Rise In Calcium Research Articles

Novel role of curcumin as inhibitor of β-amyloid-induced lamin fragmentation.

Oligomer amyloid beta 42 (Aβ) is considered the key pathogenic molecule in Alzheimer disease (AD) and causes specific lamin fragmentation. Curcumin has been recognized for its protective effects against Aβ-induced toxicity in AD, though its underlying mechanism remains unclear. In this study, the inhibitory mechanism of curcumin against Aβ-induced lamin fragmentation and cell death was investigated. Human neuroblastoma cells were used to examine Aβ-induced lamin fragmentation and lamin deformation by immunoblotting and confocal microscopy, while cell viability was measured using MTT and alamarBlue assay. Caspase and cathepsin L activity were assessed by spectrofluorometry, and Aβ aggregation was evaluated by ThT assay. Our results demonstrated that curcumin inhibited Aβ aggregation, reducing intracellular Aβ uptake by 45% compared to Aβ-treated cells. Curcumin also inhibited the Aβ-induced intracellular calcium rise, subsequently leading to a onefold reduction in cathepsin L activity. This reduction in cathepsin L activity by curcumin blocked the Aβ-induced lamin fragmentation. Collectively, these findings suggest that curcumin inhibits Aβ-induced cell death by preventing Aβ entry and lamin cleavage, providing potential new insights for AD treatment.

6980 A Case Report Of Severe Hypercalcemia In Acute Decompensated Liver Cirrhosis

Abstract Disclosure: M.M. Eid: None. R.M. Sargis: None. Introduction: Hypercalcemia in advanced liver disease in the absence of malignancy is a rare condition. Case: A 26 year old female with history of liver cirrhosis secondary to alcohol use disorder, presented with hematemesis and ascites. She was diagnosed with acute decompensated liver cell failure and transferred to our facility for liver transplantation. On Day 10 of her hospital course, she had an acute rise in serum calcium (Ca) to 10.8 mg/dl (N 8.7-10.5),albumin (Alb) 2.6 g/dl, corrected calcium (CCa) 11.9mg/dl. On day 13 Ca peaked to 13.5 mg/dl, CCa 14 mg/dl, ionized Ca 6.5mg/dl (N 4.2-5.4 mg/dl). Serum Ca was normal on day 9, Ca 8.7mg/dl, Alb 2.5 g/dl and CCa 9.9 mg/dl. She was not taking lithium, vitamin A or antacid. No personal or family history of bone disorder, fracture or kidney stone. On exam, blood pressure 85/45, heart rate 110 bpm, jaundiced with abdominal distension and respiratory distress. Labs: hemoglobin 8.1 g/dl, WBC 32.5K/Ul, platelet 136 K/Ul, serum creatinine 1.82 mg/dl, Na 133 mmol/l, K 3.5 mmol/l, Total/Direct bilirubin 29.9/18.1 mg/dl, alkaline phosphatase 166 U/L, AST/ALT 60/42U/l, Mag 2.3 mg/dl, Phos 5 mg/dl, INR 3, PTT 50 sec, parathyroid hormone (PTH) 12 pg/ml (N12-88), TSH 1.02 mciu/ml (N 0.34-4), 25 hydroxy vitamin D 17 ng/ml (N 20-80), parathyroid related peptide (PTHrP) 3.9 pmol/l (N<3.4), 1,25 di-hydroxy vitamin D 9.8 pg/ml (N 19.9-79.3), alpha fetoprotein 9.1 ng/ml (N <9). Normal anti smooth muscle and anti mitochondrial antibodies. Negative viral hepatitis serology. CT abdomen did not reveal hepatobiliary mass or tumor nor kidney stone. She was intubated and mechanically ventilated. Vasopressor support was initiated. One dose of calcitonin 4 units/kg and zoledronic acid 4 mg were given. Serum Ca decreased to 12 mg/dl, CCa 12.6 mg/dL then to 10.2 mg/dl, CCa 11mg/dl within hrs. Calcium normalized to 8.4mg/dl, CCa 9.2 mg/dl, ionized Ca 4.3 mg/dl within 24 hrs. Her condition deteriorated and withdrawal of care was decided. Conclusion: Our case demonstrates non PTH and non vitamin D mediated severe hypercalcemia in setting of acute decompensated cirrhosis and absence of malignancy. Previous literature has noted poor prognosis of hypercalcemia with acute decompensated cirrhosis. While hypercalcemia in cirrhosis may arise from paraneoplastic processes, in absence of malignancy it is speculated that acute hypercalcemia may arise from the inflammatory mediators inducing osteoclastic bone resorption as osteoclast activating factor, prostaglandin and immobilization. Some reports found an association between hypercalcemia and elevations in bilirubin and creatinine(1). Further research is needed to understand the pathophysiology and the management of hypercalcemia in acute decompensated cirrhosis.

NIR Laser Irradiation Promotes Osteogenic Differentiation of PDLSCs Through the Activation of TRPV1 Channels and Subsequent Calcium Signaling.

Near-infrared (NIR) irradiation has shown potential to stimulate osteogenic differentiation, but the mechanisms are not fully understood. The study is to investigate the effects of NIR laser irradiation on osteoblastic differentiation. Human periodontal ligament stem cells (hPDLSCs) were cultured in osteogenic medium and exposed to 810 nm NIR laser at 0.5 J/cm2 every 48 h. The transient receptor potential vanilloid (TRPV1) channel inhibitor capsazepine (CPZ) was used to evaluate the role of calcium influx. Osteogenic differentiation was assessed by proliferation (CCK-8), alkaline phosphatase (ALP) activity, mineralization (Alizarin Red), and expression of bone markers by PCR and Western blot over 2 weeks. Intracellular calcium was measured by Fluo-4M dye and flow cytometry. Results showed that NIR irradiation enhanced hPDLSC proliferation, ALP activity, mineralization, and bone marker expression, indicating increased osteogenic differentiation. These effects were inhibited by CPZ. NIR induced a transient rise in intracellular calcium peaking at 3 min, which was blocked by CPZ. In conclusion, this study demonstrates that NIR laser irradiation promotes osteogenic differentiation of PDLSCs through the activation of TRPV1 channels and subsequent calcium signaling. Further research is warranted to optimize the treatment parameters and elucidate the detailed signaling pathways involved, paving the way for the clinical application of NIR therapy in the treatment of bone disorders and periodontal disease.

High Impact AMPAkines Induce a Gq-Protein Coupled Endoplasmic Calcium Release in Cortical Neurons: A Possible Mechanism for Explaining the Toxicity of High Impact AMPAkines.

α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) positive allosteric modulators (AMPAkines) have a multitude of promising therapeutic properties. The pharmaceutical development of high impact AMPAkines has, however, been limited by the appearance of calcium-dependent neuronal toxicity and convulsions in vivo. Such toxicity is not observed at exceptionally high concentrations of low impact AMPAkines. Because most AMPAR are somewhat impermeable to calcium, the current study sought to examine the extent to which different mechanisms contribute to the rise in intracellular calcium in the presence of high impact ampakines. In the presence of AMPA alone, cytosolic calcium elevation is shown to be sodium-dependent. In the presence of high impact AMPAkines such as cyclothiazide (CTZ) or CX614, however, AMPAR potentiation also activates an additional mechanism that induces calcium release from endoplasmic reticular (ER) stores. The pathway that connects AMPAR to the ER system involves a Gq-protein, phospholipase Cβ-mediated inositol triphosphate (InsP3) formation, and ultimately stimulation of InsP3-receptors located on the ER. The same linkage was not observed using high concentrations of the low impact AMPAkines, CX516 (Ampalex), and CX717. We also demonstrate that CX614 produces neuronal hyper-excitability at therapeutic doses, whereas the newer generation low impact AMPAkine CX1739 is safe at exceedingly high doses. Although earlier studies have demonstrated a functional linkage between AMPAR and G-proteins, this report demonstrates that in the presence of high impact AMPAkines, AMPAR also couple to a Gq-protein, which triggers a secondary calcium release from the ER and provides insight into the disparate actions of high and low impact AMPAkines.

Confinement controls the directional cell responses to fluid forces

Our understanding of how fluid forces influence cell migration in confining environments remains limited. By integrating microfluidics with live-cell imaging, we demonstrate that cells in tightly-but not moderately-confined spaces reverse direction and move upstream upon exposure to fluid forces. This fluid force-induced directional change occurs less frequently when cells display diminished mechanosensitivity, experience elevated hydraulic resistance, or sense a chemical gradient. Cell reversal requires actin polymerization to the new cell front, as shown mathematically and experimentally. Actin polymerization is necessary for the fluid force-induced activation of NHE1, which cooperates with calcium to induce upstream migration. Calcium levels increase downstream, mirroring the subcellular distribution of myosin IIA, whose activation enhances upstream migration. Reduced lamin A/C levels promote downstream migration of metastatic tumor cells by preventing cell polarity establishment and intracellular calcium rise. This mechanism could allow cancer cells to evade high-pressure environments, such as the primary tumor.

A complex of the lipid transport ER proteins TMEM24 and C2CD2 with band 4.1 at cell-cell contacts.

Junctions between the ER and plasma membrane (PM) are implicated in calcium homeostasis, non-vesicular lipid transfer, and other cellular functions. Two ER proteins that function both as tethers to the PM via a polybasic C-terminus motif and as phospholipid transporters are brain-enriched TMEM24 (C2CD2L) and its paralog C2CD2. We report that both proteins also form a complex with band 4.1 family members, which in turn bind PM proteins including cell adhesion molecules such as SynCAM 1. This complex enriches TMEM24 and C2CD2 containing ER/PM junctions at sites of cell contacts. Dynamic properties of TMEM24-dependent ER/PM junctions are impacted when band 4.1 is part of the junction, as TMEM24 at cell-adjacent ER/PM junctions is not shed from the PM by calcium rise, unlike TMEM24 at non-cell adjacent junctions. Lipid transport between the ER and the PM by TMEM24 and C2CD2 at sites where cells, including neurons, contact other cells may participate in adaptive responses to cell contact-dependent signaling.

TRPV1-dependent NKCC1 activation in mouse lens involves integrin and the tubulin cytoskeleton.

Previously we showed hyperosmotic solution caused TRPV1-dependent NKCC1 activation in the lens by a mechanism that involved ERK1/2 signaling. In various tissues, integrins and the cytoskeletal network play a role in responses to osmotic stress. Here, we examined the association between integrins and TRPV1-dependent activation of NKCC1 in mouse lens epithelium. Wild-type (WT) lenses exposed to the integrin agonist leukadherin-1 (LA-1) for 10 min displayed a ~33% increase in the bumetanide-sensitive rate of Rb uptake indicating NKCC activation. Paclitaxel, a microtubule stabilizing agent, abolished the Rb uptake response. In primary cultured lens epithelium LA-1 caused a robust ERK1/2 activation response that was almost fully suppressed by paclitaxel. The TRPV1 agonist capsaicin caused a similar ERK1/2 activation response. Consistent with an association between integrins and TRPV1, the TRPV1 antagonist A889425 prevented the Rb uptake response to LA-1 as did the ERK inhibitor U0126. LA-1 did not increase Rb uptake by lenses from TRPV1 knockout mice. In cells exposed to a hyperosmotic stimulus, both the ERK1/2 activation and Rb uptake responses were prevented by paclitaxel. Taken together, the findings suggest TRPV1 activation is associated with integrins and the tubulin cytoskeleton. This aligned with the observation that LA-1 elicited a robust cytoplasmic calcium rise in cells from WT lenses but failed to increase calcium in cells from TRPV1 knockout lenses. The results are consistent with the notion that integrin activation by LA-1, or a hyperosmotic stimulus, causes TRPV1 channel opening and the consequent downstream activation of the ERK1/2 and NKCC1 responses.

Antisense oligonucleotide therapeutic approach for Timothy syndrome

Timothy syndrome (TS) is a severe, multisystem disorder characterized by autism, epilepsy, long-QT syndrome and other neuropsychiatric conditions1. TS type 1 (TS1) is caused by a gain-of-function variant in the alternatively spliced and developmentally enriched CACNA1C exon 8A, as opposed to its counterpart exon 8. We previously uncovered several phenotypes in neurons derived from patients with TS1, including delayed channel inactivation, prolonged depolarization-induced calcium rise, impaired interneuron migration, activity-dependent dendrite retraction and an unanticipated persistent expression of exon 8A2–6. We reasoned that switching CACNA1C exon utilization from 8A to 8 would represent a potential therapeutic strategy. Here we developed antisense oligonucleotides (ASOs) to effectively decrease the inclusion of exon 8A in human cells both in vitro and, following transplantation, in vivo. We discovered that the ASO-mediated switch from exon 8A to 8 robustly rescued defects in patient-derived cortical organoids and migration in forebrain assembloids. Leveraging a transplantation platform previously developed7, we found that a single intrathecal ASO administration rescued calcium changes and in vivo dendrite retraction of patient neurons, suggesting that suppression of CACNA1C exon 8A expression is a potential treatment for TS1. Broadly, these experiments illustrate how a multilevel, in vivo and in vitro stem cell model-based approach can identify strategies to reverse disease-relevant neural pathophysiology.

A phytosphingosine derivative mYG-II-6 inhibits histamine-mediated TRPV1 activation and MRGPRX2-dependent mast cell degranulation

BackgroundPhytosphingosine and its derivative are known for their skin-protective properties. While mYG-II-6, a phytosphingosine derivative, has shown anti-inflammatory and antipsoriatic effects, its potential antipruritic qualities have yet to be explored. This study aimed to investigate mYG-II-6′s antipruritic properties. MethodsThe calcium imaging technique was employed to investigate the activity of ion channels and receptors. Mast cell degranulation was confirmed through the β-hexosaminidase assay. Additionally, in silico molecular docking and an in vivo mouse scratching behavior test were utilized. ResultsUsing HEK293T cells transfected with H1R and TRPV1, we examined the impact of mYG-II-6 on histamine-induced intracellular calcium rise, a key signal in itch-mediating sensory neurons. Pretreatment with mYG-II-6 significantly reduced histamine-induced calcium levels and inhibited TRPV1 activity, suggesting its role in blocking the calcium influx channel. Additionally, mYG-II-6 suppressed histamine-induced calcium increase in primary cultures of mouse dorsal root ganglia, indicating its potential antipruritic effect mediated by histamine. Interestingly, mYG-II-6 exhibited inhibitory effects on human MRGPRX2, a G protein-coupled receptor involved in IgE-independent mast cell degranulation. However, it did not inhibit mouse MrgprB2, the ortholog of human MRGPRX2. Molecular docking analysis revealed that mYG-II-6 selectively interacts with the binding pocket of MRGPRX2. Importantly, mYG-II-6 suppressed histamine-induced scratching behaviors in mice. ConclusionsOur findings show that mYG-II-6 can alleviate histamine-induced itch sensation through dual mechanisms. This underscores its potential as a versatile treatment for various pruritic conditions.

Evaluation of the thiazide challenge test to differentiate primary from hypercalciuria-related hyperparathyroidism.

treatment of primary hyperparathyroidism (PHPT) and secondary hyperparathyroidism due to idiopathic hypercalciuria (SHPT-IH) is markedly different. Robust diagnostic tools to differentiate between both entities are however lacking. evaluate the thiazide challenge test (TCT) in clinical practice, its aid in clinical decision making, evaluate the accuracy (sensitivity, specificity) and potentially useful parameters of the TCT. monocentric observational retrospective cohort study from January 2017 to November 2023. outpatient, Ghent University Hospital (Belgium). 25 adult patients with hypercalciuria, elevated parathyroid hormone (PTH), and high-normal or elevated serum calcium that underwent a TCT. TCT. serum, urinary biochemical parameters before and after testing, clinical and imaging outcomes, treatment, and follow-up. patients with a TCT-based working diagnosis of PHPT show greater increases in albumin-adjusted calcium and total serum calcium concentration than patients with SHPT-IH (+0,11 ± 0,10 vs. + 0,0071 ± 0,10mmol/l; p = 0,025 and +0,14 ± 0,12 vs. + 0,012 ± 0,15mmol/l; p = 0,024 respectively). The TCT-based working diagnosis of PHPT has a sensitivity of 81,8%, a specificity of 77,8% and a likelihood ratio of 3,68 of estimating a correct final diagnosis.Urinary calcium excretion, PTH, calcium-phosphorous ratio, PTH-inhibition rate, and parathyroid function index do not differ significantly in patients with PHPT compared to those with SHPT-IH. the TCT aids in discriminating patients with PHPT from those with SHPT-IH based on a rise in serum calcium. Other parameters are not different between both groups. Larger prospective trials are necessary to further define the diagnostic potential of the TCT, its most appropriate biochemical outcome variables, and decision cut-offs.

Multicore fiber optic imaging reveals that astrocyte calcium activity in the mouse cerebral cortex is modulated by internal motivational state.

Astrocytes are a direct target of neuromodulators and can influence neuronal activity on broad spatial and temporal scales in response to a rise in cytosolic calcium. However, our knowledge about how astrocytes are recruited during different animal behaviors remains limited. To measure astrocyte activity calcium in vivo during normative behaviors, we utilize a high-resolution, long working distance multicore fiber optic imaging system that allows visualization of individual astrocyte calcium transients in the cerebral cortex of freely moving mice. We define the spatiotemporal dynamics of astrocyte calcium changes during diverse behaviors, ranging from sleep-wake cycles to the exploration of novel objects, showing that their activity is more variable and less synchronous than apparent in head-immobilized imaging conditions. In accordance with their molecular diversity, individual astrocytes often exhibit distinct thresholds and activity patterns during explorative behaviors, allowing temporal encoding across the astrocyte network. Astrocyte calcium events were induced by noradrenergic and cholinergic systems and modulated by internal state. The distinct activity patterns exhibited by astrocytes provides a means to vary their neuromodulatory influence in different behavioral contexts and internal states.

Monitoring mitochondrial calcium in cardiomyocytes during coverslip hypoxia using a fluorescent lifetime indicator

An increase in mitochondrial calcium via the mitochondrial calcium uniporter (MCU) has been implicated in initiating cell death in the heart during ischemia-reperfusion (I/R) injury. Measurement of calcium during I/R has been challenging due to the pH sensitivity of indicators coupled with the fall in pH during I/R. The development of a pH-insensitive indicator, mitochondrial localized Turquoise Calcium Fluorescence Lifetime Sensor (mito-TqFLITS), allows for quantifying mitochondrial calcium during I/R via fluorescent lifetime imaging. Mitochondrial calcium was monitored using mito-TqFLITS in neonatal mouse ventricular myocytes (NMVM) isolated from germline MCU-KO mice and MCUfl/fl treated with CRE-recombinase to acutely knockout MCU. To simulate ischemia, a coverslip was placed on a monolayer of NMVMs to prevent access to oxygen and nutrients. Reperfusion was induced by removing the coverslip. Mitochondrial calcium increases threefold during coverslip hypoxia in MCU-WT. There is a significant increase in mitochondrial calcium during coverslip hypoxia in germline MCU-KO, but it is significantly lower than in MCU-WT. We also found that compared to WT, acute MCU-KO resulted in no difference in mitochondrial calcium during coverslip hypoxia and reoxygenation. To determine the role of mitochondrial calcium uptake via MCU in initiating cell death, we used propidium iodide to measure cell death. We found a significant increase in cell death in both the germline MCU-KO and acute MCU-KO, but this was similar to their respective WTs. These data demonstrate the utility of mito-TqFLITS to monitor mitochondrial calcium during simulated I/R and further show that germline loss of MCU attenuates the rise in mitochondrial calcium during ischemia but does not reduce cell death.

Foveal Retinal Ganglion Cells Develop Altered Calcium Dynamics Weeks After Photoreceptor Ablation

Objective or purposePhysiological changes in retinal ganglion cells (RGCs) have been reported in rodent models of photoreceptor (PR) loss but this has not been investigated in primates. By expressing both a calcium indicator (GCaMP6s) and an optogenetic actuator (ChrimsonR) in foveal RGCs of the macaque, we reactivated RGCs in vivo and assessed their response in the weeks and years following PR loss. DesignWe used an in vivo calcium imaging approach to record optogenetically evoked activity in deafferented RGCs in primate fovea. Cellular scale recordings were made longitudinally over a 10 week period following photoreceptor ablation and compared to responses from RGCs that had lost photoreceptor input more than two years prior. ParticipantsThree eyes received photoreceptor ablation, OD of a male Macaca mulatta (M1), OS of a female Macaca fascicularis (M2) and OD of a male Macaca fascicularis (M3). Two animals were used for in vivo recording, one for histological assessment.Methods: Cones were ablated with an ultrafast laser delivered through an adaptive optics scanning light ophthalmoscope (AOSLO). A 0.5 s pulse of 25Hz 660nm light optogenetically stimulated RGCs, and the resulting GCaMP fluorescence signal was recorded using AOSLO. Measurements were repeated over 10 weeks immediately after PR ablation, at 2.3 years and in control RGCs. Main Outcome measuresThe calcium rise time, decay constant and sensitivity index of optogenetic mediated RGC were derived from GCaMP fluorescence recordings from 221 RGCs (Animal M1) and 218 RGCs (Animal M2) in vivo. ResultsFollowing photoreceptor ablation, the mean decay constant of the calcium response in RGCs decreased 1.5 fold (1.6±0.5 s to 0.6±0.3 s SD) over the 10 week observation period in subject 1 and 2.1 fold (2.5±0.5 s to 1.2±0.2 s SD) within 8 weeks in subject 2. Calcium rise time and sensitivity index were stable. Optogenetic reactivation remained possible 2.3 years after PR ablation. ConclusionsAltered calcium dynamics developed in primate foveal RGCs in the weeks after photoreceptor ablation. The mean decay constant of optogenetic mediated calcium responses decreased 1.5-2-fold. This is the first report of this phenomenon in primate retina and further work is required to understand the role these changes play in cell survival and activity.

Cultured Rat Hippocampal Neurons Exposed to the Mitochondrial Uncoupler Carbonyl Cyanide Chlorophenylhydrazone Undergo a Rapid, Presenilin-Dependent Change in Neuronal Properties.

Presenilin 1 (PS1) is a transmembrane proteolytic subunit of γ-secretase that cleaves amyloid precursor proteins. Mutations in PS1 (mPS1) are associated with early-onset familial Alzheimer's disease (AD). The link between mutated PS1, mitochondrial calcium regulation, and AD has been studied extensively in different test systems. Despite the wide-ranging role of mPS1 in AD, there is a paucity of information on the link between PS1 and neuronal cell death, a hallmark of AD. In the present study, we employed the selective mitochondrial uncoupler carbonyl cyanide chlorophenylhydrazone (CCCP) and compared the reactivity of mPS1-transfected cultured rat hippocampal neurons with PS1 and control neurons in a situation of impaired mitochondrial functions. CCCP causes a slow rise in cytosolic and mitochondrial calcium in all three groups of neurons, with the mPS1 neurons demonstrating a faster rise. Consequently, mPS1 neurons were depolarized by CCCP and measured with TMRM, a mitochondrial voltage indicator, more than the other two groups. Morphologically, CCCP produced more filopodia in mPS1 neurons than in the other two groups, which were similarly affected by the drug. Finally, mPS1 transfected neurons tended to die from prolonged exposure to CCCP sooner than the other groups, indicating an increase in vulnerability associated with a lower ability to regulate excess cytosolic calcium.

Harnessing IGF-1 and IL-2 as biomarkers for calcineurin activity to tailor optimal FK506 dosage in α-synucleinopathies.

Introduction: Rise in Calcium (Ca2+) and hyperactive Ca2+-dependent phosphatase calcineurin represent two key determinants of a-synuclein (a-syn) pathobiology implicated in Parkinson's Disease (PD) and other neurodegenerative diseases. Calcineurin activity can be inhibited with FK506, a Food and Drug Administration (FDA)-approved compound. Our previous work demonstrated a protective effect of low doses of FK506 against a-syn pathology in various models of a-syn related pathobiology. Methods: Control and a-syn-expressing mice (12-18 months old) were injected with vehicle or two single doses of FK506 administered 4 days apart. Cerebral cortex and serum from these mice were collected and assayed using a meso scale discovery quickplex SQ 120 for cytokines and Enzyme-linked immunosorbent assay for IGF-1. Results: In this study we present evidence that reducing calcineurin activity with FK506 in a-syn transgenic mice increased insulin growth factor (IGF-1), while simultaneously decreasing IL-2 levels in both cerebral cortex and serum. Discussion: The highly conserved Ca2+/calcineurin signaling pathway is known to be affected in a-syn-dependent human disease. FK506, an already approved drug for other uses, exhibits high brain penetrance and a proven safety profile. IL-2 and IGF-1 are produced throughout life and can be measured using standard clinical methods. Our findings provide two potential biomarkers that could guide a clinical trial of FK506 in PD patients, without posing significant logistical or regulatory challenges.

THU367 Hyperosmolar Hyperglycemic State In A Middle-old Male With Primary Hyperparathyroidism

Abstract Disclosure: D.M. Dimayuga: None. M.C. Isidro: None. A 79-year-old male was brought to our hospital for drowsiness. He had low-grade fever with associated cough and anorexia 1 week prior. He had a previous history of hypertension and primary hyperparathyroidism (PHPT) maintained on cinacalcet. He did not have a history of diabetes and a family history of diabetes, and his HbA1c was 5.4% three months before. On admission, the results of his physical examination and vital signs were as follows: height, 152cm; weight, 56.0 kg; BMI, 24.2 kg/m2; temperature, 36.5C; heart rate, 85 beats/min; SpO2, 98% (on room air); respiratory rate, 22 breaths/min; and blood pressure, 115/60 mm Hg. His blood glucose level was 966 mg/dL, HbA1c 13.4%, and serum osmolality 324 mOsm/kg. Serum ketones were 15 mg/dL and blood gas analysis was normal. He was diagnosed with hyperglycemic hyperosmolar state (HHS) and infusion of insulin and saline was subsequently initiated. With clinical suspicion of chronic pancreatitis given the patient’s history of PHPT, serum lipase was checked, 105 U/L (NV: 12-53 U/L). Ionized calcium was 1.36 mmol/L. On CT scan of abdomen, there was no evidence of duct dilatation and calcification, and instead, “features of diffuse fatty atrophy of the pancreas” were seen. His endogenous insulin secretory capacity was sufficient (serum C-peptide: 2.76 ng/mL, NV: 0.78-5.19 ng/mL). Eventually, the patient’s level of consciousness improved and glycemic control was achieved. Soon after, insulin was shifted to basal-bolus regimen. On the 7th day of hospitalization, patient was discharged with minimal insulin requirements. Two weeks later, on follow up, his blood glucose levels were found to be stable. It was not clear whether our patient had new-onset autoimmune or type 2 diabetes. Although autoimmune diabetes generally occurs when about 90% of the pancreatic beta cells have been destroyed, the patient could have been in the honeymoon period wherein beta cell activity was transiently regained after commencement of insulin therapy. Our plan is to monitor his C-peptide titers and test his insulin antibodies. Evidence suggests that PHPT may cause insulin resistance and glucose intolerance. The rise in free intracellular calcium may reduce glucose transport in insulin-stimulated glucose transporters, increasing the need for insulin. This could be the case in our patient hence we diagnosed him with type 2 diabetes. To the best of our knowledge, this is the first case demonstrating the co-occurrence of HHS and PHPT. Presentation: Thursday, June 15, 2023

Platelet-derived microvesicles induce intracellular calcium mobilization in human platelets.

Platelet-derived microvesicles (PMVs) represent a significant proportion of microvesicles in circulation and have been linked to various pathophysiological complications. Recent research suggests that PMVs carry significant amounts of cargo that can affect cellular functions by influencing calcium oscillations in target cells. As calcium is involved in multiple cellular processes, including hemostasis and thrombosis, this study aimed to investigate the impact of PMVs on platelet calcium mobilization. The study found that PMVs increase platelet intracellular calcium levels via both intracellular storage and extracellular space in a dose-dependent manner. The study highlighted the critical role of the dense tubular system, acidic vacuoles, mitochondrial stores, and store-operated calcium entry (SOCE) in PMV-mediated calcium release in human platelets. Moreover, the study revealed that PMV-induced calcium rise in platelets does not occur via sarcoendoplasmic reticulum calcium ATPase, and extracellular calcium addition further increases the calcium level in platelets, demonstrating the involvement of SOCE. These findings provide insights into the platelet stimulation signaling mechanisms and contributes to our understanding of platelet and cell behavior when exposed to PMV-rich environments.

Evaluation of the Remineralisation of the Demineralized Enamel Surrounding Orthodontic Brackets using the Nano Hydroxyapatite: An Original Study.

The orthodontic appliances have been known to accelerate enamel loss due to various reasons. Since there are few studies supporting the role of the nano-HAP in the mineralization of the demineralized tooth surfaces, the current study compared nano-HAP's capacity to remineralize the demineralized enamel layer surrounding braces at various concentration levels. This investigation involved 60 healthy permanent premolars that had just been excised. All specimens had 3M-Unitek brackets glued to their buccal surfaces. The samples were artificially demineralized and divided into three groups. The control group, Toothpaste ApaCare, and ApaCareTM varnish. Before and after remineralization, selected samples from each group were analyzed using a "Scanning Electron Microscope (SEM)" and evaluated using "Energy Dispersive X-Ray Analysis (EDAX)." Spectrometer and profilometer were used for the study of surface and the color. Statistics were used to analyze the outcomes. The threshold for significance was fixed at 0.05. After remineralization by nano-HAP, there was a significant rise (P < 0.001) in both calcium and phosphorus levels. This was picked up by EDAX, and SEM verified it. When compared to the control group, the nano-HAP application greatly improved the color measurements in the study groups (P < 0.001), and it also resulted in a significant decrease in surface roughness (P < 0.001). Our study's results showed that nano-HAP could be successful in restoring demineralized enamel around brackets, reducing the surface roughness and color of the enamel surface.

Circuit coordination of opposing neuropeptide and neurotransmitter signals.

Fast-acting neurotransmitters and slow, modulatory neuropeptides are co-released from neurons in the central nervous system, albeit from distinct synaptic vesicles1. The mechanisms of how co-released neurotransmitters and neuropeptides that have opposing actions-for example, stimulatory versus inhibitory-work together to exert control of neural circuit output remain unclear. This has been difficult to resolve owing to the inability to selectively isolate these signalling pathways in a cell- and circuit-specific manner. Here we developed a genetic-based anatomical disconnect procedure that utilizes distinct DNA recombinases to independently facilitate CRISPR-Cas9 mutagenesis2 of neurotransmitter- and neuropeptide-related genes in distinct cell types in two different brain regions simultaneously. We demonstrate that neurons within the lateral hypothalamus that produce the stimulatory neuropeptide neurotensin and the inhibitory neurotransmitter GABA (γ-aminobutyric acid) utilize these signals to coordinately activate dopamine-producing neurons of the ventral tegmental area. We show that GABA release from lateral hypothalamus neurotensin neurons inhibits GABA neurons within the ventral tegmental area, disinhibiting dopamine neurons and causing a rapid rise in calcium, whereas neurotensin directly generates a slow inactivating calcium signal in dopamine neurons that is dependent on the expression of neurotensin receptor 1 (Ntsr1). We further show that these two signals work together to regulate dopamine neuron responses to maximize behavioural responding. Thus, a neurotransmitter and a neuropeptide with opposing signals can act on distinct timescales through different cell types to enhance circuit output and optimize behaviour.

Developing Cost-Effective and Efficient Drinking Water Treatment Technology for the Removal of Salinity and Suspended Solids

Although a variety of economical water treatment options are available, rural residents struggle to have safe drinking water. Therefore, developing cost-effective and efficient drinking water treatment technology for the removal of selected ionic compounds and suspended solids is necessary. The present study aims to establish a cost-effective water treatment method by employing the following adsorbents Graphene Sand Composite (GSC), GSC with Moringa Oleifera seeds, Phyllanthus emblica seeds, Strychnos potatorum seeds, tea waste, sawdust, coal, coconut charcoal, and clay pot (an indigenized filter). X-ray diffraction of GSC confirms SiO2 nanoparticles, a broad peak centred at 22.5°, Graphene peaks are found at 26.73 (200), 45.8 (110) and 54.959 (222). In FT-IR, graphene oxide has a strong and wide O-H/ Si-OH stretching vibration peak at 3444 cm-1. In the Raman spectrum, the graphitic vibration band from its first-order scattering of E2g photons using sp2 carbon appeared at 1589 cm-1. Moreover, the graphitic vibration band contributes to the presence of stretching C-C bond; which is common in all sp2 carbon systems. Water’s pH, TDS, hardness, and chloride content also increased considerably in a few adsorbents. Fabricated pots with an indigenous filter using GSC and Moringa oleifera seed as filter disc has also been designed and evaluated in the present study. In this research, 100% salinity removal is achieved using GSC as an adsorbent. While there is an interesting rise trend in fluoride and calcium content to 33% and 39%, respectively. The reason for the rise in fluoride and calcium can be studied further.