUND: Primary right-sided colon cancer (RCC) is associated with a higher mortality than left-sided colon cancer (LCC), but the etiology of this phenomenon remains unclear. We sought to study whether cancer laterality is associated with the prevalence of clinical coronary artery disease, calcific atherosclerosis as measured by computed tomography (CT), and cardiovascular risk factors. METHODS: We conducted a single center retrospective study of 546 participants who had previously been diagnosed with colon cancer between January 2005 and December 2014. The presence of coronary and aortic calcifications was assessed by CT in 486 of these patients. We examined the prevalence of clinical cardiovascular disease (CAD) (prior myocardial infarction or revascularization), comorbidities, coronary and aortic calcification in patients with RCC (n=261) and LCC (n=285). Logistic regression analysis was performed to assess the likelihood of clinical CAD and calcific atherosclerosis by cancer laterality. RESULTS: Compared to patients with LCC, patients with RCC were more likely to have hypertension, hyperlipidemia, hypothyroidism and clinical CAD. In the patients with available CT scans, RCC was associated with higher prevalence of coronary, thoracic, and abdominal calcifications than LCC. On univariate and multivariate analyses, RCC was associated with higher likelihood of clinical CAD (adjusted risk ratio 2.15, 95% CI, 1.37-3.38, P=0.001) as well as radiological evidence of calcific atherosclerosis compared to LCC. CONCLUSIONS: we found that both clinical CAD and vascular calcifications are prevalent in patients with colon cancer, and are independently increased in patients with RCC compared to LCC.

Influence of mildly and moderately elevated pulmonary artery systolic pressure on post-renal transplantation survival and graft function.

BACKGROUND: Severe pulmonary hypertension (PH) has been associated with decreased post-kidney transplant survival and increased rate of long-term cardiovascular complications. Despite a high prevalence of PH in patients with end-stage renal disease, data on post-transplant renal allograft survival in recipients with pre-existing mild-to-moderate PH are limited. METHODS: The single-center retrospective study cohort consisted of 192 consecutive (2008-2015) renal transplant recipients with documented pretransplantation transthoracic echocardiogram (TTE) pulmonary artery systolic pressure (PASP). Mean age was 50.9 ± 12.4 years, 36.5% were females, and 81.25% were Caucasians. RESULTS: Elevated PASP ≥ 37 mm Hg was present in 51 patients. Elevated PASP was more common in patients with decreased <50% left ventricular ejection fraction (13.73% vs 3.55%, P = 0.010); otherwise, there were no significant differences in baseline demographic (age, ethnicity, gender, and donor status) and clinical parameters between patients with normal and elevated PASP. Four-year mortality (5.7%) was not significantly affected by elevated PASP. However, elevated PASP was associated with significantly decreased estimated glomerular filtration rate (eGFR) at 1 year (52.26 vs 60.13 mL/min, P = 0.019) and 2 years (51.04 vs 60.28 mL/min, P = 0.006) post-transplant. CONCLUSION: Mild and moderately elevated pre-kidney transplant PASP does not affect 4-year post-transplant mortality or graft loss. However, elevated pretransplant PASP is significantly associated with decreased 1 year and 2 years post-transplant eGFR. Preoperative echocardiographic evaluation for PH may be useful in predicting the probability of short-term renal graft and long-term graft dysfunction in these patients.

Case of ruptured Staphylococcus aureus aortitis: presentation and management.

Infectious aortitis with the complication of aortic aneurysm carries a high mortality rate without appropriate interventions, mostly due to aortic rupture. For this reason, early and prompt diagnoses along with surgical and medical managements play critical roles. Aortic infection with Staphylococcus aureus (SA) is uncommon, but reported cases have been usually associated with fatal complication from rapid progression into rupture. We report a 65-year-old man who developed methicillin-sensitive SA aortitis and then aortic rupture. Patient was successfully treated with staged vascular repair and long-term antibiotic use.

Lung Cancer Invading a Coronary Graft: Role of Coronary Intervention and Robotic Surgery.

The treatment of primary lung cancer of the left upper lobe in those patients with prior coronary artery bypass graft is difficult to plan and execute due to the potential for invasion into coronary grafts, particularly the left internal mammary artery. We present a patient with squamous cell carcinoma invading into coronary artery bypass grafts, but which is successfully treated by a combination of percutaneous coronary intervention followed by video-assisted thoracoscopic surgery.

Interactions of the Mechanosensitive Channels with Extracellular Matrix, Integrins, and Cytoskeletal Network in Osmosensation.

Life is maintained in a sea water-like internal environment. The homeostasis of this environment is dependent on osmosensory system translation of hydromineral information into osmotic regulatory machinery at system, tissue and cell levels. In the osmosensation, hydromineral information can be converted into cellular reactions through osmoreceptors, which changes thirst and drinking, secretion of antidiuretic vasopressin (VP), reabsorption of water and salt in the kidneys at systemic level as well as cellular metabolic activity and survival status at tissue level. The key feature of osmosensation is the activation of mechanoreceptors or mechanosensors, particularly transient receptor potential vallinoid (TRPV) and canonical (TRPC) family channels, which increases cytosolic Ca2+ levels, activates osmosensory cells including VP neurons and triggers a series of secondary reactions. TRPV channels are sensitive to both hyperosmotic and hyposmotic stimuli while TRPC channels are more sensitive to hyposmotic challenge in neurons. The activation of TRP channels relies on changes in cell volume, membrane stretch and cytoskeletal reorganization as well as hydration status of extracellular matrix (ECM) and activity of integrins. Different families of TRP channels could be activated differently in response to hyperosmotic and hyposmotic stimuli in different spatiotemporal orders, leading to differential reactions of osmosensory cells. Together, they constitute the osmosensory machinery. The activation of this osmoreceptor complex is also associated with the activity of other osmolarity-regulating organelles, such as water channel protein aquaporins, Na-K-2Cl cotransporters, volume-sensitive anion channels, sodium pump and purinergic receptors in addition to intercellular interactions, typically astrocytic neuronal interactions. In this article, we review our current understandings of the composition of osmoreceptors and the processes of osmosensation.