Congenital nephrogenic diabetes insipidus arginine vasopressin receptor 2 gene mutation at new site:A case report

BACKGROUND Congenital nephrogenic diabetes insipidus(CNDI)is a rare hereditary disorder.It is associated with mutations in the arginine vasopressin receptor 2(AVPR2)gene and aquaporin 2(AQP2)gene,and approximately 270 different mutation sites have been reported for AVPR2.Therefore,new mutations and new manifestations are crucial to complement the clinical deficiencies in the diagnosis of this disease.We report a case of a novel AVPR2 gene mutation locus and a new clinical manifestation.CASE SUMMARY We describe the case of a 48-d-old boy who presented with recurrent fever and diarrhea 5 d after birth.Laboratory tests showed electrolyte disturbances and low urine specific gravity,and imaging tests showed no abnormalities.Genetic testing revealed a novel X-linked recessive missense mutation,c.283(exon 2)C>T(p.P95S).This mutation results in the substitution of a proline residue with a serine residue in the AVPR2 protein sequence.The diagnosis of CNDI was confirmed based on the AVPR2 gene mutation.The treatment strategy for this patient was divided into two stages,including physical cooling supplemented with appropriate amounts of water in the early stage and oral hydrochlorothiazide(1-2 mg/kg)after a clear diagnosis.After follow-up of one and a half years,the patient gradually improved.CONCLUSION AVPR2 gene mutations in new loci and new clinical symptoms help clinicians understand this disease and shorten the diagnosis cycle.

SPECIFIC INHIBITION OF CONNEXIN 43 GENE EXPRESSION AFTER ACUPOINTS AND ACUPUNCTURE TREATMENT FOR PRIMARY DYSMENORRHEA

Objective To investigate the effect of acupuncture treatment on silencing the expression of Oonnexin 43 （Cx43）, and to study the analgesic mechanism of acupuncture treatment for primary dysmenorrhea （PD） in rats. Methods We used estrostilben to develop the model of primary dysmenorrhea in rat, and RNA interference technology to silence the expression of Cx43 in acupoints. Fifty female rats were randomly divided into five groups （n = 10 in each group） ： normal, model, acupuncture, acupuncture ＋ interference and acupuncture＋ interference control group, pSilencer-Cx43-shRNA and pSilencer-Oon-shRNA were injected locally into the acupoints in interference group and interference-control group, respectively. The incidence rate of writhe reaction over the period of 30 min was evaluated. The expression of the oxytocin receptor （OTR） and vasopressin receptor（VasR） in rat myometrium with Semiquantitative RT-POR and immunohistochemistry. Results （1）The mRNA and protein level of Cx43 in acupoints in interference group were significantly lower those of in the acupuncture group （P〈0.05）. There was no significant difference between acupuncture and interference-control group. （2） Acupuncture could significantly prolong the latency period of writhing body and decrease the number of writhing body as compared with that of model group and interference group. （3）The level of OTR and VasR mRNA and protein in the model group were significantly higher （P〈0.05） as compared to normal group. The results in acupuncture group and interference-control group were similar to the normal group. The results in interference group were similar to the model group. Conclusions Acupuncture may be useful in the treatment of the model of primary dysmenorrhea in the rats. Local injection of Cx43 shRNA expression vetor could silence the expression of Cx43 in acupoint and markedly influence acupuncture effect, demonstrating Cx43 is involved in acupuncture effect.

Effect of electroacupuncture on arginine vasopressin-induced endolymphatic hydrops

OBJECTIVE: To investigate the influence of electroacupuncture(EA) on experimentally induced endolymphatic hydrops(EH) in guinea pigs, and elucidate the association between the dehydrating effect of EA and changes in stria vascularis ultrastructure and expression of vasopressin type 2 receptor(V2R), cyclic adenosine monophosphate(cAMP),and aquaporin 2(AQP2) in the endolymphatic sac(ES).METHODS: The EH model was established by intraperitoneal injection of arginine vasopressin(AVP).As a treatment, EA was delivered to Baihui(GV 20)and Tinggong(SI 19) acupoints, once daily for 10 consecutive days. For histomorphological studies,degree of cochlear hydrops was evaluated by hematoxylin-eosin staining, and the ratio of scala media(SM) area to SM + scala vestibuli area was calculated. In mechanical studies, ultrastructural changes in stria vascularis tissue were examined by transmission electron microscopy. In addition, cAMP levels and mRNA expression levels of V2 R and AQP2 in the ES were compared among groups.RESULTS: EA treatment significantly reduced cochlear hydrops compared with hydropic guinea pigs(P = 0.015). Furthermore, EA attenuated ultrastructural changes in the stria vascularis tissue following EH, significantly upregulated the expression of V2 R(P = 0.016), and attenuated AVP-induced upregulation of both cAMP(P = 0.038) and AQP2 expression(P = 0.017) in the ES.CONCLUSION: Collectively, the results of the present study suggest that the dehydrating effect of EA is associated with improvement of stria vascularis ultrastructure and V2 R-cAMP-AQP2 signaling pathway regulation in the ES.

Synthesis and biological evaluation of novel phenothiazine derivatives as non-peptide arginine vasopressin V2 receptor antagonists

A series of novel phenothiazine derivatives was synthesized and tested for arginine vasopressin receptor antagonist activity. They were synthesized as novel arginine vasopressin receptor antagonists from phenothiazine as a scaffold via successive acylation, reduction and acylation reactions. Their structures were characterized by ^1H NMR, ^13C NMR and HRMS, and biological activity was evaluated by in vitro and in vivo studies. The in vitro binding assay indicated that several compounds are potent selective V2 receptor antagonists. Compounds with promising binding affinity to V2 receptors were selected to conduct the in vivo diuretic studies on Sprague-Dawley rats. Among them, 1n, 1r, It and 1v exhibited excellent diuretic activity, especially 1 r and 1v. Therefore, 1 r and 1v are potent novel AVP V2 receptor antagonist candidates.

Interactions of sex and early life social experiences at two developmental stages shape nonapeptide receptor profiles

Early life social experiences are critical to behavioral and cognitive development,and can have a tremendous influence on developing social phenotypes.Most work has focused on outcomes of experiences at a single stage of development(e.g.perinatal or post-weaning).Few studies have assessed the impact of social experience at multiple developmental stages and across sex.Oxytocin and vasopressin are profoundly important for modulating social behavior and these nonapeptide systems are highly sensitive to developmental social experience,particularly in brain areas important for social behavior.We investigated whether oxytocin receptor(OTR)and vasopressin receptor(V1aR)distributions of prairie voles(Microtus ochrogaster)change as a function of parental composition within the natal nest or social composition after weaning.We raised pups either in the presence or absence of their fathers.At weaning,offspring were housed either individually or with a same-sex sibling.We also examined whether changes in receptor distributions are sexually dimorphic because the impact of the developmental environment on the nonapeptide system could be sex-dependent.We found that differences in nonapeptide receptor expression were region-specific,sex-specific and rearing condition-specific,indicating a high level of complexity in the ways that early life experiences shape the social brain.We found many more differences in V1aR density compared to OTR density,indicating that nonapeptide receptors demonstrate differential levels of neural plasticity and sensitivity to environmental and biological variables.Our data highlight that critical factors including biological sex and multiple experiences across the developmental continuum interact in complex ways to shape the social brain.

Synthesis and biological evaluation of novel derivatives of desloratadine

Series of novel derivatives of desloratadine designed as arginine vasopressin receptor antagonists were synthesized and structurally characterized by melting points,^1H NMR and HRMS.Their in vivo diuretic activities were evaluated on rats,and several target compounds showed promising diuretic results, especially compounds 8,18,27 and 31.Further in vitro bonding assay and cAMP assay showed that these compounds had a higher affinity to vasopressin V2 receptor than VI a receptor.Our studies indicated that desloratadine may be an active substructure for novel arginine vasopressin receptor antagonist development.