Vitamin D attenuates nucleoside reverse transcriptase inhibitor induced human skeletal muscle mitochondria DNA depletion

Biomechanical Process of Skeletal Muscle under Training Condition Based on 3D Visualization Technology

With the development and popularization of 3D technology, human behavior recognition has gradually developed from plane feature recognition to elevation feature recognition. In the process of collecting motion characteristics, the research on skeletal muscle will lead to a series of data in time series, which is the basis of sports biomechanics research and sports training. Some important semantic information such as centerline and joint center can be obtained by further data processing. The results of the study showed that the three-dimensional coordinate positions of the femur and pelvic attachment points of the muscles surrounding the hip joint from the pelvis were measured and positioned. A 3D model is built to simulate the human skeletal model subjected to speeds of 3 and 7 m/s, and different motion velocities can exhibit different motions. The research in this study shows that using 3D technology and comprehensively utilizing the expertise of biomechanical analysis and graphical modeling to study the mechanical properties of bone joints and soft tissues provide new ways and methods.

Oxidative Stress and BPA Toxicity: An Antioxidant Approach for Male and Female Reproductive Dysfunction

Bisphenol A (BPA) is a non-persistent anthropic and environmentally ubiquitous compound widely employed and detected in many consumer products and food items; thus, human exposure is prolonged. Over the last ten years, many studies have examined the underlying molecular mechanisms of BPA toxicity and revealed links among BPA-induced oxidative stress, male and female reproductive defects, and human disease. Because of its hormone-like feature, BPA shows tissue effects on specific hormone receptors in target cells, triggering noxious cellular responses associated with oxidative stress and inflammation. As a metabolic and endocrine disruptor, BPA impairs redox homeostasis via the increase of oxidative mediators and the reduction of antioxidant enzymes, causing mitochondrial dysfunction, alteration in cell signaling pathways, and induction of apoptosis. This review aims to examine the scenery of the current BPA literature on understanding how the induction of oxidative stress can be considered the "fil rouge" of BPA's toxic mechanisms of action with pleiotropic outcomes on reproduction. Here, we focus on the protective effects of five classes of antioxidants-vitamins and co-factors, natural products (herbals and phytochemicals), melatonin, selenium, and methyl donors (used alone or in combination)-that have been found useful to counteract BPA toxicity in male and female reproductive functions.

1,25-Dihydroxyvitamin D3 modulates the effects of sublethal BPA on mitochondrial function via activating PI3K-Akt pathway and 17β-estradiol secretion in rat granulosa cells

Bisphenol A (BPA), an endocrine-disrupting chemical, is capable of producing reproductive toxicity. BPA results in mitochondrial DNA (mtDNA) deletion and mitochondrial dysfunction; however, the effect of BPA on the mitochondria of ovarian granulosa cells is not clear. Further, 1,25-dihydroxyvitamin D₃ (1,25D₃) may play a role in reproduction, because its receptor, VDR, contributes to the inhibition of oxidative stress and predominantly exists in the nuclei of granulosa cells. Hence, the role of 1,25D₃ in BPA-mediated effects on mitochondrial function was examined in this study. Primary rat granulosa cells treated with BPA, 1,25D₃, or both were subjected to molecular/biochemical assays to measure cell survival, mtDNA content, mtDNA deletion, superoxide dismutase activity, levels of proteins related to mitochondrial biogenesis, and mitochondrial function. We found that cell viability was dose-dependently reduced and reactive oxygen species (ROS) levels were increased by BPA treatment. BPA administration elevated Mn-superoxide dismutase (MnSOD) expression but negatively regulated total SOD activity. 1,25D₃ treatment alone increased 17β-estradiol secretion, ATP production, and cellular oxygen consumption. In cells treated with both agents, 1,25D₃ enhanced BPA-induced MnSOD protein upregulation and blocked the BPA-mediated decline in total SOD activity. Furthermore, 1,25D₃ attenuated BPA-mediated mtDNA deletion but showed no effect on BPA-induced increases in mtDNA content. Although BPA had no influence on the levels of peroxisome proliferator-activated receptor-γ coactivator-1 α, nuclear respiratory factor-1, mitochondrial transcription factor A, or cytochrome c oxidase subunit IV, 1,25D₃ plus BPA markedly increased mitochondrial biogenesis-related protein expression via the PI3K-Akt pathway. Moreover, BPA-mediated negative regulation of cytochrome c oxidase subunit I levels and 17β-estradiol secretion was attenuated by 1,25D₃ pre-treatment. Our results suggest that 1,25D₃ attenuates BPA-induced decreases in 17β-estradiol and that treatment with 1,25D₃ plus BPA regulates granulosa cell mitochondria by elevating mitochondrial biogenesis-related protein levels.

PPD-induced monocyte mitochondrial damage is associated with a protective effect to develop tuberculosis in BCG vaccinated individuals: A cohort study

Introduction

The mechanisms of mononuclear phagocyte death have been associated with the permissiveness and resistance to mycobacterial replication, but it remains unknown whether or not they help predict the risk of developing TB.

Objective

To describe the factors associated with the induction of monocyte mitochondrial and membrane damage in response to PPD as well as determine if this type of damage might predict the susceptibility of developing active tuberculosis in a cohort of household contacts (HHCs) from Medellin, Colombia from 2005 to 2008.

Methods

The prospective cohort study contains 2060 HHCs patients with pulmonary tuberculosis who were meticulously followed for two years. A survey of the socio-demographic, clinical, epidemiological factors and blood samples were collected. Mononuclear cell cultures were stimulated with or without PPD and the type of monocyte death was determined by the flow of cytometry, an indicator was also used for its analysis. Logistic regression was adjusted by the Generalized Estimations Equations and the survival was estimated with the Kaplan-Meier and Cox regression. Confidence intervals were used for estimating the association.

Results

1,859 out of 2,060 blood samples of the HHCs patients analyzed showed monocyte death. In response to PPD, 83.4% underwent mitochondrial damage while 50.9% had membrane damage. The membrane damage in response to PPD was higher in children under 4 years (OR: 1.57; (95% CI: 1.1 to 2.4) and the HHCs who slept regularly in the same household has an index case of (OR: 1.54; 95% CI: 1.0 to 2.3). After adjustment by age, comorbidities, nutritional status, proximity to index case and overcrowding, the risk of developing active TB among BCG vaccinated HHCs individuals with induction of mitochondrial damage was HR = 0.19 (95% CI: 0.1 to 0.5).

Conclusions

The induction of monocytes mitochondrial damage by PPD stimulation correlates with protection of TB disease development in BCG-vaccinated HHCs. This represents a potential tool to predict susceptibility of developing active disease in this population.

Fibroblast growth factor 23: associations with antiretroviral therapy in patients co-infected with HIV and hepatitis C

OBJECTIVES

Fibroblast growth factor 23 (FGF23) has been associated with cardiovascular mortality. We estimate associations between the level of plasma FGF23 and exposure to abacavir (ABC) and to other components of antiretroviral therapy in patients co-infected with HIV and hepatitis C.

METHODS

Both intact and c-terminal FGF23 were measured in plasma using commercial assays for a sub-cohort of 295 patients selected at random from the 1150 patients enrolled in the Canadian Co-infection Cohort. The multiplicative effects of antiretroviral drug exposures and covariates on median FGF23 were then estimated using a hierarchical Bayesian model.

RESULTS

The median level of intact FGF23 was independent of either past or recent exposure to abacavir, with multiplicative ratios of 1.00 and 1.07, 95% credible intervals 0.90-1.12 and 0.94-1.23, respectively. Median intact FGF23 tended to increase with past use of both nonnucleoside reverse-transcriptase inhibitors and protease inhibitors, but tended to decrease with recent use of either tenofovir, efavirenz or lopinavir. There were no obvious associations between the median level of c-terminal FGF23 and individual drugs or drug classes. Age, female gender, smoking and the aspartate aminotransferase to platelet ratio index were all associated with a higher median c-terminal FGF23 but not with a higher median intact FGF23.

CONCLUSIONS

The level of FGF23 in plasma was independent of exposure to ABC. Lower levels of intact FGF23 with recent use of tenofovir, efavirenz or lopinavir may reflect their adverse effects on bone and vitamin D metabolism relative to other drugs in their respective drug classes.

Vitamin D supplementation is associated with reduced immune activation levels in HIV-1-infected patients on suppressive antiretroviral therapy

BACKGROUND

A majority of HIV-1-infected patients present a severe deficit in vitamin D, which predicts short-term mortality. Vitamin D is a naturally synthesized hormone, with important immunomodulatory functions. In the general population, its deficit has been associated with increased markers of inflammation. Vitamin D deficit may therefore play a role in the establishment of elevated systemic immune activation, which persists despite suppressive antiretroviral therapy (ART) in HIV-infected patients, and is predictive of disease progression; and vitamin D supplementation may be beneficial in this context.

METHODS

We performed both a cross-sectional study (vitamin D deficit versus normal level) and a longitudinal study (upon vitamin D supplementation for 6 to 12 months) of HIV-1-infected patients receiving suppressive ART. The primary outcome measure was the percentage of activated memory CD8(+) T cells in blood, which is a robust marker associated with disease progression. Secondary outcomes included general T-lymphocyte and B-lymphocyte phenotype.

RESULTS

Although vitamin D deficiency had no influence on T-cell and B-cell subset distribution, we found an association between vitamin D and immune activation levels in HIV-1-infected patients. Vitamin D supplementation in vitamin D-deficient patients resulted in reduced immune activation levels.

CONCLUSION

The present data support the rationale of vitamin D supplementation in the routine clinical management of HIV-1-infected patients, in order to decrease immune activation levels and possibly improve long-term survival.