Transcriptome-based insights into the calcium transport mechanism of chick chorioallantoic membrane

Chorioallantoic membrane(CAM)is responsible for respiratory gas exchange,eggshell calcium transport,embryonic acid-base equilibrium,allantoic ion,and water reabsorption during avian embryonic development.To further understand the timing of CAM gene expression during chick embryonic development,especially the calcium absorption mechanism,transcriptome quantitative comparative analysis was conducted on chick CAM during the embryonic period(E)of 9,13,17,and 20 days.A total of 6378 differentially expressed genes(DEGs)were identified.Functional enrichment analysis of DEGs showed that CAM DEGs were mainly involved in biological processes such as"ion transport regulation","immune response"and"cell cycle".Time series analysis of the differential genes showed that the functional cells of CAM began to proliferate and differentiate at E9 and the calcium content of egg embryo increased significantly at E13.Simultaneously,the observation of the ultrastructure of the eggshell showed that the interstice of the fiber layer was enlarged at E13,and the mastoid layer was partly exposed.Therefore,it is preliminarily inferred that CAM calcium transport starts at E13,and genes such as TRPV6,S100 A10,and RANKL cooperate to regulate calcium release and transport.

1,25-Dihydroxyvitamin D_3 modulates calcium transport in goat mammary epithelial cells in a dose- and energydependent manner

Background： Calcium is a vital mineral and an indispensable component of milk for ruminants. The regulation of transcellular calcium transport by 1,25-dihydroxyvitamin D3 （1,25-（OH）2D3, the active form of vitamin D） has been confirmed in humans and rodents, and regulators, including vitamin D receptor （VDR）, calcium binding protein Dgk （calbindin-Dgk）, plasma membrane Ca2＋-ATPase ] b （PMCAlb）, PMAC2b and Oral1, are involved in this process. However, it is still unclear whether 1,25-（OH）2D3 could stimulate calcium transport in the ruminant mammary gland. The present trials were conducted to study the effect of 1,25-（OH）2D3 supplementation and energy availability on the expression of genes and proteins related to calcium secretion in goat mammary epithelial cells. Methods： An in vitro culture method for goat secreting mammary epithelial cells was successfully established. The cells were treated with different doses of 1,25-（OH）2D3 （0, 0.1, 1.0, 10.0 and 100.0 nmol/L） for calcium transport research, followed by a 3-bromopyruvate （3-BrPA, an inhibitor of glucose metabolism） treatment to determine its dependence on glucose availability. Cell proliferation ratios, glucose consumption and enzyme activities were measured with commercial kits, and real-time quantitative polymerase chain reaction （RT-qPCR）, and western blots were used to determine the expression of genes and proteins associated with mammary calcium transport in dairy goats, respectively. Results： 1,25-（OH）2D3 promoted cell proliferation and the expression of genes involved in calcium transport in a dose-dependent manner when the concentration did not exceed 10.0 nmol/L. In addition, 100.0 nmol/L 1,25-（OH） 2D3 inhibited cell proliferation and the expression of associated genes compared with the 10.0 nmol/L treatment. The inhibition of hexokinase 2 （HK2）, a rate-limiting enzyme in glucose metabolism, decreased the expression of PMCA1 b and PMCA2b at the mRNA and protein levels as well as the transcription of Oral1, indicating that glucose avaitability was required for goat mammary calcium transport. The optimal concentration of 1,25-（OH）2D3 that facilitated calcium transport in this study was 10.0 nmol/L. Conclusions： Supplementation with 1,25-（OH）2D3 influenced cell proliferation and regulated the expression of calcium transport modulators in a dose- and energy-dependent manner, thereby highlighting the role of 1,25-（OH）2D3 as an efficacious regulatory agent that produces calcium-enriched milk in ruminants when a suitable energy status was guaranteed.

Mechanisms of calcium transport across the placenta: Review

Studies of calcium transfer across the placenta have been reviewed because of the physiological and nutritional importance of this mineral during pregnancy, especially in order to better understand its contribution to development of the fetal skeleton. The placental transfer of maternal calcium to the fetus represents a vital mechanism for fetal development and breast-milk production, yet little meaningful information is currently available regarding the biochemical mechanisms involved in this process. Once again, the use of different animal models as rodents, rabbit, sheep and bovine have demonstrate different mechanisms of calcium transport across the placenta and contribute to better understand its effects in both fetus and mother during the gestation. In relation to the transfer of calcium from the mother to fetus data suggest it occur via an active mechanism;thus calcium concentration is higher in fetus than in maternal blood. Despite conflicting reports, several investigators agreed that calcium concentration in the fetal blood is mainly regulated by fetal parathyroid hormone and plasma concentration of vitamin D3, a metabolite that plays a key role in calcium transport through the syncytial cells.

Decreased eggshell strength caused by impairment of uterine calcium transport coincide with higher bone minerals and quality in aged laying hens

Background Deteriorations in eggshell and bone quality are major challenges in aged laying hens.This study compared the differences of eggshell quality,bone parameters and their correlations as well as uterine physiologi-cal characteristics and the bone remodeling processes of hens laying eggs of different eggshell breaking strength to explore the mechanism of eggshell and bone quality reduction and their interaction.A total of 24074-week-old Hy-line Brown laying hens were selected and allocated to a high(HBS,44.83±1.31 N)or low(LBS,24.43±0.57 N)eggshell breaking strength group.Results A decreased thickness,weight and weight ratio of eggshells were observed in the LBS,accompanied with ultrastructural deterioration and total Ca reduction.Bone quality was negatively correlated with eggshell quality,marked with enhanced structures and increased components in the LBS.In the LBS,the mammillary knobs and effective layer grew slowly.At the initiation stage of eggshell calcification,a total of 130 differentially expressed genes(DEGs,122 upregulated and 8 downregulated)were identified in the uterus of hens in the LBS relative to those in the HBS.These DEGs were relevant to apoptosis due to the cellular Ca overload.Higher values of p62 protein level,caspase-8 activity,Bax protein expression and lower values of Bcl protein expression and Bcl/Bax ratio were seen in the LBS.TUNEL assay and hematoxylin-eosin staining showed a significant increase in TUNEL-positive cells and tissue damages in the uterus of the LBS.Although few DEGs were identified at the growth stage,similar uterine tissue damages were also observed in the LBS.The expressions of runt-related transcription factor 2 and osteocal-cin were upregulated in humeri of the LBS.Enlarged diameter and more structural damages of endocortical bones and decreased ash were observed in femurs of the HBS.Conclusion The lower eggshell breaking strength may be attributed to a declined Ca transport due to uterine tissue damages,which could affect eggshell calcification and lead to a weak ultrastructure.Impaired uterine Ca transport may result in reduced femoral bone resorption and increased humeral bone formation to maintain a higher mineral and bone quality in the LBS.

Genome-Wide Comparative in silico Analysis of Calcium Transporters of Rice and Sorghum

The mechanism of calcium uptake, translocation and accumulation in Poaceae has not yet been fully understood. To address this issue, we conducted genome-wide comparative in silico analysis of the calcium （Ca2＋） transporter gene family of two crop species, rice and sorghum. Gene annotation, identification of upstream cis-acting ele- ments, phylogenetic tree construction and syntenic mapping of the gene family were performed using several bio- informatics tools. A total of 31 Ca2＋ transporters, distributed on 9 out of 12 chromosomes, were predicted from rice genome, while 28 Ca2＋ transporters predicted from sorghum are distributed on all the chromosomes except chromosome 10 （Chr 10）. Interestingly, most of the genes on Chr 1 and Chr 3 show an inverse syntenic relation- ship between rice and sorghum. Multiple sequence alignment and motif analysis of these transporter proteins re- vealed high conservation between the two species. Phylogenetic tree could very well identify the subclasses of channels, ATPases and exchangers among the gene family. The in silico c/s-regulatory element analysis suggested diverse functions associated with light, stress and hormone responsiveness as well as endosperm- and meris- tem-specific gene expression. Further experiments are warranted to validate the in silico analysis of the predicted transporter gene family and elucidate the functions of Ca2＋ transporters in various biological processes.

Abnormal calcium transport ofmyocardial mitochondria during the early stage of combined radiation－burn injury in rats

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Calcium Hydroxide Removal in Curved Root Canals with Apical Transportation In Vitro

Calcium hydroxide（CH） is applied to improve disinfection of root canals in most root canal retreatment. This study aimed to analyze the CH removal efficacy using 7 different root preparing files（K file, pre-curved K file, EndoActivator, Ultrasonic file, pre-curved ultrasonic file, F file and needle irrigation alone） with apical transportation. Standardized models of curved canal with such apical transportation or not were set up before applying CH to root canal for 7 days. Seven techniques described above were used for its removal. Then the roots were disassembled and digital photos were taken. The ratio of residual CH in the overall canal surface was calculated using the image analyzer image pro plus 6.0. The data were analyzed using one-way ANOVA with post hoc Tukey test. Results revealed that CH was effectively removed（P〈0.05） by using all 6 mechanical methods except irrigation alone. In curved root canals with apical transportation, EndoActivator, pre-curved ultrasonic file and F file were found to be more effective in removing CH than the other four file（P〈0.001）, while there was no significant difference among EndoActivator, pre-curved ultrasonic file and F file groups（P〉0.05）. The percentage of residual CH in the canal with apical transportation was higher than that in the canal without apical transportation（P〈0.05）. In conclusion, CH can be hardly removed completely. Canal with apical transportation will result in insufficient CH removal. EndoActivator, pre-curved ultrasonic file and F file are more effective in the curved root canal with apical transportation.

钙在作物生长发育中的功能及应用

钙是作物必需的中量元素之一,广泛存在于根、茎、叶、花、果实、种子中,对作物的生长发育具有重要意义。钙属于再利用难的元素,其吸收、转运受制于蒸腾作用,因此农作物常发生生理性缺钙,从而导致抗逆性减弱,产量和品质降低。作物体内的钙具有双重功能,既参与细胞壁与细胞膜的构成,还可作为细胞内第二信使参与多种环境刺激和内部生长发育信号的响应。细胞中钙的吸收和转运对于维持细胞内钙离子稳态和钙信号精准传导至关重要。近年来,钙在作物生长与发育中的功能和在作物生产中的应用得到了广泛研究。本文阐述了作物体内钙元素的分布、吸收转运和需求状况,介绍了作物缺钙症状和原因,并综述了钙的营养结构功能和第二信使功能及钙信号产生、传导和解码机制,总结了钙在作物生长发育中的作用,包括对产量、品质和抗逆性等方面的影响,同时对其未来研究方向提出了展望。

产蛋鸡子宫部钙离子转运及调控的研究进展

鸡蛋蛋壳品质下降会造成经济效益损失和食品安全风险。产蛋鸡子宫部无机钙离子(Ca^(2+))的转运涉及不同的跨膜途径、离子稳态、相关转运基因和载体的表达,是蛋壳矿化及调控的重要环节。本文综述了子宫部Ca^(2+)转运途径、Ca^(2+)转运对蛋壳矿化和蛋壳品质的影响、营养因素对Ca^(2+)转运的调控作用,旨在为通过调节蛋壳矿化,改善鸡蛋蛋壳品质提供参考。

Ketamine effect on intracellular and mitochondrial calcium mobilization

The suppressive effects of ketamine on intracellular calcium has been reported in a variety of cells although the mechanisms involved are not well understood.The aim of this work was to evaluate the ketamine effect on the mitochondrial Ca^(2+)accumulation and the cellular Ca^(2+)mobilization using FLUO4-AM and flow cytometry.The results showed that mitochondria from ketamine injected animals presented a lower ability to retain calcium at concentrations higher than 20μM,as compared with controls(saline injected animals).In ad-dition,ketamine showed a significant decreased KCl-induced intracellular calcium concentration.KCl increased calcium influx through cellular depolarization.According to the data presented herein,ketamine presents a clear inhibitory effect on cytosolic Ca2+transport mechanisms,independently from their action on the calcium channel associated NMDA receptor.

Calcium Signaling is Involved in Negative Phototropism of Rice Seminal Roots

Calcium ions （Ca2＋） act as an intracellular second messenger and affect nearly all aspects of cellular life. They are functioned by interacting with polar auxin transport, and the negative phototropism of plant roots is caused by the transport of auxin from the irradiated side to the shaded side of the roots. To clarify the role of calcium signaling in the modulation of rice root negative phototropism, as well as the relationship between polar auxin transport and calcium signaling, calcium signaling reagents were used to treat rice seminal roots which were cultivated in hydroculture and unilaterally illuminated at an intensity of 100-200 pmol/（m2.s） for 24 h. Negative phototropism curvature and growth rate of rice roots were both promoted by exogenous CaCI2 lower than 100 pmol/L, but inhibited by calcium channel blockers （verapamil and LaCI3）, calcineurin inhibitor （chlorpromazine, CPZ）, and polar auxin transport inhibitor （N-l-naphthylphthalamic acid, NPA）. Roots stopped growing and negative phototropism disappeared when the concentrations increased to 100 pmol/L verapamil, 12.500 ~Jmol/L LaCI3, 60 pmol/L CPZ, and 6 pmol/L NPA. Moreover, 100 pmol/L CaCI2 could relieve the inhibition of LaCI3, verapamil and NPA. The enhanced negative phototropism curvature was caused by the transportation of more auxin from the irradiated side to the shaded side in the presence of exogenous Ca2＋. Calcium signaling plays a key role as a second messenger in the process of light signal regulation of rice root growth and negative phototropism.

Emanuel Strehler’s work on calcium pumps and calcium signaling

Cells are equipped with mechanisms to control tightly the influx, efflux and resting level of free calcium (Ca 2+ ). Inappropriate Ca 2+ signaling and abnormal Ca 2+ levels are involved in many clinical disorders including heart disease, Alzheimer's disease and stroke. Ca 2+ also plays a major role in cell growth, differentiation and motility; disturbances in these processes underlie cell transformation and the progression of cancer. Accordingly, research in the Strehler laboratory is focused on a better understanding of the molecular "toolkit" needed to ensure proper Ca 2+ homeostasis in the cell, as well as on the mechanisms of localized Ca 2+ signaling. A longterm focus has been on the plasma membrane calcium pumps (PMCAs), which are linked to multiple disorders including hearing loss, neurodegeneration, and heart disease. Our work over the past 20 years or more has revealed a surprising complexity of PMCA isoforms with different functional characteristics, regulation, and cellular localization. Emerging evidence shows how specific PMCAs contribute not only to setting basal intracellular Ca 2+ levels, but also to local Ca 2+ signaling and vectorial Ca 2+ transport. A second major research arearevolves around the calcium sensor protein calmodulin and an enigmatic calmodulin-like protein (CALML3) that is linked to epithelial differentiation. One of the cellular targets of CALML3 is the unconventional motor protein myosin-10, which raises new questions about the role of CALML3 and myosin-10 in cell adhesion and migration in normal cell differentiation and cancer.

CaCo_1-xRu_xO_y: Role of Ru/Co Ratio on Its Transport Properties

Calcium cobaltites, especially Ca3Co4O9 with a misfit layered structure, are promising thermoelectric materials due to their suitability for high temperature applications and low densities. The existence of low spin-state electronic configurations for both and species is one of the key parameter to explain the large thermopower values. Ruthenium oxide, with a layered structure, exhibits strong electron-electron correlation and the extended nature of their 4d electrons enhances orbital overlapping which is expected to influence the transport characteristics of CaCo1-xRuxOy (CCR) samples, by affecting the spin state of the 3d Co ions. The effect on thermopower and electrical resistivity due to partial substitution of Co by Ru ions, up to 0.33 moles, from 300 to 600 K was investigated. A sharp decline in resistivity and in thermopower was observed until a transition ion ratio (TIR), (Ru/(Ru + Co)), of 0.5 is reached, beyond which both the properties became less sensitive to TIR. These variations in the transport properties are explained by the presence of 4d Ru in close proximity to the Co, which could influence the spin and oxidation state of Co ions. The Co rich and Ru rich samples exhibit very distinct microstructures and phase assemblages.

Improving Photosynthetic Responses during Recovery from Heat Treatments with Brassinosteroid and Calcium Chloride in Indian Bread Wheat Cultivars

Climate change is expected to unleash severe and frequent heat waves in future, adversely affecting crop productivity. The aim of this study was to examine the effect of two separate episodes of heat stress, mimicking heat wave conditions on the physiology of four Indian bread wheat cultivars and to study the ameliorating effects of epibrassinolide (BR) and calcium chloride on the recovery of these cultivars. The two thermo-tolerant cultivars C306 and K7903 suffered less inhibition of photosystem II efficiency as compared to the two thermo-susceptible cultivars HD2329 and PBW343. Application of BR and calcium chloride resulted in faster recovery in all the four cultivars. Measurement of the minimum fluorescence (Fo) versus temperature curves revealed a higher inflection temperature of Fo (Ti) for the two tolerant cultivars as compared to the susceptible cultivars, emphasizing greater thermo stability of the photosynthetic apparatus. The two thermo-tolerant cultivars showed higher photochemistry (ΦPSII) relative to the two susceptible cultivars. An increase in the steady state fluorescence was observed in both the susceptible cultivars as compared to the tolerant cultivars. Expression analysis revealed faster recovery of the transcripts involved in photosynthesis in tolerant cultivars as compared to susceptible cultivars. Exogenous application of the ameliorating compounds resulted in faster recovery of transcripts in all the cultivars. The result suggested that under severe stress conditions tolerant cultivars showed faster recovery and a better thermo-stability of its photosynthetic apparatus as compared to susceptible cultivars and application of epibrassinolide and calcium chloride could ameliorate the damaging effect of severe temperature stress to a considerable level in all the four cultivars under study.

基于钙超载探讨自主神经调控对HFpEF大鼠心肌结构重塑、电重塑及纤维化的影响

目的 探究自主神经调控对大鼠射血分数保留心力衰竭(HFpEF)模型结构重塑、电重塑及纤维化的影响。方法 SPF级12周龄SD大鼠44只,抽取10只作为对照组,余34只用于建立HFpEF模型。通过腹主动脉-下腔静脉瘘结扎的方式构建HFpEF模型。其中30只建模成功,4只死亡。建模成功的大鼠分为模型组、自主神经调控组(调控组)及自主神经调控+乙酰胆碱M2受体拮抗剂组(调控+拮抗组),每组10只。调控组在模型组基础上经皮耳缘迷走神经刺激。调控+拮抗组在调控组基础上每天经尾静脉注射美索曲明(0.5 mg/kg)。通过心脏超声仪测量心脏舒张末期左心室后壁厚度(LVPWD-D)、舒张末期室间隔厚度(IVS-D)及二尖瓣舒张早期/舒张晚期血流速度最大峰值(E/A)。心脏电生理刺激仪获取心脏的有效不应期(ERP)、单向动作电位时程(MAPD)。酶联免疫吸附试验(ELISA)检测B型尿钠肽前体(NT-proBNP)水平。HE染色观察心肌细胞排列及炎性细胞浸润情况。Masson染色观察心肌纤维化程度。RT-PCR和Western blot检测心肌组织基质金属蛋白酶-9(MMP-9)、金属蛋白酶组织抑制因子-1(TIMP-1)、肌浆网Ca2+-ATP酶(SERCA2a)及其调节蛋白受磷蛋白(PLB)mRNA及蛋白的表达。结果 HE染色可见模型组心肌细胞排列紊乱,细胞间隙不够明显,伴有炎性细胞浸润。Masson染色可见模型组心肌纤维排列紊乱,大量胶原纤维生成。调控组上述病理改变与模型组比较均明显减轻,而调控+拮抗组与模型组相比无明显改善。与对照组比较,模型组NT-proBNP、LVPWD-D、IVS-D、ERP、MAPD、MMP-9 mRNA及蛋白、PLB mRNA及蛋白表达均升高,E/A、TIMP-1 mRNA及蛋白、SERCA2a mRNA及蛋白表达均降低(P<0.05)。与模型组比较,调控组NT-proBNP、LVPWD-D、IVS-D、ERP、MAPD、MMP-9 mRNA及蛋白、PLB mRNA及蛋白表达均降低,E/A、TIMP-1 mRNA及蛋白、SERCA2a mRNA及蛋白表达均升高(P<0.05)。而调控+拮抗剂组上述指标与模型组比较差异无统计学意义。结论自主神经调控可能通过钙超载途径减轻HFpEF大鼠的结构重塑、电重塑以及心肌纤维化状态,改善HFpEF预后。

河流泥沙输移过程中矿物风化的碳汇效应初探——以长江干流为例

本文首先提出了河流泥沙输移过程中泥沙中的钙镁矿物溶蚀消耗水体中的CO_(2)并具有碳汇功能的观点。基于前人长江干流从源头到入海口和支流2003~2007年期间4次河流悬移质泥沙的化学元素组成和矿物组成资料,分析悬移质中CaO、MgO含量和方解石、白云石含量变化特征,定量计算了这些取样点悬移质泥沙的CO_(2)总碳汇能力和非永久性、永久性碳汇能力,分析了不同碳汇能力沿程变化规律及其原因。碳汇计算结果表明:寸滩—大通河段1956~2000年期间泥沙输移过程中钙镁矿物溶蚀产生的总碳汇量、非永久性和永久性碳汇量分别为2572万t/a、1700万t/a和872万t/a。由于输沙量减少,寸滩站—大通站河段的总碳汇量、非永久性和永久性碳汇量2006~2019年期间较1956~2000年期间相应分别减少了1852万t、1224万t和872万t。三峡水库年均淤积量1.145亿t,损失总碳汇量675.6万t,相当于三峡电站减排二氧化碳8580万t的7.9%。全球河流入海年输沙量126.1亿t,以寸滩-吴淞口河段碳汇功能0.060 t/t计,总碳汇量7.57亿t相当于全球岩石风化碳汇总量10.56亿t CO_(2)的71.6%。河流泥沙输移过程中钙镁矿物溶蚀的碳汇量具有重要的作用,其溶蚀速率大于原地风化。

卵黄高磷蛋白磷酸肽在Caco-2细胞单层模型中的促钙转运作用

结合高温低压处理、胰蛋白酶和嗜热菌蛋白酶复合酶解制备具有高钙结合能力的卵黄高磷蛋白磷酸肽(Phosvitin phosphopeptides,PPP)。通过优化确定制备PPP-Ca的最佳条件为pH 9.5,多肽与钙质量比7∶1,此条件下钙螯合率达到97%,PPP-Ca在模拟胃肠道消化中显示了极高的稳定性。使用Caco-2细胞单层模型验证PPP-Ca在体外的钙转运作用,通过细胞形态、电阻值和荧光素钠透过率等验证Caco-2细胞模型,毒性实验(MTT)结果显示PPP-Ca对Caco-2细胞呈现低毒性作用。研究PPP-Ca和PPP对Caco-2细胞转运钙离子质量浓度和碱性磷酸酶(alkaline phosphatase,AKP)活性的影响,采用RT-PCR测定Calbindin D9K mRNA的相对表达量。结果表明,PPP和PPP-Ca能够显著提高AKP活性,钙转运量从(3.06±0.08)μg增到(5.66±0.62)μg,Calbindin D9K mRNA的表达量增加2倍,进而增强人体肠道中钙的转运吸收。研究结果为开发新的钙补充剂和卵黄高磷蛋白提供了科学证据。

鸡SLC基因超家族分析及其在蛋壳形成不同时期的表达特征

【目的】鉴定出在蛋壳形成过程中可能参与钙转运的溶质载体(SLC)基因超家族成员,并分析SLC基因在蛋壳形成不同时期的表达特征,为进一步探究SLC基因与蛋壳形成的相关性及揭示钙转运调控机制打下基础。【方法】基于NCBI和Ensembl数据库,检索并整理鸡SLC基因超家族全基因信息,通过ProtParam、Pfam、TBtool、NPS@:SOPMA、Euk-mPLoc 2.0及MEGA 11.0等在线软件进行生物信息学分析,并利用实时荧光定量PCR分析钙转运相关SLC基因在蛋壳形成不同时期的表达特征。【结果】鸡SLC基因超家族包括56个亚家族,分布在包括Z染色体在内的32条染色体上,其编码蛋白主要分布在内质网和细胞膜上,大多数为疏水的碱性蛋白,涵盖81种结构域,主要参与核苷酸、糖类、氨基酸、神经递质、无机离子及有机离子等物质的运输,其中与钙离子(Ca^(2+))相关的SLC亚家族基因有SLC4、SLC8、SLC9、SLC24和SLC30。SLC8和SLC24亚家族基因在进化分支上的亲缘关系很近,存在直接与Ca^(2+)转运的结构域,主要定位在细胞膜和内质网上。实时荧光定量PCR检测结果表明,控制Ca^(2+)的SLC8和SLC24基因在产蛋鸡子宫部的表达显著高于未产蛋鸡(P<0.05,下同),进一步说明二者确实参与调控Ca^(2+)跨膜运输,但各成员间分工有所不同。【结论】鸡SLC基因超家族编码产物多为疏水的碱性蛋白,含有结合多种物质的结构域,定位于细胞或多种亚细胞结构膜上,表明SLC家族蛋白成员参与多种物质的跨膜转运过程。其中,SLC8和SLC24亚家族基因在蛋壳形成过程中协同调控Ca^(2+)从内质网释放并完成跨膜运输,分泌到输卵管子宫部而参与蛋壳的形成。

乌头提取物通过调控蛋白激酶C信号通路对心力衰竭大鼠钙转运及心肌线粒体呼吸功能的影响

目的探究乌头提取物通过调控蛋白激酶C(Protein kinase C,PKC)信号通路对心力衰竭大鼠钙转运及心肌线粒体呼吸功能的影响。方法将30只雄性SD大鼠随机分为3组,假手术组9只、模型组9只和药物组9只(假手术组大鼠造模时死亡1只,造模组造模失败1只,死亡1只)。根据人临床应用剂量及大鼠换算系数折算给药剂量,药物组大鼠灌胃乌头提取液0.04 mg/kg,其余两组大鼠均灌胃等量的生理盐水干预。均连续干预28 d后,观察比较3组大鼠心功能指标[左心室收缩压(Left ventricular systolic pressure,LVSP),左心室舒张末压(Left ventricular end diastolic pressure,LVEDP);左室内压上升最大速率(LV+dp/dt_(max));左室内压下降最大速率(LV-dp/dt_(max))];RT-PCR检测心肌细胞中DAG-β、PKC-εmRNA和心肌组织中钙转运蛋白mRNA表达;检测线粒体呼吸功能;蛋白质印迹检测线粒体呼吸链复合酶Ⅰ~Ⅴ的蛋白表达。结果模型组大鼠LVSP、LV+dp/dt_(max)、LV-dp/dt_(max)及心肌钙转运蛋白RyR2、SERCA2A mRNA表达较假手术组降低,LVEDP及DAG-β、PKC-εmRNA表达较假手术组升高,差异有统计学意义(P<0.05);药物组大鼠LVSP、LV+dp/dt_(max)、LV-dp/dtma及心肌钙转运蛋白RyR2、SERCA2A mRNA表达高于模型组,LVEDP及DAG-β、PKC-εmRNA表达较模型组低,差异有统计学意义(P<0.05)。模型组大鼠态3呼吸、最大呼吸、RCR1、RCR2值及线粒体呼吸链复合酶Ⅲ、Ⅳ表达较假手术组均降低,态4呼吸较假手术组升高,差异有统计学意义(P<0.05);模型组比较,药物组大鼠态3呼吸、最大呼吸、RCR1、RCR2值及线粒体呼吸链复合酶Ⅲ、Ⅳ表达均升高,态4呼吸降低,差异有统计学意义(P<0.05)。结论乌头提取物能抑制PCK信号通路的激活,修复心室细胞钙转运,改善线粒体呼吸功能,进而修复心衰。

胜利油田化学剂对原油金属含量影响分析

选取胜利油田开采的现河原油、海洋原油和孤岛原油3种原油为研究对象,采用原子吸收光谱仪测定原油中的金属含量及油田化学剂中的钙含量,考察采油化学剂、集输化学剂对原油中主要金属含量的影响。结果表明:胜利原油金属主要以钙、镍为主;采油化学剂与集输化学剂不会影响原油镍含量,不同集输化学剂对原油中镍、钒含量没有影响,说明原油中镍、钒含量不受脱水/盐条件及采油化学剂的影响,这可能与其存在形态有关;采油化学剂与集输化学剂的加入对钙的存在形态影响较大,影响程度与原油酸值呈正比。表面活性剂类油田化学剂会促进水中钙向原油组分中转移,其中钙以环烷酸钙的形式存在。