NCX1/Ca2+ promotes autophagy and decreases bortezomib activity in multiple myeloma through non-canonical NFκB signaling pathway.

Although bortezomib (BTZ) is the cornerstone of anti-multiple myeloma (MM) therapy, the inevitable primary and secondary drug resistance still seriously affects the prognosis of patients. New treatment strategies are in need. Sodium-calcium exchanger 1 (NCX1) is a calcium-permeable ion transporter on the membrane, and our previous studies showed that low NCX1 confers inferior viability in MM cells and suppressed osteoclast differentiation. However, the effect of NCX1 on BTZ sensitivity of MM and its possible mechanism remain unclear. In this study, we investigated the effect of NCX1 on BTZ sensitivity in MM, focusing on cellular processes of autophagy and cell viability. Our results provide evidence that NCX1 expression correlates with MM disease progression and low NCX1 expression increases BTZ sensitivity. NCX1/Ca2+ triggered autophagic flux through non-canonical NFκB pathway in MM cells, leading to attenuated the sensitivity of BTZ. Knockdown or inhibition of NCX1 could potentiate the anti-MM activity of BTZ in vitro and vivo, and inhibition of autophagy sensitized NCX1-overexpressing MM cells to BTZ. In general, this work implicates NCX1 as a potential therapeutic target in MM with BTZ resistance and provides novel mechanistic insights into its vital role in combating BTZ resistance.

NLRP14 Safeguards Calcium Homeostasis via Regulating the K27 Ubiquitination of Nclx in Oocyte-to-Embryo Transition.

Sperm-induced Ca2+ rise is critical for driving oocyte activation and subsequent embryonic development, but little is known about how lasting Ca2+ oscillations are regulated. Here it is shown that NLRP14, a maternal effect factor, is essential for keeping Ca2+ oscillations and early embryonic development. Few embryos lacking maternal NLRP14 can develop beyond the 2-cell stage. The impaired developmental potential of Nlrp14-deficient oocytes is mainly caused by disrupted cytoplasmic function and calcium homeostasis due to altered mitochondrial distribution, morphology, and activity since the calcium oscillations and development of Nlrp14-deficient oocytes can be rescued by substitution of whole cytoplasm by spindle transfer. Proteomics analysis reveal that cytoplasmic UHRF1 (ubiquitin-like, containing PHD and RING finger domains 1) is significantly decreased in Nlrp14-deficient oocytes, and Uhrf1-deficient oocytes also show disrupted calcium homeostasis and developmental arrest. Strikingly, it is found that the mitochondrial Na+ /Ca2+ exchanger (NCLX) encoded by Slc8b1 is significantly decreased in the Nlrp14mNull oocyte. Mechanistically, NLRP14 interacts with the NCLX intrinsically disordered regions (IDRs) domain and maintain its stability by regulating the K27-linked ubiquitination. Thus, the study reveals NLRP14 as a crucial player in calcium homeostasis that is important for early embryonic development.

K+-Dependent Na+/Ca2+ Exchanger Isoform 2, Nckx2, Takes Part in the Neuroprotection Elicited by Ischemic Preconditioning in Brain Ischemia.

Sodium/Calcium exchangers are neuronal plasma membrane antiporters which, by coupling Ca2+ and Na+ fluxes across neuronal membranes, play a relevant role in brain ischemia. The most brain-expressed isoform among the members of the K+-dependent Na+/Ca2+ exchanger family, NCKX2, is involved in the progression of the ischemic lesion, since both its knocking-down and its knocking-out worsens ischemic damage. The aim of this study was to elucidate whether NCKX2 functions as an effector in the neuroprotection evoked by ischemic preconditioning. For this purpose, we investigated: (1) brain NCKX2 expression after preconditioning and preconditioning + ischemia; (2) the contribution of AKT and calpain to modulating NCKX2 expression during preconditioning; and (3) the effect of NCKX2 knocking-out on the neuroprotection mediated by ischemic preconditioning. Our results showed that NCKX2 expression increased in those brain regions protected by ischemic preconditioning. These changes were p-AKT-mediated since its inhibition prevented NCKX2 up-regulation. More interestingly, NCKX2 knocking-out significantly prevented the protection exerted by ischemic preconditioning. Overall, our results suggest that NCKX2 plays a fundamental role in the neuroprotective effect mediated by ischemic preconditioning and support the idea that the enhancement of its expression and activity might represent a reasonable strategy to reduce infarct extension after stroke.

Silencing lncRNA 93358 Inhibits the Apoptosis of Myocardial Cells in Myocardial Infarction Rats by Inducing the Expression of SLC8A1.

Objective: To explore the inhibitor effects and mechanism of lncRNA 93358 against the apoptosis of myocardial cells in rats with myocardial infarction. Methods: The myocardial infarction model was established in rats, which were identified by cardiac ultrasound. TTC staining was used to evaluate the degree of heart infarction, and HE staining was utilized to determine the pathological state in myocardial tissues. The apoptotic state in myocardial tissues was confirmed by TUNEL assay. lncRNA 93358 was screened out using a high-throughput sequencing which was confirmed by RT-qPCR. The interaction between miR-466c-3p and SLC8A1 was identified using the dual-luciferase reporter assay. The expression level of Bax, Bcl-2, and SLC8A1 was determined in lncRNA 93358 knockdown cells using RT-qPCR and Western blotting. Results: Massive myocardial necrosis was observed in model rats according to the results of TTC staining, HE staining, and TUNEL assay. lncRNA 93358 and Bax were found significantly upregulated, and Bcl-2 and SLC8A1 were greatly downregulated in model rats, which were dramatically reversed by the knockdown of lncRNA 93358, accompanied by the decline area of myocardial necrosis and decreased apoptotic myocardial cells. Conclusion: Silencing lncRNA 93358 inhibits the apoptosis of myocardial cells in rats with myocardial infarction by inducing the expression of SLC8A1.

Multiomics Integrated Analysis Identifies SLC24A2 as a Potential Link between Type 2 Diabetes and Cancer.

Background: So far, type 2 diabetes (T2D) is considered as an independent risk factor for various cancers, but the underlying mechanism remains unclear. Methods. SLC24A2 was first identified as a key gene strongly associated with fasting plasma glucose (FPG). Then, overlapped differentially expressed genes (DEGs) between T2D verse control and SLC24A2-high verse SLC24A2-low were extracted and imported into weighted correlation network analysis. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, and gene set enrichment analysis were used for functional enrichment analysis of DEGs. Least absolute shrinkage and selection operator was utilized to build a T2D prediction model. Timer and K-M plotters were employed to find the expression and prognosis of SLC24A2 in pan cancer. Results: Interestingly, both DEGs between T2D verse control and SLC24A2-high verse SLC24A2-low enriched in cancer-related pathways. Moreover, a total of 3719 overlapped DEGs were divided into 8 functional modules. Grey module negatively correlated with T2D and FPG and was markedly involved in ribosome biogenesis. Ten SLC24A2-related genes (RRP36, RPF1, GRWD1, FBL, EXOSC5, BCCIP, UTP14A, TWISTNB, TBL3, and SKIV2L) were identified as hub genes, based on which the LASSO model accurately predicts the occurrence of T2D (AUC = 0.841). In addition, SLC24A2 was only expressed in islet ß cells and showed abnormal expression in 17 kinds of cancers and significantly correlated with the prognosis of 10 kinds of cancers. Conclusion: Taken together, SLC24A2 may link T2D and cancer by influencing the ribosome function of islet ß cells and play different prognostic roles in different cancers.

Enhanced NCLX-dependent mitochondrial Ca2+ efflux attenuates pathological remodeling in heart failure.

Mitochondrial calcium (mCa2+) uptake couples changes in cardiomyocyte energetic demand to mitochondrial ATP production. However, excessive mCa2+ uptake triggers permeability transition and necrosis. Despite these established roles during acute stress, the involvement of mCa2+ signaling in cardiac adaptations to chronic stress remains poorly defined. Changes in NCLX expression are reported in heart failure (HF) patients and models of cardiac hypertrophy. Therefore, we hypothesized that altered mCa2+ homeostasis contributes to the hypertrophic remodeling of the myocardium that occurs upon a sustained increase in cardiac workload. The impact of mCa2+ flux on cardiac function and remodeling was examined by subjecting mice with cardiomyocyte-specific overexpression (OE) of the mitochondrial Na+/Ca2+ exchanger (NCLX), the primary mediator of mCa2+ efflux, to several well-established models of hypertrophic and non-ischemic HF. Cardiomyocyte NCLX-OE preserved contractile function, prevented hypertrophy and fibrosis, and attenuated maladaptive gene programs in mice subjected to chronic pressure overload. Hypertrophy was attenuated in NCLX-OE mice, prior to any decline in cardiac contractility. NCLX-OE similarly attenuated deleterious cardiac remodeling in mice subjected to chronic neurohormonal stimulation. However, cardiomyocyte NCLX-OE unexpectedly reduced overall survival in mice subjected to severe neurohormonal stress with angiotensin II + phenylephrine. Adenoviral NCLX expression limited mCa2+ accumulation, oxidative metabolism, and de novo protein synthesis during hypertrophic stimulation of cardiomyocytes in vitro. Our findings provide genetic evidence for the contribution of mCa2+ to early pathological remodeling in non-ischemic heart disease, but also highlight a deleterious consequence of increasing mCa2+ efflux when the heart is subjected to extreme, sustained neurohormonal stress.

Dexamethasone Suppresses Palatal Cell Proliferation through miR-130a-3p.

Cleft lip with or without cleft palate (CL/P) is one of the most common congenital birth defects. This study aims to identify novel pathogenic microRNAs associated with cleft palate (CP). Through data analyses of miRNA-sequencing for developing palatal shelves of C57BL/6J mice, we found that miR-449a-3p, miR-449a-5p, miR-449b, miR-449c-3p, and miR-449c-5p were significantly upregulated, and that miR-19a-3p, miR-130a-3p, miR-301a-3p, and miR-486b-5p were significantly downregulated, at embryonic day E14.5 compared to E13.5. Among them, overexpression of the miR-449 family (miR-449a-3p, miR-449a-5p, miR-449b, miR-449c-3p, and miR-449c-5p) and miR-486b-5p resulted in reduced cell proliferation in primary mouse embryonic palatal mesenchymal (MEPM) cells and mouse cranial neural crest cell line O9-1. On the other hand, inhibitors of miR-130a-3p and miR-301a-3p significantly reduced cell proliferation in MEPM and O9-1 cells. Notably, we found that treatment with dexamethasone, a glucocorticoid known to induce CP in mice, suppressed miR-130a-3p expression in both MEPM and O9-1 cells. Moreover, a miR-130a-3p mimic could ameliorate the cell proliferation defect induced by dexamethasone through normalization of Slc24a2 expression. Taken together, our results suggest that miR-130-3p plays a crucial role in dexamethasone-induced CP in mice.

Circular RNA circSLC8A1 inhibits the proliferation and invasion of non-small cell lung cancer cells through targeting the miR-106b-5p /FOXJ3 axis.

Circular RNA derived from the SLC8A1 gene (circSLC8A1) has been implicated in the pathogenesis of several types of cancers. However, the role of circSLC8A1 in non-small cell lung cancer (NSCLC) remains unclear. In the present study, the expression levels of circSLC8A1 in NSCLC tissues and cell lines were determined by qRT-PCR analysis. Function-gain-assays were then carried out to further validate the role of circSLC8A1 in NSCLC in vitro. Online prediction software and the subsequent luciferase reporter assay were used to identify the target genes of circSLC8A1 and microRNA (miR)-106b-5p. CircSLC8A1 was found to be downregulated in NSCLC tissues and cell lines. Overexpression of circSLC8A1 significantly inhibited the proliferation and invasion of NSCLC cells. Further investigations shown that circSLC8A1 was able to bind to miR-106b-5p as well as inhibit the expression of miR-106b-5p in NSCLC cells. MiR-106b-5p mimics reversed the inhibitory effects of circSLC8A1 overexpression on cell proliferation and invasion. Furthermore, we found that forkhead box J3 (FOXJ3) to be a target gene of miR-106b-5p in NSCLC cells. Knockdown of FOXJ3 reversed the inhibitory effects of miR-106b-5p inhibitor on cell proliferation and invasion. Collectively, these findings indicate that circSLC8A1 exhibits anti-tumor activity in NSCLC, which might be mediated by the miR-106b-5p/FOXJ3 axis. The circSLC8A1/miR-106b-5p/FOXJ3 axis may thus represent a promising therapeutic target for the management of NSCLC.

Calcium transport in male reproduction is possibly influenced by vitamin D and CaSR.

Vitamin D is important for gonadal function in rodents, and improvement of vitamin D status in men with low sperm counts increases live birth rate. Vitamin D is a regulator of transcellular calcium transport in the intestine and kidney and may influence the dramatic changes in the luminal calcium concentration in epididymis. Here, we show spatial expression in the male reproductive tract of vitamin D receptor (VDR)-regulated factors involved in calcium transport: transient receptor potential vanilloid 5/6 , sodium/calcium exchanger 1, plasma membrane calcium ATPase 1, calbindin D9k, calcium-sensing receptor (CaSR), and parathyroid hormone-related peptide (PTHrP) in mouse and human testis and epididymis. Testicular Casr expression was lower in Vdr ablated mice compared with controls. Moreover, expression levels of Casr and Pthrp were strongly correlated in both testis and epididymis and Pthrp was suppressed by 1,25(OH)2D3 in a spermatogonial cell line. The expression of CaSR in epididymis may be of greater importance than in the gonad in mice as germ cell-specific Casr deficient mice had no major reproductive phenotype, and coincubation with a CaSR-agonist had no effect on human sperm-oocyte binding. In humans, seminal calcium concentration between 5 and 10 mM was associated with a higher fraction of motile and morphologically normal sperm cells, and the seminal calcium concentration was not associated with serum calcium levels. In conclusion, VDR regulates CaSR and PTHrP, and both factors may be involved in the regulation of calcium transport in the male reproductive tract with possible implications for sperm function and storage.

Genetic investigation of fibromuscular dysplasia identifies risk loci and shared genetics with common cardiovascular diseases.

Fibromuscular dysplasia (FMD) is an arteriopathy associated with hypertension, stroke and myocardial infarction, affecting mostly women. We report results from the first genome-wide association meta-analysis of six studies including 1556 FMD cases and 7100 controls. We find an estimate of SNP-based heritability compatible with FMD having a polygenic basis, and report four robustly associated loci (PHACTR1, LRP1, ATP2B1, and LIMA1). Transcriptome-wide association analysis in arteries identifies one additional locus (SLC24A3). We characterize open chromatin in arterial primary cells and find that FMD associated variants are located in arterial-specific regulatory elements. Target genes are broadly involved in mechanisms related to actin cytoskeleton and intracellular calcium homeostasis, central to vascular contraction. We find significant genetic overlap between FMD and more common cardiovascular diseases and traits including blood pressure, migraine, intracranial aneurysm, and coronary artery disease.

The downregulation of NCXs is positively correlated with the prognosis of stage II-IV colon cancer.

PURPOSE: Colon cancer (CC) is a very common gastrointestinal tumor that is prone to invasion and metastasis in the late stage. This study aims to observe the expression of Na+/Ca2+ exchangers (NCXs) and analyze the correlation between NCXs and the prognosis of CC. METHODS: Specimens of 111 stage II-IV CC patients were collected. We used western blotting, qPCR, and immunohistochemical staining to observe the distributions and expression levels of NCX isoforms (NCX1, NCX2, and NCX3) in CC and distal normal tissues. Cox proportional hazards models were used to assess prognostic factors for patients. RESULTS: The expression of NCXs in most tumor specimens was lower than that in normal tissues. The NCX expression levels in tumor tissues from the primary tumor, local lymph node metastasis sites, and distant liver metastasis sites were increasingly significantly lower than those in normal tissues. The results of the Kaplan-Meier survival curves showed that the downregulation of any NCX isoform was closely related to the worse prognosis of advanced CC. CONCLUSION: NCXs can be used as independent prognostic factors for CC. Our research results are expected to provide new targets for the treatment of CC.

Loss of Nckx3 Exacerbates Experimental DSS-Induced Colitis in Mice through p53/NF-κB Pathway.

Inflammatory bowel diseases (IBDs) comprises a range of chronic inflammatory conditions of the intestinal tract. The incidence and prevalence of IBDs are increasing worldwide, but the precise etiology of these diseases is not completely understood. Calcium signaling plays a regulatory role in cellular proliferation. Nckx3, a potassium-dependent Na+/Ca2+ exchanger, is not only expressed in the brain but also in the aortic, uterine, and intestinal tissues, which contain abundant smooth muscle cells. This study investigated the role of Nckx3 in intestinal inflammation. Microarray analyses revealed the upregulation of the innate immune response-associated genes in the duodenum of Nckx3 knockout (KO) mice. The Nckx3 KO mice also showed an increase in IBD- and tumorigenesis-related genes. Using dextran sodium sulfate (DSS)-induced experimental colitis mice models, the Nckx3 KO mice showed severe colitis. Furthermore, the pathways involving p53 and NF-κB signaling were significantly upregulated by the absence of Nckx3. Overall, Nckx3 plays a critical role in the innate immune and immune response and may be central to the pathogenesis of IBD.

Post-weaning protein malnutrition induces myocardial dysfunction associated with oxidative stress and altered calcium handling proteins in adult rats.

Hypercaloric low-protein diet may lead to a state of malnutrition found in the low-income population of Northeastern Brazil. Although malnutrition during critical periods in the early life is associated with cardiovascular diseases in adulthood, the mechanisms of cardiac dysfunction are still unclear. Here we studied the effects of post-weaning malnutrition due to low protein intake induced by a regional basic diet on the cardiac contractility of young adult rats. In vivo arterial hemodynamic and in vitro myocardial contractility were evaluated in 3-month-old rats. Additionally, protein content of the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA), total phospholamban (PLB) and phosphorylated at serine 16 (p-Ser(16)-PLB), α2-subunit of the Na(+)/K(+)-ATPase (α2-NKA), and Na(+)/Ca(2+) exchanger (NXC) and in situ production of superoxide anion (O2(-)) were measured in the heart. Blood pressure and heart rate increased in the post-weaning malnourished (PWM) rats. Moreover, malnutrition decreased twitch force and inotropic responses of the isolated cardiac muscle. Protein expression of SERCA, PLB/SERCA, and p-Ser(16)-PLB/PLB ratios and α2-NKA were decreased without changing NCX. The contraction dependent on transsarcolemmal calcium influx was unchanged but responsiveness to Ca(2+) and tetanic peak contractions were impaired in the PWM group. Myocardial O2(-) production was significantly increased by PWM. Our data demonstrated that this hypercaloric low-protein diet in rats is associated with myocardial dysfunction, altered expression of major calcium handling proteins, and increased local oxidative stress. These findings reinforce the attention needed for pediatric care, since chronic malnutrition in early life is related to increased cardiovascular risk in adulthood. Graphical Abstract.

NCX3 alleviates ethanol-induced apoptosis of SK-N-SH cells via the elimination of intracellular calcium ions.

Long-term alcohol intake may cause nerve cell apoptosis and induce various encephalopathies. Previously, we have shown that the expression of Na+/Ca2+ exchanger 3 (NCX3) was associated with the intracellular calcium concentration ([Ca2+]i) and apoptosis, involved in the spatial memory impairment in male C57BL/6 mice with chronic ethanol (EtOH) exposure. However, the mechanism involved is unclear. Here, we investigated the expression of NCX3 and its protective effect on SK-N-SH cells (a nerve cell line) after EtOH exposure. [Ca2+]i was measured using Fluo-3 AM reagent. Cell viability and the apoptotic rate were assayed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt (MTS) and flow cytometry, respectively. The expression of p-cAMP-responsive element binding protein1(p-CREB 1), NCX3 protein, and mRNA were observed using Western blotting and quantitative real-time polymerase chain reaction (qRT-PCR), respectively. Cleaved-caspase-3, caspase-3, rabbit anti- poly (ADP-ribose) polymerase-1 (PARP-1) and calpain-1 proteins were used to assess the degree of apoptosis. Our results showed that EtOH increased [Ca2+]i and apoptosis of SK-N-SH cells in a concentration- and time-dependent manner. The expression of NCX3 protein and mRNA was up regulated obviously after SK-N-SH cells were treated with EtOH. The phosphorylation levels of Akt and CREB 1 were up regulated in cells treated with EtOH. The expression of NCX3 protein was reduced in the SK-N-SH cells treated with Akt phosphorylation inhibitor (LY294002). The [Ca2+]i and apoptosis rate of SK-N-SH cells increased 1.31-fold and 1.52-fold after silencing NCX3 compared with those treated with 200 mM EtOH alone for 2 d. In contrast, the [Ca2+]i and apoptosis rate of SK-N-SH cells decreased 0.26-fold and 0.35-fold after overexpression of NCX3 in the 2 d-200 mM EtOH treatment group. These results suggest that NCX3 plays a critical role in neuronal protection via the elimination of intracellular Ca2+, which may be a promising target for the prevention and treatment of encephalopathy after ethanol exposure.

circSLC8A1 sponges miR-671 to regulate breast cancer tumorigenesis via PTEN/PI3k/Akt pathway.

Breast cancer is the most frequently diagnosed and the leading cause of cancer-related deaths in women worldwide. However, the role of circSLC8A1 in breast cancer remains elusive. Herein, a cohort of 77 breast tumors and paired adjacent normal mammary tissues were collected. We demonstrated that circSLC8A1 was significantly down-regulated in breast cancer tissues and cell lines, of which expression was negatively correlated with clinical severity and dismal prognosis. Overexpression of circSLC8A1 suppressed cell proliferation, migration and invasion in vitro, and inhibited tumor growth in vivo. CircSLC8A1 directly targeted miR-671 to execute tumor suppressive activities via regulating PI3k/Akt signaling. Krüppel-like factor 16 (KLF16), a transcriptional activator of PTEN, was identified as a target of miR-671. Furthermore, circSLC8A1 could sponge miR-671 to suppress breast tumor growth via PTEN/PI3k/Akt signaling in vivo. In summary, circSLC8A1/miR-671 regulates breast cancer progression through PTEN/PI3k/Akt signaling, which may provide efficient therapeutic target for this devastating cancer.

A critical role for miR­135a­5p­mediated regulation of SLC24A2 in neuropathic pain.

Neuropathic pain (NP) is a refractory and long­lasting disease caused mostly by peripheral nerve injury. Currently, the mechanism of NP is yet to be elucidated. Intracellular calcium homeostasis is critical for some physiological functions, including the occurrence of NP. NCKX2, encoded by the solute carrier family 4 member 2 (SLC24A2) gene, is an important K+­dependent Na+­Ca2+ exchanger that mediates Ca2+ extrusion. The role of NCKX2 in the development of NP is unknown. For this purpose, a sciatic nerve chronic constriction injury (CCI) model was established and it was revealed that the expression levels of SLC24A2 and its encoded protein NCKX2 were both downregulated in the posterior horn of the spinal cord. Overexpression of SLC24A2 reduced both mechanical and thermal hyperalgesia and decreased the expression of inflammatory cytokines [interleukin (IL)­1ß, IL­6 and tumor necrosis factor­α] in CCI rats. Using bioinformatics analyses, luciferase reporter assays, and a series of behavioral tests, it was demonstrated that the decrease in SLC24A2 after CCI treatment was directly regulated by increased microRNA (miR)­135a­5p in the spinal cord. Moreover, the effects of miR­135a­5p on NP were SLC24A2­dependent. In conclusion, the present results highlighted the suppressive role of NCKX2 in NP, which is mainly regulated by miR­135a­5p and mediates the release of inflammatory cytokines in the dorsal horn of the spinal cord. These findings deepen our understanding of the development of NP and provide novel candidates for NP treatment.

Dexamethasone Treatment Increases the Intracellular Calcium Level Through TRPV6 in A549 Cells.

This study investigated the effect of dexamethasone (DEX) on intracellular calcium levels and the expressions of transient receptor potential cation channel subcomponent V member 6 (TRPV6), sodium-calcium exchanger 1 (NCX1), and plasma membrane calcium ATPase 1 (PMCA1) in A549 cells. The intracellular calcium level, by using the calcium indicator pGP-CMV-GCaMP6f, increased following DEX treatment for 6, 12, and 24 h in A549 cells. In addition, Rhod-4 assay after DEX treatment for 24 h showed that DEX increased the level of intracellular calcium. The expression of the calcium influx TRPV6 gene significantly increased, whereas the expressions of the calcium outflow NCX1 and PMCA1 genes significantly decreased with DEX treatment. The mRNA levels of surfactant protein genes SFTPA1, SFTPB, SFTPC, and SFTPD and the secreted airway mucin genes MUC1 and MUC5AC were investigated by treating cells with DEX. The DEX treatment decreased the mRNA levels of SFTPA1 and SFTPB but increased the mRNA levels of SFTPC and SFTPD. The MUC1 mRNA level was increased by DEX treatment, whereas MUC5AC mRNA was significantly decreased. These results indicate that DEX influences the intracellular calcium level through TRPV6, and affects pulmonary surfactant genes and secreted airway mucin genes in A549 cells.

Maternal androgen excess induces cardiac hypertrophy and left ventricular dysfunction in female mice offspring.

AIMS: Polycystic ovary syndrome (PCOS) is a common endocrinopathy that is suggested to increase the risk for cardiovascular disease. How PCOS may lead to adverse cardiac outcomes is unclear and here we hypothesized that prenatal exposure to dihydrotestosterone (DHT) and/or maternal obesity in mice induce adverse metabolic and cardiac programming in female offspring that resemble the reproductive features of the syndrome. METHODS AND RESULTS: The maternal obese PCOS phenotype was induced in mice by chronic high-fat-high-sucrose consumption together with prenatal DHT exposure. The prenatally androgenized (PNA) female offspring displayed cardiac hypertrophy during adulthood, an outcome that was not accompanied by aberrant metabolic profile. The expression of key genes involved in cardiac hypertrophy was up-regulated in the PNA offspring, with limited or no impact of maternal obesity. Furthermore, the activity of NADPH oxidase, a major source of reactive oxygen species in the cardiovascular system, was down-regulated in the PNA offspring heart. We next explored for early transcriptional changes in the heart of newly born PNA offspring, which could account for the long-lasting changes observed in adulthood. Neonatal PNA hearts displayed an up-regulation of transcription factors involved in cardiac hypertrophic remodelling and of the calcium-handling gene, Slc8a2. Finally, to determine the specific role of androgens in cardiovascular function, female mice were continuously exposed to DHT from pre-puberty to adulthood, with or without the antiandrogen flutamide. Continuous exposure to DHT led to adverse left ventricular remodelling, and increased vasocontractile responses, while treatment with flutamide partly alleviated these effects. CONCLUSION: Taken together, our results indicate that intrauterine androgen exposure programmes long-lasting heart remodelling in female mouse offspring that is linked to left ventricular hypertrophy and highlight the potential risk of developing cardiac dysfunction in daughters of mothers with PCOS.

Nuclear Factor-κB Increases Intracellular Calcium by Upregulation of Na+-Ca2+ Exchanger 1 in Cerulein-Induced Acute Pancreatitis.

OBJECTIVES: The mechanisms underlying pathogenesis of acute pancreatitis (AP) are still not completely understood. An early, critical feature of AP is aberrant calcium (Ca) signaling, termed Ca overload, within pancreatic acinar cells. This study aimed to develop a model system in rats for AP induction to study the contribution of the Na-Ca exchanger 1 (NCX1) ion channel in AP pathogenesis. METHODS: To establish a rat model of AP induction, cerulein or L-arginine were intraperitoneally injected and tissue was histologically analyzed by hematoxylin and eosin staining. A cell culture-based model for AP induction was similarly created through cerulein treatment of AR42J cells. Induction of AP was also examined following exposure to the NXC1-targeted inhibitor KB-R7943. The expression of each gene was detected by Western blotting, immunofluorescence, immunohistochemistry, or quantitative reverse transcription polymerase chain reaction. Transcriptional regulation by nuclear factor (NF)-κB was detected using an NCX1 promoter-fusion dual luciferase reporter system. Cytosolic Ca was measured using a fluorescent calcium indicator. RESULTS: We found that cerulein induced NCX1 expression via activation of nuclear factor NF-κB, which potentially binds to the NCX1 promoter to induce its transcription. CONCLUSIONS: Our findings reveal a regulatory pathway through NF-κB/NCX1 governing Ca overload in AP development, thus providing potential targets for AP treatment.

Calcium signaling affects migration and proliferation differently in individual cancer cells due to nifedipine treatment.

Several papers have reported that calcium channel blocking drugs were associated with increased breast cancer risk and worsened prognosis. One of the most common signs of breast tumors is the presence of small deposits of calcium, known as microcalcifications. Therefore, we studied the effect of dihydropyridine nifedipine on selected calcium transport systems in MDA-MB-231 cells, originating from triple negative breast tumor and JIMT1 cells that represent a model of HER2-positive breast cancer, which possesses amplification of HER2 receptor, but cells do not response to HER2 inhibition treatment with trastuzumab. Also, we compared the effect of nifedipine on colorectal DLD1 and ovarian A2780 cancer cells. Both, inositol 1,4,5-trisphosphate receptor type 1 (IP3R1) and type 1 sodium calcium exchanger (NCX1) were upregulated due to nifedipine in DLD1 and A2780 cells, but not in breast cancer MDA-MB-231 and JIMT1 cells. On contrary to MDA-MB-231 and JIMT1 cells, in DLD1 and A2780 cells nifedipine induced apoptosis in a concentration-dependent manner. After NCX1 silencing and subsequent treatment with nifedipine, proliferation was decreased in MDA-MB-231, increased in DLD1 cells, and not changed in JIMT1 cells. Silencing of IP3R1 revealed increase in proliferation in DLD1 and JIMT1 cells, but caused decrease in proliferation in MDA-MB-231 cell line after nifedipine treatment. Interestingly, after nifedipine treatment migration was not significantly affected in any of tested cell lines after NCX1 silencing. Due to IP3R1 silencing, significant decrease in migration occurred in MDA-MB-231 cells after nifedipine treatment, but not in other tested cells. These results support different function of the NCX1 and IP3R1 in the invasiveness of various cancer cells due to nifedipine treatment.