Physiology of Calcium Homeostasis: An Overview

Cellular senescence in age-related musculoskeletal diseases

Aging is typically associated with decreased musculoskeletal function, leading to reduced mobility and increased frailty. As a hallmark of aging, cellular senescence plays a crucial role in various age-related musculoskeletal diseases, including osteoporosis, osteoarthritis, intervertebral disc degeneration, and sarcopenia. The detrimental effects of senescence are primarily due to impaired regenerative capacity of stem cells and the pro-inflammatory environment created by accumulated senescent cells. The secreted senescence-associated secretory phenotype (SASP) can induce senescence in neighboring cells, further amplifying senescent signals. Although the removal of senescent cells and the suppression of SASP factors have shown promise in alleviating disease progression and restoring musculoskeletal health in mouse models, clinical trials have yet to demonstrate significant efficacy. This review summarizes the mechanisms of cellular senescence in age-related musculoskeletal diseases and discusses potential therapeutic strategies targeting cellular senescence.

IFT80 and TRPA1 cooperatively regulate bone formation by calcium signaling in response to mechanical stimuli

BACKGROUND

Intraflagellar transport 80 (IFT80) is vital for primary cilia which can sense and transduce mechanical signals. Mechanical stimuli expedite osteoblastic differentiation and bone formation in mesenchymal stem cells (MSCs). However, how IFT80 regulates mechanical transduction in MSCs remains unclear.

BASIC PROCEDURE

To investigate the role of IFT80 in bone development and mechanical transduction, MSC-specific knock-out IFT80 (Prx1Cre; IFT80f/f) mice were generated. These mice exhibited significant skeletal abnormalities. The study further examined the effects of IFT80 deficiency on mechanical stimulation-induced osteoblastic differentiation and bone formation, as well as the underlying molecular mechanisms involving TRPA1 and calcium signaling pathways.

MAIN FINDINGS

In our study, Prx1Cre; IFT80f/f mice results in pronounced skeletal abnormalities including dwarfism, bone formation defect, malformations in the skull, limbs, and sternum, and abnormal joint structures. Furthermore, IFT80 deficiency in MSCs inhibits mechanical stimulation induced osteoblastic differentiation. Exercise training could not improve the bone formation in Prx1Cre; IFT80f/f mice. Mechanistically, IFT80 deficiency in MSCs downregulated the expression of transient receptor potential ankyrin 1 (TRPA1) and TRPA1-mediated Ca2+ influx, which further inhibited osteoblastic differentiation under mechanical stimulation by AKT and ERK signaling pathways. Finally, TRPA1 overexpression reversed impaired bone formation in Prx1Cre; IFT80f/f mice under exercise training.

PRINCIPAL CONCLUSIONS

IFT80 and TRPA1 cooperatively regulate osteoblastic differentiation and bone formation in response to mechanical stimulation. These findings suggest that IFT80 and TRPA1 are critical for skeletal homeostasis and may serve as potential therapeutic targets for skeletal disorders.

Diltiazem disrupts Ca2+-homeostasis and exerts immunotoxic effects on a marine bivalve mollusc, the blood clam (Tegillarca granosa)

The prevalence of pharmaceutical residues like diltiazem in environments raises concerns over their potential threat to non-target organisms. While the immune system poses as a potential target, little is known about the immunotoxicity of diltiazem to aquatic species such as bivalve molluscs. In this study, the binding affinity of diltiazem to the calcium channels of several aquatic species was evaluated by molecular docking. Taking blood clam as a representative, the impacts of diltiazem on Ca2+-homeostasis and immune parameters were also assessed. Our results illustrated diltiazem exhibit a high binding affinity to calcium channels of representative aquatic species. Moreover, Ca2+-homeostasis in the haemocytes of blood clam was significantly disrupted by 4-week exposure to diltiazem. Additionally, apart from exhibiting significantly lower survival rates upon pathogenic challenge, diltiazem-exposed blood clams also suffered markedly impaired immune-related hematic parameters and lower levels of immune factors. Furthermore, diltiazem exposure generally altered the expression of key Ca2+-homeostasis and immune-related genes. Collectively, our data suggest that diltiazem at environmentally relevant concentrations could severely undermine the immunity of blood clam by disrupting Ca2+-homeostasis. Given the high binding affinities of diltiazem to calcium channels of diverse aquatic species and the critical role of Ca2+-homeostasis, the far-reaching impacts of diltiazem pollution on non-target aquatic species warrant closer attention and monitoring.

Primary Hyperparathyroidism: An Analysis Amid the Co-Occurrence of Type 2 Diabetes Mellitus

BACKGROUND

Apart from classical elements in primary hyperparathyroidism (PHPT), non-classical complications, including type 2 diabetes mellitus (T2DM), are reported in some patients, but currently, they do not represent a parathyroidectomy (PTx) indication.

OBJECTIVE

to explore the latest data regarding glucose profile, particularly, T2DM and metabolic syndrome (MetS) in PHPT, including post-PTx.

METHODS

PubMed-based review included English-published original studies between January 2020 and December 2024 (n = 20).

RESULTS

Studied population: 764,485 subjects (female-to-male ratio of 1.26:1; 23,931 were PHPT patients vs. 740,502 controls). T2DM prevalence (n = 13; N = 763,645 patients; 55.92% females): 4-60% (higher vs. controls); for the largest study (N = 699,157) of 31.3%. Age-based analysis: higher T2DM prevalence at >50 vs. <50 years (14.4% vs. 2.6%, p < 0.001), but not all studies agreed. Concurrent vitamin D deficiency as a contributor to a higher risk had limited evidence. The association MetS-PHPT (n = 2) had no clear conclusion. Post-PTx showed the following: lower glycaemia, fasting insulin, insulin resistance (HOMA-IR) improvement, and reduced rate (but not all studies agreed). PHPT patients with prediabetes might represent the population sub-group with the highest post-PTx benefit.

CONCLUSIONS

The panel of PHPT-T2DM interplay remains heterogeneous. Data regarding post-PTx improvement of glucose disorders are still conflicting, recent findings suggested that surgery has beneficial effects, especially in patients with confirmed pre-existing prediabetes. Patients with the normocalcemic variant seemed to be less affected by the glucose-related disturbances, but further studies are needed. A better understanding of the intricate relationship between PHPT and glucose metabolism anomalies will help in providing optimal management to reduce the overall disease burden.

Sex-Specific Impact of Serum Calcium Levels on Acute Coronary Syndrome Risk: A 19-Year Cohort Study in Korea

Background: This study aims to investigate the association between serum calcium levels and acute coronary syndrome (ACS) risk, examining whether this relationship differs by sex, given the known differences in calcium metabolism and hormonal influences between males and females. Methods: Utilizing the Korean Genome Epidemiology Study (KoGES) prospective cohort data, our primary exposure variables were serum calcium level and sex. The incidence of ACS served as the main outcome of interest. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox regression analysis. An interaction analysis was conducted to assess the interaction effect of calcium level and sex on ACS incidence. Results: After adjusting for confounding variables, high calcium intake did not significantly increase ACS incidence, with a hazard ratio (HR) of 1.07 (95% CI: 0.90-1.26). There was also no significant difference in ACS risk between females and males (HR: 0.81, 95% CI: 0.61-1.04). However, interaction effect analysis revealed that higher calcium levels were associated with an increased risk of ACS only in females (HR: 1.24, 95% CI: 1.07-1.58), whereas the association in males was not statistically significant (HR: 0.90, 95% CI: 0.71-1.15). Conclusion: Our study results indicate that elevated serum calcium levels alone did not independently increase the risk of ACS; however, high serum calcium levels were associated with an increased risk of ACS in females but not in males, underscoring the importance of sex-specific factors in assessing and managing ACS risk and highlighting the necessity for personalized medical approaches to improve cardiovascular health outcomes for women.

Lactobacillus johnsonii Generates Cyclo(pro-trp) and Promotes Intestinal Ca2+ Absorption to Alleviate CKD-SHPT

Patients with chronic kidney disease (CKD) are at a high risk of developing secondary hyperparathyroidism (SHPT), which may cause organ dysfunction and increase patient mortality. The main clinical interventions for CKD-SHPT involve calcium supplements to boost absorption, but ineffective for some patients, and the reasons remain unclear. Here, CKD mice are divided into high and low groups based on intact parathyroid hormone (iPTH) levels. The high group exhibits significant changes in gut microbes, including a decrease in Lactobacillus, an increase in parathyroid hyperplasia, and a decrease in intestinal calcium. Fecal microbiota transplantation and L. johnsonii colonization indicate a link between gut microbes and CKD-SHPT. Clinically, higher L. johnsonii levels are correlated with milder hyperparathyroidism CKD-SHPT. The receiver operating characteristic (ROC) curve for L. johnsonii abundance and surgical risk is 0.81, with the calibration curve confirming predictive accuracy, and decision curve analysis revealing good clinical applicability. In vivo and in vitro experiments show that cyclo(pro-trp) enhance calcium inflow and lower iPTH levels in intestinal epithelial cells via a calcium-sensing receptor and transient receptor potential vanilloid 4 pathways. This study identified the crucial role of L. johnsonii in CKD-SHPT, unveiling a new mechanism for calcium imbalance and offering novel strategies for SHPT treatment and drug development.

Management of autosomal dominant hypocalcemia type 1: Literature review and clinical practice recommendations

PURPOSE

Autosomal Dominant Hypocalcemia type 1 (ADH1), caused by gain-of-function variants in the calcium-sensing receptor (CASR), is characterized by a variable degree of hypocalcemia and hypercalciuria with inappropriately low PTH. The clinical spectrum is broad, ranging from being asymptomatic to presenting with severe clinical features of hypocalcemia and end-organ damage such as nephrolithiasis and intracerebral calcifications. Although the underlying pathophysiology is different, ADH1 patients are often managed as patients with 'classical' primary hypoparathyroidism, possibly leading to (exacerbation of) hypercalciuria. New treatments such as PTH analogues and calcilytics directly targeting the CASR are in the pipeline. Specific clinical guidance for treatment and monitoring of ADH1 patients is lacking. The purpose of this study is to provide a literature review on management of ADH1, including new therapies, and to formulate practice recommendations.

METHODS

We searched for articles and ongoing clinical trials regarding management of ADH1.

RESULTS

Forty articles were included. First we review the conventional treatment of ADH1, focusing on active vitamin D, calcium supplements, thiazide diuretics, phosphorus binders and dietary recommendations. In a second part we give an overview of studies with emerging treatments in ADH1: PTH analogues (PTH1-34, rhPTH1-84, TransCon PTH and others) and calcilytics (preclinical studies and clinical trials). In a third part we discuss literature findings regarding monitoring of ADH1 patients. Finally, we formulate clinical practice recommendations.

CONCLUSION

We provide an overview of conventional and new treatments for ADH1 patients. Based on these data, we propose practical recommendations to assist clinicians in the management of ADH1 patients.

The development of thyroid autoimmunity is potentially associated with the deficiency of vitamin D3 rather than vitamin D2 in euthyroid men

OBJECTIVE

Vitamin D(VitD) deficiency has been found prevalent among patients with thyroid autoimmunity (TAI). This study aimed to investigate whether low VitD2 or VitD3 potentially contributed to the development of TAI in euthyroid male patients, which had not been reported before.

METHODS

A total of 2882 euthyroid male petroleum workers were recruited from those participants in the healthcare program at the second affiliated hospital of Dalian Medical University in 2021, whose serum VitD levels, thyroid functions, and autoantibody titers were all examined at the same time. Among them, 2587 (89.8%) individuals received the second health follow-up in 2022. Serum VitD including 25(OH)D2 (VitD2) and 25(OH)D3 (VitD3) levels were detected by liquid chromatography-tandem mass spectrometry. Thyroid functions and autoantibody titers were quantified using chemiluminescent immunoassays.

RESULTS

The serum levels of VitD and VitD3 were pronouncedly lower in the male euthyroid subjects with TAI (n = 195) than those non-TAI men (n = 2687, P < 0.05), whereas serum VitD2 was not significantly different based on the data from the initial investigation in 2021. The prevalence of subjects with TAI among the total male euthyroid subjects with TAI population was markedly increased with the decreasing levels of serum VitD and VitD3, respectively (P for trend < 0.05), but not significantly changed with that of serum VitD2. The binary logistic regression analysis revealed that either the deficiency of VitD (serum VitD < 20 ng/mL, VDD) or low VitD3 level was an independent risk factor for the development of TAI, which had been further demonstrated by the follow-up observation in 2022. Among the non-TAI men in 2021, 6.52% (n = 157) individuals became TAI patients after a one-year follow-up, and their serum VitD and VitD3 levels both exhibited significantly more reduction as compared with those of the remained non-TAI ones in 2022. More of those with VDD developed TAI than the non-VDD ones did in 2022 (8.5% vs. 5.6%, P<0.05). Additionally, the change in serum VitD over the two years was more strongly correlated with serum VitD3 (rs = 0.971, P < 0.001) when compared with that of VitD2 (rs = 0.085, P < 0.001) in the whole euthyroid male population.

CONCLUSION

Based on the cross-sectional and prospective investigations, our findings further indicate that VDD may be an independent risk factor for TAI development. Moreover, the latter is potentially associated with the deficiency of VitD3 rather than VitD2 in the euthyroid male population although the related mechanisms await in-depth exploration. Our findings also suggest that VitD3 supplementation might provide more potential benefits than VitD2 among VDD men in terms of preventing TAI development.

STUDY REGISTRATION

the Dalian Health Management Cohort (DHMC) ChiCTR2300073363.

The calcium-sensing receptor: a comprehensive review on its role in calcium homeostasis and therapeutic implications

The calcium-sensing receptor (CaSR), a key member of the family C G protein-coupled receptors (GPCRs), plays a crucial role in regulating calcium homeostasis and parathyroid hormone (PTH) secretion. It responds to various physiological ligands, including calcium ions and amino acids, activating multiple signaling pathways through interactions with different G proteins and β-arrestin. This review focuses on the structural features of CaSR, emphasizing recent advances in understanding its activation mechanisms via agonists and allosteric modulators. CaSR holds significant therapeutic potential, particularly in treating calcitropic disorders such as hyperparathyroidism and hypoparathyroidism. Current pharmacological agents, including calcimimetics such as cinacalcet and etelcalcetide, have proven effective in managing secondary hyperparathyroidism (SHPT); however, they are associated with side effects such as hypocalcemia. Emerging investigational drugs, including palopegteriparatide and other small molecules, show promise in addressing various calcium-related conditions. Despite challenges that have led to the discontinuation of some drug developments, ongoing research is focused on refining CaSR-targeted therapies to improve efficacy, reduce adverse effects, and enhance patient outcomes.

Prevalence of Hypocalcemia in Pediatrics With Lower Respiratory Tract Infections

A retrospective observational study aimed to assess blood calcium levels in children with lower respiratory tract infections (LRTIs) from September 2023 to February 2024. A total of 225 eligible records were evaluated. Calcium deficiency was observed in 44.8% of children, hyperchloremia in 42.6%, and hyperkalemia in 36.8% on admission. The mean age was 16.8 ± 16.2 months, and the mean SpO2 was 95.8 ± 2.5%. Although the risk of hypocalcemia was slightly higher in nonimmunized subjects (odds ratio = 1.04 [95% confidence interval = 0.59-1.85]), this was not statistically significant (P > .05). A negative correlation between normal calcium levels and body mass (r =-0.295, P = .001) suggests that higher body weight is linked to calcium imbalance. Immunization status and developmental history did not significantly affect the risk of hypocalcemia. The study highlights the importance of regular calcium monitoring in pediatric LRTI patients, as hypocalcemia was prevalent, particularly in those with higher body weight.

Cerebrospinal Fluid Calcium Balance in Tick-Borne Encephalitis: A Preliminary Study and Future Research Directions

Introduction: Calcium homeostasis is essential for neurophysiological functions, with dysregulation implicated in neurodegenerative diseases. Recent studies suggest that specific viral brain infections, such as tick-borne encephalitis, can initiate neuronal loss and subsequent neurodegenerative changes. This study examines alterations in calcium levels within the cerebrospinal fluid (CSF) of patients with tick-borne encephalitis (TBE). Objectives: To evaluate the concentration of calcium in the CSF of TBE patients and assess its potential as a diagnostic marker for disease severity. Materials and Methods: CSF samples were collected from 42 subjects (11 controls, 20 with TBE, 11 with other forms of meningitis). Calcium levels were measured using the Alinity c analyzer. Statistical analyses included the Shapiro-Wilk test, Mann-Whitney U test, and ROC curve analysis. Results: Calcium levels were significantly lower in TBE patients compared to controls (mean 0.85 mmol/L vs. 0.98 mmol/L). Lower calcium levels were associated with milder cases of TBE. ROC analysis (AUC 0.802, p-value 0.0053) supports the diagnostic utility of calcium concentration in differentiating TBE severity. The optimal cut-off value for calcium was >3.09 mg/dL, with a sensitivity of 84.62% and specificity of 71.43%. These findings further emphasize the potential of calcium as a diagnostic marker for TBEV. Conclusions: The observed differences in CSF calcium levels between mild and severe TBE cases highlight its potential as a diagnostic marker. Further research is warranted to elucidate calcium's role in TBE, aiming to improve clinical management and reduce complications. We emphasize that this study is one of the first to propose calcium levels as a potential biomarker for assessing the severity of tick-borne encephalitis, offering a new perspective in the diagnostic approach to this infection.

A Comparative Elemental Analysis of Espresso Coffee from Poland and Portugal

A comparative elemental analysis of espresso coffee from Poland and Portugal was carried out. Using an ICP-MS analytical procedure, samples collected from public cafes in Poland and Portugal (n = 60 and n = 44, respectively) were studied for their macromineral and trace element content. To evaluate the contribution of water to the final composition of the beverage, paired samples (i.e., collected from the same locations) of drinking water were also analysed. The mineral profile of the coffee espresso samples was quite similar: Mg > P > Ca > Rb > Mn > B > Zn > Cu > Sr > Ba > Ni > Pb > Cs > Mo > Sn > Cd > Sb > Tl for samples from Poland and Mg > P > Ca > Rb > B > Mn > Zn > Sr > Cu > Ni > Ba > Cs > Pb > Mo > Sn > Sb > Cd > Tl for samples from Portugal. For most of the elements, the espresso samples showed much higher levels than the water used in its preparation. The two most notable exceptions were Ca and Sr, where the elements present in the coffee came mainly from the water. The contribution of coffee espressos to the daily intake of essential elements seems to be reduced. Other non-essential elements like Ni (median = 81.0 µg/L and 86.8 µg/L for Polish and Portuguese espresso, respectively) and Pb (median = 14.3 µg/L and 4.43 µg/L, respectively) were observed in significant amounts in the coffee espresso samples analysed in this study. These elements have been shown to leach from coffee machines in other studies. More studies are necessary to confirm these results.

A Case of Severe Hypocalcemia During JAK1/2 Inhibitor Therapy for Myelofibrosis in a Patient with Liver Cirrhosis

We herein report a 56-year-old man with severe hypocalcemia during ruxolitinib therapy for myelofibrosis transitioning from JAK2 mutation-positive polycythemia vera. Blood transfusions were administered every one to two weeks for ruxolitinib-induced anemia. Blood tests revealed hypocalcemia with low TRACP-5b, 25-hydroxyvitamin D (25 (OH) D), and 1,25-dihydroxyvitamin D3 (1,25 (OH) 2 D3) levels within the lower reference range. Intact-PTH levels were relatively low compared to calcium levels. Severe hypocalcemia with ruxolitinib is rare and may be caused by a combination of factors, impaired vitamin D activation due to liver or renal insufficiency, accumulation of calcium-chelating agents from blood transfusions, and inadequate compensatory response to PTH.

Gastrointestinal surgery, malabsorptive conditions, and postoperative hypocalcemia after neck surgery

BACKGROUND

Postoperative hypocalcemia is a common complication of thyroid and parathyroid surgery. Patients with prior gastric bypass face increased risk of postoperative hypocalcemia, but the impact of other malabsorptive conditions is not well understood. In this study, we evaluated the relationship between multiple medical and surgical malabsorptive states and hypocalcemia after thyroid and parathyroid surgery.

METHODS

We performed a retrospective cohort study of patients who underwent total thyroidectomy and/or parathyroidectomy in Optum's deidentified Clinformatics Data Mart Database (2004-2022). Patients were categorized as having surgical (foregut/midgut: gastrectomy, intestinal bypass, enterectomy, enterostomy, pancreatectomy, or hindgut: colectomy/colostomy) or medical (Crohn or Celiac disease) malabsorptive conditions. The primary outcomes were early (<7 days) and late (7-365 days) postoperative hypocalcemia. Logistic regression was performed to determine the associations between malabsorptive conditions and outcomes.

RESULTS

Of 25,400 patients (56.9% total thyroidectomy, 40.8% parathyroidectomy, and 2.4% both procedures), 4.0% had a pre-existing malabsorptive condition. Early postoperative hypocalcemia occurred in 8.8% of patients, and late hypocalcemia in 18.3%. Thyroidectomy was associated with a greater likelihood of hypocalcemia than parathyroidectomy (odds ratio: 1.22; P < .001). Pancreatectomy was associated with twice the adjusted odds of postoperative hypocalcemia (odds ratio: 2.27; P = .031) across both procedures. Patients with prior foregut/midgut surgery were at higher risk after total thyroidectomy (odds ratio: 1.65, P = .002). This association was significant in late (odds ratio: 1.82, P < .001) rather than early hypocalcemia (odds ratio: 1.33, P = .175). Hindgut surgery and medical malabsorption did not demonstrate such associations.

CONCLUSION

Prior foregut and midgut resections may predispose patients to postoperative hypocalcemia, particularly in patients undergoing total thyroidectomy.

An electrolyte disturbance masquerading as a panic attack

ABSTRACT

Because proton pump inhibitors (PPIs) are so commonly used, their safety and potential adverse reactions often are not considered. This article describes a patient whose paresthesias and severe muscle cramps were attributed to panic attacks but actually were caused by hypocalcemia secondary to PPI-induced hypomagnesemia. This case serves as a reminder that PPIs should be used cautiously and appropriately with consideration for regular monitoring of electrolytes and vitamin B12.

Tri-o-tolyl phosphate impedes implantation: Malfunction of mitochondria and disruption of calcium homeostasis through MAPK and AKT signaling cascades

Tri-o-tolyl phosphate (TOTP), a flame retardant containing aryl compounds, is widely used in human living environments owing to its several applications. However, Due to the overuse of TOTP, its residue has been identified in various environments and non-targeted organisms, including humans. Although extensive research is being conducted to address the toxicity of this substance, its potential reproductive toxicity in females has not been sufficiently studied. In this study, human HTR-8/SVneo and JEG-3 trophoblasts were used to investigate the effects of TOTP on implantation. Results showed that TOTP decreased cell viability and inhibited cell proliferation by triggering cell cycle arrest. It also induced apoptosis and mitochondrial dysfunction, disrupted calcium homeostasis, increased the influx of calcium ions into the mitochondria, and disturbed cell aggregation and migration. Moreover, the MAPK and AKT cell signaling pathways were altered, and crosstalk between these pathways were distinguished. Thus, inhibitors of the MAPK and AKT pathways exhibited potential for managing the toxicity of TOTP. Overall, this study demonstrated the reproductive toxicity of TOTP in human females and elucidated the underlying mechanisms. Our results highlighted the potential risks associated with TOTP.

Understanding Bone Density Loss in Eating Disorders: Contributions of Weight Suppression and Speed of Weight Loss

Background/Objectives: Eating disorders (EDs), including anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED), are associated with bone density loss. Weight suppression (WS) and weight loss speed (WLS) are two critical weight-related factors that may influence bone health, yet their relationship with bone density remains underexplored. This study aimed to investigate the associations between WS, WLS, and bone density in individuals with EDs, focusing on total body and spinal bone density. Methods: We examined 270 individuals with EDs (AN: n = 187, BN: n = 57, BED: n = 26) at the onset of inpatient treatment. WS and WLS were calculated from weight history, and bone density was assessed using dual-energy X-ray absorptiometry (DXA). Regression analyses were performed separately for each diagnosis. Results: In AN, both WS and WLS were significant predictors of total (p = 0.001) and spinal (p = 0.007) bone density. WS and WLS independently predicted total bone density, with WS significantly predicting spinal bone density. In BN and BED, only WLS showed significant associations with bone density. Minimum weight was a key predictor of bone density in AN, underscoring the importance of avoiding extremely low body weight. Conclusions: WS and WLS significantly affect bone density in AN, with WLS also predicting bone density in BN and BED. These findings highlight the need to monitor weight-related factors across ED populations. In AN, avoiding extremely low body weight is crucial for preserving bone health, while in BN and BED, managing WLS is key to mitigating bone density loss.

PER1 Oscillation in Rat Parathyroid Hormone and Calcitonin Producing Cells

Many endocrine glands exhibit circadian rhythmicity, but the interplay between the central circadian clock in the suprachiasmatic nucleus (SCN), the peripheral endocrine clock, and hormones is sparsely understood. We therefore studied the cellular localizations of the clock protein PER1, parathyroid hormone (PTH) and calcitonin (CT) in the parathyroid and thyroid glands, respectively. Thyroid glands, including the parathyroids, were dissected at different time-points from rats housed in 12 h:12 h light-darkness cycles, and were double-immunostained for PER1 and PTH or CT. Sera were analyzed for PTH, CT, phosphate, and calcium. In both glands, PER1 expression peaked late at night, while limited staining was seen during the daytime. High-resolution microscopy revealed cytosolic PER1 at zeitgeber time (ZT)12, and nucleic staining at ZT24 in both PTH and CT cells. PTH peaked at Z12-ZT16, while neither CT staining nor serum CT oscillated during the daily cycle. Serum PTH was significantly higher at ZT12 than ZT24, but only phosphate was found to exhibit significant diurnal oscillation. The staining of the calcium-sensitive receptor (CSR) did not demonstrate circadian oscillation. In conclusion, PER1 expression peaked late at night/early in the morning in hormone-producing cells of both the thyroid and parathyroid glands. In the parathyroids, this was preceded by a PTH peak, while neither CT nor CRS were found to oscillate.

Resmethrin induces implantation failure by disrupting calcium homeostasis and forcing mitochondrial defects in porcine trophectoderm and uterine luminal epithelial cells

Resmethrin, a type I pyrethroid insecticide, is frequently used globally in residential and farmland areas to control pests. Owing to the repeated administration of resmethrin, and particularly because of its lipophilic nature, residues have been detected in various environments, crops, and livestock. Previous studies have shown the adverse effects of resmethrin, including neurotoxicity and hepatotoxicity. However, the toxic effects of resmethrin on the female reproductive system have rarely been investigated. In the present study, we used two cell types, porcine trophectoderm (pTr) and porcine uterine luminal epithelial (pLE) cells, to examine the toxic effects of resmethrin on implantation and its mechanisms. Our study showed that resmethrin exposure induced apoptosis and inhibited cell cycle progression, thereby reducing the viability of both cell types. In addition, calcium homeostasis was disrupted following resmethrin treatment, and disrupted calcium homeostasis impaired the mitochondrial membrane potential and mitochondrial respiration. In addition to mitochondrial dysfunction, GRP75 and ER stress-related proteins were upregulated. Furthermore, the AKT and MAPK cascades were altered, and reactive oxygen species production and inflammation occurred after resmethrin treatment. Ultimately, through various mechanisms, resmethrin decreased the migratory abilities, and it could diminish the crosstalk between the two cell lines and lower the probability of successful implantation. Overall, we demonstrated that resmethrin interfered with the implantation process by triggering various toxic mechanisms. This study presents, for the first time, evidence regarding the mechanisms through which resmethrin exerts toxic effects on the female reproductive system, thereby raising awareness regarding the potential implications of its widespread use.

EGCG suppressed activation of hepatic stellate cells by regulating the PLCE1/IP3/Ca2+ pathway

(-)-Epigallocatechin-3-O-gallate (EGCG), one of the green tea catechins, exhibits significant antioxidant properties that play an essential role in various diseases. However, the functional role and underlying mechanism of EGCG in stimulating of hepatic stellate cells (HSCs) remain unexplored in transcriptomics sequencing studies. The present study suggests that oral administration of EGCG at a dosage of 200 mg/kg/day for a duration of four weeks exhibits significant therapeutic potential in a murine model of liver fibrosis induced by CCl4. The activation of HSCs in vitro was dose-dependently inhibited by EGCG. The sequencing analysis data reveled that EGCG exerted a regulatory effect on the calcium signal in mouse HSCs, resulting in a decrease in calcium ion concentration. Further analysis revealed that EGCG inhibited the expression of phospholipase C epsilon-1 (PLCE1) and inositol 1, 4, 5-trisphosphate (IP3) in activated mouse HSCs. Additionally, EGCG contributes to the reduction the concentration of calcium ions by regulating PLCE1. After the knockdown of PLCE1, free calcium ion concentrations decreased, resulting in the inhibition of both cell proliferation and migration. Interestingly, the expression of PLCE1 and cytosolic calcium levels were regulated by reactive oxygen species(ROS). Furthermore, our findings suggest that ROS might inhibit the expression of PLCE1 by inhibiting TFEB, a transcription activator involved in the nuclear translocation process. Our study provided novel evidence regarding the regulatory effects of EGCG on activated HSCs (aHSCs) in mice by the calcium signaling pathway, emphasizing the crucial role of PLCE1 within the calcium signaling network of HSCs. The proposition was also made that PLCE1 holds promise as a novel therapeutic target for murine liver fibrosis.

Proteomic identification of potential biomarkers for heat tolerance in Caracu beef cattle using high and low thermotolerant groups

BACKGROUND

Heat stress has deleterious effects on physiological and performance traits in livestock. Within this context, using tropically adapted cattle breeds in pure herds or terminal crossbreeding schemes to explore heterosis is attractive for increasing animal production in warmer climate regions. This study aimed to identify biological processes, pathways, and potential biomarkers related to thermotolerance in Caracu, a tropically adapted beef cattle breed, by proteomic analysis of blood plasma. To achieve this goal, 61 bulls had their thermotolerance evaluated through a heat tolerance index. A subset of 14 extreme animals, including the seven most thermotolerant (HIGH group) and the seven least thermotolerant (LOW group), had their blood plasma samples used for proteomic analysis by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The differentially regulated proteins detected between HIGH and LOW groups were used to perform functional enrichment analysis and a protein-protein interaction network analysis.

RESULTS

A total of 217 proteins were detected only in the HIGH thermotolerant group and 51 only in the LOW thermotolerant group. In addition, 81 and 87 proteins had significantly higher and lower abundancies in the HIGH group, respectively. Regarding proteins with the highest absolute log-fold change values, we highlighted those encoded by DUSP5, IGFALS, ROCK2, RTN4, IRAG1, and NNT genes based on their functions. The functional enrichment analysis detected several biological processes, molecular functions, and pathways related to cellular responses to stress, immune system, complement system, and hemostasis in both HIGH and LOW groups, in addition to terms and pathways related to lipids and calcium only in the HIGH group. Protein-protein interaction (PPI) network revealed as important nodes many proteins with roles in response to stress, hemostasis, immune system, inflammation, and homeostasis. Additionally, proteins with high absolute log-fold change values and proteins detected as essential nodes by PPI analysis highlighted herein are potential biomarkers for thermotolerance, such as ADRA1A, APOA1, APOB, APOC3, C4BPA, CAT, CFB, CFH, CLU, CXADR, DNAJB1, DNAJC13, DUSP5, FGA, FGB, FGG, HBA, HBB, HP, HSPD1, IGFALS, IRAG1, KNG1, NNT, OSGIN1, PROC, PROS1, ROCK2, RTN4, RYR1, TGFB2, VLDLR, VTN, and VWF.

CONCLUSIONS

Identifying potential biomarkers, molecular mechanisms and pathways that act in response to heat stress in tropically adapted beef cattle contributes to developing strategies to improve performance and welfare traits in livestock under tropical climates.

Eucommia ulmoides extract regulates oxidative stress to maintain calcium homeostasis and improve diabetic osteoporosis

Diabetic osteoporosis (DOP) is a secondary disease that severely affects the health and quality of life of patients with diabetes mellitus. This study aimed to explore the bone protective effect of aqueous extract of Eucommia ulmoides (EUL) in DOP mice. DOP mice were established using a high-sugar, high-fat diet and streptozotocin (STZ) (35 mg/kg for three consecutive days), and the EUL aqueous extract (2.5 g/kg/day) was orally administered for 6 weeks. The serum levels of oxidative stress-related factors, calcium, and phosphorus were assessed using biochemical assays. The osteoprotective effect of EUL was assessed using micro-computer tomography, three-point bending assay, histological analysis, and immunoblotting. Quantitative real-time polymerase chain reaction and western blotting were performed to detect the expression levels of calcium transport channel factors in the kidney and small intestine tissues. Furthermore, the expression levels of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in the femur, kidney, and small intestine tissues were detected using western blotting and quantitative real-time polymerase chain reaction. EUL aqueous extract reduced blood glucose levels, increased body weight, and relieved symptoms in DOP mice (p < .05). It also increased bone mineral density, improved the bone microstructure, decreased the number of femoral osteoclasts, and increased the expression of femoral Runx2 and Bmp2 in DOP mice (p < .01). After 6 weeks of EUL aqueous extract administration, serum levels of SOD, CTA, calcium, and phosphorus were upregulated, whereas MDA levels were decreased (p < .01). The aqueous EUL extract also upregulated the expression of TRPV5, PMCA-1b, and CaBP-9 k in the kidney and small intestine of DOP mice (p < .01). Furthermore, the expression of Nrf2 and HO-1 in the kidney, small intestine, and femur tissues was increased (p < .01). EUL aqueous extract reduced blood glucose levels in DOP mice and regulated oxidative stress through the Nrf2/HO-1 pathway, thereby maintaining calcium homeostasis and ultimately improving bone quality. Our study suggested that EUL aqueous extract may be effective in the treatment of DOP.

COVID-19-Induced Refractory Symptomatic Hypocalcemia in a Patient With Parathyroid Gland Reimplantation

Background: Several cases of severe hypocalcemia in the setting of COVID-19 have been reported. The proposed mechanisms include direct viral interaction with ACE2 receptors in the parathyroid gland, viral chelation of calcium, worsening hypovitaminosis D, critical illness leading to unbound fatty acids binding calcium, and inflammatory cytokines leading to PTH resistance. Given the life-threatening nature of hypocalcemia, this underrecognized phenomenon should be on the forefront of the clinician's attention. This case highlights a rare manifestation of COVID-19 and further complicated by the patient's reimplanted parathyroid gland. Presentation: A 73-year-old female with primary hyperparathyroidism status post parathyroidectomy with reimplantation in the left forearm presented with 4 days of viral syndrome, found to have tetany and Chvostek's sign on physical exam. Pertinent laboratory abnormalities included calcium 5.3 mg/dL, ionized calcium 0.44 mmol/L, magnesium 1.4 mg/dL, phosphorous 5.5 mg/dL, PTH 242 pg/mL, and 25-OH vitamin D 56 ng/mL. Chest CT revealed multifocal pneumonia consistent with positive COVID-19 testing. She was subsequently admitted to the ICU for severe, symptomatic hypocalcemia and was initiated on a continuous calcium infusion, remdesivir, baricitinib, and steroids. Tetany resolved after 9 g calcium repletion, and she was transferred to the medical floor with an ionized calcium of 0.83 mmol/L. On hospital day 3, repeat ionized calcium was 0.78 mmol/L despite ongoing repletion. Given the persistence of hypocalcemia, a repeat PTH level was obtained which remained high at 487 pg/mL, suggesting ongoing PTH interference in the setting of COVID-19. PTH was obtained from the right (nonimplanted) arm which was normal at 74 pg/mL. This indicated an appropriate PTH response from the reimplanted gland, and that ongoing hypocalcemia may be due to insufficient PTH function to maintain systemic calcium levels or a peripheral interference with PTH level. With continued calcium supplementation and treatment of COVID-19, the patient's calcium stabilized at 8.6 mg/dL. She was discharged on oral calcium supplementation with endocrinology follow-up. Conclusion: Acute hypocalcemia strongly correlates with a profound inflammatory response in COVID-19 patients. This case corroborates the cytokine/PTH hypothesis. This patient had a high PTH sampled near the reimplanted gland but an inappropriately normal PTH from the nonimplanted arm, indicating that direct viral interaction interfering with PTH release is an unlikely mechanism. This case represents a scenario where PTH can be sampled directly from the source and this type of model could aid in the process of determining the etiology of hypocalcemia in COVID-19.

Impact of Metal Ions on Cellular Functions: A Focus on Mesenchymal Stem/Stromal Cell Differentiation

Metals play a crucial role in the human body, especially as ions in metalloproteins. Essential metals, such as calcium, iron, and zinc are crucial for various physiological functions, but their interactions within biological networks are complex and not fully understood. Mesenchymal stem/stromal cells (MSCs) are essential for tissue regeneration due to their ability to differentiate into various cell types. This review article addresses the effects of physiological and unphysiological, but not directly toxic, metal ion concentrations, particularly concerning MSCs. Overloading or unbalancing of metal ion concentrations can significantly impair the function and differentiation capacity of MSCs. In addition, excessive or unbalanced metal ion concentrations can lead to oxidative stress, which can affect viability or inflammation. Data on the effects of metal ions on MSC differentiation are limited and often contradictory. Future research should, therefore, aim to clarify the mechanisms by which metal ions affect MSC differentiation, focusing on aspects such as metal ion interactions, ion concentrations, exposure duration, and other environmental conditions. Understanding these interactions could ultimately improve the design of biomaterials and implants to promote MSC-mediated tissue regeneration. It could also lead to the development of innovative therapeutic strategies in regenerative medicine.

The impact of 25-hydroxyvitamin D and calcium on risk of age-related macular degeneration: a Mendelian randomization study

BACKGROUND

The relationships between 25-hydroxyvitamin D [25(OH)D] and calcium and age-related macular degeneration (AMD) are unclear.

OBJECTIVES

This study aimed to investigate the causal role of 25(OH)D concentrations, calcium concentrations, and dietary supplements use of vitamin D and calcium on risk of AMD and its subtypes.

METHODS

Independent genetic variants associated with 25(OH)D and calcium concentrations were used as instrumental variables in published genome-wide association studies (GWASs) of European ancestry. The bidirectional 2-sample Mendelian randomization (MR) analyses were performed using summary-level data from the UK Biobank and FinnGen datasets. Sensitivity analyses were conducted to ensure the robustness of the MR results. The meta-analyses were conducted using both fixed-effect and random-effect models to provide comprehensive and reliable estimates.

RESULTS

A standard deviation increase in calcium concentrations was linked to a 14%, 17%, and 13% reduction in the likelihood of developing AMD (95% confidence interval [CI]: 0.77, 0.97), wet AMD (95% CI: 0.73, 0.95), and dry AMD (95% CI: 0.75, 1.00), respectively. No significant causal relationships were detected between genetically predicted 25(OH)D concentrations and AMD and its subtypes (all P > 0.05). The combined analyses showed that higher calcium concentrations were associated with a reduced risk of overall AMD, with an odds ratio of 0.89 (95% CI: 0.81, 0.98).

CONCLUSIONS

This study provides evidence supporting the causal relationship between calcium concentrations and risk of AMD and its subtypes, which may have important implications for the prevention, monitoring, and treatment of AMD.

Diurnal fluctuations in biochemical parameters related to calcium homeostasis - the Bispebjerg study of diurnal variations

PURPOSE

This aim of this study was to assess the possible association between diurnal oscillations and biochemical markers associated with calcium homeostasis. This included the markers parathyroid hormone (PTH), total calcium, total alkaline phosphatase, phosphate, and 25-hydroxyvitamin D (25-OH-D). By examining the influence of circadian rhythms on these parameters, the study aimed to deepen the understanding of calcium metabolism dynamics and its clinical implications.

PATIENTS AND METHODS

Blood samples from 24 Caucasian male volunteers aged 20 to 40 (mean age 26) with normal pulse, blood pressure, and BMI were analyzed for biochemical markers related to calcium homeostasis. Data was obtained from the Bispebjerg study of diurnal variations. Blood samples were collected every three hours over a 24-hour period. Patients were fasting from 22:00 to 09:00. The participants spent 24 h in the hospital ward, receiving regular meals and engaging in low-intensity activities. They experienced 15 h of daylight and 9 h of complete darkness during sleep. Diurnal oscillations were analyzed using cosinor analysis with statistical significance set at p < 0.05.

RESULTS

Total calcium, phosphate, and PTH exhibited significant diurnal variations. Total calcium and PTH were inversely synchronized while PTH and phosphate oscillated in synchronization. The three parameters showed relatively large amplitude/reference range ratios from 25.4% to 41.5%.

CONCLUSION

This study found notable fluctuations in total calcium, phosphate, and PTH levels over a 24-hour cycle, while 25-OH-D and total alkaline phosphatase remained consistent. It highlights the importance of considering sampling times for total calcium, PTH, and phosphate in clinical settings.

Molecular regulation of calcium-sensing receptor (CaSR)-mediated signaling

Calcium-sensing receptor (CaSR), a family C G-protein-coupled receptor, plays a crucial role in regulating calcium homeostasis by sensing small concentration changes of extracellular Ca2+, Mg2+, amino acids (e.g., L-Trp and L-Phe), small peptides, anions (e.g., HCO3 - and PO4 3-), and pH. CaSR-mediated intracellular Ca2+ signaling regulates a diverse set of cellular processes including gene transcription, cell proliferation, differentiation, apoptosis, muscle contraction, and neuronal transmission. Dysfunction of CaSR with mutations results in diseases such as autosomal dominant hypocalcemia, familial hypocalciuric hypercalcemia, and neonatal severe hyperparathyroidism. CaSR also influences calciotropic disorders, such as osteoporosis, and noncalciotropic disorders, such as cancer, Alzheimer's disease, and pulmonary arterial hypertension. This study first reviews recent advances in biochemical and structural determination of the framework of CaSR and its interaction sites with natural ligands, as well as exogenous positive allosteric modulators and negative allosteric modulators. The establishment of the first CaSR protein-protein interactome network revealed 94 novel players involved in protein processing in endoplasmic reticulum, trafficking, cell surface expression, endocytosis, degradation, and signaling pathways. The roles of these proteins in Ca2+-dependent cellular physiological processes and in CaSR-dependent cellular signaling provide new insights into the molecular basis of diseases caused by CaSR mutations and dysregulated CaSR activity caused by its protein interactors and facilitate the design of therapeutic agents that target CaSR and other family C G-protein-coupled receptors.

Calcium homeostasis and endometriosis: A Mendelian randomization study

Background

Previous observational studies have investigated the correlation between calcium homeostasis modulator levels and endometriosis risk. Yet, the genetic association between body calcium homeostasis and endometriosis risk remains to be elucidated.

Methods

Four tiers of Mendelian randomization (MR) analysis were conducted, as follows: (1) single univariate MR and (2) multivariate MR to evaluate the correlation between calcium homeostasis regulators and endometriosis; (3) inverse MR to probe the influence of endometriosis on body calcium homeostasis; (4) two-sample MR to scrutinize the connection between calcium levels and endometriosis categories.

Results

The two-sample MR analysis unveiled a robust positive correlation between genetically inferred calcium levels and endometriosis risk (IVW: OR = 1.15, 95 % CI: 1.02-1.29, p = 0.018). The MVMR analysis corroborated that the positive correlation of calcium levels with endometriosis persisted after adjusting for 25(OH)D and PTH. The inverse MR analysis disclosed a significant association between endometriosis and 25(OH)D (β = 0.01, 95 % CI: 0.00-0.02, p = 0.007) and calcium (β = 0.02, 95 % CI: 0.00-0.04, p = 0.035). The two-sample MR analysis further demonstrated that calcium levels were positively linked solely to endometriosis of uterus (i.e. adenomyosis, IVW: OR = 1.23, 95 % CI: 1.01-1.49, p = 0.038), with no evidence of a influence on other endometriosis categories.

Conclusions

This study, employing various types of MR, offers some genetic evidence for the relationship between calcium homeostasis and endometriosis, augmenting the current comprehension of the complex association between the two and suggesting that calcium levels are a risk factor for endometriosis. These findings provide a unique genetic perspective that may spur further investigation and may inform future strategies for managing patients with endometriosis.

Calcium mass balance in adults during single hemodialysis and hemodiafiltration treatments using lower calcium dialysate concentrations

BACKGROUND

Debate continues as to the optimum hemodialysis (HD) dialysate calcium concentration. Although current guidelines advocate 1.25-1.5 mmol/L, some investigators have suggested these may cause calcium gains. As such we investigated whether using dialysate calcium of 1.25 mmol/L risked calcium gains, and whether there were differences between hemodiafiltration and high flux HD.

METHODS

We continuously collect an aliquot of effluent dialysate during dialysis sessions, and calculated dialysis calcium mass balance by the difference between the amount of calcium delivered as fresh dialysate and that lost in effluent dialysate.

RESULTS

We studied 106 stable outpatients, 64% male, mean age 64.4 ± 16.2 years, median dialysis vintage 32 (22-60) months. Most sessions (69%) used a 1.0 mmol/L calcium dialysate, with a median sessional loss of 13.7 (11.5-17.1) mmol, whereas using 1.25 mmol/L the median loss was 7.4 (4.9-10.1) mmol, but with 6.9% had a positive balance (p = 0.031 vs dialysate calcium 1.0 mmol/L). Most patients (85.8%) were treated by hemodiafiltration, but there was no difference in sessional losses (11.7 (8.4-15.8) vs 13.5 (8.1-16.8)) with high flux HD. Dialysis sessional calcium balance was associated with the use of lower dialysate calcium concentration (β -19.5, 95% confidence limits (95%CL) -27.7 to -11.3, p < 0.001), and sessional duration (β 0.07 (95% CL) 0.03-012, p = 0.002).

CONCLUSION

Ideally, the choice of dialysate calcium should be individualized, but clinicians should be aware, that even when using a dialysate calcium of 1.25 mmol/L, some patients are at risk of a calcium gain during hemodiafiltration and high-flux hemodialysis.

Application of capsaicin and calcium phosphate-loaded MOF system for tumor therapy involving calcium overload

Calcium overload therapy refers to the condition of intracellular Ca2+ overload, which causes mitochondrial damage and leads to the uncontrolled release of apoptotic factors into the cytoplasm through the open mitochondrial permeability pore. Based on this, it is playing an increasingly important role in the field of oncology due to its good efficacy and small side effects. However, the regulation of calcium homeostasis by cancer cells themselves, insufficient calcium ions (Ca2+) in tumor sites and low efficiency of calcium entering tumor have limited its efficacy, resulting in unsatisfactory therapeutic effect. Therefore, a novel CAP/BSA@TCP-ZIF-8 nanoparticle drug carrier system was constructed that can provide Ca2+ from exogenous sources for pH-controlled degradation and drug release at the same time. Both in vivo and in vitro experiments have proved that the nanomaterial can activate TRPV1 channels and provide exogenous Ca2+ to cause Ca2+ overload and apoptosis, thus achieving anti-tumor effects.

Plasma proteins and persistent postsurgical pelvic pain among adolescents and young adults with endometriosis

BACKGROUND

Noninvasive biomarkers that predict surgical treatment response would inform personalized treatments and provide insight into potential biologic pathways underlying endometriosis-associated pain and symptom progression.

OBJECTIVE

To use plasma proteins in relation to the persistence of pelvic pain following laparoscopic surgery in predominantly adolescents and young adults with endometriosis using a multiplex aptamer-based proteomics biomarker discovery platform.

STUDY DESIGN

We conducted a prospective analysis including 142 participants with laparoscopically-confirmed endometriosis from the Women's Health Study: From Adolescence to Adulthood observational longitudinal cohort with study enrollment from 2012-2018. Biologic samples and patient data were collected with modified World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonization Project tools. In blood collected before laparoscopic ablation or excision of endometriosis, we simultaneously measured 1305 plasma protein levels, including markers for immunity, angiogenesis, and inflammation, using SomaScan. Worsening or persistent postsurgical pelvic pain was defined as having newly developed, persistent (ie, stable), or worsening severity, frequency, or persistent life interference of dysmenorrhea or acyclic pelvic pain at 1-year postsurgery compared with presurgery. We calculated odds ratios and 95% confidence intervals using logistic regression adjusted for age, body mass index, fasting status, and hormone use at blood draw. We applied Ingenuity Pathway Analysis and STRING analysis to identify pathophysiologic pathways and protein interactions.

RESULTS

The median age at blood draw was 17 years (interquartile range, 15-19 years), and most participants were White (90%). All had superficial peritoneal lesions only and were treated by excision or ablation. One-year postsurgery, pelvic pain worsened or persisted for 76 (54%) of these participants with endometriosis, whereas pelvic pain improved for 66 (46%). We identified 83 proteins associated with worsening or persistent pelvic pain 1-year postsurgery (nominal P<.05). Compared with those with improved pelvic pain 1-year postsurgery, those with worsening or persistent pelvic pain had higher plasma levels of CD63 antigen (odds ratio, 2.98 [95% confidence interval, 1.44-6.19]) and CD47 (odds ratio, 2.68 [95% confidence interval, 1.28-5.61]), but lower levels of Sonic Hedgehog protein (odds ratio, 0.55 [95% confidence interval, 0.36-0.84]) in presurgical blood. Pathways related to cell migration were up-regulated, and pathways related to angiogenesis were down-regulated in those with worsening or persistent postsurgical pelvic pain compared with those with improved pain. When we examined the change in protein levels from presurgery to postsurgery and its subsequent risk of worsening or persistent postsurgical pain at 1-year follow-up, we observed increasing levels of Sonic Hedgehog protein from presurgery to postsurgery was associated with a 4-fold increase in the risk of postsurgical pain (odds ratio [quartile 4 vs 1], 3.86 [1.04-14.33]).

CONCLUSION

Using an aptamer-based proteomics platform, we identified plasma proteins and pathways associated with worsening or persistent pelvic pain postsurgical treatment of endometriosis among adolescents and young adults that may aid in risk stratification of individuals with endometriosis.

Digested casein phosphopeptides impact intestinal calcium transport in vitro

Calcium is the most abundant mineral in the human body and is involved in critical physiological and cellular processes. It is essential for the development, maintenance, and integrity of bone tissue throughout life. Identifying new natural food-grade chelating agents to improve calcium uptake is of increasing interest. Casein phosphopeptides (CPPs), highly phosphorylated peptides obtained after enzymatic hydrolysis of caseins, represent promising calcium-chelating candidates. The aim of this study was to investigate, using cell culture models, the ability of a digested milk matrix enriched in CPPs to regulate calcium transport through the intestinal barrier and elucidate the involved mechanisms. To this end, a CPP-preparation underwent in vitro static digestion and was subsequently incubated with an intestinal barrier model to monitor calcium uptake and transport. Our results demonstrated that the digested CPP preparation enhanced the trans-epithelial calcium transport via paracellular pathways and that CPPs, identified by peptidomics, crossed the intestinal barrier in the same time.

The Effects of Different Dietary Patterns on Bone Health

Bone metabolism is a process in which osteoclasts continuously clear old bone and osteoblasts form osteoid and mineralization within basic multicellular units, which are in a dynamic balance. The process of bone metabolism is affected by many factors, including diet. Reasonable dietary patterns play a vital role in the prevention and treatment of bone-related diseases. In recent years, dietary patterns have changed dramatically. With the continuous improvement in the quality of life, high amounts of sugar, fat and protein have become a part of people's daily diets. However, people have gradually realized the importance of a healthy diet, intermittent fasting, calorie restriction, a vegetarian diet, and moderate exercise. Although these dietary patterns have traditionally been considered healthy, their true impact on bone health are still unclear. Studies have found that caloric restriction and a vegetarian diet can reduce bone mass, the negative impact of a high-sugar and high-fat dietary (HSFD) pattern on bone health is far greater than the positive impact of the mechanical load, and the relationship between a high-protein diet (HPD) and bone health remains controversial. Calcium, vitamin D, and dairy products play an important role in preventing bone loss. In this article, we further explore the relationship between different dietary patterns and bone health, and provide a reference for how to choose the appropriate dietary pattern in the future and for how to prevent bone loss caused by long-term poor dietary patterns in children, adolescents, and the elderly. In addition, this review provides dietary references for the clinical treatment of bone-related diseases and suggests that health policy makers should consider dietary measures to prevent and treat bone loss.

Biomarkers of food intake and their relevance to metabolic syndrome

Metabolic syndrome (MetS) constitutes a prevalent risk factor associated with non communicable diseases such as cardiovascular disease and type 2 diabetes. A major factor impacting the etiology of MetS is diet. Dietary patterns and several individual food constituents have been related to the risk of developing MetS or have been proposed as adjuvant treatment. However, traditional methods of dietary assessment such as 24 h recalls rely greatly on intensive user-interaction and are subject to bias. Hence, more objective methods are required for unbiased dietary assessment and efficient prevention. While it is accepted that some dietary-derived constituents in blood plasma are indicators for certain dietary patterns, these may be too unstable (such as vitamin C as a marker for fruits/vegetables) or too broad (e.g. polyphenols for plant-based diets) or reflect too short-term intake only to allow for strong associations with prolonged intake of individual food groups. In the present manuscript, commonly employed biomarkers of intake including those related to specific food items (e.g. genistein for soybean or astaxanthin and EPA for fish intake) and novel emerging ones (e.g. stable isotopes for meat intake or microRNA for plant foods) are emphasized and their suitability as biomarker for food intake discussed. Promising alternatives to plasma measures (e.g. ethyl glucuronide in hair for ethanol intake) are also emphasized. As many biomarkers (i.e. secondary plant metabolites) are not limited to dietary assessment but are also capable of regulating e.g. anti-inflammatory and antioxidant pathways, special attention will be given to biomarkers presenting a double function to assess both dietary patterns and MetS risk.

Association between tobacco smoke exposure and serum parathyroid hormone levels among US adults (NHANES 2003-2006)

Tobacco smoke exposure has been demonstrated to impede bone remodeling and diminish bone density, yet research regarding its correlation with parathyroid hormone (PTH) remains limited. This study aims to investigate the relationship between tobacco smoke exposure and serum PTH levels in adults aged 20 years and older. This study included 7,641 participants from two cycles of the National Health and Nutrition Examination Survey (NHANES, United States, 2003- 2006). Reflect tobacco smoke exposure through serum cotinine levels, and use an adjusted weighted multivariate linear regression model to test the independent linear relationship between serum cotinine and PTH. Stratified analysis was conducted to validate the sensitivity of the conclusions. Smooth curve fitting and threshold effect analysis were performed to assess the non-linear relationship. After comprehensive adjustment using weighted multivariate regression analysis, a negative correlation was found between serum cotinine and PTH levels. The interaction p-values in subgroup analyses were all greater than 0.05. Moreover, smooth curve fitting indicated a non-linear relationship between serum cotinine and PTH, with a turning point observed. Our research indicates that tobacco smoke exposure is negatively correlated and independent of serum parathyroid hormone levels, indicating that long-term tobacco smoke exposure may lead to parathyroid dysfunction in adults.

[Electrolyte disorders in oncological patients]

Electrolyte disorders (ED) are common in patients with cancer and in most cases, the etiologies do not differ from the general population. They may also be induced by the cancer, its therapy or paraneoplastic syndromes. ED are associated with poor outcomes, increased morbidity and mortality in this population. Hyponatremia is the most common disorder, often multifactorial, iatrogenic or secondary to the syndrome of inappropriate antidiuretic hormone secretion, usually due to small cell lung cancer. More rarely, hyponatremia may reveal adrenal insufficiency. Hypokalemia is generally multifactorial and associated with other ED. Cisplatin and ifosfamide induce proximal tubulopathies with hypokalemia and/or hypophosphatemia. Hypomagnesemia is often iatrogenic, related to cisplatin or cetuximab, but can be prevented by supplementation. Hypercalcemia can impair life quality and be life-threatening in the most severe cases. Hypocalcemia is less common and often of iatrogenic origin. Finally, the tumor lysis syndrome is a diagnostic and therapeutic emergency that affects the prognosis of patients. Its incidence tends to increase in solid oncology, related to the improvement of therapies. Prevention and early diagnosis of ED are essential to optimize the overall management of patients with underlying cancer and cancer therapy. The aim of this review is to synthesize most frequent ED and their management.

Risk factors associated with intraoperative persistent hypotension in pancreaticoduodenectomy

BACKGROUND

Intraoperative persistent hypotension (IPH) during pancreaticoduodenectomy (PD) is linked to adverse postoperative outcomes, yet its risk factors remain unclear.

AIM

To clarify the risk factors associated with IPH during PD, ensuring patient safety in the perioperative period.

METHODS

A retrospective analysis of patient records from January 2018 to December 2022 at the First Affiliated Hospital of Nanjing Medical University identified factors associated with IPH in PD. These factors included age, gender, body mass index, American Society of Anesthesiologists classification, comorbidities, medication history, operation duration, fluid balance, blood loss, urine output, and blood gas parameters. IPH was defined as sustained mean arterial pressure < 65 mmHg, requiring prolonged deoxyepinephrine infusion for > 30 min despite additional deoxyepinephrine and fluid treatments.

RESULTS

Among 1596 PD patients, 661 (41.42%) experienced IPH. Multivariate logistic regression identified key risk factors: increased age [odds ratio (OR): 1.20 per decade, 95% confidence interval (CI): 1.08-1.33] (P < 0.001), longer surgery duration (OR: 1.15 per additional hour, 95%CI: 1.05-1.26) (P < 0.01), and greater blood loss (OR: 1.18 per 250-mL increment, 95%CI: 1.06-1.32) (P < 0.01). A novel finding was the association of arterial blood Ca2+ < 1.05 mmol/L with IPH (OR: 2.03, 95%CI: 1.65-2.50) (P < 0.001).

CONCLUSION

IPH during PD is independently associated with older age, prolonged surgery, increased blood loss, and lower plasma Ca2+.

Deletion of FNDC5/irisin modifies murine osteocyte function in a sex-specific manner

Irisin, released from exercised muscle, has been shown to have beneficial effects on numerous tissues but its effects on bone are unclear. We found significant sex and genotype differences in bone from wildtype (WT) mice compared to mice lacking Fndc5 (knockout [KO]), with and without calcium deficiency. Despite their bone being indistinguishable from WT females, KO female mice were partially protected from osteocytic osteolysis and osteoclastic bone resorption when allowed to lactate or when placed on a low-calcium diet. Male KO mice have more but weaker bone compared to WT males, and when challenged with a low-calcium diet lost more bone than WT males. To begin to understand responsible molecular mechanisms, osteocyte transcriptomics was performed. Osteocytes from WT females had greater expression of genes associated with osteocytic osteolysis and osteoclastic bone resorption compared to WT males which had greater expression of genes associated with steroid and fatty acid metabolism. Few differences were observed between female KO and WT osteocytes, but with a low-calcium diet, the KO females had lower expression of genes responsible for osteocytic osteolysis and osteoclastic resorption than the WT females. Male KO osteocytes had lower expression of genes associated with steroid and fatty acid metabolism, but higher expression of genes associated with bone resorption compared to male WT. In conclusion, irisin plays a critical role in the development of the male but not the female skeleton and protects male but not female bone from calcium deficiency. We propose irisin ensures the survival of offspring by targeting the osteocyte to provide calcium in lactating females, a novel function for this myokine.

Association between serum calcium and prognosis in patients with acute ischemic stroke in ICU: analysis of the MIMIC-IV database

BACKGROUND

While serum Ca has proven to be a reliable predictor of mortality across various diseases, its connection with the clinical outcomes of ischemic stroke (IS) remains inconclusive. Our research aimed to explore the relationships between serum total Ca (tCa) and serum ionized Ca (iCa) and mortality among acute IS (AIS) patients.

METHODS

We gathered data from 1773 AIS patients in the Medical Information Mart for Intensive Care Database IV, including baseline demographic data, comorbidities, vital signs, laboratory-based data, and scoring systems. Endpoints for the study encompassed 30-d, 90-d, and 365-d all-cause mortalities. Employing restricted cubic spline Cox regression, we explored potential nonlinear relationships between admission serum iCa and tCa levels and mortality. Participants were categorized into four groups based on serum iCa and tCa quartiles. Multivariable Cox regression analysis was then conducted to evaluate the independent association of iCa and tCa quartiles with all-cause mortality.

RESULTS

The restricted cubic spline revealed a U-shaped association between iCa and 30-d and 90-d mortality (P<0.05), while the relationship between iCa and 365-d mortality was linear (P<0.05). After adjusting for confounders, multivariable Cox analysis demonstrated that the lowest serum iCa level quartile was independently associated with increased risks of 30-d, 90-d, and 365-d mortality. Similarly, the highest serum iCa level quartile was independently associated with increased risks of 30-d and 90-d mortality, but not 365-d mortality. Notably, serum tCa level showed no association with increased risks of 30-d, 90-d, and 365-d mortality.

CONCLUSIONS

Our findings suggest that serum iCa, rather than tCa, is linked to ischemic stroke prognosis. Both high and low serum iCa levels are associated with poor short-term prognosis, while only low serum iCa is associated with poor long-term prognosis in AIS patients.

Deletion of FNDC5/Irisin modifies murine osteocyte function in a sex-specific manner

Irisin, released from exercised muscle, has been shown to have beneficial effects on numerous tissues but its effects on bone are unclear. We found significant sex and genotype differences in bone from wildtype (WT) mice compared to mice lacking Fndc5 (KO), with and without calcium deficiency. Despite their bone being indistinguishable from WT females, KO female mice were partially protected from osteocytic osteolysis and osteoclastic bone resorption when allowed to lactate or when placed on a low-calcium diet. Male KO mice have more but weaker bone compared to WT males, and when challenged with a low-calcium diet lost more bone than WT males. To begin to understand responsible molecular mechanisms, osteocyte transcriptomics was performed. Osteocytes from WT females had greater expression of genes associated with osteocytic osteolysis and osteoclastic bone resorption compared to WT males which had greater expression of genes associated with steroid and fatty acid metabolism. Few differences were observed between female KO and WT osteocytes, but with a low calcium diet, the KO females had lower expression of genes responsible for osteocytic osteolysis and osteoclastic resorption than the WT females. Male KO osteocytes had lower expression of genes associated with steroid and fatty acid metabolism, but higher expression of genes associated with bone resorption compared to male WT. In conclusion, irisin plays a critical role in the development of the male but not the female skeleton and protects male but not female bone from calcium deficiency. We propose irisin ensures the survival of offspring by targeting the osteocyte to provide calcium in lactating females, a novel function for this myokine.

How to Suppress Mineral Loss and Stimulate Anabolism in Postmenopausal Bones with Appropriate Timing of Exercise and Nutrients

Background. Bone Health and Osteoporosis Foundation (BHOF) reports that as of 2023, approximately 10 million of older Americans have osteoporosis and another 44 million have low bone density. Osteoporosis is a serious handicap for the elderly and, in particular, for estrogen-deficient postmenopausal women, as it increases the risk of debilitating bone weakness and fractures. The BHOF recommendations for prevention of osteopenia, osteoporosis and bone fractures are to perform weight-bearing and muscle-strengthening exercises and to take recommended amounts of daily calcium and vitamin D. Methods. The purpose of this review is to describe and discuss recent evidence-based research on how to effectively utilize timing of exercise and calorie intake for stimulation of postmenopausal bone anabolism, and to provide this new information in the form of specific and actionable recommendations. Results. The five evidence-based recommendations are as follows: 1. Select an appropriate circadian time of day for exercise; 2. Increase walking speed to raise the movement momentum; 3. Eat a weight-maintenance meal one or two hours before the exercise bout; 4. Sustain the duration of walking activity (impulse) for 40 to 45 min; and 5. Repeat effective exercise stimulus 7 to 8 h after the first one to double the anabolic effect. Osteogenesis can also be increased with subthreshold mechanical loading, where needed, under several special circumstances. Conclusions. This review should provide pragmatic actionable pointers on how to utilize the idiosyncratic bone responsiveness to timing of movement and meals to prevent osteoporosis and encourage research toward a better understanding of how bone detects adequacy of a mechanical stimulus and determines duration of necessary rest to recover its sensitivity to mechanical stimulation and nutrients.

The Prognostic Value of Serum Calcium Levels in Elderly Dilated Cardiomyopathy Patients

Background

It is unclear whether serum calcium on admission is associated with clinical outcomes in dilated cardiomyopathy (DCM). In this study, we conducted a retrospective study spanning a decade to investigate the prognostic value of baseline calcium in elderly patients with DCM.

Methods

A total of 1,089 consecutive elderly patients (age ≥60 years) diagnosed with DCM were retrospectively enrolled from January 2010 to December 2019. Univariate and multivariate analyses were performed to investigate the association of serum calcium with their clinical outcomes.

Results

In this study, the average age of the subjects was 68.36 ± 6.31 years. Receiver operating characteristic (ROC) curve analysis showed that serum calcium level had a great sensitivity and specificity for predicting in-hospital death, with an AUC of 0.732. Kaplan-Meier survival analysis showed that patients with a serum calcium >8.62 mg/dL had a better prognosis than those with a serum calcium ≤8.62 mg/dL (log-rank χ2 40.84, p < 0.001). After adjusting for several common risk factors, a serum calcium ≤8.62 mg/dL was related to a higher risk of long-term mortality (HR: 1.449; 95% CI: 1.115~1.882; p = 0.005).

Conclusions

Serum calcium level could be served as a simple and affordable tool to evaluate patients' prognosis in DCM.

Oral Release Kinetics, Biodistribution, and Excretion of Dopants from Barium-Containing Bioactive Glass in Rats

Background: Inorganic biomaterials are biologically active and are used as implants and drug delivery system. They have therapeutically active elements present in their framework that are released in the physiological milieu. Release of these dopants above the supraphysiological limit may produce adverse effects and physicochemical interactions with the loaded drugs. Therefore, this necessitates evaluating the in vivo release kinetics, biodistribution, and excretion profiles of dopants from barium-doped bioglass (BaBG) that has potential anti-inflammatory, antiulcer, and regenerative properties. Methods: In vitro leaching of Ca, Si, and Ba from BaBG was analyzed in simulated body fluid. Release kinetics post single-dose oral administration (1, 5, and 10 mg/kg) was performed in rats. Blood was collected at different time points, and pharmacokinetic parameters of released elements were calculated. The routes of excretion and biodistribution in major organs were evaluated using ICP-MS. Results: Elements were released after the oral administration of BaBG into the plasma. They showed dose-dependent release kinetics and mean residence time. Cmax was observed at 24 h for all elements, followed by a downhill fall. There was also a dose-dependent increase in the volume of distribution, and the clearance of dopants was mostly through feces. Ba and Si were biodistributed significantly in the liver, spleen, and kidneys. However, by the end of day 7, there was a leveling-off effect observed for all elements. Conclusion: All of the dopants exhibited a dose-dependent increase in release kinetics and biodistribution in vital organs. This study will help in dose optimization and understanding of various physicochemical and pharmacokinetic interactions when BaBG is used for future pharmacological studies.

Comparative clinical study of phosphorous necrosis and medical-related osteonecrosis of the jaws

BACKGROUND

Phosphorous necrosis of the jaw (PNJ) exhibits similar clinical and pathological features as medical-related osteonecrosis of the jaw (MRONJ). This study aims at comparing the similarities and differences between PNJ and MRONJ regarding pathological features and to provide a theoretical basis for the clinical diagnosis and management of PNJ.

MATERIAL AND METHODS

A retrospective analysis was conducted to assess clinical differences among 38 PNJ patients and 31 MRONJ patients, who were diagnosed and treated between January 2009 and October 2022. Pathological alterations in bone tissue were evaluated using EDS, H&E, Masson, and TRAP staining on five specimens from both MRONJ and PNJ cases; furthermore, immunohistochemistry was used to determine the expression levels of OPG, RANKL, and Runx2. The mandibular coronoid process was removed from individuals with temporomandibular joint ankylosis to serve as a control.

RESULTS

CBCT imaging demonstrated necrotic bone formation in block, strip, or plaque shapes. EDS analysis showed that the calcium/phosphorus ratio in the bone tissue of PNJ and MRONJ was significantly lower than that of the control group (P < 0.05). Additionally, staining indicated reduced osteoblast counts, disrupted bone trabecular structure, and decreased collagen fiber content in the bone tissues of PNJ and MRONJ. Immunohistochemistry demonstrated that RANKL expression was significantly lower in MRONJ compared to PNJ and control groups (P < 0.05). Conversely, Runx2 expression was significantly higher in PNJ than in MRONJ and control groups (P < 0.05), and there was no significant difference in OPG expression.

CONCLUSION

PNJ and MRONJ demonstrate comparable clinical manifestations and pathological traits, although disparities may exist in their underlying exhibit comparable clinical manifestations, pathological traits, and molecular mechanisms.

Nanoapatite-Loaded κ-Carrageenan/Poly(vinyl alcohol)-Based Injectable Cryogel for Hemostasis and Wound Healing

Immediate control of excessive bleeding and prevention of infections are of utmost importance in the management of wounds. Cryogels have emerged as promising materials for the rapid release of medication and achieving hemostasis. However, their quick release properties pose the challenge of exposing patients to high concentrations of drugs. In this study, hybrid nanocomposites were developed to address this issue by combining poly(vinyl alcohol) and κ-carrageenan with whitlockite nanoapatite (WNA) particles and ciprofloxacin, aiming to achieve rapid hemostasis and sustained antibacterial effects. A physically cross-linked cryogel was obtained by subjecting a blend of poly(vinyl alcohol) and κ-carrageenan to successive freezing-thawing cycles, followed by the addition of WNA. Furthermore, ciprofloxacin was introduced into the cryogel matrix for subsequent evaluation of its wound healing properties. The resulting gel system exhibited a 3D microporous structure and demonstrated excellent swelling, low cytotoxicity, and outstanding mechanical properties. These characteristics were evaluated through analytical and rheological experiments. The nanocomposite cryogel with 4% whitlockite showed extended drug release of 71.21 ± 3.5% over 21 days and antibacterial activity with a considerable growth inhibition zone (4.19 ± 3.55 cm). Experiments on a rat model demonstrated a rapid hemostasis property of cryogels within an average of 83 ± 4 s and accelerated the process of wound healing with 96.34% contraction compared to the standard, which exhibited only ∼78% after 14 days. The histopathological analysis revealed that the process of epidermal re-epithelialization took around 14 days following the skin incision. The cryogel loaded with WNAs and ciprofloxacin holds great potential for strategic utilization in wound management applications as an effective material for hemostasis and anti-infection purposes.

Ion homeostasis in diabetic kidney disease

The complications of type 2 diabetes are a major global public health problem with high incidence and mortality, affecting almost all individuals with diabetes worldwide. Diabetic kidney disease (DKD) is one such primary complication and has become a leading cause of end-stage renal disease in patients with diabetes. Progression from diabetes to DKD is a complex process typically involving multiple mechanisms. Recent remarkable clinical benefits of sodium-glucose cotransporter 2 (SGLT2) inhibitors in diabetes and DKD highlight the critical impact of renal ion homeostasis on disease progression. This review comprehensively examines the impact of ion homeostasis on the transition from diabetes to DKD, outlining possible therapeutic interventions and addressing the ongoing challenges in this rapidly developing field.

Recommended calcium intake in adults and children with chronic kidney disease-a European consensus statement

Mineral and bone disorders (MBD) are common in patients with chronic kidney disease (CKD), contributing to significant morbidity and mortality. For several decades, the first-line approach to controlling hyperparathyroidism in CKD was by exogenous calcium loading. Since the turn of the millennium, however, a growing awareness of vascular calcification risk has led to a paradigm shift in management and a move away from calcium-based phosphate binders. As a consequence, contemporary CKD patients may be at risk of a negative calcium balance, which, in turn, may compromise bone health, contributing to renal bone disease and increased fracture risk. A calcium intake below a certain threshold may be as problematic as a high intake, worsening the MBD syndrome of CKD, but is not addressed in current clinical practice guidelines. The CKD-MBD and European Renal Nutrition working groups of the European Renal Association (ERA), together with the CKD-MBD and Dialysis working groups of the European Society for Pediatric Nephrology (ESPN), developed key evidence points and clinical practice points on calcium management in children and adults with CKD across stages of disease. These were reviewed by a Delphi panel consisting of ERA and ESPN working groups members. The main clinical practice points include a suggested total calcium intake from diet and medications of 800-1000 mg/day and not exceeding 1500 mg/day to maintain a neutral calcium balance in adults with CKD. In children with CKD, total calcium intake should be kept within the age-appropriate normal range. These statements provide information and may assist in decision-making, but in the absence of high-level evidence must be carefully considered and adapted to individual patient needs.

Effect of Zinc Supplementation on Altered Calcium Homeostasis, Parathyroid Gland, Bone, and Skeletal Muscle Histology Induced by Subchronic Oral Exposure to Glyphosate-Based Herbicide (GOBARA®) in Wistar Rats

Objectives

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.

Methods

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.

Results

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.

Conclusion

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.

Recent progress in the role of endogenous metal ions in doxorubicin-induced cardiotoxicity

Doxorubicin is a widely used anticancer drug in clinical practice for the treatment of various human tumors. However, its administration is associated with cardiotoxicity. Administration of doxorubicin with low side effects for cancer treatment and prevention are, accordingly, urgently required. The human body harbors various endogenous metal ions that exert substantial influences. Consequently, extensive research has been conducted over several decades to investigate the potential of targeting endogenous metal ions to mitigate doxorubicin's side effects and impede tumor progression. In recent years, there has been a growing body of research indicating the potential efficacy of metal ion-associated therapeutic strategies in inhibiting doxorubicin-induced cardiotoxicity (DIC). These strategies offer a combination of favorable safety profiles and potential clinical utility. Alterations in intracellular levels of metal ions have been found to either facilitate or mitigate the development of DIC. For instance, ferroptosis, a cellular death mechanism, and metal ions such as copper, zinc, and calcium have been identified as significant contributors to DIC. This understanding can contribute to advancements in cancer treatment and provide valuable insights for mitigating the cardiotoxic effects of other therapeutic drugs. Furthermore, potential therapeutic strategies have been investigated to alleviate DIC in clinical settings. The ultimate goal is to improve the efficacy and safety of Dox and offer valuable insights for future research in this field.