Metallothionein 3 promotes osteoclast differentiation and survival by regulating the intracellular Zn2+ concentration and NRF2 pathway

Possible implication of exposure to VOCs with the development of osteoporosis in the North American population according to NHANES

OBJECTIVE

Osteoporosis is a prevalent bone disorder influenced by both genetic and environmental factors. Volatile organic compounds (VOCs), common environmental pollutants, have been linked to various diseases, but their role in osteoporosis remains unclear. This study examines the potential association between VOC exposure and osteoporosis using NHANES data.

METHODS

Data from six cycles of the National Health and Nutrition Examination Survey (NHANES) (2005-2018) were utilized to examine the relationship between urinary VOC levels and osteoporosis. Urinary VOC metabolites were measured using ultra-performance liquid chromatography coupled with electrospray tandem mass spectrometry (UPLC-ESI/MSMS), and their concentrations were adjusted for creatinine. Osteoporosis status was self-reported. Multivariable logistic regression models were used to assess the association between VOC exposure and osteoporosis, controlling for demographic, behavioral, and clinical covariates.

RESULTS

Analysis of 14,945 NHANES participants (2005-2018) revealed elevated osteoporosis risk associated with urinary volatile organic compounds (VOCs). Participants with osteoporosis were older (48.4 vs. 38.8 years, p < 0.001), more likely female (53.9 % vs. 47.4 %), and had higher smoking rates (49.3 % vs. 47.8 %). Urinary levels of CEMA, 3HPMA, HMPMA, 2HPMA, and X2MHA were significantly higher in osteoporosis groups (all p < 0.05). In adjusted models, dose-dependent risks were observed for higher quartiles of CEMA (Q4 OR: 32.38, 95 % CI: 26.32-39.84) and 3HPMA (Q4 OR: 254.02, 95 % CI: 149.16-432.58) (p < 0.001). Log-transformed VOC exposures, including HMPMA_log (OR: 1.22-1.33) and X2HPMA_log (OR: 3.87-4.08), further predicted osteoporosis risk. Subgroup analyses confirmed consistency across demographics, smoking status, and comorbidities.

CONCLUSION

Exposure to specific VOCs, including CEMA, 3HPMA, and X2MHA, may increase osteoporosis risk, highlighting the need for further research into their role in bone health.

Transcriptional Regulation Mechanisms in AsAFL1-mediated Drought Tolerance for Creeping Bentgrass (Agrostis stolonifera)

Drought stress is a major environmental stress that impairs plant growth and development. The At14a-like1 (AFL1) gene encodes a stress-induced membrane protein involved in endocytosis, signal transduction, and proline accumulation. The objective of the present study was to investigate biological functions and underlying mechanisms of AFL1 regulation of drought tolerance in a perennial grass species, creeping bentgrass (Agrostis stolonifera). AsAFL1 was cloned from creeping bentgrass, and its expression was induced by drought stress. Motif analysis showed that AsAFL1 has five epidermal growth factor structural domains and one β1-integrin structural domain. Transient expression in tobacco epidermal cells indicated that AsAFL1 was localized at the plasma membrane. Overexpression of AsAFL1 in creeping bentgrass significantly enhanced drought tolerance, as manifested by significantly increased leaf relative water content, chlorophyll and proline contents but lower electrolyte leakage and malondialdehyde content. Comparative transcriptomic and weighted correlation network analysis (WGCNA) revealed that AsAFL1-mediated drought tolerance was related to transcriptional regulation of genes involved in phytohormone (abscisic acid, auxin, and strigolactone) biosynthesis and signaling, redox homeostasis, and biosynthesis of second metabolites (lignin, cutin, suberin and wax), as well as nutrient transport and mobilization.

Navigating the redox landscape: reactive oxygen species in regulation of cell cycle

Objectives: To advance our knowledge of disease mechanisms and therapeutic options, understanding cell cycle regulation is critical. Recent research has highlighted the importance of reactive oxygen species (ROS) in cell cycle regulation. Although excessive ROS levels can lead to age-related pathologies, ROS also play an essential role in normal cellular functions. Many cell cycle regulatory proteins are affected by their redox status, but the precise mechanisms and conditions under which ROS promote or inhibit cell proliferation are not fully understood.Methods: This review presents data from the scientific literature and publicly available databases on changes in redox state during the cell cycle and their effects on key regulatory proteins.Results: We identified redox-sensitive targets within the cell cycle machinery and analysed different effects of ROS (type, concentration, duration of exposure) on cell cycle phases. For example, moderate levels of ROS can promote cell proliferation by activating signalling pathways involved in cell cycle progression, whereas excessive ROS levels can induce DNA damage and trigger cell cycle arrest or cell death.Discussion: Our findings encourage future research focused on identifying redox-sensitive targets in the cell cycle machinery, potentially leading to new treatments for diseases with dysregulated cell proliferation.

Evidence for chromium crosses blood brain barrier from the hypothalamus in chromium mice model

It has been shown that exposure to hexavalent Chromium, Cr (Ⅵ), via nasal cavity can have neurotoxicological effects and induces behavioral impairment due to the fact that blood brain barrier (BBB) does not cover olfactory bulb. But whether Cr (Ⅵ) can cross the BBB and have a toxicological effects in central nervous system (CNS) remains unclear. Therefore, we investigated the effects of Cr (Ⅵ) on mice treated with different concentrations and exposure time (14 days and 28 days) of Cr (Ⅵ) via intraperitoneal injection. Results revealed that Cr accumulated in hypothalamus (HY) in a timely dependent manner. Much more severer neuropathologies was observed in the group of mice exposed to Cr (Ⅵ) for 28 days than that for 14 days. Gliosis, neuronal morphological abnormalities, synaptic degeneration, BBB disruption and neuronal number loss were observed in HY. In terms of mechanism, the Nrf2 related antioxidant stress signaling dysfunction and activated NF-κB related inflammatory pathway were observed in HY of Cr (Ⅵ) intoxication mice. And these neuropathologies and signaling defects appeared in a timely dependent manner. Taking together, we proved that Cr (Ⅵ) can enter HY due to weaker BBB in HY and HY is the most vulnerable CNS region to Cr (Ⅵ) exposure. The concentration of Cr in HY increased along with time. The accumulated Cr in HY can cause BBB disruption, neuronal morphological abnormalities, synaptic degeneration and gliosis through Nrf2 and NF-κB signaling pathway. This finding improves our understanding of the neurological dysfunctions observed in individuals who have occupational exposure to Cr (Ⅵ), and provided potential therapeutic targets to treat neurotoxicological pathologies induced by Cr (Ⅵ).