Spinal Sirtuin 3 Contributes to Electroacupuncture Analgesia in Mice With Chronic Constriction Injury–Induced Neuropathic Pain

BackgroundElectroacupuncture (EA) is a traditional Chinese therapeutic technique that has a beneficial effect on neuropathic pain; however, the specific mechanism remains unclear. In this study, we investigated whether EA inhibits spinal Ca/calmodulin-dependent protein kinase II (CaMKIIα) phosphorylation through Sirtuin 3 (SIRT3) protein, thus relieving neuropathic pain.Materials and MethodsWe used wild-type and SIRT3 knockout (SIRT3^−/−) mice and used chronic constriction injury (CCI) as a pain model. We performed Western blotting, immunostaining, von Frey, and Hargreaves tests to gather biochemical and behavioral data. Downregulation and overexpression and spinal SIRT3 protein were achieved by intraspinal injection of SIRT3 small interfering RNA and intraspinal injection of lentivirus-SIRT3. To test the hypothesis that CaMKIIα signaling was involved in the analgesic effects of EA, we expressed CaMKIIα-specific designer receptors exclusively activated by designer drugs (DREADDs) in the spinal dorsal horn (SDH) of mice.ResultsThese results showed that the mechanical and thermal hyperalgesia induced by CCI was related to the decreased spinal SIRT3 expression in the SDH of mice. A significant reduction of mechanical and thermal thresholds was found in the SIRT3^−/− mice. SIRT3 overexpression or EA treatment alleviated CCI-induced neuropathic pain and prevented the spinal CaMKIIα phosphorylation. Most importantly, EA increased the expression of spinal SIRT3 protein in the SDH. Downregulation of spinal SIRT3 or CaMKIIα Gq-DREADD activation inhibited the regulatory effect of EA on neuropathic pain.ConclusionOur results showed that CaMKIIα phosphorylation was inhibited by spinal SIRT3 in neuropathic pain and that EA attenuated CCI-induced neuropathic pain mainly by upregulating spinal SIRT3 expression in the SDH of mice.     

用于治疗多囊卵巢综合征的中药药理学作用机制研究进展

多囊卵巢综合征(polycystic ovary syndrome,PCOS)是一种异质性内分泌紊乱性疾病,以高雄激素、胰岛素抵抗和持续无排卵为特征,是青春期和育龄期妇女常见的内分泌系统与代谢系统疾病之一,严重威胁着患者的健康。目前国内外西医主要通过降低雄激素、改善胰岛素抵抗、诱发排卵等手段改善患者症状,但西药不良反应较大,长期治疗不能为患者所接受。近年来中医药治疗PCOS已经取得了一定疗效,中医药具有多靶点、多环节、多途径效应,可以同时调节PCOS患者内分泌与代谢紊乱,且相对安全。该文通过查阅临床和动物实验方面的文献,阐述了中医对PCOS的认识、用药分析和中药对PCOS治疗的药理学机制,发现中药在调节下丘脑-垂体-性轴功能、纠正性激素紊乱、影响基因及调控因子的表达、改善胰岛素抵抗、纠正糖脂代谢紊乱、改善子宫内膜容受性、提高妊娠率和改善卵巢形态等方面发挥作用。该文对中医对PCOS的认识及中医药在PCOS治疗方面的积极作用加以归纳总结,为中医药防治PCOS的推广应用提供科学依据。     

孕前超重、孕期过度增重与巨大儿发生风险的前瞻性队列研究

目的 探讨巨大儿发生与孕前超重、孕期过度增重的直接关联及关联强度。方法 2015年1月起在上海市浦东新区妇幼保健院建立孕妇队列,创建孕妇健康档案,收集孕期及分娩信息,包括一般人口学特征、孕前体重、孕期增重、分娩体重、孕期健康状况及各种孕期并发症、分娩情况等,计算孕前BMI及孕期增重,收集新生儿出生体重,了解巨大儿发生与孕前超重、孕期过度增重之间的关系。结果 巨大儿发生率为6.6%（149/2 243）。不同孕前BMI组巨大儿发生率差异有统计学意义（P=0.001）。在控制了孕妇年龄、孕产史等因素后,logistic回归分析结果显示,与孕前BMI适宜的孕妇比,孕前BMI超重以及肥胖的孕妇生产巨大儿的风险均增加（OR=3.12,95%CI：1.35~7.22,P=0.008; OR=2.99,95%CI：1.17~7.63,P=0.022）。不同孕期增重组巨大儿发生率差异有统计学意义（P=0.002）。在控制了孕妇年龄、孕产史、孕期并发症等因素后,logistic回归分析结果显示,与孕期增重适宜的孕妇比,孕期增重不足的孕妇生产巨大儿的风险降低（OR=0.52,95%CI：0.30~0.90,P=0.019）。而孕期过度增重在调整了各种孕期指标后,与孕期增重适宜的孕妇比,巨大儿发生风险差异有统计学意义（OR=1.41,95%CI：0.96~2.09,P=0.084）。结论 孕前超重或肥胖是巨大儿发生的风险因素。     

Biphasic regulation of InsP3 receptor gating by dual Ca2+ release channel BH3-like domains mediates Bcl-xL control of cell viability

Antiapoptotic Bcl-2 family members interact with inositol trisphosphate receptor (InsP₃R) Ca²⁺ release channels in the endoplasmic reticulum to modulate Ca²⁺ signals that affect cell viability. However, the molecular details and consequences of their interactions are unclear. Here, we found that Bcl-x_L activates single InsP₃R channels with a biphasic concentration dependence. The Bcl-x_L Bcl-2 homology 3 (BH3) domain-binding pocket mediates both high-affinity channel activation and low-affinity inhibition. Bcl-x_L activates channel gating by binding to two BH3 domain-like helices in the channel carboxyl terminus, whereas inhibition requires binding to one of them and to a previously identified Bcl-2 interaction site in the channel-coupling domain. Disruption of these interactions diminishes cell viability and sensitizes cells to apoptotic stimuli. Our results identify BH3-like domains in an ion channel and they provide a unifying model of the effects of antiapoptotic Bcl-2 proteins on the InsP₃R that play critical roles in Ca²⁺ signaling and cell viability.The inositol trisphosphate receptors (InsP₃R) are a family of intracellular cation channels that release Ca²⁺ from the endoplasmic reticulum (ER) in response to a variety of extracellular stimuli (1). Three InsP₃R isoforms are ubiquitously expressed and regulate diverse cell processes, including cell viability (1). Activation of the channels by InsP₃ elicits changes in cytoplasmic Ca²⁺ concentration ([Ca²⁺]_i) that provide versatile signals to regulate molecular processes with high spatial and temporal fidelity (1). Regions of close proximity to mitochondria enable localized Ca²⁺ release events to be transduced to mitochondria (2, 3). Ca²⁺ released from the ER during cell stimulation modulates activities of effector molecules and is taken up by mitochondria to stimulate oxidative phosphorylation and enhance ATP production (4–6) to match energetic supply with enhanced demand. In addition, cells in vivo are constantly exposed to low levels of circulating hormones, transmitters, and growth factors that bind to plasma membrane receptors to provide a background level of cytoplasmic InsP₃ (7) that generates low-level stochastic InsP₃R-mediated localized or propagating [Ca²⁺]_i signals (8–10). Such signals also play an important role in maintenance of cellular bioenergetics (8). Nevertheless, under conditions of cell stress the close proximity of mitochondria to Ca²⁺ release sites may result in mitochondrial Ca²⁺ overload and initiate Ca²⁺-dependent forms of cell death, including necrosis and apoptosis (11–13). It has been suggested that high levels of ER Ca²⁺ (14–16) and enhanced activity of the InsP₃R (17–19) promote cell death by providing a higher quantity of released Ca²⁺ to mitochondria (3, 20, 21).Protein interactions modulate the magnitude and quality of InsP₃R-mediated [Ca²⁺]_i signals that regulate apoptosis and cell viability. Notable in this regard is the Bcl-2 protein family. Proapoptotic Bcl-2–related proteins Bax and Bak initiate cytochrome C release from mitochondria in response to diverse apoptotic stimuli, whereas antiapoptotic Bcl-2–related proteins, including Bcl-2 and Bcl-x_L, antagonize Bax/Bak by forming heterodimers that prevent their oligomerization and apoptosis initiation (22, 23). Heterodimerization is mediated by interactions of proapoptotic Bcl-2 homology 3 (BH3) domains with a hydrophobic groove on the surface of antiapoptotic Bcl-2 proteins (23) that is a therapeutic target in diseases, including cancer (22). Whereas a central feature of molecular models of apoptosis is the control of outer mitochondrial membrane permeability by Bcl-2–related proteins, a substantial body of evidence has demonstrated that these proteins localize to the ER (24, 25), bind to InsP₃Rs (26–32) and, by modulating InsP₃R-mediated Ca²⁺ release, regulate ER-mediated cell death and survival (15, 27, 32–34). Nevertheless, a unified understanding of the detailed molecular mechanisms by which Bcl-2 family proteins interact with and regulate InsP₃R channel activity is lacking. The Bcl-2 family member homolog NrZ interacts with the amino-terminal InsP₃-binding region via its helix 1 BH4 domain and inhibits Ca²⁺ release (28). Bcl-2 also interacts with the InsP₃R (26) via its BH4 domain (35), but in contrast it associates with a region in the central coupling domain (35). Whereas this interaction also inhibits Ca²⁺ release (26), Bok interacts with the channel 500 residues C-terminal to the Bcl-2 binding sequence via its BH4 domain but does not affect Ca²⁺ release (29). Conversely, the Bcl-x_L BH4 domain may lack this interaction (36). Inhibition of the Bcl-2 BH4 domain interaction with the channel enhanced InsP₃R-mediated Ca²⁺ signals and apoptosis sensitivity in white blood cells (18, 35, 37). However, it is unclear if Bcl-2 inhibits Ca²⁺ signaling directly by binding to the channel or if it acts indirectly, as a hub in a protein complex that influences channel phosphorylation (38). Conversely, we demonstrated that Bcl-x_L, Bcl-2, and Mcl-1 bind to the carboxyl (C)-terminus of all three InsP₃R isoforms, and showed that these interactions activated single InsP₃R channels and promoted InsP₃R-mediated Ca²⁺ release and apoptosis resistance (27, 31, 32). Furthermore, Bcl-x_L mediates an interaction of oncogenic K-RAS with the InsP₃R C terminus that regulates its biochemical and functional interaction and cell survival (39). However, the molecular details of the interactions of antiapoptotic protein with the InsP₃R C terminus are unknown. Furthermore, the relationship between Bcl-2 family protein binding in the coupling domain and C terminus is unclear. Thus, the mechanisms whereby Bcl-2 and Bcl-x_L affect InsP₃R activity and the effects of this modulation on cell viability remain to be determined.Here, we used single-channel electrophysiology of native ER membranes to explore the detailed mechanisms of the effects of Bcl-x_L on the InsP₃R, and the role of this interaction on cell viability. Surprisingly, our results reveal that whereas Bcl-x_L activates the channel at low concentrations, it inhibits it at higher concentrations, resulting in a biphasic response of channel activation on [Bcl-x_L]. Remarkably, the Bcl-x_L BH3 domain-binding pocket is required for both effects. Low [Bcl-x_L] activates the channel by simultaneous binding to two BH3 domain-like helices in the channel C terminus, whereas channel inhibition at high [Bcl-x_L] requires binding to only one of them and to a site previously identified as the Bcl-2 binding site in the channel-coupling domain. Disruption of these interactions diminishes cell viability. Our results provide a unifying model of the effects of antiapoptotic Bcl-2 proteins on the InsP₃R that play critical roles in Ca²⁺ signaling and cell viability.     

The relationships among the skeletal muscle mass index,cardiorespiratory fitness and the prevalence of coronary artery disease in the elderly population

ObjectiveFew studies have investigated the association between cardiorespiratory fitness (CRF) impairment and coronary artery disease (CAD) and the mediating mechanism. Therefore, we investigated the impact of skeletal muscle mass (SMM) on the relationship between CRF and coronary artery disease (CAD) in elderly people.MethodsIn this cross-sectional study, 109 elderly patients with coronary artery stenosis ≥50% were included in the CAD group, and 148 patients with coronary artery stenosis <50% were included as controls. Mediation analyses were performed to determine the role of the skeletal muscle index (SMI) in the relationship between CRF and the prevalence of CAD. A receiver operating characteristic (ROC) curve analysis was used to evaluate the predictive value of CRF markers and the SMI.ResultsThe oxygen pulse, VO₂ max, and MET max were significantly associated with the SMI. In the multiple logistic regression analyses, the oxygen pulse and SMI were both independently correlated with the prevalence of CAD. The mediation analyses showed that the SMI affects the relationship between CRF markers (oxygen pulse, VO₂ max, and MET max) and the prevalence of CAD. The receiver operating characteristic (ROC) curve analysis showed that when CRF and the SMI are considered together, the predictive power for CAD is stronger than that of the CRF alone.ConclusionEnhancing CRF can facilitate improvement in SMM and decrease the prevalence of CAD in the elderly population. The addition of the SMI to CRF markers may increase the predictive value of CAD.     

Contraception,unintended pregnancy,and induced abortion within 24 months of delivery in China: a retrospective cohort study

ObjectiveTo explore the prevalence of contraceptive use, unintended pregnancy, and induced abortions within 24 months postpartum in eastern, central, and western regions of China and in China overall.Study DesignWe conducted a retrospective cohort study and selected women who delivered a live birth between 12 and 24 months before the survey at 60 hospitals in eastern, central, and western regions of China. We used structured questionnaires for data collection and applied life-table analyses to estimate the prevalence of contraception, unintended pregnancy, and abortions. We used clustered log-rank tests to compare trends and rate differences at each time interval between/among regions.ResultsA total of 19,939 postpartum women were contacted, and 18,045 (90.5%) of them agreed to be interviewed. The 6-, 12-, and 24-month rates for modern contraceptive methods were 62.7% (95% confidence interval [CI] 58.9–66.4), 72.4% (95% CI 68.8–75.7), and 73.2% (95% CI 69.6–76.6), respectively. Condoms accounted for 79% of contraceptive initiators. The 6-, 12-, and 24-month rates were 1.4% (95% CI 1.2–1.7), 5.3% (95% CI 4.5-–6.1), and 13.1% (95% CI 11.3–14.8) for unintended pregnancy; and 1.1% (95% CI 0.8–1.3), 4.0% (95% CI 3.4–4.6), and 10.4% (95% CI 8.9–11.8) for induced abortion, respectively. By 24 months postpartum, 3-quarters of unintended pregnancies ended in abortion. The 24-month rates of modern contraceptive methods (75.2% vs73.4%, 71.1%), unintended pregnancy (15.3% vs 11.1%, 12.6%), and induced abortion (11.8% vs 9.9%, 9.4%) were higher in the western region relative to the eastern or central regions.ConclusionPostpartum contraception use was relatively high in China but dominated by less-effective methods, and these may contribute to higher risks of unintended pregnancy and induced abortion during the postpartum period. Use of long-acting reversible contraceptives and effective and reliable short-acting methods should thus be fostered in postpartum family planning services in China.ImplicationsA national postpartum family planning program is needed in China. Service providers should work on counselling postpartum women and their partners with respect to long-acting reversible contraceptive methods, and to effectively and reliably use short-acting methods during the postpartum period.