Administration of sodium hydrosulfide reduces remote organ injury by an anti-oxidant mechanism in a rat model of varicocele

The effect of adipose-derived mesenchymal stem cell transplantation on ovarian mitochondrial dysfunction in letrozole-induced polycystic ovary syndrome in rats: the role of PI3K-AKT signaling pathway

OBJECTIVE

The present study aimed to elucidate how mesenchymal stem cells (MSCs) application could efficiently attenuate pathological changes of letrozole-induced poly cystic ovary syndrome (PCOS) by modulating mitochondrial dynamic via PI3K-AKT pathway.

METHODS

Thirty-two female rats were randomly divided into four experimental groups: Sham, PCOS, PCOS + MSCs, and PCOS + MSCs + LY294002. The Sham group received 0.5% w/v carboxymethyl cellulose (CMC); the PCOS group received letrozole (1 mg/kg, daily) in 0.5% CMC for 21 days. Animals in the PCOS + MSCs group received 1 × 106 MSCs/rat (i.p,) on the 22th day of the study. In the PCOS + MSCs + LY294002 group, rats received LY294002 (PI3K-AKT inhibitor) 40 min before MSC transplantation. Mitochondrial dynamic gene expression, mitochondrial membrane potential (MMP), citrate synthase (CS) activity, oxidative stress, inflammation, ovarian histological parameters, serum hormone levels, homeostatic model assessment for insulin resistance (HOMA-IR), insulin and glucose concentrations, p-PI3K and p-AKT protein levels were evaluated at the end of the experiment.

RESULTS

PCOS rats showed a significant disruption of mitochondrial dynamics and histological changes, lower MMP, CS, ovary super oxide dismutase (SOD) and estrogen level. They also had a notable rise in insulin and glucose concentrations, HOMA-IR, testosterone level, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels, ovarian malondialdehyde (MDA) content as well as a notable decrease in p-PI3K and p-AKT protein levels compared to the Sham group. In the PCOS + MSCs group, the transplantation of MSCs could improve the above parameters. Administration of LY294002 (PI3K-AKT pathway inhibitor) deteriorated mitochondrial dynamic markers, oxidative stress status, inflammation markers, hormonal levels, glucose, and insulin levels and follicular development compared to the PCOS + MSCs group.

CONCLUSIONS

This study demonstrated that the protective effects of MSC transplantation in regulating mitochondrial dynamics, promoting mitochondrial biogenesis, competing with redox status and inflammation response were mainly mediated through the PI3K-AKT pathway in the PCOS model.

Dissolving sodium hydrosulfide in drinking water is not a good source of hydrogen sulfide for animal studies

Hydrogen sulfide (H2S) has many physiological and pathological roles in the human body. Sodium hydrosulfide (NaHS) is widely used as a pharmacological tool for assessing H2S effects in biological experiments. Although H2S loss from NaHS solution is a matter of minutes, some animal studies use NaHS in solution as an H2S-donating compound in drinking water. This study addresses whether 30 μM NaHS in drinking water prepared in rat/mouse water bottles remains stable for at least 12-24 h, as presumed by some authors. NaHS solutions (30 μM) were prepared in drinking water and immediately transferred to rat/mice water bottles. Samples were obtained from the tip of water bottles and from inside of the bottles at 0, 1, 2, 3, 4, 5, 6, 12, and 24 h for sulfide measurement using the methylene blue method. Furthermore, NaHS (30 μM) was administered to male and female rats for two weeks, and serum sulfide concentrations were measured every other day in the first week and at the end of the second week. NaHS solution was unstable in the samples obtained from the tip of water bottles; it declined by 72% and 75% after 12 and 24 h, respectively. In the samples obtained from the inside of the water bottles, the decline in the NaHS was not significant until 2 h; however, it decreased by 47% and 72% after 12 and 24 h, respectively. NaHS administration did not affect serum sulfide levels in male and female rats. In conclusion, NaHS solution prepared in drinking water can not be used for H2S donation as the solution is unstable. This route of administration exposes animals to variable and lower-than-expected amounts of NaHS.

Beneficial effects of combination therapy with testosterone and hydrogen sulfide by reducing oxidative stress and apoptosis: Rat experimental varicocele model

Background

Despite the effectiveness of testosterone therapy in conditions associated with testosterone deficiency, including varicocele, several dose-dependent side effects limit the clinical use of testosterone therapy. Hydrogen sulfide, a toxic gas in high concentrations but a beneficial molecule in low concentrations, acts as both a major effector and an important inducer of testosterone.

Objective

This study investigated whether a subeffective dose of testosterone combined with a subeffective dose of hydrogen sulfide donor sodium hydrosulfide (NaHS) can be effective in an experimental varicocele model through a possible additive effect.

Materials and Methods

Thirty Wistar rats weighing 200-250 gr were divided into 5 groups as (n = 6/each): sham, varicocele, testosterone (200 µg/kg, 5 times per wk for 4 consecutive weeks), NaHS (15 μmol/L, daily for 4 consecutive wk) and testosterone + NaHS (200 µg/kg, 5 times per wk + 15 μmol/L, daily, both for 4 consecutive wk). All animals, except in the sham group, underwent varicocele induction.

Results

The coadministration of testosterone and NaHS significantly increased serum testosterone (10.23 ± 0.95, p = 0.01), testicular H₂S levels (608.94 ± 21.09, p < 0.001), and testicular superoxide dismutase activity (66.14 ± 1.56, p < 0.001), decreased malondialdehyde levels (0.77 ± 0.52, p < 0.001), and B-cell lymphoma 2-associated X protein to B-cell lymphoma 2 (0.16 ± 0.01, p < 0.001) protein expression ratio in the testicular tissues and improved sperm parameters and testicular histopathology compared to the varicocele group.

Conclusion

The combination therapy of subeffective doses of testosterone and NaHS can attenuate the varicocele-induced damages by reducing testicular oxidative stress and apoptosis and thus can be considered an effective approach with fewer side effects.

Mesenchymal stem cells and their conditioned medium as potential therapeutic strategies in managing comorbid anxiety in rat sepsis induced by cecal ligation and puncture

OBJECTIVES

Sepsis-associated encephalopathy (SAE) is a common brain dysfunction following sepsis. Due to the beneficial effects of mesenchymal stem cells (MSCs) therapy on anxiety, an extreme and early manifestation of SAE, we hypothesized that MSCs-derived conditioned medium (CM) may be able to attenuate anxiety in cecal ligation and puncture (CLP)-induced sepsis.

MATERIALS AND METHODS

Rats were assigned into 4 groups: sham, CLP, MSC, and CM. All animals, except in the sham group, underwent the CLP procedure to induce sepsis. Two hours after sepsis induction, the rats in MSC and CM groups, received 1×10⁶ MSCs and CM derived from the same number of cells, respectively. 48 hr after the treatments, anxiety-related behaviors were assessed, and brain and right hippocampal tissues were collected.

RESULTS

MSCs and CM enhanced the percentages of open arm entries and time spent in the open arms of the elevated plus-maze and the time spent in the light side of the light-dark box. MSCs and CM decreased the Evans blue content and decreased the IL-6 and TNF-α levels in the brain tissue samples. Reductions in the expression of 5-HT2A receptors and phosphorylation of ERK1/2 and an increase in the expression of 5-HT1A receptors in the hippocampal tissue samples were observed in the MSC and CM groups.

CONCLUSION

MSCs and MSCs-derived CM attenuated anxiety-related behaviors to an equal extent by reducing inflammation, modifying 5-HT receptor expression changes, and inhibiting the ERK pathway. Therefore, MSCs-derived CM may be considered a promising therapy for comorbid anxiety in septic patients.