The effect of diabetes on ovaries in a rat model: the role of interleukin-33 and apoptosis

Intergenerational Hyperglycemia Impairs Mitochondrial Function and Follicular Development and Causes Oxidative Stress in Rat Ovaries Independent of the Consumption of a High-Fat Diet

We analyzed the influence of maternal hyperglycemia and the post-weaning consumption of a high-fat diet on the mitochondrial function and ovarian development of the adult pups of diabetic rats. Female rats received citrate buffer (Control-C) or Streptozotocin (for diabetes induction-D) on postnatal day 5. These adult rats were mated to obtain female pups (O) from control dams (OC) or from diabetic dams (OD), and they received a standard diet (SD) or high-fat diet (HFD) from weaning to adulthood and were distributed into OC/SD, OC/HFD, OD/SD, and OD/HFD. In adulthood, the OGTT and AUC were performed. These rats were anesthetized and euthanized for sample collection. A high percentage of diabetic rats were found to be in the OD/HFD group (OD/HFD 40% vs. OC/SD 0% p < 0.05). Progesterone concentrations were lower in the experimental groups (OC/HFD 0.40 ± 0.04; OD/SD 0.30 ± 0.03; OD/HFD 0.24 ± 0.04 vs. OC/SD 0.45 ± 0.03 p < 0.0001). There was a lower expression of MFF (OD/SD 0.34 ± 0.33; OD/HFD 0.29 ± 0.2 vs. OC/SD 1.0 ± 0.41 p = 0.0015) and MFN2 in the OD/SD and OD/HFD groups (OD/SD 0.41 ± 0.21; OD/HFD 0.77 ± 0.18 vs. OC/SD 1.0 ± 0.45 p = 0.0037). The number of follicles was lower in the OD/SD and OD/HFD groups. A lower staining intensity for SOD and Catalase and higher staining intensity for MDA were found in ovarian cells in the OC/HFD, OD/SD, and OD/HFD groups. Fetal programming was responsible for mitochondrial dysfunction, ovarian reserve loss, and oxidative stress; the association of maternal diabetes with an HFD was responsible for the higher occurrence of diabetes in female adult pups.

Ageing and chronic disease-related changes in the morphometric characteristics of ovarian follicles in cynomolgus monkeys (Macaca fascicularis)

STUDY QUESTION

How is the localisation of ovarian follicles affected by ageing and chronic diseases?

SUMMARY ANSWER

Ovarian follicles shift deeper towards the medulla, due to thickening of the tunica albuginea (TA), with ageing and some major common chronic diseases.

WHAT IS KNOWN ALREADY

The ovary undergoes morphological and functional changes with ageing. The follicular pool follows these changes with alterations in the amount and distribution of residual follicles. Diseases causing a chronic inflammatory process are associated with morphological changes and impaired ovarian function.

STUDY DESIGN, SIZE, DURATION

We conducted a cross-sectional study, examining 90 ovaries from 90 female monkeys. The samples were collected from April 2018 to March 2019 at Tsukuba Primate Research Center in National Institutes of Biomedical Innovation, Health and Nutrition, Japan.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Ovarian samples were obtained from cynomolgus monkeys that died from natural causes or were euthanised. Ovarian sections were stained with haematoxylin and eosin (H&E) for histological analyses. In ovarian sections from 64 female macaques aged 0-25 years, a total of 13 743 follicles at different developmental stages (primordial, intermediary, primary, early secondary and late secondary) were assessed to determine the depth of each follicle from the outer surface of the ovarian cortex to the far end of the follicle, by using a digital imaging software. TA thickness was measured as sum of basal membrane and tunica collagen layer for each ovary under H&E staining. To explore the possibility of age-related trends in ovarian morphometric characteristics, samples were divided into four different age groups (0-3 years (pre-menarche), 4-9 years, 10-14 years and 15-20 years). To evaluate the effect of common chronic diseases on ovarian morphometric characteristics, macaques with diabetes mellitus (DM) (n = 10), endometriosis (n = 8) or inflammatory bowel disease (IBD) (n = 8) were compared to age-matched controls without chronic diseases.

MAIN RESULTS AND THE ROLE OF CHANCE

Ovarian morphometric analysis revealed that the relative location of follicles became deeper in all age groups according to development of follicles (P < 0.05). Total follicle distance from the ovarian surface was increased with ageing (P < 0.05). In a sub-analysis according to developmental stage, only primordial and intermediary follicles were localised deeper with increasing age (P < 0.05). TA thickness was also increased with ageing (P < 0.05). The localisation of the total number of follicles became deeper in ovaries from monkeys with DM, endometriosis or IBD as compared to the control group (P < 0.05). With DM, analysis of follicles distance at almost each developmental stage was significantly deeper compared to controls (P < 0.05) with the exception of early secondary follicles. With endometriosis, follicles at primary and early and late secondary stages were significantly deeper compared to controls (P < 0.05). Also with IBD, follicles at primary and early and late secondary follicles were significantly deeper compared to controls (P < 0.001). The TA was thicker with DM and endometriosis compared to controls (P < 0.05), but not with IBD (P = 0.16).

LARGE SCALE DATA

NA.

LIMITATIONS, REASONS FOR CAUTION

Two-dimensional histology was used to assess follicle localisation. The possibility of minimal variations between the measured distance to the actual distance in a spherical structure cannot be excluded. Additionally, the severity of disease was not assessed.

WIDER IMPLICATIONS OF THE FINDINGS

This study is the first step towards enhancing our understanding of how ageing and chronic diseases affect the relative localisation of dormant and developing follicles. These observations, combined with possible future human studies, may have managerial implications in the field of fertility preservation and other conditions involving ovarian tissue cryopreservation.

STUDY FUNDING/COMPETING INTEREST(S)

The present work was supported by the Grant-in-Aid for Scientific Research B (19H03801) (to K.K.), Challenging Exploratory Research (18K19624), Japan Agency for Medical Research and Development, Mochida Memorial Foundation for Medical and Pharmaceutical Research, Takeda Science Foundation and Naito Foundation (to K.K.). All authors have no conflicts of interest directly relevant to the content of this article.

Pistacia atlantica's effect on ovary damage and oxidative stress in streptozotocin-induced diabetic rats

Objective:

Diabetes mellitus (DM) is associated with numerous complications, including gonadal dysfunction. There are specific traditional medicine remedies for DM, including medicinal herbs. Our study aimed to evaluate the role of Pistacia atlantica’s extract in the protection against ovary damage by streptozotocin (STZ)-induced DM in rats.

Methods:

We ran this experimental study on 40 adult female Wistar rats. We divided the animals into five groups, control (A); DM (STZ by 60 mg/kg- intraperitoneally) (B); DM + hexane extract of P. atlantica (200 mg/kg -orally) (C); P. atlantica extract (D) and DM + glibenclamide (200 mg/kg -orally) (F). The experiment continued for four weeks, and we administered the extract daily. After slaughtering the rats, we removed the ovaries. We assessed parameters, such as blood glucose and levels of oxidative stress markers as well as histological ovary structure.

Results:

Blood glucose, malondialdehyde (MDA) levels, and the number of atretic follicles were elevated; catalase (CAT), superoxide dismutase (SOD) levels and the number of corpora lutea were significantly decreased in the untreated diabetic rats. These changes returned to normal or diminished with P. atlantica extract and glibenclamide in the treated rats.

Conclusions:

The extract of P. atlantica has antihyperglycemic and antioxidative properties, and it decreased ovarian complications in experimental diabetes mellitus.

Could interleukin-33 and its suppressor of tumorigenicity 2 (ST2) receptor have a role in cervical human papillomavirus (HPV) infections?

Why most women can clear human papillomavirus (HPV) infections while others can develop permanent infections. The stimulation of immunotolerance of the immune system of the host by the persistent HPV infection may be the answer to this question. Interleukin-33 (IL-33) may play a role in the pathogenesis of HPV infection, this hypothesis was thought to be due to the rapid release of IL-33 from damaged cells following tissue damage, necrosis, and activation of the inflammasome. Thus, in this study, the role of IL-33/suppressor of tumorigenicity 2 (ST2) was emphasized in HPV positive and HPV negative cervical tissues. A total of 80 were assessed. The reduced levels of IL-33 and ST2 are associated with cervical HPV infections. There was a statistically significant 42% positive correlation between IL-33 and ST2 in the HPV-positive group. Surprisingly, our data showed no significant difference between the expression levels of IL-33 or ST2 and working status, type of delivery, pre- and post-operative pathology, cigarette, educational status, locality, birth control method, gynecological, and colposcopic findings. We found that as a result of our study; low IL-33 and ST2 levels were associated with HPV infections.