Kaiming Zhang

Promoter methylation status of p15 and p21 genes in HPP-CFCs of bone marrow of patients with psoriasis

Psoriasis is an inflammatory disease related to dysfunctional immunity. The dysfunctional immunity may influence the haematopoietic microenvironment or haematopoiesis in psoriasis. However, direct evidence is lacking. Our objective was to investigate the proliferation of hematopoietic cells from psoriatic patients and any link between the promoter methylation status of p15 and p21 genes and the colony formation ability of high proliferative potential colony-forming cells (HPP-CFCs). Marrow mononuclear cells were isolated from the bone marrow of psoriatic patients and normal controls by density gradient centrifugalization. Colony forming assays of HPP-CFCs were performed in vitro in methylcellulose semi-solid culture medium. mRNA expression and the promoter methylation status of p15 and p21 genes in HPP-CFCs were studied by semi-quantitative RT-PCR and methylation-specific PCR respectively. In methycellulose semi-solid culture system, the colony count of HPP-CFCs in bone marrow of psoriatic patients was significantly less than that of normal controls. Moreover, significantly lower positive frequencies of promoter methylation and higher transcription levels for p15 and p21 genes were observed in psoriasis in comparison to normal volunteers. The lower promoter methylation of p15 and p21 genes may be an important mechanism for the dysfunctional growth regulation pathways in HPP-CFCs in psoriasis.

DNA methylation of dermal MSCs in psoriasis: Identification of epigenetically dysregulated genes

BACKGROUNDnMesenchymal stem cells (MSCs) are likely involved in pathological processes of immune-related diseases, including psoriasis, because of their immunoregulatory and pro-angiogenic effects. DNA methylation plays an essential role in regulating gene expression and maintaining cell function.nnnOBJECTIVEnThis study aimed to investigate the gene methylation profile of dermal MSCs from patients with psoriasis.nnnMETHODSnWe isolated and expanded dermal MSCs from psoriatic patients and normal controls using the attachment assay and conducted genome-wide DNA methylation profile and gene ontology analyses using microarray.nnnRESULTSnThe cultured cells were indentified as MSCs by surface marker and differentiation assays. The genome-wide promoter methylation profile of MSCs from psoriatic derma was markedly different from the normal derma derived MSCs. Genes involved in cell communication, surface receptor signaling pathway, cellular response to stimulus, and cell migration were differently methylated. Several aberrantly methylated genes related epidermal proliferation, angiogenesis, and inflammation were found differently expressed in psoriatic patients.nnnCONCLUSIONSnThese results indicated that the MSCs from dermal of psoriasis are probably participant in the pathogenesis and development of psoriasis through an extraordinarily complex mechanism.

Differential cytokine secretion of cultured bone marrow stromal cells from patients with psoriasis and healthy volunteers

Psoriasis is a chronic inflammatory skin disorder associated with a host of immune abnormalities. We have recently proposed that psoriasis is related to aberrant hematopoiesis and hypothesized that aberrant hematopoiesis in psoriasis is due to the differential hematopoietic microenvironment. To investigate whether the hematopoietic microenvironment is altered in patients with psoriasis by comparing the levels of cytokines secreted from BMSCs in patients with psoriasis and those in healthy volunteers, flow cytometry analysis was used to examine the proportion of the positive cells and direct ELISA was used to measure the concentrations of cytokines secreted from BMSCs in patients with psoriasis and healthy volunteers. In comparison with normal controls, BMSCs from patients with psoriasis showed increased secretions of SCF, G-CSF, and IL-6, decreased secretions of IL-1alpha, IL-1beta, IL-3, IL-8, EGF, VEGF, TNF-alpha, LIF, HGF, PDGF and no alteration in the levels of GM-CSF, IL-11, IL-7 and the cell surface markers CD29, CD34, CD45 and HLA-DR. Our data demonstrate for the first time that the hematopoietic microenvironment is altered in patients with psoriasis, suggesting that an aberrant hematopoietic microenvironment may be one mechanism for the pathogenesis of the disease.

Functional characterization of T cells differentiated in vitro from bone marrow‐derived CD34+ cells of psoriatic patients with family history

Please cite this paper as: Functional characterization of T cells differentiated in vitro from bone marrow‐derived CD34+ cells of psoriatic patients with family history. Experimental Dermatology 2010; 19: e128–e135.

Lymphocyte inhibition is compromised in mesenchymal stem cells from psoriatic skin.

BackgroundPsoriasis is a chronic inflammatory skin disorder associated with a host of immune abnormalities. Mesenchymal stem cells (MSCs) have immunosuppressive properties and, in earlier studies, we found that the bone marrow MSCs of patients with psoriasis exhibit abnormal cytokine secretion. Since MSCs can be isolated from skin, we hypothesized that the biological characteristics of MSCs in psoriatic skin lesions might reflect the pathogenesis of psoriasis.ObjectiveTo investigate the effects of MSCs from psoriatic skin lesions on T-cell proliferation.Materials and MethodsMSCs obtained from psoriatic skin lesions and healthy human skin were examined by flow cytometry and cell differentiation assays. MSCs were co-cultured with normal peripheral blood T cells to assess changes in T-cell proliferation. Concentrations of interleukin (IL)-6, IL-11, hepatocyte growth factor (HGF), and transforming growth factor (TGF)-β1 in the MSC culture supernatants were measured by enzyme-linked immunosorbent assays.ResultsSurface markers and differentiation capacity were similar in MSCs from both sources. MSCs in psoriatic skin lesions were weaker inhibitors of T-cell proliferation (p<0.05) and exhibited increased secretion of IL-11 and reduced secretion of IL-6 and HGF (p<0.05). Secretion of TGF-β1 was unchanged (p>0.05).ConclusionThis study demonstrated abnormalities in MSCs derived from psoriatic skin lesions. We suggest that the attenuated inhibitory effect on T-cell proliferation might be one of the pathogenic mechanisms of psoriasis.

Biological characteristics and gene expression pattern of bone marrow mesenchymal stem cells in patients with psoriasis

Mesenchymal stem cells (MSCs) have immunoregulatory and proangiogenic effects and are suggested to be involved in the pathological processes of immune‐related diseases, including psoriasis. Biological characteristics of bone marrow MSCs (BMSCs) from patients with autoimmune diseases, such as systemic lupus erythematosus or rheumatoid arthritis, but not psoriasis, have been characterized. We compared the gene expression profile and biological characteristics of BMSCs from patients with psoriasis and healthy controls. Although the phenotype, differentiation potential and ability to support CD34+ cell proliferation were similar to those of normal BMSCs, psoriatic BMSCs showed aberrant proliferative activity, increased apoptosis rate and a characteristic gene expression profile. These aberrations may develop after the abnormal immune response in psoriasis and result in BMSC dysfunction. The functionally deficient BMSCs may then fail to suppress overactive immune cells, thereby contributing to the pathogenesis of psoriasis.

Differential gene expression in peripheral blood T cells from patients with psoriasis, lichen planus, and atopic dermatitis

BACKGROUNDnPsoriasis, lichen planus (LP), and atopic dermatitis (AD) are common chronic inflammatory skin diseases mediated by immune responses.nnnOBJECTIVEnWe used RNA sequencing to investigate messenger RNA expression patterns in peripheral T cells of Chinese patients with psoriasis, LP, or AD and of healthy individuals.nnnMETHODSnAfter peripheral T-cell proliferation, messenger RNA expression patterns were investigated by RNA sequencing, and 6 randomly selected genes were verified by real-time reverse transcriptase polymerase chain reaction.nnnRESULTSnSix genes were down-regulated and 33 were up-regulated in these diseases. Gene ontology analysis revealed enrichment of genes involved in positive regulation of T-cell activation. Regulation of nuclear premessenger RNA domain containing 1B (RPRD1B) expression was enhanced in psoriasis.nnnLIMITATIONSnThe role of hereditary factors in RPRD1B expression in T cells was not considered. Immunomodulators (thymopeptide, levamisole, BCG polysaccharide, nucleic acid injection, and transfer factor) were previously given to patients with psoriasis and LP, but not to patients with AD; the effects of these immunomodulators on gene expression is uncertain.nnnCONCLUSIONnRPRD1B may be involved in T-cell activation in our Chinese psoriatic cohort, and may play a role in stimulating epidermal hyperproliferation.

Abnormalities in cytokine secretion from mesenchymal stem cells in psoriatic skin lesions

BACKGROUNDnPsoriasis is a chronic inflammatory and proliferative skin disease associated with immune abnormalities. In our preliminary studies, it was found that bone marrow mesenchymal stem cells (BMSCs) were abnormal in patients with psoriasis. Mesenchymal stem cells (MSCs) are not only present in the bone marrow, but can also be separated from the skin.We reasoned that an investigation into the biological characteristics of MSCs in psoriatic skin lesions could more realistically reflect the actual conditions for the pathogenesis of psoriasis.nnnOBJECTIVEnTo reveal whether MSCs in psoriatic skin lesions are abnormal.nnnMETHODSnWe obtained MSCs from psoriatic skin lesions and healthy human skin and identified these cells using flow cytometry and a cell differentiation assay; cytokine concentrations in the culture supernatants were measured with the ELISA assay. We compared cytokine concentrations in culture supernatants of MSCs derived from psoriatic skin lesions as well as those from healthy human skin.nnnRESULTSnCompared with healthy control skintissue, in psoriatic skin lesions, MSC secretion of EGF, SCF, and IL-11 increased; secretion of bFGF, IL-3, IL-6, IL-8, and HGF decreased (p<0.05); and secretion of VEGF, M-CSF, G-CSF, GM-CSF, LIF, IL-1, IL-7, IL-10, and TNF-α showed no significant difference (p>0.05). Surface markers and the differentiation capacity of cells from the two sources were similar.nnnCONCLUSIONnThis study demonstrated that MSCs derived from psoriatic skin lesions had abnormalities, which may be one of the pathogenic mechanisms of psoriasis.

Screening of differentially expressed genes and predominant expression of β variable region of T cell receptor in peripheral T cells of psoriatic patients

UNLABELLEDnPsoriasis is a skin disease featuring epithelial cell hyper-proliferation and T cell infiltration. Abnormal T cell immune responses play an important role in psoriatic pathogenesis. To screen differentially expressed genes in T cells of patients with plaque psoriasis, analyze the predominant expression of the β variable region of T cell receptors and discuss the role of T cells in the pathogenesis of psoriasis. High throughput RNA sequencing and Real-time PCR were used.nnnRESULTSnA total of 907 genes were differentially expressed in peripheral T cells of patients with psoriasis. Among them, 695 genes were mapped to the Gene Ontology database, 14 gene terms were significantly enriched, and 418 genes were involved in signaling pathways such as apoptosis, B cell receptor signaling and T cell receptor signaling. TRBV2, TRBV5-7, TRBV6-6/6-9, TRBV12, TRBV24 and TRBV29 were significantly up-regulated in psoriatic patients compared to healthy subjects, among which, TRBV6-6/6-9, TRBV12 and TRBV29 are predominantly expressed in psoriatic patients. Many genes were differentially expressed in T cells of psoriatic patients, especially the TRBV gene family, which were predominantly expressed in T cells and might play an important role in abnormal immune responses of T cells in psoriatic patients.

Stem cells in psoriasis

Psoriasis is a complex chronic relapsing inflammatory disease. Although the exact mechanism remains unknown, it is commonly accepted that the development of psoriasis is a result of multi-system interactions among the epidermis, dermis, blood vessels, immune system, neuroendocrine system, metabolic system, and hematopoietic system. Many cell types have been confirmed to participate in the pathogenesis of psoriasis. Here, we review the stem cell abnormalities related to psoriasis that have been investigated recently.