ABSTRACT
The purpose of this review was to carry out an analysis of the liver regenerative process focusing on the molecular interactions involved in this process. The authors undertook a review of scientific publications with a focus on the liver regeneration.The cellular processes involved in liver regeneration require multiple systematic actions related to cytokines and growth factors. These interactions result in the initiation of mitogenic potential of the hepatocytes. The action of these modulators in the regenerative process require a processing in the extra-cellular matrix. Serines and metal proteins are responsible for the bio availability of cytokines and growth factors so that they can interact as receptors in the cellular membrane generating signaling events for the beginning and end of the liver regenerative process. The exact mechanism of interaction between cells, cytokines and growth factors is not well established yet. A series of ordered events that result in the hepatic tissue regeneration has been described. The better understanding of these interactions should provide a new approach of the treatment for liver diseases, aiming at inducing the regenerative process.
O objetivo desta revisão foi desenvolver uma análise do processo regenerativo do fígado, focando as interações moleculares envolvidas neste processo.Os processos celulares envolvidos na regeneração hepática requerem múltiplas ações sistemáticas relacionadas com citoquinas e fatores de crescimento. Estas interações resultam na iniciação do potencial mitogênico dos hepatócitos. A ação destes moduladores do processo regenerativo necessita de processamento no meio extra celular. As serinas e metaloproteínas são responsáveis pela biodisponibilização de citoquinas e fatores de crescimento, para que então possam interagir com receptores na membrana celular gerando os eventos sinalizadores para o inicio e o término do processo regenerativo hepático.O exato mecanismo de interação entre células, citoquinas e fatores de crescimento não está bem estabelecido. Tem-se descrito uma série de eventos ordenados que resulta na regeneração do tecido hepático. O melhor entendimento destas interações leva a uma nova abordagem de tratamento para doenças hepáticas, objetivando a indução do processo regenerativo.
Subject(s)
Humans , Cell Proliferation , Hepatocyte Growth Factor/metabolism , Hepatocytes/metabolism , Liver Regeneration/physiology , Liver/metabolism , Extracellular Matrix/metabolism , Hepatocytes/cytology , Kupffer Cells/cytology , Kupffer Cells/metabolism , Liver/cytology , NF-kappa B/metabolism , Tumor Necrosis Factor-alpha/metabolism , Vascular Endothelial Growth Factors/metabolismABSTRACT
Objective To investigate whether mesenchymal stem cells can promote the recovery of acute renal tubular damage induced by mercuric chloride and to explore its possible mechanism.Methods Acute renal failure rat model was established by intraperitoneal injection of mercuric chloride.SD rats were randomly divided into three groups which were MSCs injection group, saline infusion group and normal control group.Seven days later,the changes of rat weight,survival,renal function and pathology were observed;PCNA,ED-1 and GFP were detected by immunohistochemistry; The expression of cytokines in kidney and the distribution of GFP plasmid-transfected MSCs in kidney were examined by RT-PCR.Results MSCs infusion ameliorated the decline of rat weight,survival, renal function,and pathological changes.PCNA and ED-1 positive cells in MSCs group were fewer than those in saline group.Expression of growth factors EGF,PDGF,HGF were obviously up- regulated and pre-inflammatory cytokines TNF-?was significantly reduced in MSCs-treated kidneys. GFP-labelled MSCs occurred occasionally in renal interstitium of MSCs-treated rats,but not in renal tubules.Conclusions Bone marrow mesenchymal stem cells can promote the recovery of acute renal tubular epithelial cells damage caused by mercuric chloride.The mechanism may partly depend on regulating the excretion of cytokines in renal microenvironment rather than completely depend on their differentiation to tubular cells.