Protective effects of trehalose on frozen-thawed ovarian granulosa cells of cattle

Trehalose Alleviates D-Galactose-Induced Aging-Related Granulosa Cell Death in Ovaries

Ovarian dysfunction caused by aging restricts female reproductive capacity and is accompanied by oxidative stress and impaired autophagy. Recent studies have shown that trehalose (Tre) can activate autophagy and have antioxidant effects. However, whether Tre can be used to attenuate ovarian aging remains unclear. Therefore, the anti-aging effects of Tre on the ovary were explored both in vivo and in vitro. D-galactose (D-gal) was administered i.p. daily (200 mg/kg body weight) for 8 weeks to establish the mouse ovarian aging model (n = 10). We found that Tre significantly reversed ovarian weight loss and reduced the number of TUNEL-positive granulosa cells caused by D-gal in mouse ovaries. Tre elevated the protein expression levels of LC3-II, Parkin, PINK1, Beclin1, and LAMP2 in ovaries. Mitochondrial-related proteins TOM20 and COX IV expression levels were increased by Tre administration. In vitro studies further supported these findings, showing that Tre treatment significantly reduced the number of SA-β-gal and PI-positive cells, and decreased ROS levels in cultured granulosa cells. Thus, Tre alleviates ovarian aging by activating mitophagy and reducing oxidative stress, suggesting its potential as an anti-aging agent for ovarian health.

Trehalose in cryopreservation. Applications, mechanisms and intracellular delivery opportunities

Cryopreservation is crucial to fields including immune and stem cell therapies, reproductive technology, blood banking, regenerative medicine and across all biotechnology. During cryopreservation, cryoprotectants are essential to protect cells from the damage caused by exposure to freezing temperatures. The most common penetrating cryoprotectants, such as DMSO and glycerol do not give full recovery and have a cytotoxicity limit on the concentration which can be applied. The non-reducing disaccharide trehalose has been widely explored and used to supplement these, inspired by its use in nature to aid survival at extreme temperatures and/or desiccation. However, trehalose has challenges to its use, particular its low membrane permeability, and how its protective role compares to other sugars. Here we review the application of trehalose and its reported benefit and seek to show where chemical tools can improve its function. In particular, we highlight emerging chemical methods to deliver (as cargo, or via selective permeation) into the intracellular space. This includes encapsulation, cell penetrating peptides or (selective) modification of hydroxyls on trehalose.

Trehalose attenuates testicular aging by activating autophagy and improving mitochondrial quality

BACKGROUND

Reproductive aging can adversely affect male fertility and the health of offspring. The aging process is accompanied by impaired autophagy. Recent studies have shown that Trehalose plays an important role in the prevention of various diseases by regulating autophagy. However, the roles of Trehalose in testicular aging and reproductive decline remain to be clarified.

OBJECTIVE

The present study aimed to evaluate the protective effects of Trehalose on testes in an aging mouse model.

MATERIALS AND METHODS

In this study, an in vivo aging model in mice by administering D-galactose was established to explore the protective effect of Trehalose on testicular aging. We examined histological changes and related indicators of apoptosis, autophagy, mitochondrial biogenesis, and sperm quality.

RESULTS

D-galactose treatment induced oxidative stress, apoptosis, and impairment of autophagy of testicular cells in mouse testes. Trehalose administration significantly reduced germ cell apoptosis and DNA damage caused by D-galactose-induced oxidative stress. Notably, Trehalose activated autophagy activity and improved mitochondrial function in testicular cells. Furthermore, Trehalose treatment increased the expression level of the tight junction protein ZO-1, and accelerated clearance of damaged mitochondria in Sertoli cells, indicating that Trehalose ameliorated Sertoli cell function in D-galactose-induced aging testes.

DISCUSSION AND CONCLUSION

These findings suggest that Trehalose administration activated the autophagy activity in testicular cells and improved mitochondrial function, thereby effectively preventing testicular aging. Trehalose and its activated autophagy are crucial for preventing testicular aging, thus restoring autophagy activity by administering Trehalose could be a promising means to delay aging.

A rapid and robust method for the cryopreservation of human granulosa cells

Human primary granulosa cells (GCs) derived from women undergoing oocyte retrieval can be cultured and used as a cellular model for the study of human ovarian function. In vitro, they change rapidly, initially resembling cells of the preovulatory follicle and then cells of the corpus luteum. They are derived from individual patients, whose different medical history, lifestyle and age lead to heterogeneity. Thus, cells can rarely be ideally matched for cellular experiments or, if available, only in small quantities. We reasoned that cryopreservation of human GCs may be helpful to improve this situation. Previous studies indicated the feasibility of such an approach, but low survival of human GCs was reported, and effects on human GC functionality were only partially evaluated. We tested a slow freezing protocol (employing FCS and DMSO) for human GCs upon isolation from follicular fluid. We compared cryopreserved and subsequently thawed cells with fresh, non-cryopreserved cells from the same patients. About 80% of human GCs survived freezing/thawing. No differences were found in cell morphology, survival rate in culture, or transcript levels of mitochondrial (COX4, OPA1, TOMM20), steroidogenic (CYP11A1, CYP19A1) or cell-cell contact genes (GJA1) between the two groups in cells cultured for 1-5 days. A proteomic analysis revealed no statistically significant change in the abundance of a total of 5962 proteins. The two groups produced comparable basal levels of progesterone and responded similarly to hCG with elevation of progesterone. Taken together, our results show this to be a rapid and readily available method for the cryopreservation of human GCs. We anticipate that it will allow future large-scale experiments and may thereby improve cellular studies with human ovarian cells.

Effective cryopreservation protocol for preservation of male primate (Macaca fascicularis) prepubertal fertility

RESEARCH QUESTION

Can specimen types (cells versus tissues) and additive cryoprotectant agents contribute to efficient cryopreservation of primate spermatogonial stem cells (SSC)?

DESIGN

Testicular tissues or cells from four prepubertal monkeys were used in this study. The freezing efficacy of testicular tissue was compared with cell suspensions using conventional freezing media (1.4 mol/l dimethyl sulfoxide [DMSO]) and the efficacy of cryoprotectant additives (1.4 mol/l DMSO combined with trehalose 200 mmol/l, hypotaurine 14 mmol/l, necrostatin-1 50 µmol/l or melatonin 100 µmol/l) was evaluated in testicular tissue freezing.

RESULTS

The survival rate (46.0 ± 4.8% versus 33.7 ± 6.0%; P = 0.0286) and number of recovered cells (5.0 ± 1.5 × 10⁶ cells/g versus 0.7 ± 0.8 × 10⁶ cells/g; P = 0.0286) were significantly higher in frozen tissues than in frozen cell suspensions. After tissue freezing, a higher number of recovered PGP9.5⁺ cells were observed with 200 mmol/l trehalose treatment than in DMSO controls (2.4 ± 0.6 × 10⁶ cells/g versus 1.1 ± 0.3 × 10⁶ cells/g; P = 0.0164). Normal establishment of donor-derived colony was observed in SSC after tissue freezing with 200 mmol/l trehalose.

CONCLUSIONS

Testicular tissue freezing is more effective than single cell suspension freezing for higher recovery of undifferentiated spermatogonia. Moreover, it was verified that slow freezing using 200 mmol/l trehalose, 1.4 mol/l DMSO and 10% KnockOut™ Serum Replacement in Dulbecco's phosphate-buffered saline is an effective cryopreservation protocol for primate testicular tissue.

Effect of cryopreservation on the ability of granulosa cells to support in vitro development of oocytes derived from porcine early antral follicles

Granulosa cells (GCs) contribute to oocyte development. The present study addressed the effect of cryopreservation on the ability of GCs to support oocyte development. GCs were collected from antral follicles. Oocyte granulosa cell complexes (OGCs) derived from early antral follicles were cultured with additional fresh-GCs or frozen-thawed-GCs for 14 days, and the developmental ability and characteristics of the oocytes grown in vitro were examined. Furthermore, fresh- or frozen-thawed-GCs were cultured for two days, and the effects of cryopreservation on the characteristics of GCs were examined. The developmental ability of blastocysts and the acetylation levels of H4K12 in oocytes grown in vitro did not significantly differ among the three culture conditions: OGCs cultured with additional fresh-GCs, frozen-thawed-GCs, or without additional GCs. Although both fresh- and frozen-thawed-GCs exhibited increased ATP content compared with that in oocytes developed without additional GCs, only fresh-GCs showed significantly increased lipid content in oocytes grown in vitro. ATP content, reactive oxygen content, mitochondrial membrane potential, and mitochondrial DNA copy number were greater in cultured frozen-thawed-GCs compared with fresh-GCs. In contrast, lipid content of cultured frozen-thawed-GCs was lower than that of fresh-GCs. Both fresh- and frozen-GCs support oocyte growth, but cryopreservation changes the properties of GCs in a manner that affects the energy status of oocytes grown in vitro.

Phospholipase C inhibits apoptosis of porcine primary granulosa cells cultured in vitro

Phospholipase C (PLC) can participate in cell proliferation, differentiation and aging. However, whether it has a function in apoptosis in porcine primary granulosa cells is largely uncertain. The objective of this study was to examine the effects of PLC on apoptosis of porcine primary granulosa cells cultured in vitro. The mRNA expression of BAK, BAX and CASP3, were upregulated in the cells treated with U73122 (the PLC inhibitor). The abundance of BCL2 mRNA, was upregulated, while BAX and CASP3 mRNA expression was decreased after treatment with m-3M3FBS (the PLC activator). Both the early and late apoptosis rate were maximized with 0.5 μM U73122 for 4 h. The rate of early apoptosis was the highest at 4 h and the rate of late apoptosis was the highest at 12 h in the m-3M3FBS group. The protein abundance of PLCβ1, protein kinase C β (PKCβ), calmodulin-dependent protein kinaseII α (CAMKIIα) and calcineurinA (CalnA) were decreased by U73122, and CAMKIIα protein abundance was increased by m-3M3FBS. The mRNA expression of several downstream genes (CDC42, NFATc1, and NFκB) was upregulated by PLC. Our results demonstrated that apoptosis can be inhibited by altering PLC signaling in porcine primary granulosa cells cultured in vitro, and several calcium^-sensitive targets and several downstream genes might take part in the processes.