Kisspeptin-10 Improves Testicular Redox Status but Does Not Alter the Unfolded Protein Response (UPR) That Is Downregulated by Hypothyroidism in a Rat Model

Hypothyroidism compromises the testicular redox status and is associated with reduced sperm quality and infertility in men. In this regard, studies have demonstrated the antioxidant potential of kisspeptin in reproductive and metabolic diseases. In this study, we evaluate the effects of kisspeptin-10 (Kp10) on the testicular redox, as well as mediators of the unfolded protein response (UPR) in adult rats with hypothyroidism. Adult male Wistar rats were randomly separated into the Control (n = 15), Hypo (n = 13) and Hypo + Kp10 (n = 14) groups, and hypothyroidism was induced with 6-propyl-2-thiouracil (PTU) for three months. In the last month, half of the hypothyroid animals received Kp10. Testis samples were collected for enzymatic, immunohistochemical and/or gene evaluation of mediators of oxidative stress (TBARs, lipid hydroperoxides (LOOH), ROS, peroxynitrite, SOD, CAT and GPX), endoplasmic reticulum stress (GRP78, ATF6, PERK, CHOP, HO-1 and sXBP1) and antiapoptocytes (BCL-2). Hypothyroidism increased apoptosis index, TBARS and LOOH concentrations, and reduced testicular gene expression of Sod1, Sod2 and Gpx1, as well as the expression of Grp78, Atf6, Ho1 and Chop. Treatment with Kp10, in turn, reduced testicular apoptosis and the production of peroxynitrite, while increased SOD1 and GPX ½ expression, and enzymatic activity of CAT, but did not affect the lower expression of UPR mediators caused by hypothyroidism. This study demonstrated that hypothyroidism causes oxidative stress and dysregulated the UPR pathway in rat testes and that, although Kp10 does not influence the low expression of UPR mediators, it improves the testicular redox status, configuring it as an important antioxidant factor in situations of thyroid dysfunction.

Kisspeptin treatment improves fetal-placental development and blocks placental oxidative damage caused by maternal hypothyroidism in an experimental rat model

Maternal hypothyroidism is associated with fetal growth restriction, placental dysfunction, and reduced kisspeptin/Kiss1R at the maternal-fetal interface. Kisspeptin affects trophoblastic migration and has antioxidant and immunomodulatory activities. This study aimed to evaluate the therapeutic potential of kisspeptin in the fetal-placental dysfunction of hypothyroid Wistar rats. Hypothyroidism was induced by daily administration of propylthiouracil. Kisspeptin-10 (Kp-10) treatment was performed every other day or daily beginning on day 8 of gestation. Feto-placental development, placental histomorphometry, and expression levels of growth factors (VEGF, PLGF, IGF1, IGF2, and GLUT1), hormonal (Dio2) and inflammatory mediators (TNFα, IL10, and IL6), markers of hypoxia (HIF1α) and oxidative damage (8-OHdG), antioxidant enzymes (SOD1, Cat, and GPx1), and endoplasmic reticulum stress mediators (ATF4, GRP78, and CHOP) were evaluated on day 18 of gestation. Daily treatment with Kp-10 increased free T3 and T4 levels and improved fetal weight. Both treatments reestablished the glycogen cell population in the junctional zone. Daily treatment with Kp-10 increased the gene expression levels of Plgf, Igf1, and Glut1 in the placenta of hypothyroid animals, in addition to blocking the increase in 8-OHdG and increasing protein and/or mRNA expression levels of SOD1, Cat, and GPx1. Daily treatment with Kp-10 did not alter the higher protein expression levels of VEGF, HIF1α, IL10, GRP78, and CHOP caused by hypothyroidism in the junctional zone compared to control, nor the lower expression of Dio2 caused by hypothyroidism. However, in the labyrinth zone, this treatment restored the expression of VEGF and IL10 and reduced the GRP78 and CHOP immunostaining. These findings demonstrate that daily treatment with Kp-10 improves fetal development and placental morphology in hypothyroid rats, blocks placental oxidative damage, and increases the expression of growth factors and antioxidant enzymes in the placenta.

Feline Idiopathic Pulmonary Fibrosis

Background: Feline idiopathic pulmonary fibrosis is an irreversible disease that is rarely reported in veterinary clinical routine, with this case as the second reported in Brazil. This study aimed to describe a case of idiopathic pulmonary fibrosis in a domestic cat.Case: A 10-year-old female cat with a history of respiratory distress was treated at the Veterinary Hospital of the State University of Santa Cruz (HV-UESC). The first signs were observed three months before clinical care, characterized mainly by dyspnea that was more pronounced during nighttime. There was no history of previous illnesses or prior drug use. The cat lived with two other domiciled cats, did not have access to the street, and had restricted access to the terrace of the building, from where other animals could have possibly entered. Physical examination showed a poor body condition with a temperature of 37°C and dehydration estimated at 9%.The animal was observed to remain in an orthopedic position, with tachypnea (109 mvm), wheezing through the mouth, and severe expiratory dyspnea. Pulmonary auscultation detected fine discontinuous adventitious noises. There were no changes in the cardiac function in terms of rhythm, frequency, or auscultation. Oxygen therapy and slow administration of 0.9% NaCl solution were performed; moreover, blood was collected for complete blood count, in which no abnormalities were observed. Thoracic radiography was performed on the cat, and the results showed a mixed pulmonary pattern characterized by bronchiectasis, thickening of the bronchiolar wall, and an unstructured interstitial pattern throughout the pulmonary area. Shortly after the beginning of the clinical care, the animal died due to respiratory arrest and was necropsied. The main macroscopic finding was pulmonary edema. Lung samples were subjected to microscopic evaluation, which revealed extensive multifocal areas of alveolar septa thickening characterized by smooth muscle hyperplasia, hypertrophy associated with intense fibroplasia, type II pneumocyte hyperplasia, and discrete intra-alveolar and interstitial lymphohistiocytic inflammatory infiltrate. Based on the clinical, radiographic, macroscopic, and histopathological findings, the diagnosis of idiopathic pulmonary fibrosis was established. Discussion: This is the second case of feline idiopathic pulmonary fibrosis reported in Brazil. The observations in the physical examination, namely, the orthopedic positioning, dyspnea, and mouth breathing, are characteristic of respiratory distress and showed the severity of the lesions in the respiratory system. The clinical manifestation of idiopathic pulmonary fibrosis in cats reveals that gas exchange had already been compromised, which indicates an advanced stage of disease. In addition to respiratory signs, systemic signs such as apathy, anorexia, weight loss, and dehydration also confirm the severity of the condition. Because of the severity of the clinical condition at the time of the clinical care, it was not possible to adopt a more aggressive therapeutic approach, and the animal eventually died. Taken together, the clinical, radiographic, macroscopic, and histopathological findings led to the diagnosis of idiopathic pulmonary fibrosis. Literature states that the diagnosis of idiopathic pulmonary fibrosis requires clinical, radiographic, and histopathological findings consistent with the alterations observed in this cat. Much remains to be understood with regard to idiopathic pulmonary fibrosis in felines, since the currently available information is sparse and divergent. The description of these cases is extremely important to increase the available knowledge and to improve the prognosis and therapy for this serious disease.