Efficiency of C-type natriuretic peptide on improvement of Iraqi local ram's epididymal sperms.

Background: Fertility plays a great role in animal reproduction since high-quality semen improves sheep industry reproduction. The current worldwide data revealed the close relation of C-type natriuretic peptide (CNP) to the reproductive function of rams. Aims: Evaluation of the effect of CNP on cooled sperms using traditional and molecular assays. Methods: Totally, of 20 testicular samples were collected, processed to obtain the semen samples, and divided into two parts; one was treated with a suitable dose of CNP, and the other served as a control. Sperm samples of both groups were cooled for 3 days and tested at 0, 24, 48, and 72 hours. Results: The findings revealed that the suitable dose of CNP-treated sperms was 0.01 × 10-13. Values of individual motility, live sperms, and sperm concentration were reduced significantly in CNP-24h, CNP-48h, and CNP-72h when compared to control; however, abnormal sperms were increased in both control and CNP groups at 24, 48, and 72 hours when compared to values of 0 hour. Concerning turbidmetric analysis, a significant reduction in values of lag time was observed in CNP when compared to control at all times of cooling intervals. In both CNP and control groups, motility index was decreased at 24, 48, and 72 hours when compared to 0 hour. For velocity, significant increases were shown in CNP compared with control at all cooling intervals. However, values of both groups were increased significantly at 24, 48, and 72 hours times when compared to 0 hour. Fraction of rapidly moving sperm of CNP was elevated at 0 hour and decreased at 24, 48, and 72 hours when compared to control. Expression of the hNPR-B gene was reduced gradually in sperms of CNP and control groups at times of cooling intervals. Conclusion: To the best of our knowledge, this first Iraqi study targets the effect of CNP on epididymal sperms of rams. However, changes that occur after excessive CNP exposure remain unclear, and the toxicological profile of CNP requires furthermore supplements.

The Rectal Gland of the Shark: The Road to Understanding the Mechanism and Regulation of Transepithelial Chloride Transport.

Pictured, described, and speculated on, for close to 400 years, the function of the rectal gland of elasmobranchs remained unknown. In the late 1950s, Burger discovered that the rectal gland of Squalus acanthias secreted an almost pure solution of sodium chloride, isosmotic with blood, which could be stimulated by volume expansion of the fish. Twenty five years later, Stoff discovered that the secretion of the gland was mediated by adenyl cyclase. Studies since then have shown that vasoactive intestinal peptide (VIP) is the neurotransmitter responsible for activating adenyl cyclase; however, the amount of circulating VIP does not change in response to volume expansion. The humoral factor involved in activating the secretion of the gland is C-type natriuretic peptide, secreted from the heart in response to volume expansion. C-type natriuretic peptide circulates to the gland where it stimulates the release of VIP from nerves within the gland, but it also has a direct effect, independent of VIP. Sodium, potassium, and chloride are required for the gland to secrete, and the secretion of the gland is inhibited by ouabain or furosemide. The current model for the secretion of chloride was developed from this information. Basolateral NaKATPase maintains a low intracellular concentration of sodium, which establishes the large electrochemical gradient for sodium directed into the cell. Sodium moves from the blood into the cell (together with potassium and chloride) down this electrochemical gradient, through a coupled sodium, potassium, and two chloride cotransporter (NKCC1). On activation, chloride moves from the cell into the gland lumen, down its electrical gradient through apical cystic fibrosis transmembrane regulator. The fall in intracellular chloride leads to the phosphorylation and activation of NKCC1 that allows more chloride into the cell. Transepithelial sodium secretion into the lumen is driven by an electrical gradient through a paracellular pathway. The aim of this review was to examine the history of the origin of this model for the transport of chloride and suggest that it is applicable to many epithelia that transport chloride, both in resorptive and secretory directions.

A Redesigned Method for CNP-Synchronized In Vitro Maturation Inhibits Oxidative Stress and Apoptosis in Cumulus-Oocyte Complexes and Improves the Developmental Potential of Porcine Oocytes.

In vitro embryo production depends on high-quality oocytes. Compared with in vivo matured oocytes, in vitro oocytes undergo precocious meiotic resumption, thus compromising oocyte quality. C-type natriuretic peptide (CNP) is a follicular factor maintaining meiotic arrest. Thus, CNP-pretreatment has been widely used to improve the in vitro maturation (IVM) of oocytes in many species. However, the efficacy of this strategy has remained unsatisfactory in porcine oocytes. Here, by determining the functional concentration and dynamics of CNP in inhibiting spontaneous meiotic resumption, we improved the current IVM system of porcine oocytes. Our results indicate that although the beneficial effect of the CNP pre-IVM strategy is common among species, the detailed method may be largely divergent among them and needs to be redesigned specifically for each one. Focusing on the overlooked role of cumulus cells surrounding the oocytes, we also explore the mechanisms relevant to their beneficial effect. In addition to oocytes per se, the enhanced anti-apoptotic and anti-oxidative gene expression in cumulus cells may contribute considerably to improved oocyte quality. These findings not only emphasize the importance of screening the technical parameters of the CNP pre-IVM strategy for specific species, but also highlight the critical supporting role of cumulus cells in this promising strategy.

C-type natriuretic peptide improves maternally aged oocytes quality by inhibiting excessive PINK1/Parkin-mediated mitophagy.

The overall oocyte quality declines with aging, and this effect is strongly associated with a higher reactive oxygen species (ROS) level and the resultant oxidative damage. C-type natriuretic peptide (CNP) is a well-characterized physiological meiotic inhibitor that has been successfully used to improve immature oocyte quality during in vitro maturation. However, the underlying roles of CNP in maternally aged oocytes have not been reported. Here, we found that the age-related reduction in the serum CNP concentration was highly correlated with decreased oocyte quality. Treatment with exogenous CNP promoted follicle growth and ovulation in aged mice and enhanced meiotic competency and fertilization ability. Interestingly, the cytoplasmic maturation of aged oocytes was thoroughly improved by CNP treatment, as assessed by spindle/chromosome morphology and redistribution of organelles (mitochondria, the endoplasmic reticulum, cortical granules, and the Golgi apparatus). CNP treatment also ameliorated DNA damage and apoptosis caused by ROS accumulation in aged oocytes. Importantly, oocyte RNA-seq revealed that the beneficial effect of CNP on aged oocytes was mediated by restoration of mitochondrial oxidative phosphorylation, eliminating excessive mitophagy. CNP reversed the defective phenotypes in aged oocytes by alleviating oxidative damage and suppressing excessive PINK1/Parkin-mediated mitophagy. Mechanistically, CNP functioned as a cAMP/PKA pathway modulator to decrease PINK1 stability and inhibit Parkin recruitment. In summary, our results demonstrated that CNP supplementation constitutes an alternative therapeutic approach for advanced maternal age-related oocyte deterioration and may improve the overall success rates of clinically assisted reproduction in older women.

The FSH-mTOR-CNP signaling axis initiates follicular antrum formation by regulating tight junction, ion pumps, and aquaporins.

The initial formation of the follicular antrum (iFFA) serves as a dividing line between gonadotropin-independent and gonadotropin-dependent folliculogenesis, enabling the follicle to sensitively respond to gonadotropins for its further development. However, the mechanism underlying iFFA remains elusive. Herein, we reported that iFFA is characterized by enhanced fluid absorption, energy consumption, secretion, and proliferation and shares a regulatory mechanism with blastula cavity formation. By use of bioinformatics analysis, follicular culture, RNA interference, and other techniques, we further demonstrated that the tight junction, ion pumps, and aquaporins are essential for follicular fluid accumulation during iFFA, as a deficiency of any one of these negatively impacts fluid accumulation and antrum formation. The intraovarian mammalian target of rapamycin-C-type natriuretic peptide pathway, activated by follicle-stimulating hormone, initiated iFFA by activating tight junction, ion pumps, and aquaporins. Building on this, we promoted iFFA by transiently activating mammalian target of rapamycin in cultured follicles and significantly increased oocyte yield. These findings represent a significant advancement in iFFA research, further enhancing our understanding of folliculogenesis in mammals.

The oocyte cumulus complex regulates mouse sperm migration in the oviduct.

As the time of ovulation draws near, mouse spermatozoa move out of the isthmic reservoir, which is a prerequisite for fertilization. However, the molecular mechanism remains unclear. The present study revealed that mouse cumulus cells of oocytes-cumulus complexes (OCCs) expressed transforming growth factor-ß ligand 1 (TGFB1), whereas ampullary epithelial cells expressed the TGF-ß receptors, TGFBR1 and TGFBR2, and all were upregulated by luteinizing hormone (LH)/human chorionic gonadotropin (hCG). OCCs and TGFB1 increased natriuretic peptide type C (NPPC) expression in cultured ampullae via TGF-ß signaling, and NPPC treatment promoted spermatozoa moving out of the isthmic reservoir of the preovulatory oviducts. Deletion of Tgfb1 in cumulus cells and Tgfbr2 in ampullary epithelial cells blocked OCC-induced NPPC expression and spermatozoa moving out of the isthmic reservoir, resulting in compromised fertilization and fertility. Oocyte-derived paracrine factors were required for promoting cumulus cell expression of TGFB1. Therefore, oocyte-dependent and cumulus cell-derived TGFB1 promotes the expression of NPPC in oviductal ampulla, which is critical for sperm migration in the oviduct and subsequent fertilization.

C Type Natriuretic Peptide Receptor Activation Inhibits Sodium Channel Activity in Human Aortic Endothelial Cells by Activating the Diacylglycerol-Protein Kinase C Pathway.

The C-type natriuretic peptide receptor (NPRC) is expressed in many cell types and binds all natriuretic peptides with high affinity. Ligand binding results in the activation or inhibition of various intracellular signaling pathways. Although NPRC ligand binding has been shown to regulate various ion channels, the regulation of endothelial sodium channel (EnNaC) activity by NPRC activation has not been studied. The objective of this study was to investigate mechanisms of EnNaC regulation associated with NPRC activation in human aortic endothelial cells (hAoEC). EnNaC protein expression and activity was attenuated after treating hAoEC with the NPRC agonist cANF compared to vehicle, as demonstrated by Western blotting and patch clamping studies, respectively. NPRC knockdown studies using siRNA's corroborated the specificity of EnNaC regulation by NPRC activation mediated by ligand binding. The concentration of multiple diacylglycerols (DAG) and the activity of protein kinase C (PKC) was augmented after treating hAoEC with cANF compared to vehicle, suggesting EnNaC activity is down-regulated upon NPRC ligand binding in a DAG-PKC dependent manner. The reciprocal cross-talk between NPRC activation and EnNaC inhibition represents a feedback mechanism that presumably is involved in the regulation of endothelial function and aortic stiffness.

Efficacy of vosoritide in the treatment of achondroplasia.

Achondroplasia is the commonest form of dwarfism and results from a mutation in the fibroblast growth factor receptor 3 (FGFR3) gene on chromosome 4p16.3. The mutation is at nucleotide 1138 resulting in a G-to-A transition (134934.0001). This condition is characterized by full penetration meaning that everyone with this genetic mutation will exhibit the phenotypic characteristics of achondroplasia. It is a gain-of function mutation that causes increased inhibition of cartilage formation. C-type natriuretic peptide (CNP) acts on the growth plate through the natriuretic peptide receptor-B (NPR-B) causing the transformation of guanosine 5'-triphosphate into cyclic guanosine monophosphate. However, CNP cannot be used in the treatment of achondroplasia because it is rapidly degraded by neutral endopeptidase. Vosoritide is a modified recombinant human CNP and has a half-life 10 times that of CNP. Clinical trials have demonstrated that vosoritide is effective in significantly increasing the annualized growth velocity in children with achondroplasia before the fusion of the epiphyses.

C-Type Natriuretic Peptide (CNP) Could Improve Sperm Motility and Reproductive Function of Asthenozoospermia.

This study is to analyze the effect of C-type natriuretic peptide (CNP) on sperm motility of asthenozoospermia and explore the influence mechanism of CNP on the reproductive system and sperm motility. Our results showed that the concentration of CNP in asthenospermia patients' semen was lower than in normal people's. The motility of sperm could be improved markedly by CNP and 8-Br-cGMP, while the effect of CNP was inhibited by NPR-B antagonist and KT5823. In the asthenozoospermia mouse model induced by CTX, CNP injection could improve sperm motility in the epididymis, alleviate tissue damage in the testes and epididymis, and increase testosterone levels. The asthenospermia mouse model showed high activity of MDA and proinflammatory factors (TNF-α, IL-6), as well as low expression of antioxidants (SOD, GSH-Px, CAT) in the testis and epididymis, but this situation could be significantly ameliorated after being treated with CNP. Those studies indicated that the concentration of CNP in the semen of asthenospermia patients is lower than in normal people and could significantly promote sperm motility through the NPR-B/cGMP pathway. In the asthenospermia mouse model induced by CTX, CNP can alleviate the damage of cyclophosphamide to the reproductive system and sperm motility. The mechanism may involve increasing testosterone and reducing ROS and proinflammatory factors to damage the tissue and sperm.

Guanylyl Cyclase-B Dependent Bone Formation in Mice is Associated with Youth, Increased Osteoblasts, and Decreased Osteoclasts.

C-type natriuretic peptide (CNP) activation of guanylyl cyclase-B (GC-B) catalyzes the synthesis of cGMP in chondrocytes and osteoblasts. Elevated cGMP stimulates long bone growth, and inactivating mutations in CNP or GC-B reduce cGMP, which causes dwarfism. GC-B7E/7E mice that express a GC-B mutant that cannot be inactivated by dephosphorylation exhibit increased CNP-dependent GC-B activity, which increases bone length, as well as bone mass and strength. Importantly, how GC-B increases bone mass is not known. Here, we injected 12-week-old, wild type mice once daily for 28 days with or without BMN-111 (Vosoritide), a proteolytically resistant CNP analog. We found that BMN-111 treated mice had elevated levels of osteocalcin and collagen 1 C-terminal telopeptide (CTX) as well as increased osteoblasts and osteoclasts. In BMN-111 injected mice, tibial mRNAs for Rank ligand and osteoprotegrin were increased and decreased, respectively, whereas sclerostin mRNA was elevated 400-fold, consistent with increased osteoclast activity and decreased osteoblast activity. Mineral apposition rates and trabecular bone mass were not elevated in response to BMN-111. Because 9-week-old male GC-B7E/7E mice have increased bone mass but do not exhibit increased mineral apposition rates, we examined 4-week-old male GC-B7E/7E mice and found that these animals had increased serum osteocalcin, but not CTX. Importantly, tibias from these mice had 37% more osteoblasts, 26% fewer osteoclasts as well as 36% and 40% higher mineral apposition and bone formation rates, respectively. We conclude that GC-B-dependent bone formation is coupled to an early juvenile process that requires both increased osteoblasts and decreased osteoclasts.

The loading of C-type natriuretic peptides improved hemocompatibility and vascular regeneration of electrospun poly(ε-caprolactone) grafts.

As a result of thrombosis or intimal hyperplasia, synthetic artificial vascular grafts had a low success rate when they were used to replace small-diameter arteries (inner diameter < 6 mm). C-type natriuretic peptides (CNP) have anti-thrombotic effects, and can promote endothelial cell (EC) proliferation and inhibit vascular smooth muscle cell (SMC) over-growth. In this study, poly(ε-caprolactone) (PCL) vascular grafts loaded with CNP (PCL-CNP) were constructed by electrospinning. The PCL-CNP grafts were able to continuously release CNP at least 25 days in vitro. The results of scanning electron microscopy (SEM) and mechanical testing showed that the loading of CNP did not change the microstructure and mechanical properties of the PCL grafts. In vitro blood compatibility analysis displayed that PCL-CNP grafts could inhibit thrombin activity and reduce platelet adhesion and activation. In vitro cell experiments demonstrated that PCL-CNP grafts activated ERK1/2 and Akt signaling in human umbilical vein endothelial cells (HUVECs), as well as increased cyclin D1 expression, enhanced proliferation and migration, and increased vascular endothelial growth factor (VEGF) secretion and nitric oxide (NO) production. The rabbit arteriovenous (AV)-shunt ex vitro indicated that CNP loading significantly improved the antithrombogenicity of PCL grafts. The assessment of vascular grafts in rat abdominal aorta implantation model displayed that PCL-CNP grafts promoted the regeneration of ECs and contractile SMCs, modulated macrophage polarization toward M2 phenotype, and enhanced extracellular matrix remodeling. These findings confirmed for the first time that loading CNP is an effective approach to improve the hemocompatibility and vascular regeneration of synthetic vascular grafts. STATEMENT OF SIGNIFICANCE: Small-diameter (< 6 mm) vascular grafts (SDVGs) have not been made clinically available due to their prevalence of thrombosis, limited endothelial regeneration and intimal hyperplasia. The incorporation of bioactive molecules into SDVGs serves as an effective solution to improve hemocompatibility and endothelialization. In this study, for the first time, we loaded C-type natriuretic peptides (CNP) into PCL grafts by electrospunning and confirmed the effectiveness of loading CNP on improving the hemocompatibility and vascular regeneration of artificial vascular grafts. Regenerative advantages included enhancement of endothelialization, modulation of macrophage polarization toward M2 phenotypes, and improved contractile smooth muscle cell regeneration. Our investigation brings attention to CNP as a valuable bioactive molecule for modifying cardiovascular biomaterial.

C-type natriuretic peptide and its contribution to bone growth.

INTRODUCTION AND OBJECTIVE: The expression of the C-type natriuretic peptide (CNP) gene has been detected in the growth cartilage of the long bones and vertebrae. This article provides an overview of the role of CNP in bone growth and presents the results of the authors' research on the concentration of the NTproCNP and its relationship with growth velocity and bone markers in healthy school-age children. MATERIAL AND METHODS: The study involved 75 girls and 59 boys aged from 9.0-11.8 years (mean 10.29±0.74). Body weight, height and lower limb length were measured, and blood samples were collected twice at six-month intervals. In the first serum sample, the concentrations of NTproCNP, C-terminal propeptide type I (CICP), C-terminal telopeptide type I collagen (ICTP) osteocalcin (OC) and bone-specific alkaline phosphatase (BAP) were determined. In the second sample, NTproCNP concentration was assessed. RESULTS: During the six-month follow-up period, the increase in body height and weight of girls was greater than boys (p<0.000; p=0.003, respectively). While during the first examination the concentration of NTproCNP in girls and boys was similar, during the second examination it was higher in girls than in boys (p=0.04). Weak positive correlations between the increase in body height and NTproCNP, CICP, BAP as well as OC were found. There were no correlations between NTproCNP and the bone markers. CONCLUSIONS: The results suggest that NTproCNP concentration depends on growth velocity in children. There is increasing evidence that a better knowledge of CNP biology contributes to a better understanding of bone growth mechanisms.

Molecular Mechanism of Induction of Bone Growth by the C-Type Natriuretic Peptide.

The skeletal development process in the body occurs through sequential cellular and molecular processes called endochondral ossification. Endochondral ossification occurs in the growth plate where chondrocytes differentiate from resting, proliferative, hypertrophic to calcified zones. Natriuretic peptides (NPTs) are peptide hormones with multiple functions, including regulation of blood pressure, water-mineral balance, and many metabolic processes. NPTs secreted from the heart activate different tissues and organs, working in a paracrine or autocrine manner. One of the natriuretic peptides, C-type natriuretic peptide-, induces bone growth through several mechanisms. This review will summarize the knowledge, including the newest discoveries, of the mechanism of CNP activation in bone growth.

A Series of Substituted Bis-Aminotriazines Are Activators of the Natriuretic Peptide Receptor C.

C-type natriuretic peptide (CNP) is involved in the regulation of vascular homeostasis, which is at least partly mediated through agonism of natriuretic peptide receptor C (NPR-C), and loss of this signaling has been associated with vascular dysfunction. As such, NPR-C is a novel therapeutic target to treat cardiovascular diseases. A series of novel small molecules have been designed and synthesized, and their structure-activity relationships were evaluated by a surface plasmon resonance binding assay. The biological activity of hit compounds was confirmed through organ bath assays measuring vascular relaxation and inhibition of cAMP production, which was shown to be linked to its NPR-C activity. Lead compound 1 was identified as a potent agonist (EC50 ∼ 1 µM) with promising in vivo pharmacokinetic properties.

C-type natriuretic peptide facilitates autonomic Ca2+ entry in growth plate chondrocytes for stimulating bone growth.

The growth plates are cartilage tissues found at both ends of developing bones, and vital proliferation and differentiation of growth plate chondrocytes are primarily responsible for bone growth. C-type natriuretic peptide (CNP) stimulates bone growth by activating natriuretic peptide receptor 2 (NPR2) which is equipped with guanylate cyclase on the cytoplasmic side, but its signaling pathway is unclear in growth plate chondrocytes. We previously reported that transient receptor potential melastatin-like 7 (TRPM7) channels mediate intermissive Ca2+ influx in growth plate chondrocytes, leading to activation of Ca2+/calmodulin-dependent protein kinase II (CaMKII) for promoting bone growth. In this report, we provide evidence from experiments using mutant mice, indicating a functional link between CNP and TRPM7 channels. Our pharmacological data suggest that CNP-evoked NPR2 activation elevates cellular cGMP content and stimulates big-conductance Ca2+-dependent K+ (BK) channels as a substrate for cGMP-dependent protein kinase (PKG). BK channel-induced hyperpolarization likely enhances the driving force of TRPM7-mediated Ca2+ entry and seems to accordingly activate CaMKII. Indeed, ex vivo organ culture analysis indicates that CNP-facilitated bone growth is abolished by chondrocyte-specific Trpm7 gene ablation. The defined CNP signaling pathway, the NPR2-PKG-BK channel-TRPM7 channel-CaMKII axis, likely pinpoints promising target proteins for developing new therapeutic treatments for divergent growth disorders.

The heart, an endocrine gland: Natriuretic peptides.

The natriuretic peptide family consists of three biologically active peptides: atrial natriuretic peptide (ANP), brain (or B-type) natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). ANP and BNP, secreted by the heart, act as cardiac hormones, whereas CNP is an endothelial peptide. The aim of this manuscript is to review the production, action mechanisms, effects and clinical applications of natriuretic peptides.

CNP regulates cardiac contractility and increases cGMP near both SERCA and TnI: difference from BNP visualized by targeted cGMP biosensors.

AIMS: Guanylyl cyclase-B (GC-B; natriuretic peptide receptor-B, NPR-B) stimulation by C-type natriuretic peptide (CNP) increases cGMP and causes a lusitropic and negative inotropic response in adult myocardium. These effects are not mimicked by NPR-A (GC-A) stimulation by brain natriuretic peptide (BNP), despite similar cGMP increase. More refined methods are needed to better understand the mechanisms of the differential cGMP signalling and compartmentation. The aim of this work was to measure cGMP near proteins involved in regulating contractility to understand compartmentation of cGMP signalling in adult cardiomyocytes. METHODS AND RESULTS: We constructed several fluorescence resonance energy transfer (FRET)-based biosensors for cGMP subcellularly targeted to phospholamban (PLB) and troponin I (TnI). CNP stimulation of adult rat cardiomyocytes increased cGMP near PLB and TnI, whereas BNP stimulation increased cGMP near PLB, but not TnI. The phosphodiesterases PDE2 and PDE3 constrained cGMP in both compartments. Local receptor stimulation aided by scanning ion conductance microscopy (SICM) combined with FRET revealed that CNP stimulation both in the t-tubules and on the cell crest increases cGMP similarly near both TnI and PLB. In ventricular strips, CNP stimulation, but not BNP, induced a lusitropic response, enhanced by inhibition of either PDE2 or PDE3, and a negative inotropic response. In cardiomyocytes from heart failure rats, CNP increased cGMP near PLB and TnI more pronounced than in cells from sham-operated animals. CONCLUSION: These targeted biosensors demonstrate that CNP, but not BNP, increases cGMP near TnI in addition to PLB, explaining how CNP, but not BNP, is able to induce lusitropic and negative inotropic responses.

Mechanism of quercetin on the improvement of ovulation disorder and regulation of ovarian CNP/NPR2 in PCOS model rats.

PURPOSE: To investigate the effects of quercetin on ovulation disorder and expression of androgen receptor (AR) and C-type natriuretic peptide (CNP) / Natriuretic Peptide Receptor 2 (NPR2) in dehydroepiandrosterone (DHEA)-induced polycystic ovary syndrome (PCOS) rat model. METHODS: DHEA was used to construct the PCOS rat model. After intervention with quercetin, metformin, and AR, the estrous cycle, ovarian and uterine weight of rats were measured. The morphological changes of ovarian and uterine were detected by hematoxylin-eosin staining (HE staining). Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were measured by Enzyme linked immunosorbent assay (ELISA). Immunohistochemical detection of interleukin-6 (IL-6), interleukin-1ß (IL-1ß), tumor necrosis factor-alpha (TNF-α), B-cell lymphoma-2 (BCL-2), BCL2-Associated X (Bax) and AR expression in ovarian. Determination of the expression of CNP and NPR2 mRNA by qRT-PCR. Chromatin immunocoprecipitation (ChIP) was used to detect the ability of AR to bind to CNP or NPR2 promoter. RESULTS: The results showed that quercetin could significantly reduce the expression of Testosterone (T) , Estradiol (E2) , LH, Bax, IL-1ß, IL-6 and TNF-α, increase the expression of FSH and Bcl-2, inhibit the expression of AR, regulate the expression of CNP / NPR2 gene and protein by affecting the combination of AR with the specific sequence of CNP and NPR2 gene promoters, restore the maturation of oocyte and ovulation. CONCLUSION: The results suggest that quercetin can alleviate the hormone, metabolic and ovulatory aberrations caused by PCOS, and provide experimental basis for the clinical application of quercetin in PCOS.

Evidence of feedback regulation of C-type natriuretic peptide during Vosoritide therapy in Achondroplasia.

Evidence from genetic disorders of CNP signalling suggests that plasma concentrations of CNP are subject to feedback regulation. In subjects with Achondroplasia (Ach), CNP intracellular activity is suppressed and plasma concentrations are raised but the therapeutic impact of exogenous CNP agonists on endogenous CNP is unknown. In this exploratory dose finding and extension study of 28 Ach children receiving Vosoritide over a 5 year period of treatment, endogenous CNP production was assessed using measurements of plasma aminoterminal proCNP (NTproCNP) adjusted for age and sex and normalised as standard deviation score (SDS), and then related to skeletal growth. Before treatment NTproCNP SDS was raised. Within the first 3 months of accelerating growth, levels were significantly reduced. Across the 5 years of sustained growth, levels varied widely and were markedly increased in some subjects during adolescence. Plasma NTproCNP was suppressed at 4 h post-injection in proportion to the prevailing level of hormone resistance as reflected by SDS before injection. We conclude CNP remains subject to regulation during growth promoting doses of Vosoritide. Fall in CNP during accelerating growth is consistent with an indirect feedback whereas the fall at 4 h is likely to be a direct effect from removal of intra cellular CNP resistance.

C-Type Natriuretic Peptide Ameliorates Vascular Injury and Improves Neurological Outcomes in Neonatal Hypoxic-Ischemic Brain Injury in Mice.

C-type natriuretic peptide (CNP) is an important vascular regulator that is present in the brain. Our previous study demonstrated the innate neuroprotectant role of CNP in the neonatal brain after hypoxic-ischemic (HI) insults. In this study, we further explored the role of CNP in cerebrovascular pathology using both in vivo and in vitro models. In a neonatal mouse HI brain injury model, we found that intracerebroventricular administration of recombinant CNP dose-dependently reduces brain infarct size. CNP significantly decreases brain edema and immunoglobulin G (IgG) extravasation into the brain tissue, suggesting a vasculoprotective effect of CNP. Moreover, in primary brain microvascular endothelial cells (BMECs), CNP dose-dependently protects BMEC survival and monolayer integrity against oxygen-glucose deprivation (OGD). The vasculoprotective effect of CNP is mediated by its innate receptors NPR2 and NPR3, in that inhibition of either NPR2 or NPR3 counteracts the protective effect of CNP on IgG leakage after HI insult and BMEC survival under OGD. Of importance, CNP significantly ameliorates brain atrophy and improves neurological deficits after HI insults. Altogether, the present study indicates that recombinant CNP exerts vascular protection in neonatal HI brain injury via its innate receptors, suggesting a potential therapeutic target for the treatment of neonatal HI brain injury.