Effect of Polypeptides on Cell Proliferation and Apoptosis during Aging

Testicular toxicity in mice exposed to terephthalic acid in utero and during lactation

Terephthalic acid (TPA) is a worldwide aromatic compound widely used to manufacture resins and the raw material for the polymerization reaction with ethylene glycol to produce polyethylene terephthalate, known as PET. The use of TPA extends to the synthesis of phthalates, plasticizers used in various industrialized products such as toys and cosmetics. The present study aimed to evaluate the testicular toxicity of terephthalic acid on male mice exposed in utero and during lactation to TPA in different developmental windows. The animals were treated intragastric with TPA at stock dispersal dosages corresponding to 0.0014 g/ml and 0.56 g/ml of TPA in 0.5% v/v carboxymethylcellulose as well as the control dose, composed solely of dispersion of carboxymethylcellulose (0.5% v/v). Four experimental windows were established: group I-treatment in utero, in the fetal period (gestational day-GD 10.5-18.5), with euthanasia at GD 18.5; group II-treatment in utero, in the fetal period (GD 10.5-18.5) and the lactational period (postnatal day (PND-15)), with euthanasia at 15 days; group III-treatment in utero in the fetal period (DG 10.5-18.5) with euthanasia at 70 days (age of sexual maturity, PND 70); group IV-treatment in utero, in the fetal period (GD 10.5-18.5) and the lactational period (PND-15), with euthanasia at 70 days (PND70). The results indicate that TPA changes the reproductive parameters (testicular weight, GI, penis size, and anogenital index) only at the dose of 0.56 g/ml in the fetal period. Data on the volumetric ratio of the testis elements show that the dispersion with the highest concentration of TPA significantly altered the blood vessel/capillary, lymphatic vessel, and connective tissue percentages. Only at the dose of 0.56 g/ml TPA was it effective in decreasing the Leydig and Sertoli cell numbers of the euthanized animals at GD 18.5. In group II, TPA increased the diameter and lumen of seminiferous tubules, which indicates that TPA accelerated the maturation process of Sertoli cells without changing the number and the nuclear volume of these cells. The Sertoli and Leydig cell numbers of the 70-day animals exposed to TPA in the gestational and lactational period were similar to the control. Therefore, the present study is the first in the literature to show that TPA presents a testicular toxicity during fetal (DG18.5) and postnatal life (PND15), without repercussion in adulthood (70 days).

Wound healing in weaning, adult, and old rats with provoked incisional hernias. A comparative study

BACKGROUND

Incisional hernias are more frequent in adults than in children. It is hypothesized that a more efficient healing process in pediatric patients could explain this difference in incidence. Certain elements of healing such as neovascularization, degree of inflammation, percentage of mature and immature collagen, the proliferation of fibroblasts, and expression of certain genes could explain why healing in children is more efficient when compared to the adult and elderly populations.

MATERIALS AND METHODS

Seventy-one rats of 3 different age groups (weaning, adult, and old) underwent surgery with 3 different incisions (vertical, oblique, and horizontal). During the procedure, the skin and abdominal wall of the animal were sectioned and only the skin was sutured to mimic incisional hernia in the animals. Four weeks after surgery, the rats were euthanized, their skin was removed, and the extent of scar tissue formed in the muscle opening was measured. In addition, samples of the scar tissue were collected for histological, immunohistochemical, and molecular analyzes. Nine rats served as controls.

RESULTS

Shorter-length hernias were formed in weaning rats when compared to old ones when the surgical incision was horizontal (p = 0.03). There was a greater proliferation of fibroblasts in rats in the younger age groups, regardless of the type of incision. The Lox gene was more expressed in weaning rats with vertical and oblique incisions.

CONCLUSIONS

These differences could explain the better healing and lower incidence of hernias in the pediatric population, although this aspect requires further studies.

The Use of Thymalin for Immunocorrection and Molecular Aspects of Biological Activity

The polypeptide drug thymalin is used for various diseases associated with immune dysfunction, viral and bacterial infections, regeneration normalization, immunodepression, and the depression of hematogenesis after chemical and radiotherapy. The molecular mechanism of the action of thymalin and its components, EW dipeptide (the drug thymogen), the dipeptide KE, and the tripeptide EDP, are analyzed. These short peptides regulate gene expression and the synthesis of heat-shock protein, cytokines, fibrinolysis, gerontogenes, and the differentiation, proliferation, apoptosis of cells. Thymalin and thymogen have practically no side effects and are used for various viral infections. These peptide drugs can likely be effective in the complex therapy for the coronavirus infection COVID-19.

Ameliorative effect of urolithin A ond-gal-induced liver and kidney damage in aging miceviaits antioxidative, anti-inflammatory and antiapoptotic properties

Urolithin A, a metabolite produced by human colon microflora from ellagic acid and related compounds, has been reported to have antioxidant, anti-inflammatory and antiapoptotic properties. The present study investigates the protective effects of urolithin A (Uro A) on d-galactose (d-gal)-induced liver and kidney injury and the possible mechanisms in mice. In this study, we first investigated the antioxidant ability of Uro A in vitro. Then mice were treated with d-gal subcutaneously (150 mg kg⁻¹ d⁻¹), followed by Uro A at different dosages (50, 100, 150 mg kg⁻¹ d⁻¹, administered orally) for 8 weeks. The levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine (Cr) in the serum were tested. Histopathological features were assessed by hematoxylin and eosin (HE) staining followed by an assessment of the antioxidant and anti-inflammatory activities. Furthermore, we also evaluated the expression levels of the genes Bax, Bcl-2 and cleaved caspase-3 in the liver and kidney. The results showed that Uro A treatment obviously attenuated d-gal-induced liver and kidney damage. The beneficial effects of Uro A were accompanied by a decline in malondialdehyde (MDA) levels and a rise in the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), catalase (CAT), and total antioxidant capacity (T-AOC) activity in the liver and kidney and downregulation of the levels of inflammatory cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6), in serum. Moreover, Uro A could modulate the expression of Bax, Bcl-2 and cleaved caspase-3 in the livers and kidneys of aging mice. These findings suggested that Uro A ameliorated d-gal-induced liver and kidney injury through attenuating oxidative stress, inflammatory responses and apoptosis.

Urolithin A, a metabolite produced by human colon microflora from ellagic acid and related compounds, has been reported to have antioxidant, anti-inflammatory and antiapoptotic properties.