Imbalance Of Calcium Homeostasis Research Articles

Serum SERCA2a levels in heart failure patients are associated with adverse events after discharge.

Calcium homeostasis imbalance is one of the important pathological mechanisms in heart failure. Sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a), a calcium ATPase on the sarcoplasmic reticulum in cardiac myocytes, is a myocardial systolic-diastolic Ca2 + homeostasis regulating enzyme that is not only involved in cardiac diastole but also indirectly affects cardiac myocyte contraction. SERCA2a expression was found to be decreased in myocardial tissue in heart failure, however, there are few reports on serum SERCA2a expression in patients with heart failure, and this study was designed to investigate whether serum SERCA2a levels are associated with the occurrence of adverse events after discharge in patients hospitalized with heart failure. Patients with heart failure hospitalized in the cardiovascular department of the Second Affiliated Hospital of Guangdong Medical University, China, from July 2018 to July 2019 were included in this study, and serum SERCA2a concentrations were measured; each enrolled patient was followed up by telephone after 6 months (6 ± 1 months) for general post-discharge patient status. The correlation between serum SERCA2a levels and the occurrence of adverse events (death or readmission due to heart failure) after hospital discharge was assessed using multiple analysis and trend analysis. Seventy-one patients with heart failure were finally included in this study, of whom 38 (53.5%) were men and 33 (46.5%) were women (All were postmenopausal women). Multiple analysis revealed no correlation between serum SERCA2a levels and the occurrence of adverse events in the total study population and in male patients, but serum SERCA2a levels were associated with the occurrence of adverse outcome events after hospital discharge in female patients (OR = 1.02, P = .047). Further analysis using a trend analysis yielded a 4.0% increase in the risk of adverse outcomes after hospital discharge for each unit increase in SERCA2a in female patients (OR = 1.04; P = .02), while no significant difference was seen in men. This study suggests that serum SERCA2a levels at admission are associated with the occurrence of post-discharge adverse events in postmenopausal female patients hospitalized with heart failure.

Thiamine-modified metabolic reprogramming of human pluripotent stem cell-derived cardiomyocyte under space microgravity

During spaceflight, the cardiovascular system undergoes remarkable adaptation to microgravity and faces the risk of cardiac remodeling. Therefore, the effects and mechanisms of microgravity on cardiac morphology, physiology, metabolism, and cellular biology need to be further investigated. Since China started constructing the China Space Station (CSS) in 2021, we have taken advantage of the Shenzhou-13 capsule to send human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) to the Tianhe core module of the CSS. In this study, hPSC-CMs subjected to space microgravity showed decreased beating rate and abnormal intracellular calcium cycling. Metabolomic and transcriptomic analyses revealed a battery of metabolic remodeling of hPSC-CMs in spaceflight, especially thiamine metabolism. The microgravity condition blocked the thiamine intake in hPSC-CMs. The decline of thiamine utilization under microgravity or by its antagonistic analog amprolium affected the process of the tricarboxylic acid cycle. It decreased ATP production, which led to cytoskeletal remodeling and calcium homeostasis imbalance in hPSC-CMs. More importantly, in vitro and in vivo studies suggest that thiamine supplementation could reverse the adaptive changes induced by simulated microgravity. This study represents the first astrobiological study on the China Space Station and lays a solid foundation for further aerospace biomedical research. These data indicate that intervention of thiamine-modified metabolic reprogramming in human cardiomyocytes during spaceflight might be a feasible countermeasure against microgravity.

The Diverse Roles of Reactive Astrocytes in the Pathogenesis of Amyotrophic Lateral Sclerosis.

Astrocytes displaying reactive phenotypes are characterized by their ability to remodel morphologically, molecularly, and functionally in response to pathological stimuli. This process results in the loss of their typical astrocyte functions and the acquisition of neurotoxic or neuroprotective roles. A growing body of research indicates that these reactive astrocytes play a pivotal role in the pathogenesis of amyotrophic lateral sclerosis (ALS), involving calcium homeostasis imbalance, mitochondrial dysfunction, abnormal lipid and lactate metabolism, glutamate excitotoxicity, etc. This review summarizes the characteristics of reactive astrocytes, their role in the pathogenesis of ALS, and recent advancements in astrocyte-targeting strategies.

Evaluating the capability of soybean peptides as calcium ion carriers: a study through sequence analysis and molecular dynamics simulations.

Calcium homeostasis imbalance in the body can lead to a variety of chronic diseases. Supplement efficiency is essential. Peptide calcium chelate, a fourth-generation calcium supplement, offers easy absorption and minimal side effects. Its effectiveness relies on peptide's calcium binding capacity. However, research on amino acid sequences in peptides with high calcium binding capacity (HCBC) is limited, affecting the efficient identification of such peptides. This study used soybean peptides (SP), separated and purified by gel chromatography, to obtain HCBC peptide (137.45 μg mg-1) and normal peptide (≤95.78 μg mg-1). Mass spectrometry identified the sequences of these peptides, and an analysis of the positional distribution of characteristic amino acids followed. Two HCBC peptides with sequences GGDLVS (271.55 μg mg-1) and YEGVIL (272.54 μg mg-1) were discovered. Molecular dynamics showed that when either aspartic acid is located near the N-terminal's middle, or glutamic acid is near the end, or in cases of continuous Asp or Glu, the binding speed, probability, and strength between the peptide and calcium ions are superior compared to those at other locations. The study's goal was to clarify how the positions of characteristic amino acids in peptides affect calcium binding, aiding in developing peptide calcium chelates as a novel calcium supplement.

Chronic activation of the small-conductance, calcium-activated potassium channel precipitates age-dependent depressive-like behavior and cognitive deficits and reduces klotho concentration.

Depression is a common mood disorder with a multifaceted, complex pathophysiology. An abnormal level of corticosteroids in the brain can cause structural change in the hippocampus. It may cause an imbalance in calcium homeostasis leading to functional impairment in the activity of the voltage-insensitive, small conductance, calcium-activated potassium channel (SKC). Deficit in the longevity protein klotho is also implicated in stress-induced depression. We ascertained whether chronic activation of SKCs can cause age-dependent depressive-like behavior and cognitive deficits, accompanied by disturbances in klotho concentration. We tested the effect of repeated activation of SKCs by the potent SKC agonist, 1-EBIO (1.0 mg/kg, IP, once daily for 15 days) in young (3 months) and mid-life (12 months) male BALB/c mice. We conducted a battery of behavioral tests to investigate depressive-like behavior and cognitive functions. Then, we used an enzyme-linked immunosorbent assay (ELISA) on brain homogenates to determine the change in total klotho concentration in the prefrontal cortex, hippocampus, and dorsal raphe. We found that chronic 1-EBIO treatment decreased locomotor activity, sucrose preference, and alternation index in an age-dependent manner. The drug does not affect stress-coping behavior in the forced swim test. The behavioral deficits were accompanied by a significant decrease in total klotho concentration in the hippocampus but not in the prefrontal cortex or dorsal raphe, observed in an age-dependent manner. Based on these results, we surmise that chronic activation of SKCs results in concurrent cognitive and depressive-like phenotypes in mid-aged mice. Therefore, this could represent a putative therapeutic target for age-related psycho-affective disorders.

Trpc6 knockout protects against renal fibrosis by restraining the CN‑NFAT2 signaling pathway in T2DM mice.

Diabetic kidney disease (DKD), one of the common complications of type‑2 diabetes mellitus (T2DM), has become the principal cause of end‑stage kidney disease. Transient receptor potential channel 6 (TRPC6), one of non‑selective cation channels with significant calcium‑permeability, is associated with renal fibrosis. However, the mechanism of TRPC6 in T2DM‑induced renal fibrosis is still not entirely understood. The present study explored the potential mechanism of Trpc6 knockout in T2DM‑induced renal fibrosis in Trpc6‑/‑ mice. The results showed that Trpc6 knockout inhibited the loss of body weight and the increase of fasting blood glucose (FBG) and significantly improved renal dysfunction and glomerular fibrosis in T2DM mice. The present study also indicated that Trpc6 knockout significantly lowered the expression of phosphorylated (p‑)SMAD2/3, TGF‑β, calcineurin (CN), nuclear factor of activated T‑cell (NFAT)2 and Nod‑like receptor (NLR) 3 inflammasome‑associated proteins. Calcium imaging results revealed that Trpc6 knockdown could decrease the levels of [Ca2+]i and inhibited calcium homeostasis imbalance. Moreover, it was found that knockout of Trpc6 had no significant influence on lipid disposition and reactive oxygen species generation in the kidney cortex. The present study suggested that knockout of Trpc6 may alleviate glomerular fibrosis and delay DKD progression by reducing [Ca2+]i overload and inhibiting the CN‑NFAT2 pathway in T2DM mice.

Transcriptomic Landscape of Circulating Extracellular Vesicles in Heart Transplant Ischemia-Reperfusion.

Ischemia-reperfusion injury (IRI) is an inevitable event during heart transplantation, which is known to exacerbate damage to the allograft. However, the precise mechanisms underlying IRI remain incompletely understood. Here, we profiled the whole transcriptome of plasma extracellular vesicles (EVs) by RNA sequencing from 41 heart transplant recipients immediately before and at 12 h after transplant reperfusion. We found that the expression of 1317 protein-coding genes in plasma EVs was changed at 12 h after reperfusion. Upregulated genes of plasma EVs were related to metabolism and immune activation, while downregulated genes were related to cell survival and extracellular matrix organization. In addition, we performed correlation analyses between EV transcriptome and intensity of graft IRI (i.e., cardiomyocyte injury), as well as EV transcriptome and primary graft dysfunction, as well as any biopsy-proven acute rejection after heart transplantation. We ultimately revealed that at 12 h after reperfusion, 4 plasma EV genes (ITPKA, DDIT4L, CD19, and CYP4A11) correlated with both cardiomyocyte injury and primary graft dysfunction, suggesting that EVs are sensitive indicators of reperfusion injury reflecting lipid metabolism-induced stress and imbalance in calcium homeostasis. In conclusion, we show that profiling plasma EV gene expression may enlighten the mechanisms of heart transplant IRI.

Ahf-Caltide, a Novel Polypeptide Derived from Calpastatin, Protects against Oxidative Stress Injury by Stabilizing the Expression of CaV1.2 Calcium Channel.

Reperfusion after ischemia would cause massive myocardial injury, which leads to oxidative stress (OS). Calcium homeostasis imbalance plays an essential role in myocardial OS injury. CaV1.2 calcium channel mediates calcium influx into cardiomyocytes, and its activity is modulated by a region of calpastatin (CAST) domain L, CSL54-64. In this study, the effect of Ahf-caltide, derived from CSL54-64, on myocardial OS injury was investigated. Ahf-caltide decreased the levels of LDH, MDA and ROS and increased heart rate, coronary flow, cell survival and SOD activity during OS. In addition, Ahf-caltide permeated into H9c2 cells and increased CaV1.2, CaVβ2 and CAST levels by inhibiting protein degradation. At different Ca2+ concentrations (25 nM, 10 μM, 1 mM), the binding of CSL to the IQ motif in the C terminus of the CaV1.2 channel was increased in a H2O2 concentration-dependent manner. CSL54-64 was predicted to be responsible for the binding of CSL to CaV1.2. In conclusion, Ahf-caltide exerted a cardioprotective effect on myocardial OS injury by stabilizing CaV1.2 protein expression. Our study, for the first time, proposed that restoring calcium homeostasis by targeting the CaV1.2 calcium channel and its regulating factor CAST could be a novel treatment for myocardial OS injury.

Transcription factor EB: A potential integrated network regulator in metabolic-associated cardiac injury.

With the worldwide pandemic of metabolic diseases, such as obesity, diabetes, and non-alcoholic fatty liver disease (NAFLD), cardiometabolic disease (CMD) has become a significant cause of death in humans. However, the pathophysiology of metabolic-associated cardiac injury is complex and not completely clear, and it is important to explore new strategies and targets for the treatment of CMD. A series of pathophysiological disturbances caused by metabolic disorders, such as insulin resistance (IR), hyperglycemia, hyperlipidemia, mitochondrial dysfunction, oxidative stress, inflammation, endoplasmic reticulum stress (ERS), autophagy dysfunction, calcium homeostasis imbalance, and endothelial dysfunction, may be related to the incidence and development of CMD. Transcription Factor EB (TFEB), as a transcription factor, has been extensively studied for its role in regulating lysosomal biogenesis and autophagy. Recently, the regulatory role of TFEB in other biological processes, including the regulation of glucose homeostasis, lipid metabolism, etc. has been gradually revealed. In this review, we will focus on the relationship between TFEB and IR, lipid metabolism, endothelial dysfunction, oxidative stress, inflammation, ERS, calcium homeostasis, autophagy, and mitochondrial quality control (MQC) and the potential regulatory mechanisms among them, to provide a comprehensive summary for TFEB as a potential new therapeutic target for CMD.

Transient receptor potential channel 3 in human liver and gallbladder – An investigation in body donors

Since the discovery of TRP proteins in 1969, during studies of the fruit fly Drosophila melanogaster, interest around them and the subfamily of TRPC channels has remained high. TRPC3 was able to be detected in a number of organs in rodents, such as rats and mice, and also in various human tissues. For the most part, these investigations were carried out using gene expression of TRPC3. Further work has already confirmed the relevance of TRPC3 in the context of neurodegenerative diseases, such as spinocerebellar ataxia, and carcinogenic entities, such as ovarian carcinoma. An association with TRPC3 has also been demonstrated for diseases that affect the liver. In order to confirm the expression of TRPC3 in the human liver, this study uses samples taken from eight (n = 8) fixated human body donors and analyzed with immunohistochemistry. In accordance with the macroscopic anatomy of the organs, six samples (n = 6) of liver tissue and three (n = 3) of gallbladder tissue were obtained. TRPC3 was clearly detected in all liver and gallbladder samples examined. Thus, it is not unlikely that TRPC3 plays a role in the extensive metabolic processes of the liver and could also serve as a target for pharmacological interventions in an imbalance of calcium homeostasis.

Disruption of Intracellular Calcium Homeostasis Leads to ERLIN2-Linked Hereditary Spastic Paraplegia in Patient-Derived Stem Cell Models

Hereditary spastic paraplegia (HSP) is a category of neurodegenerative illnesses with significant clinical and genetic heterogeneity. Homozygous truncated variants of the ERLIN2 gene lead to HSP18 (MIM #611225). However, it is still unclear whether there is an autosomal dominant pathogenic pattern. The specific molecular mechanism needs to be investigated. We generated patient-derived iPSC models to study the mechanism of ERLIN2 heterogeneous variants leading to HSP. We identified a heterozygous missense variant p.Val71Ala of ERLIN2 in an HSP family. Based on IP-mass spectrometry, we found that the ERLIN2 heterozygous missense variant protein recruited the ubiquitin E3 ligase RNF213 to degrade IP3R1. The degradation of IP3R1 leads to the reduction of intracellular free calcium, which triggered endoplasmic reticulum (ER) stress-mediated apoptosis. Calcium homeostasis imbalance inhibited the MAPK signaling pathway that contributed to decreased cell proliferation. In summary, these results suggest that the autosomal dominant inheritance of heterozygous missense variants in ERLIN2 is a novel pathogenic mode of HSP. Furthermore, the disruption of intracellular calcium homeostasis is the pathological mechanism.

Ahnak is required to balance calcium ion homeostasis and smooth muscle development in the urinary system

BackgroundVarious renal abnormalities, including hydronephrosis, polycystic kidney disease, and hydroureter, have been reported, and these abnormalities are present in DiGeorge syndrome, renal dysplasia, and acute kidney failure. Previous studies have shown that various genes are associated with renal abnormalities. However, the major target genes of nonobstructive hydronephrosis have not yet been elucidated.ResultsWe examined neuroblast differentiation-associated protein Ahnak localization and analyzed morphogenesis in developing kidney and ureter. To investigated function of Ahnak, RNA-sequencing and calcium imaging were performed in wild type and Ahnak knockout (KO) mice. Ahnak localization was confirmed in the developing mouse kidneys and ureter. An imbalance of calcium homeostasis and hydronephrosis, which involves an expanded renal pelvis and hydroureter, was observed in Ahnak KO mice. Gene Ontology enrichment analysis on RNA-seq results indicated that ‘Channel Activity’, ‘Passive Transmembrane Transporter Activity’ and ‘Cellular Calcium Ion Homeostasis’ were downregulated in Ahnak KO kidney. ‘Muscle Tissue Development’, ‘Muscle Contraction’, and ‘Cellular Calcium Ion Homeostasis’ were downregulated in Ahnak KO ureter. Moreover, peristaltic movement of smooth muscle in the ureter was reduced in Ahnak KO mice.ConclusionsAbnormal calcium homeostasis causes renal disease and is regulated by calcium channels. In this study, we focused on Ahnak, which regulates calcium homeostasis in several organs. Our results indicate that Ahnak plays a pivotal role in kidney and ureter development, and in maintaining the function of the urinary system.

Melittin treatment prevents colorectal cancer from progressing in mice through ER stress-mediated apoptosis.

The primary goal of the current study was to investigate the effect of melittin on colorectal cancer (CRC). The viability of cancer cells was tested using the MTT assay, and the apoptosis of tumour cells was assayed using Annexin V/PI staining in vitro or TUNEL staining in vivo. The in vivo toxicity and efficacy of melittin were assessed in a xenograft mouse model. Melittin inhibited the viability of CRC cell lines and induced apoptosis in SW480 cells by regulating apoptosis-related proteins. Melittin triggered endoplasmic reticulum (ER) stress and caused an imbalance in calcium homeostasis in SW480 cells. An absence of melittin triggered ER stress via the calcium chelating agent BAPTA/AM, and the IP3R inhibitor 2-aminoethoxydiphenyl borate (2-APB) impaired melittin-induced apoptosis in SW480 cells. Melittin treatment suppressed tumour growth but did not affect the body weight of SW480 tumour-bearing mice. Unlike cisplatin and 5-fluorouracil, melittin treatment did not change the biochemical and haematological parameters of the tumour-bearing mice. Finally, in these mice, melittin treatment induced ER stress, which was then blocked by BAPTA/AM, whilst 2-APB impaired the growth inhibitory effect of melittin. Melittin treatment inhibits CRC progression by inducing ER stress and an imbalance in calcium homeostasis.

A Review on the Toxicity Mechanisms and Potential Risks of Engineered Nanoparticles to Plants

Studies have reported that typical nanomaterials (NMs) have been applied on a large scale to various human consumer products due to their rapid development. Nanoparticles (NPs) flowing into the environment inevitably exhibit toxicological effects on organisms at the physiological and molecular levels. To identify the mechanisms of phytotoxicity regulation of typical metal-based engineered NPs, a review of ecotoxicological effects and environmental risks of particles is required. The biological transport of NPs in cells frequently affects the physiological state of plants, resulting in growth restriction of seedlings and structural damage to cellular tissues. Subsequently, excessive accumulation of reactive oxygen species (ROS) enhances oxidative stress, metabolic disorders, cell death, and DNA damage. The transcriptome and metabolome of the antioxidant system were also highly activated to resist ROS, which inevitably caused cytotoxicity and dysregulation of metabolic activity. At the biological process, protein folding, imbalance of calcium homeostasis, impaired mitosis, abnormal electron transport in photosynthesis, and dysregulation of TCA cycle in respiration have been extensively explored in the nanotoxicology field. Trophic transfer in the food chain indicates that ingested NPs are highly probable to accumulate in aquatic and terrestrial food chains and eventually pose potential threats to human health. Overall, this review aims to emphasize the toxicological effects of typical NMs on plants, reveal the toxicity mechanisms of plant cells with metal-based NPs in the environment, and discuss potential risks of particles in aquatic and terrestrial food chains, paving a bright path for environmental risk studies of NMs.

Sleep Disturbances in Generalized Anxiety Disorder: The Role of Calcium Homeostasis Imbalance

Patients with a generalized anxiety disorder (GAD) often report preeminent sleep disturbances. Recently, calcium homeostasis gained interest because of its role in the regulation of sleep-wake rhythms and anxiety symptoms. This cross-sectional study aimed at investigating the association between calcium homeostasis imbalance, anxiety, and quality of sleep in patients with GAD. A total of 211 patients were assessed using the Hamilton Rating Scale for Anxiety (HAM-A), Pittsburgh Sleep Quality Index questionnaire (PSQI) and Insomnia Severity Index (ISI) scales. Calcium, vitamin D, and parathyroid hormone (PTH) levels were evaluated in blood samples. A correlation and linear regression analysis were run to evaluate the association of HAM-A, PSQI, and ISI scores with peripheral markers of calcium homeostasis imbalance. Significant correlations emerged between HAM-A, PSQI, ISI, PTH, and vitamin D. The regression models showed that patients with GAD displaying low levels of vitamin D and higher levels of PTH exhibit a poor subjective quality of sleep and higher levels of anxiety, underpinning higher psychopathological burden. A strong relationship between peripheral biomarkers of calcium homeostasis imbalance, insomnia, poor sleep quality, and anxiety symptomatology was underlined. Future studies could shed light on the causal and temporal relationship between calcium metabolism imbalance, anxiety, and sleep.

Endoplasmic reticulum stress associates with the development of intervertebral disc degeneration.

Endoplasmic reticulum (ER) is an important player in various intracellular signaling pathways that regulate cellular functions in many diseases. Intervertebral disc degeneration (IDD), an age-related degenerative disease, is one of the main clinical causes of low back pain. Although the pathological development of IDD is far from being fully elucidated, many studies have been shown that ER stress (ERS) is involved in IDD development and regulates various processes, such as inflammation, cellular senescence and apoptosis, excessive mechanical loading, metabolic disturbances, oxidative stress, calcium homeostasis imbalance, and extracellular matrix (ECM) dysregulation. This review summarizes the formation of ERS and the potential link between ERS and IDD development. ERS can be a promising new therapeutic target for the clinical management of IDD.

Analysis of reproductive damage in earthworms (Amynthas corticis) exposed to cypermethrin.

Cypermethrin contamination was a potential threat to soil organisms. In the present work, reproductive damage in earthworms (Amynthas corticis) exposed to cypermethrin was investigated. It was found that earthworms could absorb and accumulate residual cypermethrin in soil, and also earthworm activities helped accelerate the degradation of cypermethrin in soil. The accumulation of cypermethrin in earthworms induced sperm damage, and cypermethrin not only caused the imbalance of calcium homeostasis in earthworm sperm cells by inhibiting earthworm sperm Ca2+-ATP and Ca2+-Mg2+-ATP enzyme activities but also caused barriers in acrosome reaction. It also affected sperm energy supply of earthworms by inhibiting the activity of Na+-K+-ATPase and Mg2+-ATPase of earthworm sperm. Meanwhile, the inhibition of acrosome enzyme activity of earthworm sperm by cypermethrin led to hinder fertilization and reduced cocoon production of earthworms, and the damage of cypermethrin to sperm of earthworm was a significant cause of its reproductive toxicity. The results of the evaluation of IBR index showed that reproductive toxicity of cypermethrin to earthworms reduced with the increasing time. The decreased reproductive toxicity of cypermethrin to earthworms at the later stage of exposure (42-56 d) might be due to a combination of reduced absorption of cypermethrin in soil by earthworms, decreased accumulation of cypermethrin in the body, and improved sperm capacitation.

P21-activated kinase 1 (PAK1) as a therapeutic target for cardiotoxicity.

The p21-activated kinase 1 (PAK1), an effector protein of the small G protein Rac and cell division cycle protein 42 (Cdc42), is highly expressed in cardiac tissue. Although a large number of studies have explored the molecular basis and biological function of PAK1, research on PAK1 as a therapeutic target for cardiotoxicity remains in a stage of continuous innovation, and further clarification of its role in cardiotoxicity is required. In this review, we examine the important role of PAK1 in the programmed death (apoptosis, autophagy, and pyroptosis) of cardiomyocytes, and its involvement in oxidative stress and inflammatory responses, which are based on mitochondrial dysfunction and calcium homeostasis imbalance. We also summarize the related signaling pathways through which PAK1 may cause oxidative stress and inflammatory response in cardiotoxicity, and discuss the PAK1-mediated contributions of the gut microbiome and micro RNAs to cardiotoxicity. We propose that PAK1 holds great promise for novel therapeutic strategies to facilitate improvements in the treatment of complex and diverse cardiovascular diseases.

Blockage of Orai1-Nucleolin interaction meditated calcium influx attenuates breast cancer cells growth

As an important second messenger, calcium (Ca2+) regulates a wide variety of physiological processes. Disturbance of intracellular calcium homeostasis implicated in the occurrence of multiple types of diseases. Orai1 is the major player in mediating store-operated calcium entry (SOCE) and regulates calcium homeostasis in non-excitable cells. Over-expression and activation of Orai1 have been reported in breast cancer. However, its molecular mechanisms are still not very clear. Here, we demonstrated that Nucleolin (NCL) was a novel interacting partner of Orai1. NCL is a multifunctional nucleocytoplasmic protein and is upregulated in human breast tumors. The binding of C-termini of NCL (NCL-CT) to N-termini of Orai1 (Orai1-NT) is critical for mediating calcium influx and proliferation of breast cancer cells. Blocking the NCL-Orai1 interaction by synthesized Orai1 peptide can effectively reduce the intracellular calcium influx and suppress the proliferation of breast cancer cells in vitro and in vivo. Our findings reveal a novel activation mechanism of Orai1 via direct interaction with NCL, which may lead to calcium homeostasis imbalance and promote the proliferation of breast cancer cells. Blocking NCL-Orai1 interaction might be an effective treatment of breast cancer.

Does Vitamin D matter? The role of calcium homeostasis imbalance in clinical severity of psychiatric patients

IntroductionVitamin D modulates the biosynthesis of neurotransmitters and neurotrophic factors and it is involved in the modulation of inflammatory responses, with a potential impact on clinical status of patients with severe mental disorders. Moreover, available evidences report that decreased blood levels of Vitamin D are associated to a worse course of psychotic and affective disorders.ObjectivesWe assessed calcium homeostasis imbalance in a sample of inpatients and outpatients, referring to the Department of Psychiatry of University of Campania “Luigi Vanvitelli” in order to explore levels of Calcium, PTH and Vitamin D and their influence in clinical severity among this different subgroups.MethodsAll patients were administered The Brief Psychiatric Rating Scale (BPRS) to assess different domains of psychopathology. Vitamin D, Calcium and PTH levels were assessed in all patients. An-ad hoc schedule was administered for socio-demographic and clinical characteristics.ResultsThe total sample consisted of 152 patients (75 males and 77 females with 47.3 ± 14.4 age at admission, 74 inpatients and 78 outpatients). Patients with lower level of Vitamin D are more likely to present higher number of relapses (p<0.05) and to be inpatients (<0.01). Finally, serum levels of Vitamin D were negatively correlated with all the BPRS subscales (p < 0.01).ConclusionsLower levels of Vitamin D correlate with a worse clinical outcome of patients with different psychiatric diagnosis. Our results highlight the importance to routinely assess PTH, Vit D and calcium levels, especially in inpatients. Moreover, Vitamin D may represent a valid add-on treatment for these patients.DisclosureNo significant relationships.