AIM: Recent studies in both rodents and humans indicated that bone marrow (BM)-derived stem cells were able to home to the liver after they were damaged and demonstrated plasticity in becoming hepatocytes. However, th...AIM: Recent studies in both rodents and humans indicated that bone marrow (BM)-derived stem cells were able to home to the liver after they were damaged and demonstrated plasticity in becoming hepatocytes. However, the question remains as to how these stem cells are activated and led to the liver and where the signals initiating the mechanisms of activation and differentiation of stem cells originate. The aim of this study was to investigate the influence of serumfrom liver-damaged rats on differentiation tendency of bone marrow-derived stem cells.METHODS: Serum samples were collected from rats treated with a 2-acetylaminofluorene (2-AAF)/carbon tetrachloride (CCl4) program for varying time points and then used as stimulators of cultured BM stem cells. Expression of M2- and L-type isozymes of rat pyruvate kinase, albumin as well as integrin-β1 were then examined by reverse transcription polymerase chain reaction (RT-PCR) to estimate the differentiation state of BM stem cells.RESULTS: Expression of M2-type isozyme of pyruvate kinase (M2-PK), a marker of immature hepatocytes, was detected in each group stimulated with experimental serum, but not in controls including mature hepatocytes, BM stem cells without serum stimulation, and BM stem cells stimulated with normal control serum. As a marker expressed in the development of liver, the expression signal of integrin-131 was also detectable in each group stimulated with experimental serum. However, expression of L-type isozyme of pyruvate kinase (L-PK) and albumin, marker molecules of mature hepatocytes, was not detected in groups stimulated with experimental serum.CONCLUSION: Under the influence of serum from rats with liver failure, BM stem cells begin to differentiate along a direction to hepatoo/te lineage and to possess some featuresof immature hepatocytes.展开更多
Objective:To characterize chemokine receptor CCR5 expression on the conjunctival epithelium in dry eye syndromes.Methods:Conjunctival impression cytology samples were obtained from normal subjects(n=15)and patients wi...Objective:To characterize chemokine receptor CCR5 expression on the conjunctival epithelium in dry eye syndromes.Methods:Conjunctival impression cytology samples were obtained from normal subjects(n=15)and patients with dry eye syndrome(n=45).Cells were harvested from impression cytology samples,and flow cytometry was performed to quantitatively analyze the cell surface expression of chemokine receptor CCR5.Characterization of CCR5-positive cells was done by 2-color flow cytometry using fluorescein-conjugated anti-CCR5 and phycoerythrin-conjugated anti-CD45 antibodies(whereCD45 is a marker for bone marrow-derivedcells).To study CCR5 messenger RNA transcripts,real-time polymerase chain reaction was done on RNA isolated from the impression cytology samples of normal subjects(n=5)and patients with dry eye syndrome(n=14).Results:We found significant upregulation in cell surface expression of CCR5 in patients with both aqueous tear-deficient and evaporative forms of dry eye syndrome(P <.001).The real-time polymerase chain reaction results(for messenger RNA)corroborated the flow cytometry data(for protein).The majority of the cells expressing CCR5 were non-bone marrow-derived resident epithelial cells of the conjunctiva.Conclusion:Our findings suggest that CCR5 up-regulation is significantly associated with dry eye syndrome-associated ocular surface disease.Clinical Relevance:Chemokine receptor CCR5 or its ligands may serve as useful targets for modulation of tissue immunoinflammatory responses in dry eye syndromes.展开更多
基金Supported by the National Natural Science Foundation of China,No.30170473
文摘AIM: Recent studies in both rodents and humans indicated that bone marrow (BM)-derived stem cells were able to home to the liver after they were damaged and demonstrated plasticity in becoming hepatocytes. However, the question remains as to how these stem cells are activated and led to the liver and where the signals initiating the mechanisms of activation and differentiation of stem cells originate. The aim of this study was to investigate the influence of serumfrom liver-damaged rats on differentiation tendency of bone marrow-derived stem cells.METHODS: Serum samples were collected from rats treated with a 2-acetylaminofluorene (2-AAF)/carbon tetrachloride (CCl4) program for varying time points and then used as stimulators of cultured BM stem cells. Expression of M2- and L-type isozymes of rat pyruvate kinase, albumin as well as integrin-β1 were then examined by reverse transcription polymerase chain reaction (RT-PCR) to estimate the differentiation state of BM stem cells.RESULTS: Expression of M2-type isozyme of pyruvate kinase (M2-PK), a marker of immature hepatocytes, was detected in each group stimulated with experimental serum, but not in controls including mature hepatocytes, BM stem cells without serum stimulation, and BM stem cells stimulated with normal control serum. As a marker expressed in the development of liver, the expression signal of integrin-131 was also detectable in each group stimulated with experimental serum. However, expression of L-type isozyme of pyruvate kinase (L-PK) and albumin, marker molecules of mature hepatocytes, was not detected in groups stimulated with experimental serum.CONCLUSION: Under the influence of serum from rats with liver failure, BM stem cells begin to differentiate along a direction to hepatoo/te lineage and to possess some featuresof immature hepatocytes.
文摘Objective:To characterize chemokine receptor CCR5 expression on the conjunctival epithelium in dry eye syndromes.Methods:Conjunctival impression cytology samples were obtained from normal subjects(n=15)and patients with dry eye syndrome(n=45).Cells were harvested from impression cytology samples,and flow cytometry was performed to quantitatively analyze the cell surface expression of chemokine receptor CCR5.Characterization of CCR5-positive cells was done by 2-color flow cytometry using fluorescein-conjugated anti-CCR5 and phycoerythrin-conjugated anti-CD45 antibodies(whereCD45 is a marker for bone marrow-derivedcells).To study CCR5 messenger RNA transcripts,real-time polymerase chain reaction was done on RNA isolated from the impression cytology samples of normal subjects(n=5)and patients with dry eye syndrome(n=14).Results:We found significant upregulation in cell surface expression of CCR5 in patients with both aqueous tear-deficient and evaporative forms of dry eye syndrome(P <.001).The real-time polymerase chain reaction results(for messenger RNA)corroborated the flow cytometry data(for protein).The majority of the cells expressing CCR5 were non-bone marrow-derived resident epithelial cells of the conjunctiva.Conclusion:Our findings suggest that CCR5 up-regulation is significantly associated with dry eye syndrome-associated ocular surface disease.Clinical Relevance:Chemokine receptor CCR5 or its ligands may serve as useful targets for modulation of tissue immunoinflammatory responses in dry eye syndromes.
