Thymoquinone Upregulates Catalase Gene Expression and Preserves the Structure of the Renal Cortex of Propylthiouracil-Induced Hypothyroid Rats.

BACKGROUND: The association between hypothyroidism and renal diseases has been described in many studies. Nigella Sativa was among the recently reported natural product that has the potential to prevent renal tissue damage and fibrosis. The aim of this study was to evaluate the possible protective effect of thymoquinone on the structure of the renal cortex of hypothyroid rats and explore the mechanism behind it. METHODS: An experimental model of hypothyroidism was induced in adult male Wistar rats by administration of propylthiouracil (6 mg/kg/body weight). One hypothyroid group was treated with thymoquinone at the dose of 50 mg/kg/body weight and compared to the untreated group. Thyroid function and oxidant/antioxidant status were assessed in the serum. Catalase gene expression was assessed using the real-time polymerase chain reaction. The kidney was assessed both histologically and immunohistochemically. RESULTS: Administration of propylthiouracil resulted in a significant decrease in the serum levels of nitric oxide, reduced glutathione, and superoxide dismutase activity while the level of malondialdehyde significantly (p < 0.001) increased. Administration of thymoquinone alleviated this effect on the thyroid hormones and significantly increased the serum levels of antioxidants. Thymoquinone significantly (p < 0.001) upregulated catalase transcription by about 24-fold and could block the hypothyroidism-induced glomerular and tubular injury. CONCLUSION: Thymoquinone may have a potential protective effect against hypothyroidism-induced renal injury acting through the attenuation of the oxidative stress and upregulation of renal catalase gene expression.

Periostin expression and characters of human adipose tissue-derived mesenchymal stromal cells were aberrantly affected by in vitro cultivation.

BACKGROUND: Human adipose tissue-derived mesenchymal stromal cells (AD-MSCs) have been under focus in regenerative medicine since their discovery as a suitable source of MSCs. AD-MSCs are heterogeneous cells and exhibit variations in population doubling time, morphology and proliferative capacity. This study investigated if human AD-MSCs are developing, during in vitro long-term cultivation, in an unwanted or aberrant way. METHODS: This study monitored AD-MSCs during their in vitro culture till the tenth passage investigating proliferation kinetics, DNA index and surface markers expression. Also, periostin gene expression was examined. RESULTS: The proliferation capacity and colony forming unit were decreased after passage 6 and the population doubling time was increased. Flow cytometric analysis revealed that newly cultivated population strongly expressed MSCs markers, furthermore, reduction of CD105 expression appeared in passage 5 onwards, the later was associated with significant increase in expression of CD34 (a hematopoietic cell marker). Also, reduction of CD73 and CD90 expression was observed from passage 8. Furthermore, during the first six passages, periostin expression was significantly unchanged, with significant upregulation in late passages. CONCLUSIONS: Long-term cultivation of human AD-MSCs changed their characters in an aberrant way and the first four passages might be the most appropriate passages for therapy. More investigation and understanding of these variations are needed to help in standardizing the expansion of MSCs-based therapies.

Thymoquinone reverses nonalcoholic fatty liver disease (NAFLD) associated with experimental hypothyroidism.

OBJECTIVES: To assess the efficacy of thymoquinone (TQ), the most active constituent in Nigella sativa, which is a medicinal plant from the Ranunculaceae family, in restoring the normal liver structure after 6-propyl-2-thiouracil (PTU)-induced hypothyroidism and explore the mechanism behind this. MATERIALS AND METHODS: Hypothyroidism was induced in rats by injection of PTU [6 mg∕kg body weight (b.w.)] for six weeks. Twenty-four adult male Wistar rats were divided into four groups; the control, TQ-treated at the dose 400 mg∕kg b.w., untreated hypothyroidism and TQ-treated hypothyroid groups. Serum levels of thyroid hormones and antioxidant profile were measured. Real-time polymerase chain reaction was used to assess gene expression of catalase (CAT). Liver was histopathologically examined using routine and immunohistochemical techniques. RESULTS: Livers of rats with hypothyroidism displayed nonalcoholic fatty liver disease (NAFLD) in the form of steatosis as well as nonalcoholic steatohepatitis (NASH). Moreover, there was an intralobular inflammatory reaction associated with significant (p<0.05) increases in the density of resident hepatic macrophages [cluster of differentiation 68 (CD68)+ cells], as well as in activated hepatic stellate cells, alpha-smooth muscle actin (α-SMA) index in livers with hypothyroidism. Resolution of hypothyroid NAFLD was observed in livers after treatment with TQ. The significantly increased (p<0.05) steatosis, lobular inflammation, NAFLD activity scores, α-SMA index as well as CD68+ cells induced by hypothyroidism were corrected after TQ administration. Up-regulation of the CAT gene in livers with hypothyroidism after treatment with TQ supported our hypothesis of its antioxidant mechanistic hepatoprotective action. CONCLUSIONS: TQ efficiently restores the normal liver histology in hypothyroid rats with up-regulation of the antioxidant CAT gene.

Red grape juice protects the rat thyroid gland against hypercholesterolemic changes. Ultrastructural and biochemical evidences.

OBJECTIVES: This study aimed to assess the impact of high cholesterol diet (HCD)-induced hypercholesterolemia on the rat thyroid gland and investigate the role of grape juice (GJ) in reducing such impact through biochemical and histopathological methods. MATERIALS AND METHODS: Thirty male Wistar rats sorted into three groups (the control, HCD-fed group, and the HCD+GJ fed group for 13 weeks) were used in this study. Lipid profile, blood glucose and insulin, thyroid hormones, some oxidants/antioxidants parameters were assessed. After the end of the experiment, thyroid glands were dissected out and processed for histopathological assessment using the light and electron microscopy. RESULTS: Based on the lipid profile, HCD induced hypercholesterolemia in rats after 13 weeks. This resulted in significant (p<0.001) increase of the levels of insulin, blood glucose, thyroid-stimulating hormone (TSH) (596.4±17 IU∕mL), thyroxine (T4) (202.8±14.1 ng∕mL) and malondialdehyde (MDA) (21.2±4.9 nmol∕mg protein), while the levels of triiodothyronine (T3) (12.6±1.9 ng∕mL) and total antioxidant capacity (TAOC) (21.2±4.9 U∕mg protein) decreased in HCD-fed rats compared to that of the controls. Structurally, thyroid gland follicles of HCD-fed rats showed cytoplasmic vacuolation, stratification and increased thickness of some lining cells. Ultrastructurally, some of follicular and parafollicular cells showed heterochromatic nuclei, degenerated mitochondria, intracytoplasmic lipid droplets and deposition of collagen fibers between the follicles. GJ could improve the lipid and antioxidants profiles, reduced blood glucose level, thyroid hormones, and alleviated the HCD-induced structural changes in the thyroid. CONCLUSIONS: GJ administrated simultaneously with HCD ameliorated the negative impact of the function and structure of the thyroid.

Histochemical study of perineuronal nets in the retrosplenial cortex of adult rats.

The retrosplenic cortex of rats, similar to many cortical or subcortical regions, is provided with special subsets of neurons that exhibited a fenestrated or reticular coat of condensed extracellular matrix on their soma, initial dendrites and proximal axon segment. This pericellular coating, currently termed "Perineuronal Nets", was detected on the surfaces of some neurons distributing throughout the cortical layers II-V. They presented direct interconnections with each other, and appeared in close association to the astroglial processes. In addition to their collagenous ligands, the perineuronal nets (PNs) were enriched with proteoglycans (PGs, sulfated glycoconjugates) and/or glycoproteins (GPs, unsulfated glycoconjugates with terminal N-acetylgalactosamine). Accordingly, the PNs were differentially identified as belonging to three categories, depending upon their organic nature or chemical composition. First, coats exclusively formed of PGs (stained with iron colloid); second, coats formed of GPs (labeled with plant lectins binding to terminal N-acetylgalactosamine); and third, complex coats formed of PG networks intermingled with glycoprotein molecules (double stained with iron colloid and lectin). Since differential distribution of protein containing substances (GPs and/or PGs) in the extracellular matrix contributes to functional terms, we suggest that these biochemical or morphological differences in the microenvironment of some retrosplenial neurons might reflect certain functional aspects concerned with processing of navigation or episodic memory.