Elevation Of Calcium Concentration Research Articles

Impact and accumulation of calcium on soft-shell mud crab Scylla paramamosain in recirculating aquaculture system

Soft-shell crabs are highly valued for their commercial significance and culinary appeal. To enhance production of soft-shell crabs, careful attention should be paid to the water calcium concentration in their culture. This study investigated the influences of different levels of calcium concentrations on the molting and growth of mud crab (Scylla paramamosain) within a meticulously controlled recirculating aquaculture system (RAS). We established three distinct water calcium concentration gradients (200, 300, and 450 mg/L) to comprehensively assess feeding habits, molting patterns, growth, and tissue calcium levels of mud crab. Initially, we observed a gradual reduction in water calcium concentrations with increments of crab molting events in RAS. Throughout one molting cycle, the feeding incidence of the crabs remained consistently high from 4 days to 37 days post-molt, irrespective of different calcium concentrations. Nonetheless, high water calcium levels (300 and 450 mg/L) significantly shortened molt intervals and accelerated exoskeletal calcification. Specifically, the molt intervals were 52.30 ± 2.72 d, 41.65 ± 5.24 d, and 37.70 ± 3.02 d, while the carapace hardening durations were 21.51 ± 4.33 h, 17.23 ± 3.38 h, and 13.46 ± 2.76 h at water calcium concentrations of 200, 300, and 450 mg/L, respectively. Moreover, elevated calcium concentrations also significantly enhanced weight gain of the mud crab during molting. Noteworthy, regardless of fluctuations in water calcium concentration, the condition factor of the molting crabs was approximately 63%, which could be an indicator of crab selection in soft-shell crab cultivation. Furthermore, the dynamic changes in calcium concentrations were disparate among different tissues in the post-molt stage. Gill and exoskeleton tissues exhibited an upward trend in calcium concentrations, while hemolymph and hepatopancreas tissues displayed distinct patterns of decrease followed by increase. Gill and exoskeleton tissues were identified as primary sites for calcium absorption and utilization, evidenced by a positive correlation between high calcium concentrations and increased calcium content in these tissues at 6 h and 3 d post-molt. Overall, our findings provide practical evidence for optimizing aquaculture management strategies through adjustments in water calcium concentration, thus to enhance production efficiency and profitability in soft-shell mud crab aquaculture.

Intestinal Piezo1 aggravates intestinal barrier dysfunction during sepsis by mediating Ca2+ influx

IntroductionIntestinal barrier dysfunction is a pivotal factor in sepsis progression. The mechanosensitive ion channel Piezo1 is associated with barrier function; however, its role in sepsis-induced intestinal barrier dysfunction remains poorly understood.MethodsThe application of cecal ligation and puncture (CLP) modeling was performed on both mice of the wild-type (WT) variety and those with Villin-Piezo1flox/flox genetic makeup to assess the barrier function using in vivo FITC-dextran permeability measurements and immunofluorescence microscopy analysis of tight junctions (TJs) and apoptosis levels. In vitro, Caco-2 monolayers were subjected to TNF-α incubation. Moreover, to modulate Piezo1 activation, GsMTx4 was applied to inhibit Piezo1 activation. The barrier function, intracellular calcium levels, and mitochondrial function were monitored using calcium imaging and immunofluorescence techniques.ResultsIn the intestinal tissues of CLP-induced septic mice, Piezo1 protein levels were notably elevated compared with those in normal mice. Piezo1 has been implicated in the sepsis-mediated disruption of TJs, apoptosis of intestinal epithelial cells, elevated intestinal mucosal permeability, and systemic inflammation in WT mice, whereas these effects were absent in Villin-Piezo1flox/flox CLP mice. In Caco-2 cells, TNF-α prompted calcium influx, an effect reversed by GsMTx4 treatment. Elevated calcium concentrations are correlated with increased accumulation of reactive oxygen species, diminished mitochondrial membrane potential, and TJ disruption.ConclusionsThus, Piezo1 is a potential contributor to sepsis-induced intestinal barrier dysfunction, influencing apoptosis and TJ modification through calcium influx-mediated mitochondrial dysfunction.

REVIEW OF THE PHYTOTHERAPY FOR NEPHROLITHIASIS

Nephrolithiasis (kidney stone) cases have a prevalence ranging from 1% to 13%. The disease not only hampers kidney function but also elevates the risk of chronic kidney diseases. The pathophysiology of nephrolithiasis is closely linked to elevated concentrations of calcium, oxalate, and/or uric acid in the urine. Pharmacotherapy to manage nephrolithiasis includes thiazide diuretics, allopurinol, citrate supplements, and alpha-blockers that have been prescribed to relieve symptoms. In addition, there is growing interest in exploring the potential of phytotherapy. This review aims to identify suitable phytotherapy approaches by examining relevant articles on nephrolithiasis. The research methodology involved searching PubMed articles using the keywords of (("Plant Extracts") AND ("Nephrolithiasis")) OR ("Ureterolithiasis"). The articles obtained from the initial search were n =123. 2 authors screened articles for their eligibility. The inclusion criteria were limited to articles written in English, topics related to nephrolithiasis and not other kidney diseases, the botanical names of the plants and the method of extraction are clearly described, complete studies with clear descriptions regarding the methods and results, not synthetic drugs, and not involving medical instruments or laser to remove the stones. Articles included in the review were n = 17. Water and hydro-alcohol were the solvents used to extract the plants. Twenty-two plants have confirmed their anti-nephrolithiasis activity, and nine articles described the assay by in vivo study, two by in vitro study, three by both in vitro and in vivo study, and only one article mentioned a study in humans by a randomized-control trial on a mixture of herbs. It is concluded that Rhizoma alismatis, Poria cocos, Polyporus umbellatus, Atractylodis macrocephalae, and Cinnamomi Cassiae prepared as a mixture in the Wu-Ling-San formula have a potential therapeutic effect on nephrolithiasis, as this formula has been studied in humans.

A steady-state pH-control model for the biological production of elemental sulfur from sulfate in mining-influenced water

We developed a model to predict pH, alkalinity, and the Langelier Saturation Index (LSI) in coupled systems of hydrogen-based autotrophic sulfate reduction and aerobic oxidation of sulfide to elemental sulfur. To neutralize the biologically generated base, the model allows for the addition of CO2 as part of the gas mixture, the independent addition of HCl or CO2, or a combination of the alternatives. The model was evaluated against the results from a laboratory system for the production of elemental sulfur from sulfate present in mine-tailings water, which is characterized by the presence of elevated sulfate and calcium concentrations. Model results were consistent with measurements of pH, alkalinity, and LSI. The model showed how the acid demands of the coupled reactors vary with pH, being approximately equivalent at pH over 8, when ionized sulfide predominates. Also, while the sulfidogenic reactor was well buffered due to the production of ionized sulfide, the sulfidotrophic reactor in the absence of sulfide and carbonate alkalinity was prone to pH declines. Considering that both reactors operated in the positive range of LSI, the model also indicated that addition of CO2 should be minimized due to increase in the bicarbonate concentration and its effect on increasing the LSI. Furthermore, the model also showed that exclusive reliance on HCl for pH control can be incompatible with Cl− effluent standards, which means that a compromise must be reached between CO2 and HCl additions.

Regulatory effect of bacterial melanin on the isoforms of new superoxide-producing associates from rat tissues in rotenone-induced Parkinson’s disease

According to recent research, selective neuronal vulnerability in Parkinson’s disease (PD) results from several phenotypic traits, including calcium-dependent, feed-forward control of mitochondrial respiration leading to elevated reactive oxygen species and cytosolic calcium concentration, an extensive axonal arbor, and a reactive neurotransmitter. Therefore, antioxidant therapy is a promising direction in the treatment of PD. In vitro studies have indicated the survival-promoting activity of bacterial melanin (BM) on midbrain dopaminergic neuron cultures. It has been established that BM has a number of protective and anti-inflammatory properties, so there is a high probability of a protective effect of BM in the early stages of PD. In this study, PD was induced through the unilateral intracerebral administration of rotenone followed by bacterial melanin. Tissues (brain, lungs, and small intestine) from the observed groups underwent isolation and purification to extract isoforms of new thermostable superoxide (О2−)-producing associates between NADPH-containing lipoprotein (NLP) and NADPH oxidase-Nox (NLP-Nox). The optical absorption spectral characteristics, specific amounts, stationary concentration of the produced О2−, and the content of NADPH in the observed associates were determined. The optical absorption spectra of the NLP-Nox isoforms in the visible and UV regions in the experimental groups did not differ from those of the control group. However, compared with the control group, the specific content of the total fractions of NLP-Nox isoforms associated with PD groups was higher, especially in the small intestine. These findings suggest that the described changes may represent a novel mechanism for rotenone-induced PD. Furthermore, bacterial melanin demonstrated antioxidant properties and regulated membrane formation in the brain, lung, and small intestine. This regulation occurred by inhibiting the release of new membrane-bound formations (NLP-Nox associates) from these membranes while simultaneously regulating the steady-state concentration of the formed О2−.

CaMKK2 and CHK1 phosphorylate human STN1 in response to replication stress to protect stalled forks from aberrant resection

Keeping replication fork stable is essential for safeguarding genome integrity; hence, its protection is highly regulated. The CTC1-STN1-TEN1 (CST) complex protects stalled forks from aberrant MRE11-mediated nascent strand DNA degradation (NSD). However, the activation mechanism for CST at forks is unknown. Here, we report that STN1 is phosphorylated in its intrinsic disordered region. Loss of STN1 phosphorylation reduces the replication stress-induced STN1 localization to stalled forks, elevates NSD, increases MRE11 access to stalled forks, and decreases RAD51 localization at forks, leading to increased genome instability under perturbed DNA replication condition. STN1 is phosphorylated by both the ATR-CHK1 and the calcium-sensing kinase CaMKK2 in response to hydroxyurea/aphidicolin treatment or elevated cytosolic calcium concentration. Cancer-associated STN1 variants impair STN1 phosphorylation, conferring inability of fork protection. Collectively, our study uncovers that CaMKK2 and ATR-CHK1 target STN1 to enable its fork protective function, and suggests an important role of STN1 phosphorylation in cancer development.

Food-grade titanium dioxide and zinc oxide nanoparticles induce toxicity and cardiac damage after oral exposure in rats

BackgroundMetallic nanoparticles (NPs) are widely used as food additives for human consumption. NPs reach the bloodstream given their small size, getting in contact with all body organs and cells. NPs have adverse effects on the respiratory and intestinal tract; however, few studies have focused on the toxic consequences of orally ingested metallic NPs on the cardiovascular system. Here, the effects of two food-grade additives on the cardiovascular system were analyzed.MethodsTitanium dioxide labeled as E171 and zinc oxide (ZnO) NPs were orally administered to Wistar rats using an esophageal cannula at 10 mg/kg bw every other day for 90 days. We evaluated cardiac cell morphology and death, expression of apoptotic and autophagic proteins in cardiac mitochondria, mitochondrial dysfunction, and concentration of metals on cardiac tissue.ResultsHeart histology showed important morphological changes such as presence of cellular infiltrates, collagen deposition and mitochondrial alterations in hearts from rats exposed to E171 and ZnO NPs. Intracellular Cyt-C levels dropped, while TUNEL positive cells increased. No significant changes in the expression of inflammatory cytokines were detected. Both NPs altered mitochondrial function indicating cardiac dysfunction, which was associated with an elevated concentration of calcium. ZnO NPs induced expression of caspases 3 and 9 and two autophagic proteins, LC3B and beclin-1, and had the strongest effect compared to E171.ConclusionsE171 and ZnO NPs induce adverse cardiovascular effects in rats after 90 days of exposure, thus food intake containing these additives, should be taken into consideration, since they translocate into the bloodstream and cause cardiovascular damage.

SAT182 Effects Of An Orally Bioavailable Nonpeptide Parathyroid Hormone Receptor Type 1 (PTH1R) Antagonist In Rodent Models Of Primary Hyperparathyroidism (PHPT)

Abstract Disclosure: A.S. Antwan: Employee; Self; Crinetics Pharmaceuticals. E. Rico-Bautista: Employee; Self; Crinetics Pharmaceuticals. J. Pontillo: Employee; Self; Crinetics Pharmaceuticals. S. Wang: Employee; Self; Crinetics Pharmaceuticals. M. Johns: Employee; Self; Crinetics Pharmaceuticals. B. Ramms: Employee; Self; Crinetics Pharmaceuticals. M.A. Fowler: Employee; Self; Crinetics Pharmaceuticals. J.B. Nguyen: Employee; Self; Crinetics. A.A. Castellanos Gonzalez: Employee; Self; Crinetics. B. Fleck: Employee; Self; Crinetics Pharmaceuticals. K. Retting: Employee; Self; Crinetics Pharmaceuticals. D. Dalvie: Employee; Self; Crinetics Pharmaceuticals. S.F. Betz: Employee; Self; Crinetics Pharmaceuticals. S. Markison: Employee; Self; Crinetics Pharmaceuticals. Primary hyperparathyroidism (PHPT) is a condition resulting from an over-secretion of parathyroid hormone (PTH) from one or more overactive parathyroid glands. PTH is a peptide hormone that regulates blood calcium concentrations through effects on bone, intestines, and kidney. PTH acts on parathyroid hormone receptor type 1 (PTH1R) in the kidney to increase calcium reabsorption and block phosphate reabsorption. The loss of phosphate ions then causes an increase in ionized calcium in the blood and cAMP in the urine. At the bone, continuous PTH infusion stimulates osteoclast activity while inhibiting osteoblast activity, leading to breakdown of bone and release of calcium into the extracellular fluid. Conditions that cause excess PTH, such as PHPT, result in elevated concentrations of plasma calcium, increased bone loss, increased fracture risk, and higher susceptibility to kidney stone development. PHPT affects approximately 100,000 patients per year, but many patients are asymptomatic and remain undiagnosed. While a partial or total parathyroidectomy may be suitable for patients diagnosed with severe cases of PHPT, there are limited treatment options for those who do not meet the criteria or do not wish to undergo surgery. The goals for medicinal treatment are to normalize blood calcium levels and urinary calcium excretion, as well as increase bone mineral density to reduce fracture risk. Blocking PTH action directly via a potent PTH1R antagonist may provide an important new therapeutic mechanism to treat patients with PHPT. Using iterative medicinal chemistry and pharmacology, Crinetics has identified several potent and orally bioavailable PTH1R antagonists with good drug-like properties. Lead molecules were evaluated in vivo in preclinical rodent models for their ability to suppress the effects of excess PTH on serum calcium, bone turnover, and cAMP levels in the kidney. One of these compounds, ANT-5, was characterized as a potent negative allosteric modulator of both human and rat PTH1R. In rats, oral administration of ANT-5 dose-dependently suppressed PTH-induced hypercalcemia. ANT-5 also suppressed PTH-stimulated urinary cAMP in rats, indicating its ability to inhibit the actions of PTH in the kidney. We further evaluated the effect of ANT-5 in a rodent model of continuous PTH infusion-induced bone turnover. Once-daily oral administration of ANT-5 mitigated PTH-induced bone resorption, suggesting that inhibiting PTH1R may have beneficial clinical effects on bone density. The culmination of these studies has led to a subset of candidate molecules that are being evaluated in safety studies to identify the compound(s) suitable for evaluation in human clinical trials. Support: Crinetics Pharmaceuticals. Presentation: Saturday, June 17, 2023

Impact of Arbuscular mycorrhizal Fungal Strains Isolated from Soil on the Growth, Yield, and Fruit Quality of Tomato Plants under Different Fertilization Regimens

Arbuscular mycorrhizal fungi (AMF) have emerged as a promising and environmentally friendly solution for sustainable agriculture, offering a reduction in dependence on chemical inputs. The objective of this greenhouse experiment was to assess the efficacy of a natural endomycorrhizal inoculum obtained from leek root fragments, which acted as a trap plant to capture indigenous fungal spores present in the soil of the Guercif region in Morocco. The investigation aimed to comprehensively evaluate the influence of this inoculum on various parameters related to tomato plant growth, yield, and sensory quality. Additionally, different levels of chemical fertilizers, equivalent to 50%, 75%, and 100% of the recommended dosage, were administered in combination with or without the inoculum. The findings elucidated significant advantages associated with mycorrhizal inoculation. The plants subjected to inoculation exhibited increased plant height, augmented leaf and root dry weights, and improved nutrient uptake compared to the control group. Notably, tomato plants treated with 75% of the recommended chemical fertilizer dosage yielded the highest crop production, with no statistically significant difference observed when compared to those receiving the full dosage (100%). Intriguingly, tomato plants grown in substrates receiving 50% chemical fertilizers demonstrated the highest levels of mycorrhization, exhibiting a frequency (F) of 100% and an intensity (M) of 63%. Importantly, the combination of inoculation with a reduced dose of NPK fertilizer (50% of the recommended amount) resulted in significantly elevated concentrations of calcium (Ca), potassium (K), iron (Fe), zinc (Zn), and phosphorus (P) in the plants, attributable to the heightened mycorrhizal colonization of the roots. In terms of fruit characteristics, no significant variations were detected in pH and electrical conductivity (EC) among the treatment groups. However, the inoculated plants exhibited a notable increase in the Brix index, an indicator of sweetness, compared to the control group across all fertilizer doses. Furthermore, inoculation positively influenced the levels of total carotenoids in the fruits. Remarkably, the values of these compounds in the inoculated plants subjected to 50% of the recommended fertilizer dosage surpassed those recorded in the non-inoculated plants receiving the full dosage.

Recent advances in the structure and activation mechanisms of metabolite-releasing Pannexin 1 channels.

Pannexin 1 (PANX1) is a widely expressed large-pore ion channel located in the plasma membrane of almost all vertebrate cells. It possesses a unique ability to act as a conduit for both inorganic ions (e.g. potassium or chloride) and bioactive metabolites (e.g. ATP or glutamate), thereby activating varying signaling pathways in an autocrine or paracrine manner. Given its crucial role in cell-cell interactions, the activity of PANX1 has been implicated in maintaining homeostasis of cardiovascular, immune, and nervous systems. Dysregulation of PANX1 has also been linked to numerous diseases, such as ischemic stroke, seizure, and inflammatory disorders. Therefore, the mechanisms underlying different modes of PANX1 activation and its context-specific channel properties have gathered significant attention. In this review, we summarize the roles of PANX1 in various physiological processes and diseases, and analyze the accumulated lines of evidence supporting diverse molecular mechanisms associated with different PANX1 activation modalities. We focus on examining recent discoveries regarding PANX1 regulations by reversible post-translational modifications, elevated intracellular calcium concentration, and protein-protein interactions, as well as by irreversible cleavage of its C-terminal tail. Additionally, we delve into the caveats in the proposed PANX1 gating mechanisms and channel open-closed configurations by critically analyzing the structural insights derived from cryo-EM studies and the unitary properties of PANX1 channels. By doing so, we aim to identify potential research directions for a better understanding of the functions and regulations of PANX1 channels.

The Use of Tricaine Methanesulfonate (MS-222) in Asian Seabass (Lates calcarifer) at Different Temperatures: Study of Optimal Doses, Minimum Effective Concentration, Blood Biochemistry, Immersion Pharmacokinetics, and Tissue Distributions.

This study was conducted to determine the optimal doses and minimum effective concentrations (MECs) of tricaine methanesulfonate (MS-222) in marketable-size Asian seabass reared at two temperatures (22 and 28 °C). Serum biochemical parameters, pharmacokinetics, and tissue distributions of MS-222 following immersion at the determined optimal doses were also evaluated in order to delineate possible mechanisms dictating the temperature difference. The definition of optimal dose is set as the dose when fish attain stage III anesthesia within 5 min, sustain this stage for 3 min, and re-attain equilibrium within 5 min. The MEC is the fish serum MS-222 concentration when stage III anesthesia is reached. The results showed that water temperature exerted no or minimal impact on the designated parameters. The optimal doses at 22 and 28 °C were 140 and 150 µg/mL, while the MECs were 70.48 and 78.27 µg/mL, respectively. Fish exposed to the optimal doses of MS-222 had significantly elevated blood concentrations of lactate, glucose, calcium, magnesium, and sodium, while the blood pH was significantly decreased. The fish eliminated MS-222 faster at 28 °C than at 22 °C, with serum half-lives of 18.43 and 37.01 h, respectively. Tissue-specific distribution patterns were evident. Irrespective of water temperature, MS-222 peaked at 5 min for the brain and gill but peaked slightly later at 10-20 min for the liver and kidney. Most tissues exhibit a gradual decline of drug concentration except for the gill, which was maintained at a steady level. Muscle is the least perfused tissue with the lowest drug concentration throughout the 90 min period. This study provided physiological and pharmacokinetic evidence contributing to a better understanding of the actions of MS-222 in Asian seabass at different temperatures.

Leveraging Plasma Membrane Repair Therapeutics for Treating Neurodegenerative Diseases.

Plasma membrane repair is an essential cellular mechanism that reseals membrane disruptions after a variety of insults, and compromised repair capacity can contribute to the progression of many diseases. Neurodegenerative diseases are marked by membrane damage from many sources, reduced membrane integrity, elevated intracellular calcium concentrations, enhanced reactive oxygen species production, mitochondrial dysfunction, and widespread neuronal death. While the toxic intracellular effects of these changes in cellular physiology have been defined, the specific mechanism of neuronal death in certain neurodegenerative diseases remains unclear. An abundance of recent evidence indicates that neuronal membrane damage and pore formation in the membrane are key contributors to neurodegenerative disease pathogenesis. In this review, we have outlined evidence supporting the hypothesis that membrane damage is a contributor to neurodegenerative diseases and that therapeutically enhancing membrane repair can potentially combat neuronal death.

Calpain-mediated Mechanoptosis in Breast Adenocarcinoma.

Calpains belong to a family of important calcium-dependent cysteine proteases. They are involved in intracellular processes including cytoskeleton disorganization and substrate proteolysis. They also enhance apoptosis and cell to cell adhesion. Calpains demonstrate also a mechanosensory function in neoplastic and malignant cells due to their implication in mechanoptosis. This is a specific type of apoptotic death induced by strong external mechanical stimuli. Anti-cytoskeleton rigidity inhibition strategies based on calpain induction lead to increased apoptosis of tumor transformed cells. Elevated intracellular calcium concentration mediated by specific receptors and channels activates calpains. In the current molecular review, we explored the role of calpains in calcium-dependent signa transduction pathways in breast adenocarcinoma in conjunction with novel agents that activate their important anti-tumor functions.

The role of Ca2+ signalling in the pathology of exocrine pancreas

Exocrine pancreas has been the field of many successful studies in pancreatic physiology and pathology. However, related disease - acute pancreatitis (AP) is still takes it toll with more than 100,000 related deaths worldwide per year. In spite of significant scientific progress and several human trials currently running for AP, there is still no specific treatment in the clinic. Studies of the mechanism of initiation of AP have identified two crucial conditions: sustained elevations of cytoplasmic calcium concentration (Ca2+ plateau) and significantly reduced intracellular energy (ATP depletion). These hallmarks are interdependent, i.e., Ca2+ plateau increase energy demand for its clearance while energy production is greatly affected by the pathology. Result of long standing Ca2+ plateau is destabilisation of the secretory granules and premature activation of the digestive enzymes leading to necrotic cell death. Main attempts so far to break the vicious circle of cell death have been concentrated on reduction of Ca2+ overload or reduction of ATP depletion. This review will summarise these approaches, including recent developments of potential therapies for AP.

MicroRNA-423-5p Mediates Cocaine-Induced Smooth Muscle Cell Contraction by Targeting Cacna2d2.

Cocaine abuse increases the risk of atherosclerotic cardiovascular disease (CVD) and causes acute coronary syndromes (ACS) and hypertension (HTN). Significant research has explored the role of the sympathetic nervous system mediating the cocaine effects on the cardiovascular (CV) system. However, the response of the sympathetic nervous system alone is insufficient to completely account for the CV consequences seen in cocaine users. In this study, we examined the role of microRNAs (miRNAs) in mediating the effect of cocaine on the CV system. MiRNAs regulate many important biological processes and have been associated with both response to cocaine and CV disease development. Multiple miRNAs have altered expression in the CV system (CVS) upon cocaine exposure. To understand the molecular mechanisms underlying the cocaine response in the CV system, we studied the role of miRNA-423-5p and its target Cacna2d2 in the regulation of intracellular calcium concentration and SMC contractility, a critical factor in the modulation of blood pressure (BP). We used in vivo models to evaluate BP and aortic stiffness. In vitro, cocaine treatment decreased miR-423-5p expression and increased Cacna2d2 expression, which led to elevated intracellular calcium concentrations and increased SMC contractility. Overexpression of miR-423-5p, silencing of its target Cacna2d2, and treatment with a calcium channel blocker reversed the elevated SMC contractility caused by cocaine. In contrast, suppression of miR-423-5p increased the intracellular calcium concentration and SMC contractibility. In vivo, smooth muscle-specific overexpression of miR-423-5p ameliorated the increase in BP and aortic stiffness associated with cocaine use. Thus, miR-423-5p regulates SMC contraction by modulating Cacna2d2 expression increasing intracellular calcium concentrations. Modulation of the miR-423-5p-Cacna2d2-Calcium transport pathway may represent a novel therapeutic strategy to improve cocaine-induced HTN and aortic stiffness.

Nanomechanical Profiling of Aβ42 Oligomer-Induced Biological Changes in Single Hippocampus Neurons.

Understanding how Aβ42 oligomers induce changes in neurons from a mechanobiological perspective has important implications in neuronal dysfunction relevant to neurodegenerative diseases. However, it remains challenging to profile the mechanical responses of neurons and correlate the mechanical signatures to the biological properties of neurons given the structural complexity of cells. Here, we quantitatively investigate the nanomechanical properties of primary hippocampus neurons upon exposure to Aβ42 oligomers at the single neuron level by using atomic force microscopy (AFM). We develop a method termed heterogeneity-load-unload nanomechanics (HLUN), which exploits the AFM force spectra in the whole loading-unloading cycle, allowing comprehensive profiling of the mechanical properties of living neurons. We extract four key nanomechanical parameters, including the apparent Young's modulus, cell spring constant, normalized hysteresis, and adhesion work, that serve as the nanomechanical signatures of neurons treated with Aβ42 oligomers. These parameters are well-correlated with neuronal height increase, cortical actin filament strengthening, and calcium concentration elevation. Thus, we establish an HLUN method-based AFM nanomechanical analysis tool for single neuron study and build an effective correlation between the nanomechanical profile of the single neurons and the biological effects triggered by Aβ42 oligomers. Our finding provides useful information on the dysfunction of neurons from the mechanobiological perspective.

A prognostication system based on clinical parameters and [18F]-FDG PET/CT in patients with newly diagnosed multiple myeloma.

This study aimed to assess prognosis of patients with newly diagnosed multiple myeloma (NDMM) by combining [18F]-FDG positron emission tomography (PET)/CT parameters and clinical indices. Clinical data and PET/CT parameters of 133 NDMM patients were retrospectively analyzed for associations between clinical indices and PET/CT parameters. Independent predictors of progression-free survival (PFS) and overall survival (OS) were determined. A new prognostic prediction system (NPPS) was constructed based on our findings. Prediction effectiveness was compared among the NPPS, International Staging System (ISS), Revised ISS (R-ISS), and R2-ISS. Prevalence of elevated β2-microglobulin, serum creatinine (sCr), serum calcium (sCa), and C-reactive protein concentrations was higher in patients with higher SUVmax (≥ 5.3). Prevalence of elevated sCa, sCr, and extramedullary disease (EMD) was higher in patients with a higher number of focal lesions (≥ 10). SUVmax, serum free-light chain (sFLC) ratio, and EMD were independent predictors of PFS and OS. The NPPS used SUVmax, sFLC ratio, and EMD could effectively predict OS and was more effective at prognostication than the ISS, R-ISS, and R2-ISS. [18F]-FDG PET/CT parameters play a significant role in predicting prognosis in NDMM patients. The NPPS based on SUVmax, sFLC ratio, and EMD outperformed the ISS, R-ISS, and R2-ISS in prognostication.

Influence of long-term sodium-glucose cotransporter 2 inhibition on cardiac remodeling in rats with type 1 diabetes mellitus

Abstract Background Sodium-glucose cotransporter 2 (SGLT2) inhibitors have beneficial effects on the cardiovascular system in diabetes mellitus (DM) patients. However, as most clinical trials were performed in type 2 DM, the effects of SGLT2 inhibitors in patients with type 1 DM still need further clarification. In this study, we evaluated the effects of long-term treatment with the SGLT2 inhibitor dapagliflozin on cardiac remodeling, myocardial function, and energy metabolism in rats with type 1 DM. Methods Male Wistar rats were divided into three groups: control (C, n=15); DM (n=15); and DM treated with dapagliflozin (DM+DAPA, n=15) for 30 weeks. DM was induced by streptozotocin; DAPA was added to the rat chow (5 mg/kg/day). Cardiac performance was evaluated by echocardiogram and myocardial function in isolated left ventricular (LV) papillary muscle preparations. Myocardial energy metabolism enzyme activities were evaluated by spectrophotometry. Statistical analyzes: ANOVA and Tukey or Kruskal-Wallis and Dunn. Results DM+DAPA had lower glycemia than DM [C 112 (108–116); DM 531 (522–535)*; DM+DAPA 267 (179–339) mg/dL; p<0.05 vs C and DM+DAPA]. Echocardiogram showed that DM and DM+DAPA had left atrium and left ventricle dilatation with systolic and diastolic dysfunction; in DM+DAPA, the changes were attenuated in relation to DM. Developed tension and +dT/dt were higher in DM+DAPA than DM in basal condition. After inotropic stimulation with post-pause contraction, extracellular calcium concentration elevation, and isoproterenol addition to the nutrient solution, +dT/dt and –dT/dt were higher in DM+DAPA than DM. Hexokinase, phosphofructokinase, and pyruvate kinase activity was lower in DM than the C. Phosphofructokinase and pyruvate kinase activity was higher in DM+DAPA than DM. Conclusion Long-term dapagliflozin treatment attenuates cardiac remodeling and myocardial dysfunction and preserves hexokinase, phosphofructokinase and pyruvate kinase activity in rats with type 1 diabetes mellitus. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): CNPq - National Council for Scientific and Technological Developmentdoctor

A revised calcium-dependent model of transcranial magnetic theta-burst stimulation

ObjectiveCalcium dependency is presently an essential assumption in modelling the neuromodulatory effects of transcranial magnetic stimulation. Y.Z.Huang et al.developed the first neuromodulation model to explain the bidirectional effects of theta-burst stimulation (TBS) based on the postsynaptic intracellular calcium concentration elevation. However, we discover that the published computer code is not consistent with the model formulation, neither do the parameters and derived plots consequently match the formulations. Here we intend to fix the computer code and re-calibrate the model. MethodsWe corrected the affected difference equations and re-calibrated the revised model with experimental data using non-convex optimisation based on a L2 penalty. ResultsThe revised model outperforms the initial model in characterising the relative motor-evoked potential levels of TBS-induced after-effects in various conditions. ConclusionsWe corrected the inconsistencies in the previous model and computer code and provided a complete calibration to support the research that is based on it. SignificanceThis work improves the accuracy and secures the scope of the model, which is necessary to retain a rich body of research resulting from the model. Furthermore, this model provides both a quantitative model for several parameters of TBS and a basic model foundation for future refinement.

Elevated and Sustained Intracellular Calcium Signalling Is Necessary for Efficacious Induction of the Human Sperm Acrosome Reaction.

Progesterone and prostaglandin E1 are postulated to trigger the human sperm acrosome reaction (AR). However, their reported efficacy is very variable which likely, in part, reflects the plethora of experimental conditions and methodologies used to detect this physiologically relevant event. The purpose of this study was to develop an assay for the robust induction and objective measurement of the complete AR. Sperm from healthy volunteers or patients undertaking IVF were treated with a variety of ligands (progesterone, prostaglandin E1 or NH4Cl, alone or in combinations). AR, motility and intracellular calcium measurements were measured using flow cytometry, computer-assisted sperm analysis (CASA) and fluorimetry, respectively. The AR was significantly increased by the simultaneous application of progesterone, prostaglandin E1 and NH4Cl, following an elevated and sustained intracellular calcium concentration. However, we observed notable inter- and intra-donor sample heterogeneity of the AR induction. When studying the patient samples, we found no relationship between the IVF fertilization rate and the AR. We conclude that progesterone and prostaglandin E1 alone do not significantly increase the percentage of live acrosome-reacted sperm. This assay has utility for drug discovery and sperm toxicology studies but is not predictive for IVF success.