RESUMO
PURPOSE: The histopathological study of brain tissue is a common method in neuroscience. However, efficient procedures to preserve the intact hypothalamic-pituitary brain specimens are not available in mice for histopathological study. METHOD: We describe a detailed procedure for obtaining mouse brain with pituitary-hypothalamus continuity. Unlike the traditional methods, we collect the brain via a ventral approach. We cut the intraoccipital synchondrosis, transection the endocranium of pituitary, broke the spheno-occipital synchondrosis, expose the posterior edge of pituitary, separate the trigeminal nerve, then the intact pituitary gland was preserved. RESULT: We report an more effective and practical method to obtain continuous hypothalamus -pituitary preparations based on the preserve of leptomeninges. COMPARED WITH THE EXISTING METHODS: Our procedure effectively protects the integrity of the fragile infundibulum preventing the pituitary from separating from the hypothalamus. This procedure is more convenient and efficient. CONCLUSION: We present a convenient and practical procedure to obtain intact hypothalamic-pituitary brain specimens for subsequent histopathological evaluation in mice.
Assuntos
Doenças da Hipófise , Neuro-Hipófise , Camundongos , Animais , Hipófise/patologia , Neuro-Hipófise/patologia , Hipotálamo/patologia , Sistema Hipotálamo-Hipofisário , Doenças da Hipófise/cirurgia , Doenças da Hipófise/patologiaRESUMO
Body fluid homeostasis is critical to survival. The integrity of the hypothalamo-neurohypophysial system (HNS) is an important basis of the precise regulation of body fluid metabolism and arginine vasopressin (AVP) hormone release. Clinically, some patients with central diabetes insipidus (CDI) due to HNS lesions can experience recovery compensation of body fluid metabolism. However, whether the hypothalamus has the potential for structural plasticity and self-repair under pathological conditions remains unclear. Here, we report the repair and reconstruction of a new neurohypophysis-like structure in the hypothalamic median eminence (ME) after pituitary stalk electrical lesion (PEL). We show that activated and proliferating adult neural progenitor cells differentiate into new mature neurons, which then integrate with remodeled AVP fibers to reconstruct the local AVP hormone release neural circuit in the ME after PEL. We found that the transcription factor of NK2 homeobox 1 (NKX2.1) and the sonic hedgehog signaling pathway, mediated by NKX2.1, are the key regulators of adult hypothalamic neurogenesis. Taken together, our study provides evidence that adult ME neurogenesis is involved in the structural reconstruction of the AVP release circuit and eventually restores body fluid metabolic homeostasis during hypothalamic self-repair.
Assuntos
Líquidos Corporais , Eminência Mediana , Arginina Vasopressina/metabolismo , Líquidos Corporais/metabolismo , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Humanos , Hipotálamo/metabolismo , Eminência Mediana/metabolismo , Neurogênese , Hipófise/metabolismoRESUMO
BACKGROUND: The histopathological study of brain tissue is a conventional method in neuroscience. However, procedures specifically developed to recover intact hypothalamic-pituitary brain specimens, are not available. NEW METHOD: We describe a detailed protocol for obtaining intact rat brain with pituitary-hypothalamus continuity through an intact infundibulum. The brain is collected via a ventral approach through removing the skull base. Membranous structures surrounding the hypothalamus-pituitary system can be preserved, including vasculature. RESULTS: We report a retaining sphenoid and dura technique to obtain intact hypothalamic-pituitary brain preparations, and we confirm the practicability of this method. By combination of this technique with histological analysis or 3D brain tissue clearing and imaging methods, the functional morphology structure of the hypothalamus-pituitary can be further explored. COMPARISON WITH EXISTING METHOD: The current procedure is limited in showing the connection between the hypothalamus and the pituitary. Our procedure effectively protects the integrity of the fragile infundibulum and thus prevents the pituitary from separating from the hypothalamus. CONCLUSIONS: We present a convenient and practical approach to obtain intact hypothalamus-pituitary brain specimens for subsequent histopathological evaluation.
Assuntos
Hipotálamo , Hipófise , Animais , Encéfalo/diagnóstico por imagem , RatosRESUMO
Epigallocatechin3gallate (EGCG) is a polyphenolic compound extracted and isolated from green tea, which has a variety of important biological activities in vitro and in vivo, including antitumor, antioxidation, antiinflammation and lowering blood pressure. The aim of the present study was to investigate the protective effect of EGCG against secondary osteoporosis in a mouse model via the Wnt/ßcatenin signaling pathway. Reverse transcriptionquantitative polymerase chain reaction (RTqPCR) and western blotting were used to analyze runtrelated transcription factor 2 and osterix mRNA expression, and the protein expression of cyclin D1, Wnt and ßcatenin, and suppressed peroxisome proliferatoractivated receptor γ protein expression. The protective effect of EGCG against secondary osteoporosis was examined and its potential mechanism was analyzed. Treatment with EGCG significantly decreased serum calcium, urinary calcium, body weight and body fat, and increased leptin levels in mice with secondary osteoporosis. In addition, EGCG treatment significantly inhibited the structure score of articular cartilage and cancellous bone in proximal tibia metaphysis in mice with secondary osteoporosis. Treatment also significantly decreased alkaline phosphatase activity, runtrelated transcription factor 2 and osterix mRNA expression. EGCG also significantly induced the protein expression of cyclin D1, Wnt and ßcatenin, and suppressed peroxisome proliferatoractivated receptor γ protein expression in mice with secondary osteoporosis. Taken together, these results suggest that EGCG may be a possible new drug in clinical settings.