Guohua Yin

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

BACKGROUND Mesenchymal 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. OBJECTIVE This study aimed to investigate the gene methylation profile of dermal MSCs from patients with psoriasis. METHODS We 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. RESULTS The 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. CONCLUSIONS These 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.

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

BACKGROUND Psoriasis, lichen planus (LP), and atopic dermatitis (AD) are common chronic inflammatory skin diseases mediated by immune responses. OBJECTIVE We 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. METHODS After 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. RESULTS Six 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. LIMITATIONS The 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. CONCLUSION RPRD1B may be involved in T-cell activation in our Chinese psoriatic cohort, and may play a role in stimulating epidermal hyperproliferation.

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

UNLABELLED Psoriasis 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. RESULTS A 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.

Expression of Notch Receptor and Its Target Gene Hes-1 in Bone Marrow CD34+ Cells from Patients with Psoriasis

Psoriasis is an autoimmune disease mediated mainly by dysfunctional peripheral blood T cells. Both CD4+/CD8+ T cells and CD4+CD25+ regulatory T cells derived from psoriatic CD34+ bone marrow cells in vitro have been found to be functionally similar to those psoriatic circulating and lesional T cells. Notch signaling participates in diverse cell fate decisions during T cell development and has been reported to influence the proliferation of hematopoietic stem cells and the differentiation of T cells. The purpose of this study was to investigate the expression levels of Notch receptor 1, 2 and its target gene Hes-1 in CD34+ cells from patients with psoriasis. The total RNA and protein of CD34+ cells were extracted, and the mRNA as well as protein expression of Notch1, Notch2 and Hes-1 were investigated using real-time PCR and Western blot assays. We found that the mRNA and protein expression levels of Notch1 and Hes-1 in psoriasis patients were higher compared to normal controls, while the Notch2 mRNA and protein expression levels in psoriasis patients were similar to those of normal controls. The elevated Notch1 and Hes-1 expression levels in psoriatic CD34+ cells might be one reason for the immune disorders which are mainly mediated by T cells.

Psoriatic T cells reduce epidermal turnover time and affect cell proliferation contributed from differential gene expression.

Psoriasis is mediated primarily by T cells, which reduce epidermal turnover time and affect keratinocyte proliferation. We aimed to identify differentially expressed genes (DEG) in T cells from normal, five pairs of monozygotic twins concordant or discordant for psoriasis, to determine whether these DEG may account for the influence to epidermal turnover time and keratinocyte proliferation. The impact of T cells on keratinocyte proliferation and epidermal turnover time were investigated separately by immunohistochemistry and cultured with 3H‐TdR. mRNA expression patterns were investigated by RNA sequencing and verified by real‐time reverse transcription polymerase chain reaction. After co‐culture with psoriatic T cells, the expression of Ki‐67, c‐Myc and p53 increased, while expression of Bcl‐2 and epidermal turnover time decreased. There were 14 DEG which were found to participate in the regulation of cell proliferation or differentiation. Psoriatic T cells exhibited the ability to decrease epidermal turnover time and affect keratinocyte proliferation because of the differential expression of PPIL1, HSPH1, SENP3, NUP54, FABP5, PLEKHG3, SLC9A9 and CHCHD4.