Cardiovascular diseases (CVDs) represent a significant public health concern because of their associations with inflammation, oxidative stress, and abnormal remodeling of the heart and blood vessels. In this review, we discuss the intricate interplay between mitochondria-associated membranes (MAMs) and cardiovascular inflammation, highlighting their role in key cellular processes such as calcium homeostasis, lipid metabolism, oxidative stress management, and ERS. We explored how these functions impact the pathogenesis and progression of various CVDs, including myocardial ischemia-reperfusion injury, atherosclerosis, diabetic cardiomyopathy, cardiovascular aging, heart failure, and pulmonary hypertension. Additionally, we examined current therapeutic strategies targeting MAM-related pathways and proteins, emphasizing the potential of MAMs as therapeutic targets. Our review aims to provide new insights into the mechanisms of cardiovascular inflammation and propose novel therapeutic approaches to improve cardiovascular health outcomes.

ATP and BzATP increase free cytosolic Ca2+ concentration ([Ca2+]i) in conjunctival goblet cells (CGCs) resulting in mucin secretion. The purpose of this study was to investigate the source of the Ca2+i mobilized by ATP and BzATP. First passage cultured rat CGCs were incubated with Fura-2/AM and [Ca2+]i was measured under several conditions with ATP and BzATP stimulation. The following conditions were used: 1) preincubation with the Ca2+ chelator EGTA, 2) preincubation with the SERCA inhibitor thapsigargin (10-6 M) which depletes ER Ca2+ stores, 3) preincubation with phospholipase C (PLC) or protein kinase A (PKA) inhibitor, or 4) preincubation with the voltage-gated calcium channel antagonist nifedipine (10-5 M) and the ryanodine receptor (RyR) antagonist dantrolene (10-5 M). Immunofluorescence microscopy (IF) and RT-qPCR were used to investigate RyR presence in rat and human CGCs. ATP stimulated peak [Ca2+]i was significantly lower after chelating Ca2+i with 2 mM EGTA in Ca2+-free buffer. The peak [Ca2+]i increase in CGCs preincubated with thapsigargin, PKA inhibitor H89, nifedipine and dantrolene, but not the PLC inhibitor, was reduced for ATP at 10-5 M and BzATP at 10-4 M. Incubating CGCs with dantrolene alone decreased [Ca2+]i, and induced CGC cell death at a high concentration. RyR3 was detected in rat and human CGCs with IF and RT-qPCR. We conclude that ATP and BzATP-induced Ca2+i increases originate from the ER, and that RyR3 may be an essential regulator of CGC [Ca2+]i. This study contributes to the understanding of diseases arising from defective Ca2+ signaling in non-excitable cells.

In the last years, 5-pyrazolyl ureas and 5-aminopyrazoles have been investigated for their antiangiogenetic properties and their potential interaction with the ubiquitous Ca2+ binding protein Calreticulin. Based on the structure of the active compounds I and GeGe-3, novel 5-arylamino pyrazoles 2 and 3 were synthesized through a stepwise procedure. In MTT assays, all the new derivatives proved to be non-cytotoxic against eight different tumor cell lines, normal fibroblasts, and endothelial cells. Furthermore, selected derivatives showed relevant antiangiogenetic properties, resulting more effective than reference molecules I and GeGe-3 in inhibiting HUVEC endothelial tube formation. 5-Arylamino pyrazoles 2a and 2d were identified as the most interesting compounds and significantly prevented tube formation of tumor secretome-stimulated HUVEC. Furthermore, the two compounds inhibited HUVEC migration in wound healing assay and altered cell invasion capability. Additionally, 2a and 2d strongly affected Ca2+ mobilization and cytoskeletal organization of HUVEC cells, being as active as the reference compound GeGe-3. Differently from previous studies, molecular docking simulations suggested a poor affinity of 2a towards Calreticulin, one of the interacting partners of the lead compound GeGe-3. Collectively, this new amino-pyrazole library further extends the structure-activity relationships of the previously prepared derivatives and confirmed the biological attractiveness of this chemical scaffold as antiangiogenetic agents.

Water-to-land transition is a hallmark of terrestrialization for land plants and requires molecular adaptation to resist water deficiency. Lineages- or species-specific genes are widespread across eukaryotes, and yet the majority of those are functionally unknown and not annotated. Recent studies have revealed that some of such genes could play a role in adapting to environmental stress responses. Here, we identified a novel gene PpBCG1 (Bryophyte Co-retained Gene 1) in the moss Physcomitrium patens that was responsive to dehydration and rehydration. Under de- and rehydration treatments, PpBCG1 was significantly co-expressed with the dehydrin-encoding gene PpDHNA. Microarray data revealed that PpBCG1 was highly expressed in tissues of spores, female organ archegonia, and mature sporophytes. In addition, the Ppbcg1 mutant showed reduced ability of dehydration tolerance, whose plants were accompanied by a relatively low level of chlorophyll content during recovery. Comprehensive transcriptomics uncovered a detailed set of regulatory processes that were affected by the PpBCG1 disruption. Moreover, experimental evidence showed that PpBCG1 might function in the antioxidant activity, abscisic acid (ABA) pathway, and intracellular calcium (Ca2+) homeostasis to resist desiccation. Together, our study provides insights into the roles of one bryophyte co-retained gene in the desiccation tolerance.

UNASSIGNED: The study was carried out to assess the effect of zinc supplementation on changes in calcium homeostasis, and parathyroid gland, bone, and skeletal muscle histology in rats exposed to subchronic oral glyphosate-based herbicide (GBH, GOBARA®) toxicity.
UNASSIGNED: Sixty male Wistar rats in 6 equal groups (DW, Z, G1, G2, ZG1, ZG2) were used: DW and Z were given 2 mL/kg distilled water and 50 mg/kg of zinc chloride (2%), respectively; G1 and G2 received 187.5 mg/kg and 375 mg/kg of glyphosate (in GBH), respectively; ZG1 and ZG2 were pretreated with 50 mg/kg of zinc chloride before receiving glyphosate, 1 hour later, at 187.5 and 375 mg/kg, respectively. Treatments were by gavage once daily for 16 weeks. Serum calcium, vitamin D, and parathormone were estimated. Histopathological examination of parathyroid gland, femoral bone and biceps femoris muscle was done.
UNASSIGNED: GBH exposure caused significant (P = .0038) decrease in serum calcium concentration in G1, significant (P = .0337) decrease in serum vitamin D concentration in G1, significant increases in parathormone in G1 (P = .0168) and G2 (P = .0079) compared to DW. Significant (P > .05) changes did not occur in the other parameters of G2 compared to DW. Dose-dependent effect in GBH exposure was not observed after comparing G1 and G2. Necrotic changes occurred in parathyroid gland cells, osteocytes, and muscle cells in G1 and G2. In ZG1 and ZG2, significant (P > .05) variations in the parameters were not observed and tissue lesions were absent.
UNASSIGNED: Subchronic GBH exposure impaired calcium homeostasis observed as hypocalcemia, hypovitaminemia D, and secondary hyperparathyroidism and caused tissue damage in parathyroid gland, bone, and muscle of rats and these were mitigated by zinc chloride pretreatment.

Zinc (Zn) and copper (Cu) are essential for normal brain functions. In particular, Zn and Cu are released to synaptic clefts during neuronal excitation. Synaptic Zn and Cu regulate neuronal excitability, maintain calcium (Ca) homeostasis, and play central roles in memory formation. However, in pathological conditions such as transient global ischemia, excess Zn is secreted to synaptic clefts, which causes neuronal death and can eventually trigger the pathogenesis of a vascular type of senile dementia. We have previously investigated the characteristics of Zn-induced neurotoxicity and have demonstrated that low concentrations of Cu can exacerbate Zn neurotoxicity. Furthermore, during our pharmacological approaches to clarify the molecular pathways of Cu-enhanced Zn-induced neurotoxicity, we have revealed the involvement of Ca homeostasis disruption. In the present review, we discuss the roles of Zn and Cu in the synapse, as well as the crosstalk between Zn, Cu, and Ca, which our study along with other recent studies suggest may underlie the pathogenesis of vascular-type senile dementia.

UNASSIGNED: Heart failure (HF) is a leading cause of morbidity and mortality worldwide. RNA-binding proteins are identified as regulators of cardiac disease; DDX5 (dead-box helicase 5) is a master regulator of many RNA processes, although its function in heart physiology remains unclear.
UNASSIGNED: We assessed DDX5 expression in human failing hearts and a mouse HF model. To study the function of DDX5 in heart, we engineered cardiomyocyte-specific Ddx5 knockout mice. We overexpressed DDX5 in cardiomyocytes using adeno-associated virus serotype 9 and performed transverse aortic constriction to establish the murine HF model. The mechanisms underlined were subsequently investigated using immunoprecipitation-mass spectrometry, RNA-sequencing, alternative splicing analysis, and RNA immunoprecipitation sequencing.
UNASSIGNED: We screened transcriptome databases of murine HF and human dilated cardiomyopathy samples and found that DDX5 was significantly downregulated in both. Cardiomyocyte-specific deletion of Ddx5 resulted in HF with reduced cardiac function, an enlarged heart chamber, and increased fibrosis in mice. DDX5 overexpression improved cardiac function and protected against adverse cardiac remodeling in mice with transverse aortic constriction-induced HF. Furthermore, proteomics revealed that DDX5 is involved in RNA splicing in cardiomyocytes. We found that DDX5 regulated the aberrant splicing of Ca2+/calmodulin-dependent protein kinase IIδ (CamkIIδ), thus preventing the production of CaMKIIδA, which phosphorylates L-type calcium channel by serine residues of Cacna1c, leading to impaired Ca2+ homeostasis. In line with this, we found increased intracellular Ca2+ transients and increased sarcoplasmic reticulum Ca2+ content in DDX5-depleted cardiomyocytes. Using adeno-associated virus serotype 9 knockdown of CaMKIIδA partially rescued the cardiac dysfunction and HF in Ddx5 knockout mice.
UNASSIGNED: These findings reveal a role for DDX5 in maintaining calcium homeostasis and cardiac function by regulating alternative splicing in cardiomyocytes, identifying the DDX5 as a potential target for therapeutic intervention in HF.

BACKGROUND: Apheresis is practiced widely to collect single donor platelets (SDPs). This procedure utilizes an anticoagulant acid citrate dextrose to prevent clotting of blood in the extracorporeal circuit which chelates divalent ions like calcium. This alters the calcium homeostasis resulting in hypocalcemia causing acute adverse events.
OBJECTIVE: The study aimed to know the calcium homeostasis in apheresis platelet donors.
METHODS: This cross-sectional study was conducted from January 2020 to December 2020 in the department of transfusion medicine. The sample size was 50. Donors who walk in for voluntary SDP donation were selected. Total and ionized calcium, pH, and serum albumin for all the donors at baseline and ionic calcium at the end of the procedure and 30 min after the procedure were measured.
RESULTS: According to statistical analysis of the ionic calcium level at pre procedure, immediate post procedure and 30 minutes post procedure, there was decrease in the value immediate post procedure and values returned to baseline within 30 minutes. The levels of pH change were analyzed. On comparing the preprocedure and immediate postprocedure values, there was a significant lowering of pH value from the baseline (P = 0.5), indicating acute lowering of pH immediate postprocedure. Hence, most of the citrate metabolism can be achieved within 30 min after completion of the apheresis procedure.
CONCLUSIONS: SDP collection is essentially a safe procedure with minimal adverse effects. Toxicity of citrate is not much pronounced. Recovery of calcium levels is within 30 min of completion of plateletpheresis.

Limb-Girdle Muscular Dystrophy R1/2A (LGMD R1/2A) is caused by mutations in the CAPN3 gene encoding Calpain 3, a skeletal-muscle specific, Ca2+-dependent protease. Localization of Calpain 3 within the triad suggests it contributes to Ca2+ homeostasis. Through live-cell Ca2+ measurements, muscle mechanics, immunofluorescence, and electron microscopy (EM) in Capn3 deficient (C3KO) and wild-type (WT) mice, we determined whether loss of Calpain 3 altered Store-Operated Calcium Entry (SOCE) activity. Direct Ca2+ influx measurements revealed loss of Capn3 elicits elevated resting SOCE and increased resting cytosolic Ca2+, supported by high incidence of calcium entry units (CEUs) observed by EM. C3KO and WT mice were subjected to a single bout of treadmill running to elicit SOCE. Within 1HR post-treadmill running, C3KO mice exhibited diminished force production in extensor digitorum longus muscles and a greater decay of Ca2+ transients in flexor digitorum brevis muscle fibers during repetitive stimulation. Striking evidence for impaired exercise-induced SOCE activation in C3KO mice included poor colocalization of key SOCE proteins, stromal-interacting molecule 1 (STIM1) and ORAI1, combined with disappearance of CEUs in C3KO muscles. These results demonstrate that Calpain 3 is a key regulator of SOCE in skeletal muscle and identify SOCE dysregulation as a contributing factor to LGMD R1/2A pathology.

Electroacupuncture pretreatment is considered as an optimal strategy for inducing cerebral ischaemic tolerance. However, the underlying neuroprotective mechanism of this approach has never been explored from the perspective of calcium homeostasis. Intracellular calcium overload is a key inducer of cascade neuronal injury in the early stage after cerebral ischaemia attack and the Na+/Ca2+ exchanger (NCX) is the main plasma membrane calcium extrusion pathway maintaining post-ischaemic calcium homeostasis. This study aims to investigate whether the regulation of NCX-mediated calcium transport contributes to the cerebroprotective effect of electroacupuncture pretreatment against ischaemic injury and to elucidate the underlying mechanisms involved in this process. Following five days of repeated electroacupuncture stimulation on Baihui (GV20), Neiguan (PC6), and Sanyinjiao (SP6) acupoints in rats, in vivo and in vitro models of cerebral ischaemia were induced through middle cerebral artery occlusion and oxygen/glucose deprivation (OGD), respectively. Firstly, we verified the neuroprotective effect of electroacupuncture pretreatment from the perspective of neurological score, infarct volume and neuronal apoptosis. Our findings from brain slice patch-clamp indicated that electroacupuncture pretreatment enhanced the Ca2+ efflux capacity of NCX after OGD. NCX1 expression in the ischaemic penumbra exhibited a consistent decline from 1 to 24 h in MCAO rats. Electroacupuncture pretreatment upregulated the expression of NCX1, especially at 24 h, and silencing NCX1 by short hairpin RNA (shRNA) administration reversed the protective effect of electroacupuncture pretreatment against cerebral ischaemic injury. Furthermore, we administered LY294002, a phosphatidylinositol 3 kinase (PI3K) inhibitor, prior to inducing ischaemia to investigate the upstream regulatory mechanism of electroacupuncture pretreatment on NCX1 expression. Electroacupuncture pretreatment activates PI3K/Akt pathway, leading to an increase in the expression of NCX1, which facilitates calcium extrusion and exerts a neuroprotective effect against cerebral ischaemia. These findings provided a novel insight into the prevention of ischemic stroke and other similar conditions characterized by brain ischaemia or hypoperfusion.