Vitamin D3 treatment regulates apoptosis, antioxidant defense system, and DNA integrity in the epididymal sperm of an aged rat model

Distinct signatures on d-galactose-induced aging and preventive/protective potency of two low-dose vitamin D supplementation regimens on working memory, muscular damage, cardiac and cerebral oxidative stress, and SIRT1 and calstabin2 downregulation

Chronic administration of d-galactose (d-gal) in rodents reproduces the overproduction of reactive oxygen species of physiological aging. The present research shows for the first time distinct signatures on d-gal-induced aging (500 mg/kg, 6 weeks) and the preventive and protective potential of two vitamin D (50 IU) supplementation regimens (pre-induction and simultaneous, respectively) in two vital organs (heart and brain). d-gal-induced notorious alterations in working memory, a strong increase in brain malondialdehyde (MDA) oxidative levels, and strong downregulation of sirtuin 1 (SIRT1) in the heart and hippocampus and of calstabin2 in the heart. Cardiac and brain superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic antioxidant capacities were damaged, brain calstabin2 was downregulated, and neuropathology was observed. Heart damage also included a moderate increase in MDA levels, serologic lactate dehydrogenase (LDH), total creatine kinase (CK) activities, and histopathological alterations. The used dose of vitamin D was enough to prevent cognitive impairment, avoid muscular damage, hamper cardiac and cerebral oxidative stress, and SIRT1 and calstabin2 downregulation. Most importantly, the potencies of the two preventive schedules depended on the tissue and level of study. The pre-induction schedule prevented d-gal-induced aging by 1 order of magnitude higher than simultaneous administration in all the variables studied except for SIRT1, whose strong downregulation induced by d-gal was equally prevented by both schedules. The benefits of vitamin D for oxidative stress were stronger in the brain than in the heart. Brain MDA levels were more sensitive to damage, while SOD and GPx antioxidant enzymatic activities were in the heart. In this order, the magnitude of SOD, MDA, and GPx oxidative stress markers was sensitive to prevention. In summary, the results unveiled distinct aging induction, preventive signatures, and sensitivity of markers depending on different levels of study and tissues, which are relevant from a mechanistic view and in the design of targeted interventions.

1α,25-dihydroxyvitamin D3 supplementation alleviates perfluorooctanesulfonate acid-induced reproductive injury in male mice: Modulation of Nrf2 mediated oxidative stress response

Perfluorooctanesulfonate acid (PFOS) is a typical persistent organic pollutant that widely exists in the environment. To clarify the toxic effects and mechanisms of PFOS and to find effective intervention strategies have been attracted global attention. Here, we investigated the effects of PFOS on the male reproductive system and explored the potential protective role of 1α,25-dihydroxyvitamin D₃ (1α,25(OH)₂ D₃ ). Our results showed that 1α,25(OH)₂ D₃ intervention significantly improved PFOS-induced sperm quality decline and testicular damage. Moreover, 1α,25(OH)₂ D₃ aggrandized the total antioxidant capacity. Furthermore, after PFOS exposure, the transcription factor nuclear factor erythroid-related factor 2 (Nrf2) was adaptively increased together with its target genes, such as HO-1, NQO1, and SOD2. Meanwhile, 1α,25(OH)₂ D₃ ameliorated PFOS-induced augment of Nrf2 and target genes. These findings indicated that 1α,25(OH)₂ D₃ might attenuate PFOS-induced reproductive injury in male mice via Nrf2-mediated oxidative stress.

Effects of Fdft 1 gene silencing and VD3 intervention on lung injury in hypoxia-stressed rats

BACKGROUND

Hypoxia can induce lung injury such as pulmonary arterial hypertension and pulmonary edema. And in the rat model of hypoxia-induced lung injury, the expression of Farnesyl diphosphate farnesyl transferase 1 (Fdft 1) was highly expressed and the steroid biosynthesis pathway was activated. However, the role of Fdft 1 and steroid biosynthesis pathway in hypoxia-induced lung injury remains unclear.

OBJECTIVE

The study aimed to further investigate the relationship between Fdft1 and steroid biosynthesis pathway with hypoxia-induced lung injury.

METHODS

A rat model of lung injury was constructed by hypobaric chamber with hypoxic stress, the adenovirus interference vector was used to silence the expression of Fdft 1, and the exogenous steroid biosynthesis metabolite Vitamin D3 (VD3) was used to treat acute hypoxia-induced lung injury in rats.

RESULTS

Sh-Fdft 1 and exogenous VD3 significantly inhibited the expression of Fdft 1 and the activation of the steroid pathway in hypoxia-induced lung injury rats, which showed a synergistic effect on the steroid activation pathway. In addition, sh-Fdft 1 promoted the increase of pulmonary artery pressure and lung water content, the decrease of oxygen partial pressure and oxygen saturation, and leaded to the increase of lung cell apoptosis and the aggravation of mitochondrial damage in hypoxia-stressed rats. And VD3 could significantly improve the lung injury induced by hypoxia and sh-Fdft 1 in rats.

CONCLUSIONS

Fdft 1 gene silencing can promote hypoxic-induced lung injury, and exogenous supplement of VD3 has an antagonistic effect on lung injury induced by Fdft 1 gene silencing and hypoxic in rats, suggesting that VD3 has a preventive and protective effect on the occurrence and development of hypoxia-induced lung injury.

Vitamin D and Ocular Diseases: A Systematic Review

The contributory roles of vitamin D in ocular and visual health have long been discussed, with numerous studies pointing to the adverse effects of vitamin D deficiency. In this paper, we provide a systematic review of recent findings on the association between vitamin D and different ocular diseases, including myopia, age-related macular degeneration (AMD), glaucoma, diabetic retinopathy (DR), dry eye syndrome (DES), thyroid eye disease (TED), uveitis, retinoblastoma (RB), cataract, and others, from epidemiological, clinical and basic studies, and briefly discuss vitamin D metabolism in the eye. We searched two research databases for articles examining the association between vitamin D deficiency and different ocular diseases. One hundred and sixty-two studies were found. There is evidence on the association between vitamin D and myopia, AMD, DR, and DES. Overall, 17 out of 27 studies reported an association between vitamin D and AMD, while 48 out of 54 studies reported that vitamin D was associated with DR, and 25 out of 27 studies reported an association between vitamin D and DES. However, the available evidence for the association with other ocular diseases, such as glaucoma, TED, and RB, remains limited.

Role of vitamin D in diabetic retinopathy: Pathophysiological and clinical aspects

Epidemiological data predict a dramatic increase in the prevalence of diabetes and of diabetic retinopathy (DR) - the most common complication of diabetes-for which however we do not have so far effective tools for prevention and treatment. Since hypovitaminosis D is very frequent in patients with diabetes and vitamin D (VD) has vascular protective properties, several studies have addressed the association of VD deficiency with DR and its severity and progression, whereas the effects of VD supplementation on its natural history are largely unknown. Here we review the available evidence that supports the possible protective role of VD in DR and suggests to determine the VD levels in DR patients calling for a definitive randomized clinical trial to ascertain whether VD supplementation could protect against DR.

Male infertility: Role of vitamin D and oxidative stress markers

Spermatozoa are vulnerable to oxidative stress because of their inherent reduced antioxidant defence and DNA repair mechanisms. Polyunsaturated fatty acids in sperm plasma membrane break down to cytotoxic lipid aldehyde, 4-Hydroxynonenal, whereas 3-Nitrotyrosine is generated by peroxynitrite induced tyrosine nitration. Both oxidative stress markers contribute to altered sperm function and infertility. Vitamin D, a membrane antioxidant, has a potential scavenger capacity. We compared oxidative stress markers and vitamin D in male subjects with normal and altered sperm parameters and explored association of these markers: 4-Hydroxynonenal and 3-Nitrotyrosine with Vitamin D. Higher 4-Hydroxynonenal levels in altered sperm parameter group and a negative correlation with sperm count, motility and morphology (p < 0.001) was observed. Vitamin D serum concentration in altered sperm parameters was less (p = 0.016) showing a significant positive correlation with sperm count and morphology. 4-Hydroxynonenal was significantly higher in altered sperm parameters showing negative correlation with vitamin D. Highest serum concentrations of 4-Hydroxynonenal were observed in vitamin D-deficient subjects. Significantly higher concentration of 4-Hydroxynonenal was estimated in altered sperm parameters of vitamin D sufficient group (p < 0.001). This suggests 4-Hydroxynonenal as an oxidative stress marker leading to altered sperm function and infertility with some association with vitamin D; needs to be explored.