ABSTRACT
Cell encapsulation is an alternative to avoid rejection of grafted tissue, thus bringing an interesting alternative in cell therapy. It is particularly relevant in ailments where only the implant of small quantities of tissues is warranted. In such circumstances, the use of immunosuppressive therapy in patients implanted with tissues from donors is debatable, yet unavoidable at present in order to prevent rejection and/or sensitization of the host to the tissue, in turn jeopardizing the success of successive implants. Hence, a new line of thought, which aims to provide an immunoprivileged site for the grafted tissue, while at the same time insure its nutrition, as well as its survival and continued function, appears as a most attractive possibility. To achieve these goals, cells or tissues harvested for transplant could be encapsulated in biologically compatible matrices. Among the matrices currently in existence, sodium alginate is the most widely used polymer for tissue encapsulation.In the present chapter, we present a technique used to encapsulate parathyroid tissue, for use as cell transplant therapy in patients with secondary hypoparathyroidism. With this procedure, implanted tissue survives and remains functional for up to 18 months.
Subject(s)
Alginates/chemistry , Cells, Immobilized/cytology , Hypoparathyroidism/therapy , Parathyroid Glands/cytology , Capsules/chemistry , Cell Culture Techniques/methods , Cells, Cultured , Cells, Immobilized/transplantation , Cryopreservation/methods , Drug Compounding/methods , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Humans , Parathyroid Glands/transplantation , Tissue Preservation/methodsABSTRACT
Background: Cell therapy could be an alternative for the treatment of hypoparathyroidism. Therefore efforts have been made to establish a cell line of parathyroid cells. Aim: To establish a continuous functional and non-tumorigenic human parathyroid cell line. Material and Methods: Nineteen tissue samples from 15 patients subjected to parathyroidectomy due to primary or secondary hyperparathyroidism were obtained. Functional, morphological and tumorigenic properties of the obtained cells were analyzed. Results: After two months of culture in conditions of immortalization, cells had an exponential growth without experiencing senescence. Therefore, more than 200 sub cultures have been performed. The cell line was denominated RCPTH. Morphological characterization showed monolayer growth with contact inhibition and a duplication time of 30 hours. On light microscopy, pleomorphism and low number of mitoses were observed. Cells accumulated glycogen, expressed calcium sensing receptor and had positive PTH cytoplasmic clusters. The line secreted PTH initially but subsequently, PTH production became undetectable. The cell line did not have tumor or metastatic growth. Conclusions: A parathyroid cell line has been established. The lack of PTH production is a problem that will require the search for mechanisms to activate it.
Subject(s)
Humans , Animals , Mice , Cell Transformation, Neoplastic , Cell Transplantation , Parathyroid Glands/cytology , Cell Culture Techniques , Cell Line , Parathyroid Glands/transplantation , Immunocompromised Host , Mice, Inbred NOD , Mice, SCID , Cell Proliferation , Time Factors , Transplantation, HomologousABSTRACT
Myosin-Va is a Ca(2+)/calmodulin-regulated unconventional myosin involved in the transport of vesicles, membranous organelles, and macromolecular complexes composed of proteins and mRNA. The cellular localization of myosin-Va has been described in great detail in several vertebrate cell types, including neurons, melanocytes, lymphocytes, auditory tissues, and a number of cultured cells. Here, we provide an immunohistochemical view of the tissue distribution of myosin-Va in the major endocrine organs. Myosin-Va is highly expressed in the pineal and pituitary glands and in specific cell populations of other endocrine glands, especially the parafollicular cells of the thyroid, the principal cells of the parathyroid, the islets of Langerhans of the pancreas, the chromaffin cells of the adrenal medulla, and a subpopulation of interstitial testicular cells. Weak to moderate staining has been detected in steroidogenic cells of the adrenal cortex, ovary, and Leydig cells. Myosin-Va has also been localized to non-endocrine cells, such as the germ cells of the seminiferous epithelium and maturing oocytes and in the intercalated ducts of the exocrine pancreas. These data provide the first systematic description of myosin-Va localization in the major endocrine organs of rat.