Novel Role of Calcium-Sensitive Receptors in Chronic Hypoxia-Induced Proliferation of Pulmonary Vein Smooth Muscle Cells

Objective:Vascular remodeling due to chronic hypoxia(CH)occurs not only in the pulmonary arteries but also in the pulmonary veins.Pulmonary vascular remodeling arises from the proliferation of pulmonary vascular myocytes.However,the mechanism by which CH induces the proliferation of pulmonary vein smooth muscle cells(PVSMCs)is unknown.This study aimed to investigate the mechanism by which CH affects the proliferation of PVSMCs.Methods:PVSMCs were isolated from rat distal pulmonary veins and exposed to CH(4%O2,60h),and the expression of the calcium-sensitive receptor(CaSR)was detected by Western blotting and immunofluorescence.MTT assay was used to detect the proliferation viability of the cells,and the changes in the intracellular calcium concentration were detected by laser confocal scanning technique.Results:CaSR expression was present in rat distal PVSMCs,and CaSR protein expression was upregulated under hypoxia.The positive regulator spermine not only enhanced CH-induced CaSR upregulation but also enhanced CH-induced increase in cell viability and calcium ion concentration.The negative CaSR regulator NPS2143 not only attenuated CH-induced CaSR upregulation but also inhibited CH-induced cell viability and calcium ion concentration.Conclusion:CaSR-mediated hyperproliferation is a novel pathogenic mechanism for the development of proliferation in distal PVSMCs under CH conditions.

Activation of calcium-sensing receptors is associated with apoptosis in a model of simulated cardiomyocytes ischemia/reperfusion

Objective： Calcium-sensing receptors （CaSRs） are G-protein coupled receptors which maintain systemic calcium homeostasis and participate in hormone secretion, activation of ion channels, cell apoptosis, proliferation, and differentiation. Previous studies have shown that CaSRs induce apoptosis in isolated adult rat heart and in normal neonatal rat cardiomyocytes by G-protein-PLC-IP3 signaling transduction. However, little knowledge is presently available concerning the role of CaSRs in the apoptosis induced by ischemia and reperfusion in neonatal cardiomyocytes. Methods： Primary neonatal rat ventricular cardiomyocytes were incubated in ischemiamimetic solution for 2 h, and then re-incubated in normal culture medium for 24 h to establish a model of simu- lated ischemia/reperfusion （I/R）. Cardiomyocyte apoptosis was detected by terminal deoxynucleotidyl transferase- mediated dUTP nick end labeling （TUNEL）. The expression of CaSRs mRNA was detected by real-time reverse transcription polymerase chain reaction （RT-PCR）. In addition, the expressions of caspase-3 and Bcl-2 were analyzed by western blot. Results： The simulated I/R enhanced the expression of CaSRs and cardiomyocyte apoptosis. GdCl3, a specific activator of CaSRs, further increased the expression of CaSRs and cardiomyocyte apoptosis, along with up-regulation of caspase-3 and down-regulation of Bcl-2. Conclusion： CaSRs are associated with UR injury and apoptosis in neonatal rat ventricular cardiomyocytes via suppressing Bcl-2 and promoting caspase-3 expression.

Phenytoin-Induced Elevation of the Intracellular Calcium Concentration by Stimulation of Calcium-Sensing Receptors in Gingival Fibroblasts

Background:The mechanism concerning gingival overgrowth as a side effect of phenytoin, a therapeutic drug for epilepsy has been still unclear. As one of mechanisms, by measuring the intracellular calcium concentration ([Ca2+]i) of the gingival fibroblasts, it has been advocated that there is relationship between gingival overgrowth and phenytoin-induced alterations in the [Ca2+]i in gingival fibroblasts. To confirm that phenytoin elevates the [Ca2+]i, and if so, to find out its mode of action. Methods: The [Ca2+]i was measured with the Ca2+-sensitive fluorescent dye fura-2/AM. Cells were soaked in a flexiperm chamber and perfused by a saline. Drugs at appropriate concentrations were added to the perfusate. Results: Phenytoin concentration-dependently elevated the [Ca2+]i. NPS2390, a calcium-sensing receptor (CaSR) blocker, significantly suppressed the phenytoin-induced [Ca2+]i elevation. U73122, a phospholipase C (PLC) inhibitor, inihibited the phenytoin-induced [Ca2+]i elevation. TMB-8, a blocker of inositol triphophate (IP3) receptors in ER, significantly depressed the phenytoin-induced [Ca2+]i elevation. m-3M3FBS, a PLC activator, enhanced the phenytoin-induced [Ca2+]i elevation. From the findings obtained, it is discussed as follows: The Ca2+-free saline and NPS2390, a CaSR antagonist, inhibited the phenytoin-induced [Ca2+]i rise;These results indicate that CaSRs exist in gingival fibroblasts and that CaSRs are involved in the phenytoin-induced [Ca2+]i rise;U73122 and TMB-8 depressed the phenytoin-induced [Ca2+]i elevation and furthermore, m-3M3FBS enhanced the phenytoin-induced [Ca2+]i elevation, showing that the Ca2+ release from the ER is involved in the phenytoin-induced [Ca2+]i elevation. Conclusion: We have concluded that phenytoin elevates the [Ca2+]i by activating CaSRs and enhancing the Ca2+ release from the Ca2+ stores in gingival fibroblasts.

Altered expression of stromal interaction molecule(STIM)-calcium release-activated calcium channel protein(ORAI) and inositol1,4,5-trisphosphate receptors(IP_3Rs)in cancer:will they become a new battlefield for oncotherapy?

The stromal interaction molecule(STIM)-calcium release-activated calcium channel protein(ORAI) and inositol1,4,5-trisphosphate receptors(IP_3Rs) play pivotal roles in the modulation of Ca^(2+)-regulated pathways from gene transcription to cell apoptosis by driving calcium-dependent signaling processes.Increasing evidence has implicated the dysregulation of STIM-ORAI and IP_3Rs in tumorigenesis and tumor progression.By controlling the activities,structure,and/or expression levels of these Ca^(2+)-transporting proteins,malignant cancer cells can hijack them to drive essential biological functions for tumor development.However,the molecular mechanisms underlying the participation of STIM-ORAI and IP_3Rs in the biological behavior of cancer remain elusive.In this review,we summarize recent advances regarding STIM-ORAI and IP_3Rs and discuss how they promote cell proliferation,apoptosis evasion,and cell migration through temporal and spatial rearrangements in certain types of malignant cells.An understanding of the essential roles of STIM-ORAI and IP_3Rs may provide new pharmacologic targets that achieve a better therapeutic effect by inhibiting their actions in key intracellular signaling pathways.

Association between calcium sensing receptor gene polymorphisms and chronic pancreatitis in a US population:Role of serine protease inhibitor Kazal 1type and alcohol

AIM： To test the hypothesis that calcium sensing receptor （CASR） polymorphisms are associated with chronic pancreatitis （CP）, and to determine whether serine protease inhibitor Kazal 1type （SPINK1） N34S or alcohol are necessary co-factors in its etiology. METHODS： Initially, 115 subjects with pancreatitis and 66 controls were evaluated, of whom 57 patients and 21 controls were predetermined to carry the high-risk SPINK1 N34S polymorphism. We sequenced CASR gene exons 2, 3, 4, 5 and 7, areas containing the majority of reported polymorphisms and novel mutations. Based on the initial results, we added 223 patients and 239 controls to analyze three common nonsynonymous single nucleotide polymorphisms （SNPs） in exon 7 （A986S, R990G, and Q1011E）. RESULTS： The CASR exon 7 R990G polyrnorphism was significantly associated with CP （OR, 2.01; 95% CI, 1.12-3.59; P = 0.015）. The association between CASR R990G and CP was stronger in subjects who reported moderate or heavy alcohol consumption （OR, 3.12; 95% CI, 1.14-9.13; P = 0.018）. There was no association between the various CASR genotypes and SPINK1 N34S in pancreatitis. None of the novel CASR polymorphisms reported from Germany and India was detected. CONCLUSION： Our United States-based study confirmed an association of CASR and CP and for the first time demonstrated that CASR R990G is a significant risk factor for CP. We also conclude that the risk of CP with CASR R990G is increased in subjects with moderate to heavy alcohol consumption.

Effects of gamma-aminobutyric acid receptors on muscarinic receptor-mediated free calcium ion levels in the facial nucleus following facial nerve injury

Muscarinic receptors and nicotine receptors can increase free calcium ion levels in the facial nucleus via different channels following facial nerve injury. In addition, γ-aminobutyric acid A （GABAA） receptors have been shown to negatively regulate free calcium ion levels in the facial nucleus by inhibiting nicotine receptors. The present study investigated the influence of GABAA, γ-aminobutyric acid B （GABAB） and C （GABAc） receptors on muscarinic receptors in rats with facial nerve injury by confocal laser microscopy. GABAA and GABAB receptors exhibited significant dose-dependent inhibitory effects on increased muscarinic receptor-mediated free calcium ion levels following facial nerve injury. Results showed that GABAA and GABAB receptors negatively regulate muscarinic receptor effects and interplay with cholinergic receptors to regulate free calcium ion levels for facial neural regeneration.

Potential physiological and pathological roles for axonal ryanodine receptors

Clinical disability following trauma or disease to the spinal cord often involves the loss of vital white matter elements including axons and glia.Although excessive Cais an established driver of axonal degeneration,therapeutically targeting externally sourced Cato date has had limited success in both basic and clinical studies.Contributing factors that may underlie this limited success include the complexity of the many potential sources of Caentry and the discovery that axons also contain substantial amounts of stored Cathat if inappropriately released could contribute to axonal demise.Axonal Castorage is largely accomplished by the axoplasmic reticulum that is part of a continuous network of the endoplasmic reticulum that provides a major sink and source of intracellular Cafrom the tips of dendrites to axonal terminals.This“neuron-within-a-neuron”is positioned to rapidly respond to diverse external and internal stimuli by amplifying cytosolic Calevels and generating short and long distance regenerative Cawaves through Cainduced Carelease.This review provides a glimpse into the molecular machinery that has been implicated in regulating ryanodine receptor mediated Carelease in axons and how dysregulation and/or overstimulation of these internodal axonal signaling nanocomplexes may directly contribute to Ca-dependent axonal demise.Neuronal ryanodine receptors expressed in dendrites,soma,and axonal terminals have been implicated in synaptic transmission and synaptic plasticity,but a physiological role for internodal localized ryanodine receptors remains largely obscure.Plausible physiological roles for internodal ryanodine receptors and such an elaborate internodal binary membrane signaling network in axons will also be discussed.

The glutamate receptor gene GLR3.3:A bridge of calciummediated root development in poplar

Poplar is one of the fastest-growing temperate trees in the world and is widely used in ornamental horticulture for shade.The root is essential for tree growth and development and its utilization potential is huge.Calcium(Ca),as a signaling molecule,is involved in the regulation of plant root development.However,the detailed underlying regulatory mechanism is elusive.In this study,we analyzed the morphological and transcriptomic variations of 84K poplar(Populus alba×P.glandulosa)in response to different calcium concentrations and found that low Ca^(2+)(1 mmol·L^(-1))promoted lateral root development,while deficiency(0.1 mmol·L^(-1)Ca^(2+))inhibited lateral root development.Co-expression analysis showed that Ca^(2+)channel glutamate receptors(GLRs)were present in various modules with significance for root development.Two GLR paralogous genes,PagGLR3.3a and Pag GLR3.3b,were mainly expressed in roots and up-regulated under Ca^(2+)deficiency.The CRISPR/Cas9-mediated signal gene(crispr-PagGLR3.3a,PagGLR3.3b)and double gene(crispr-PagGLR3.3ab)mutants presented more and longer lateral roots.Anatomical analysis showed that crispr-PagGLR3.3ab plants had more xylem cells and promoted the development of secondary vascular tissues.Further transcriptomic analysis suggested that knockout of PagGLR3.3a and PagGLR3.3b led to the up-regulation of several genes related to protein phosphorylation,auxin efflux,lignin and hemicellulose biosynthesis as well as transcriptional regulation,which might contribute to lateral root growth.This study not only provides novel insight into how the Ca^(2+)channels mediated root growth and development in trees,but also provides a directive breeding of new poplar species for biofuel and bioenergy production.

An increase in intracelluar free calcium ions modulated by cholinergic receptors in rat facial nucleus

Background Ca^2＋ in the central nervous system plays important roles in brain physiology, including neuronal survival and regeneration in rats with injured facial motoneurons. The present research was to study the modulations of intracellular free Ca^2＋ concentrations by cholinergic receptors in rat facial nucleus, and the mechanisms of the modulations. Methods The fluorescence intensity of facial nucleus in Fluo-3 AM loaded acute brainstem slices was detected by applying intracellular free Ca^2＋ measurement technique via confocal laser scanning microscope. The changes of fluorescence intensity of facial nucleus indicate the average changes of intracellular free Ca^2＋ levels of the neurons. Results Acetylcholine was effective at increasing the fluorescence intensity of facial nucleus. Muscarine chloride induced a marked increase of fluorescence intensity in a concentration dependent fashion. The enhancement of fluorescence intensity by muscarine chloride was significantly reduced by thapsigargin （depletor of intracellular Ca^2＋ store; P 〈0.01）, rather than Ca^2＋ free artifical cerebrospinal fluid or EGTA （free Ca^2＋ chelator; P〉0.05）. And the increase of fluorescence intensity was also significantly inhibited by pirenzepine （M1 subtype selective antagonist; P 〈0.01） and 4-DAMP （M3 subtype selective antagonist; P 〈0.01）. In addition, fluorescence intensity was markedly increased by nicotine. The enhancement of fluorescence intensity by nicotine was significantly reduced by EGTA, nifedipine （L-type voltage-gated Ca^2＋ channel blocker）, dihydro-β-erythroidine （α4β2 subtype selective antagonist）, and in Ca^2＋ free artificial cerebrospinal fluid （P 〈0.01）, but not in the presence of mibefradil （M-type voltage-gated Ca^2＋ channel blocker） or thapsigargin （P〉0.05）. Conclusions The data provide the evidence that muscarinic receptors may induce the increase of intracellular free Ca^2＋ levels through the Ca^2＋ release of intracellular Ca^2＋ stores, in a manner related to M1 and M3 subtypes of muscarinic receptors in rat facial nucleus. Nicotine may increase intracellular free Ca^2＋ concentrations via the influx of extracellular Ca^2＋ mainly across L-type voltacle-clated Ca^2＋ channels, in a manner related to the α4β2 subtype of nicotinic receptors.

Formaldehyde increases intracellular calcium concentration in primary cultured hippocampal neurons partly through NMDA receptors and T-type calcium channels

Objective Formaldehyde at high concentrations is a contributor to air pollution. It is also an endogenous metabolic product in cells, and when beyond physiological concentrations, has pathological effects on neurons. Formaldehyde induces mis-folding and aggregation of neuronal tau protein, hippocampal neuronal apoptosis, cognitive impairment and loss of memory functions, as well as excitation of peripheral nociceptive neurons in cancer pain models. Intracellular calcium （[Ca2＋]i） is an important intracellular messenger, and plays a key role in many pathological processes. The present study aimed to investigate the effect of formaldehyde on [Ca2＋]i and the possible involvement of N-methyl-D-aspartate receptors （NMDARs） and T-type Ca2＋ channels on the cell membrane. Methods Using primary cultured hippocampal neurons as a model, changes of [Ca2＋]i in the presence of formaldehyde at a low concentration were detected by confocal laser scanning microscopy. Results Formaldehyde at 1 mmol/L approximately doubled [Ca2＋]i. （2R）-amino-5-phosphonopentanoate （AP5, 25 μmol/L, an NMDAR antagonist） and mibefradil （MIB, 1 μmol/L, a T-type Ca2＋ channel blocker）, given 5 min after formaldehyde perfusion, each partly inhibited the formaldehyde-induced increase of [Ca：＋]i, and this inhibitory effect was reinforced by combined application of AP5 and MIB. When applied 3 min before formaldehyde perfusion, AP5 （even at 50μmol/L） did not inhibit the formaldehyde-induced increase of [Ca2＋]i, but MIB （1 μmol/L） significantly inhibited this increase by 70%. Conclusion These results suggest that formaldehyde at a low concentration increases [Ca2＋]i in cultured hippocampal neurons; NMDARs and T-type Ca2＋ channels may be involved in this process.

High-voltage-activated calcium current and its modulation by dopamine D_4 and pituitary adenylate cyclase activating polypeptide receptors in cerebellar granule cells

小脑颗粒细胞是离体单细胞水平中枢神经元生物学研究的理想模型．随着细胞发育，其ＨＶＡ钙电流的基因表达、门控性质和药理学特征发生明显变化，提示钙电流涉及颗粒细胞的成熟和兴奋性的产生．多巴胺通过激活膜上的Ｄ４受体抑制Ｌ型钙电流，这种抑制效应并不需要腺苷酸环化酶系统的参与．功能性Ｄ４受体的首次发现不仅有助于研究抗精神病药，更揭示了多巴胺也参与小脑神经元之间的兴奋传递过程．ＰＡＣＡＰ则通过激活其Ｉ受体增加钙内流和钙库的释放使胞浆内钙浓度提高，ＰＡＣＡＰ的钙通道刺激效应可能需要ＰＬＣ系统的介导，并与颗粒细胞的成熟和成活有关．

Antagonizing amyloid-β/calcium-sensing receptor signaling in human astrocytes and neurons: a key to halt Alzheimer's disease progression?

Astrocytes＇ roles in late-onset Alzheimer＇s disease （LOAD） promotion are important, since they survive soluble or fibrillar amyloid-β peptides （Aβs） neurotoxic effects, undergo alterations of intracellular and intercellular Ca2＋ signaling and gliotransmitters release via the Aβ/a7-nAChR （αT-nicotinic acetylcholine receptor） signaling, and overproduce/oversecrete newly synthesized Aβ42 oligomers, NO, and VEGF-A via the Aβ/CaSR （calcium-sensing receptor） signaling. Recently, it was suggested that the NMDAR （N-methyl-D-aspartate receptor） inhibitor nitromemantine would block the synapse-destroying effects of Aβ/α7-nAChR signaling. Yet, this and the progressive extracellular accrual and spreading of Aβ42 oligomers would be stopped well upstream by NPS 2143, an allosteric CaSR antagonist （calcilytic）.

Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination

During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.

Molecular regulation of calcium-sensing receptor(CaSR)-mediated signaling

Calcium-sensing receptor(CaSR),a family C G-protein-coupled receptor,plays a crucial role in regulating calcium homeostasis by sensing small concentration changes of extracellular Ca^(2+),Mg^(2+),amino acids(e.g.,L-Trp and L-Phe),small peptides,anions(e.g.,HCO_(3)^(-)and PO_(4)^(3-)),and pH.CaSR-mediated intracellular Ca^(2+)signaling regulates a diverse set of cellular processes including gene transcription,cell proliferation,differentiation,apoptosis,muscle contraction,and neuronal transmission.Dysfunction of CaSR with mutations results in diseases such as autosomal dominant hypocalcemia,familial hypocalciuric hypercalcemia,and neonatal severe hyperparathyroidism.CaSR also influences calciotropic disorders,such as osteoporosis,and noncalciotropic disorders,such as cancer,Alzheimer's disease,and pulmonary arterial hypertension.This study first reviews recent advances in biochemical and structural determination of the framework of CaSR and its interaction sites with natural ligands,as well as exogenous positive allosteric modulators and negative allosteric modulators.The establishment of the first CaSR protein-protein interactome network revealed 94 novel players involved in protein processing in endoplasmic reticulum,trafficking,cell surface expression,endocytosis,degradation,and signaling pathways.The roles of these proteins in Ca^(2+)-dependent cellular physiological processes and in CaSR-dependent cellular signaling provide new insights into the molecular basis of diseases caused by CaSR mutations and dysregulated CaSR activity caused by its protein interactors and facilitate the design of therapeutic agents that target CaSR and other family C G-protein-coupled receptors.

Calhex231通过细胞焦亡改善大鼠心肌梗死面积及心肌纤维化

目的研究钙敏感受体(CaSR)负性变构调节剂Calhex231是否能改善大鼠的心肌梗死(MI)面积和心肌纤维化。方法健康Wistar大鼠随机分为3组:sham组、MI组和MI+Calhex231组。TTC染色评估MI面积和坏死情况。Masson染色、免疫组织化学及电镜检查心肌纤维化、Ⅲ型胶原蛋白及成纤维细胞胶原合成情况。免疫荧光和Western blot检测CaSR表达变化。Western blot检测含NOD样受体热蛋白结构域相关蛋白3(NLRP3)、胱天蛋白酶-1(Casp-1)、gasdermin D(GSDMD)、GSDMD N-末端结构域(NT-GSDMD)和白细胞介素-1β(IL-1β)的蛋白表达变化。并采用免疫组织化学法评估NT-GSDMD和IL-1β的表达情况。结果与sham组相比,MI组大鼠MI面积和纤维化明显增加,心肌组织Ⅲ型胶原蛋白沉积和成纤维细胞胶原合成明显增加,而且CaSR、NLRP3、Casp-1、GSDMD、NT-GSDMD和IL-1β表达水平也明显升高。进一步免疫组织化学染色确认了NT-GSDMD和IL-1β表达增加。MI+Calhex231组与MI组相比较,Calhex231可抑制上述改变。结论Calhex231可通过CaSR抑制细胞焦亡和Ⅲ型胶原蛋白沉积,改善大鼠MI面积和心肌纤维化,有助于Calhex231在心肌纤维化疾病中临床转化。

TRPV4在眼病理生理功能中的研究进展

瞬时受体电位香草醛受体4(TRPV4)是一种非选择性阳离子通道,负责感知细胞肿胀、温度、机械牵张、剪切应力和渗透压的变化,通过调节跨膜钙信号进而影响基因表达、细胞形态和细胞骨架等构建。TRPV4在全身广泛表达。在眼内,TRPV4在角膜、晶状体、睫状体、小梁网和视网膜等组织均有功能性表达。本文就TRPV4在眼内各个组织中的表达及生理病理功能方面进行阐述。随着TRPV4在眼部病理生理功能中的深入研究,TRPV4在角膜损伤修复、青光眼及视网膜血管生成方面可能成为潜在的新兴药物靶点,但仍需进一步的深入研究。

Role of nucleic acid sensing in the pathogenesis of type 1 diabetes

During infections,nucleic acids of pathogens are also engaged in recognition via several exogenous and cytosolic pattern recognition receptors,such as the toll-like receptors,retinoic acid inducible gene-I-like receptors,and nucleotide-binding and oligomerization domain-like receptors.The binding of the pathogen-derived nucleic acids to their corresponding sensors initiates certain downstream signaling cascades culminating in the release of type-I interferons(IFNs),especially IFN-αand other cytokines to induce proinflammatory responses towards invading pathogens leading to their clearance from the host.Although these sensors are hardwired to recognize pathogen associated molecular patterns,like viral and bacterial nucleic acids,under unusual physiological conditions,such as excessive cellular stress and increased apoptosis,endogenous self-nucleic acids like DNA,RNA,and mitochondrial DNA are also released.The presence of these self-nucleic acids in extranuclear compartments or extracellular spaces or their association with certain proteins sometimes leads to the failure of discriminating mechanisms of nucleic acid sensors leading to proinflammatory responses as seen in autoimmune disorders,like systemic lupus erythematosus,psoriasis and to some extent in type 1 diabetes(T1D).This review discusses the involvement of various nucleic acid sensors in autoimmunity and discusses how aberrant recognition of self-nucleic acids by their sensors activates the innate immune responses during the pathogenesis of T1D.

血清S100钙结合蛋白A12、可溶性晚期糖基化终末产物受体水平与维持性血液透析患者骨质疏松的相关性分析

目的探讨维持性血液透析(MHD)患者血清S100钙结合蛋白A12(S100A12)、可溶性晚期糖基化终末产物受体(sRAGE)的水平变化及与骨质疏松的关系。方法选取2020年1月~2022年6月在本院血透室治疗的MHD患者110例,根据T值将其分为骨质疏松组(42例,T值≤-2.5 g/cm2)及非骨质疏松组(68例,T值>-2.5 g/cm2),同期选取在本院健康体检者50例为对照组。收集所有受试者的一般资料(性别、年龄、BMI、透析龄)及临床资料并进行组间比较。相关性分析采用Pearson相关分析。采用受试者工作特征(ROC)曲线评估血清sRAGE和S100A12水平对MHD患者骨质疏松的预测价值。采用多重线性回归分析探讨MHD患者发生骨质疏松的影响因素。结果与对照组相比,非骨质疏松组与骨质疏松组患者血钙、血磷、骨密度、sRAGE水平均降低,全段甲状旁腺激素(iPTH)、尿素氮(BUN)、血肌酐(SCr)、白蛋白(Alb)、S100A12水平均升高(P<0.05)。与非骨质疏松组相比,骨质疏松组患者血清iPTH、S100A12水平均升高,血磷、骨密度、sRAGE水平均降低(P<0.05)。Pearson相关分析结果显示,MHD患者血清sRAGE与S100A12表达呈负相关;血清sRAGE与血磷、骨密度均呈正相关,与iPTH呈负相关;血清S100A12与血磷、骨密度均呈负相关,与iPTH呈正相关(P<0.05)。ROC曲线分析结果显示,血清S100A12、sRAGE联合预测MHD患者骨质疏松的ROC曲线下面积(AUC)、特异度均高于二者单独预测。多重线性回归分析结果显示,MHD患者S100A12、sRAGE、iPTH均与骨质疏松发生有关(P<0.05)。结论MHD患者骨质疏松发生与sRAGE、S100A12密切相关,联合检测二者可作为诊断MHD患者骨质疏松发生的指标。

结肠癌病人血清S100钙结合蛋白A12、可溶性晚期糖基化终产物受体水平与肠道菌群失调及化疗效果的关系

目的探讨结肠癌病人血清S100钙结合蛋白A12(S100A12)、可溶性晚期糖基化终产物受体(sRAGE)水平与肠道菌群失调及化疗效果的相关性。方法选择2020年12月至2021年12月黄河水利委员会黄河中心医院收治的116例中、晚期结肠癌病人作为结肠癌组,另选取在该院同期健康体检人员120例作为对照组。采用酶联免疫吸附测定(ELISA)检测血清S100A12、sRAGE水平,检测病人肠道菌群,并对病人化疗后进行随访,Pearson法分析结肠癌病人血清S100A12、sRAGE水平与菌群失调相关性,受试者操作特征曲线(ROC曲线)分析化疗前血清S100A12、sRAGE水平对结肠癌化疗效果的诊断价值。结果与对照组比较,结肠癌组病人化疗前血清S100A12、sRAGE水平显著升高(P<0.05)。与化疗前菌群正常组[(265.34±45.78)μg/L、(381.54±36.75)ng/L]比较,菌群失调Ⅰ度组[(301.52±56.95)μg/L、(440.63±48.71)ng/L]、菌群失调Ⅱ度组[(339.29±52.35)μg/L、(432.75±49.20)ng/L]病人血清S100A12、sRAGE水平显著升高(P<0.05);与菌群失调Ⅰ度组比较,菌群失调Ⅱ度组病人血清S100A12、sRAGE水平显著升高(P<0.05)。相关性分析显示,结肠癌病人血清S100A12、sRAGE水平与大肠杆菌、粪肠球菌数量呈正相关(P<0.05),与双歧杆菌、乳酸杆菌数量呈负相关(P<0.05)。与化疗前比较,结肠癌病人化疗后血清S100A12、sRAGE水平显著降低(P<0.05);与化疗缓解组[(272.33±55.36)μg/L、(403.24±40.54)ng/L]比较,化疗无效组[(330.09±42.64)μg/L、(482.85±43.61)ng/L]病人化疗前血清S100A12、sRAGE水平显著较高(P<0.05)。血清S100A12、sRAGE联合诊断结肠癌化疗无效的曲线下面积(AUC)为0.91[95%CI:(0.84,0.96),P<0.001],灵敏度为86.05%,特异度为80.82%。结论结肠癌病人血清S100A12、sRAGE升高,与肠道菌群失调及化疗效果有关,对化疗疗效评估与预后评价有一定指导意义。

IP3R2及RYR2介导Ca^(2+)信号在急性一氧化碳中毒迟发性脑病小鼠模型中的表达

背景:研究发现星形胶质细胞中Ca^(2+)的表达与认知功能密切相关,目前由1,4,5-三磷酸肌醇受体(Inositol 1,4,5-trisphosphate receptors,IP3Rs)2、兰尼碱受体(ryanodine receptors,RYRs)2受体及其调控的Ca^(2+)信号通路已经成为认知障碍相关疾病研究的热点。目的:研究急性一氧化碳中毒迟发性脑病动物模型中,海马组织内星形胶质细胞和IP3R2、RYR2介导的Ca^(2+)信号的表达情况,探索急性一氧化碳中毒迟发性脑病可能的发病机制。方法:Morris水迷宫实验筛选认知功能合格的C57BL小鼠随机分为对照组、实验组,实验组小鼠采用静态吸入一氧化碳建立急性一氧化碳中毒迟发性脑病模型,对照组小鼠吸入等量空气。造模后第21天,利用Morris水迷宫、苏木精-伊红染色、Western blot、免疫荧光双标法、Ca^(2+)荧光探针检测中毒小鼠行为学及神经元改变、星形胶质细胞特异性标记物胶质纤维酸性蛋白及IP3R2、RYR2受体、星形胶质细胞内Ca^(2+)浓度变化。结果与结论:①Morris水迷宫实验发现与对照组相比,实验组小鼠逃避潜伏期明显延长(P<0.05);②苏木精-伊红染色表明实验组小鼠海马锥体细胞数减少、细胞结构紊乱、细胞核碎裂伴溶解;③免疫荧光检测表明海马区IP3R2、RYR2分别和胶质纤维酸性蛋白存在共表达,且实验组海马区IP3R2、RYR2和胶质纤维酸性蛋白表达均上调(P<0.05);④Western blot检测显示实验组海马区IP3R2、RYR2及胶质纤维酸性蛋白的蛋白表达均增多(P<0.05);⑤Ca^(2+)荧光探针法检测表明实验组小鼠海马区星形胶质细胞内Ca^(2+)浓度明显升高(P<0.05);⑥结果说明,星形胶质细胞可能通过介导IP3R2、RYR2受体影响Ca^(2+)信号,进而使一氧化碳中毒的小鼠认知功能受损,最终导致急性一氧化碳中毒迟发性脑病发生。