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Rectifying Attenuated Store-Operated Calcium Entry as a Therapeutic Approach for Alzheimer's Disease.
Huang, AS, Tong, BCK, Wu, AJ, Chen, X, Sreenivasmurthy, SG, Zhu, Z, Liu, J, Su, C, Li, M, Cheung, KH
Current Alzheimer research. 2020;(12):1072-1087
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder. Although the pathological hallmarks of AD have been identified, the derived therapies cannot effectively slow down or stop disease progression; hence, it is likely that other pathogenic mechanisms are involved in AD pathogenesis. Intracellular calcium (Ca2+) dyshomeostasis has been consistently observed in AD patients and numerous AD models and may emerge prior to the development of amyloid plaques and neurofibrillary tangles. Thus, intracellular Ca2+ disruptions are believed to play an important role in AD development and could serve as promising therapeutic intervention targets. One of the disrupted intracellular Ca2+ signaling pathways manifested in AD is attenuated storeoperated Ca2+ entry (SOCE). SOCE is an extracellular Ca2+ entry mechanism mainly triggered by intracellular Ca2+ store depletion. Maintaining normal SOCE function not only provides a means for the cell to replenish ER Ca2+ stores but also serves as a cellular signal that maintains normal neuronal functions, including excitability, neurogenesis, neurotransmission, synaptic plasticity, and gene expression. However, normal SOCE function is diminished in AD, resulting in disrupted neuronal spine stability and synaptic plasticity and the promotion of amyloidogenesis. Mounting evidence suggests that rectifying diminished SOCE in neurons may intervene with the progression of AD. In this review, the mechanisms of SOCE disruption and the associated pathogenic impacts on AD will be discussed. We will also highlight the potential therapeutic targets or approaches that may help ameliorate SOCE deficits for AD treatment.
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Pharmacokinetic and Pharmacodynamic Properties of Cinacalcet (KRN1493) in Chinese Healthy Volunteers: A Randomized, Open-label, Single Ascending-dose and Multiple-dose, Parallel-group Study.
Liu, H, Wang, H, Liu, T, Jiang, J, Chen, X, Gao, F, Hu, P
Clinical therapeutics. 2016;(2):348-57
Abstract
PURPOSE The aim of this study was to assess the pharmacokinetic (PK) and pharmacodynamic (PD) properties and safety of single and multiple doses of cinacalcet in Chinese healthy volunteers (HVs) for the purposes of a New Drug Application package for the Chinese Food and Drug Administration. METHODS In this randomized, open-label, single ascending-dose and multiple-dose, parallel-group study, 42 Chinese HVs were randomized to receive a single oral dose of 25, 50, or 100 mg of cinacalcet and multiple doses of 50 mg of cinacalcet once daily for 7 days. Plasma cinacalcet concentrations were analyzed by HPLC-MS/MS. The PK parameters were assessed with noncompartmental analysis. Plasma intact parathyroid hormone, serum calcium, and phosphorus concentrations were measured for PD evaluation. The safety profile was also assessed. Adverse events (AEs) were noted during the study. FINDINGS Of the 42 randomized HVs, 41 completed the study per protocol; 1 prematurely discontinued the study because of AEs. Cinacalcet has nonlinear PK properties over a dose range of 25 to 100 mg after a single dose. Mean (SD) Cmax values were 7.68 (4.25), 17 (6.33), and 31.3 (16.42) ng/mL with single doses of 25, 50, and 100 mg of cinacalcet, respectively. Mean (SD) AUC0- last values were 58.4 (25.38), 187 (70.7), and 367 (180.03) hr∙ng/mL with single doses of 25, 50, and 100 mg of cinacalcet, respectively. Steady state was attained within 7 doses of successive daily administration of 50 mg of cinacalcet. At steady state, the mean (SD) Cmax and AUC0-last values were 20.6 (9.63) ng/mL and 297 (146.15) ng∙h/mL. The accumulation ratios of Cmax and AUC (AUCτ/AUC0-24) were 1.21 and 1.32. Plasma intact parathyroid hormone and serum calcium concentrations had similar patterns, both decreased after administration of cinacalcet, whether after single dose or multiple doses. A total of 52 AEs were reported in 20 HVs (47.6%). The most frequently reported AEs after single-dose and multiple-dose cinacalcet administration were hypocalcemia, numbness, dizziness, and muscle soreness. No serious AEs were reported. IMPLICATIONS Cinacalcet was well tolerated and effective after administration of a single oral dose up to 100 mg and multiple doses of 50 mg of cinacalcet once daily for 7 days. Cinacalcet has nonlinear PK properties over a dose range of 25 to 100 mg after a single dose. PK profiles after multiple doses were similar to those after a single dose with no accumulation. Cinacalcet had similar PK and safety profiles between Chinese and Western HVs at the same dose levels.
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Maternal calcium metabolic stress and fetal growth.
Scholl, TO, Chen, X, Stein, TP
The American journal of clinical nutrition. 2014;(4):918-25
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Abstract
BACKGROUND Suboptimal maternal calcium intake and vitamin D status may or may not adversely influence fetal growth. OBJECTIVE It was hypothesized that maternal calcium metabolic stress in early pregnancy, rather than suboptimal calcium intake or insufficient vitamin D, influences the risk of small-for-gestational-age (SGA) births and other aspects of fetal growth. Stress to calcium metabolism was defined as elevated intact parathyroid hormone (PTH) (>62 pg/mL) accompanied by a very low calcium intake [<60% of the Estimated Average Requirement (EAR)] or insufficient 25-hydroxyvitamin D [25(OH)D] (<20 ng/mL). DESIGN This was a prospective cohort study of 1116 low-income and minority gravidae at entry to care of 13.8 ± 5.6 wk (mean ± SD). RESULTS The PTH concentration depended on circulating 25(OH)D and total calcium intake. When 25(OH)D was insufficient, even a high calcium intake (which equaled or exceeded the Recommended Dietary Allowance) was unable to maintain PTH or to moderate the proportion of patients with an elevated PTH. When examined one at a time, very low calcium intake (<60% of EAR), very low 25(OH)D (<12 ng/mL), and elevated PTH (>62 pg/mL) each had a small but significant association with birth weight. Elevated PTH was also related to birth length and risk of SGA birth. Elevated PTH accompanied by insufficient 25(OH)D or very low calcium intake was associated with a 2- to 3-fold increased risk of SGA birth and a significantly lower birth weight, birth length, and head circumference, even after women who developed preeclampsia were excluded. Infants born to gravidae with insufficient 25(OH)D or very low calcium intake without elevated PTH or with elevated PTH alone were unaffected. CONCLUSION Maternal calcium metabolic stress, rather than low calcium intake or insufficient vitamin D, has an adverse influence on fetal growth. This trial was registered at clinicaltrials.gov as NIH 0320070046.
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Evaluation of anemia and serum iPTH, calcium, and phosphorus in patients with primary glomerulonephritis.
Li, Y, Zhang, W, Ren, H, Wang, W, Shi, H, Li, X, Chen, X, Shen, P, Wu, X, Xie, J, et al
Contributions to nephrology. 2013;:31-40
Abstract
Glomerulonephritis (GN) remains a major cause of morbidity and mortality in chronic kidney disease (CKD). Our study aimed to investigate the prevalence of anemia, abnormal serum intact parathyroid hormone (iPTH), calcium, and phosphorus in a Chinese patient population with primary GN. Medical histories and laboratory test results were collected from 2,924 patients with primary GN hospitalized in Ruijin Hospital of Shanghai between January 2003 and August 2009. The leading cause of CKD was primary glomerular diseases, which were responsible for up to 53.5% of all cases. IgA nephropathy was the most common cause, accounting for 38.7%, followed by focal segmental glomerulosclerosis (FSGS). The anemia rate of GN patients in early stages of CKD (stages 1-2 and 3) was 16-36%, and rapidly accelerated to 65.8 and 80.2% in advanced CKD stage 4 and stage 5, respectively. There was no significant decline observed in the level of serum calcium in patients with CKD stages 1-4 (p > 0.05). However, in patients with CKD stage 5 the prevalence of hypocalcaemia increased significantly (13.7%, p = 0.000). The prevalence of hyperphosphatemia did not significantly increase in patients with CKD stages 1-3 (p < 0.05), but was much higher in patients with CKD stages 4 and 5 (p = 0.001 and p = 0.021, respectively) and showed a negative correlation with renal function. Serum iPTH levels did not increase significantly in GN patients with CKD stages 1-2. The median iPTH levels were 54.7, 88.6, and 289.2 pg/ml (p = 0.000) for CKD stages 3-5, respectively, all of which showed negative correlation with renal function. The proportion of vitamin D insufficiency and deficiency increased to 29.3 and 11.2%, respectively, as the glomerular filtration rate fell below 15 ml/min/1.73 m(2). Primary glomerular disease remains the major cause of CKD in China, and complications such as anemia and metabolic bone disease are frequently present in GN patients.