UVB Induces HIF-1α-Dependent TSLP Expression via the JNK and ERK Pathways

Thymic stromal lymphopoietin (TSLP) may have a key role in the initiation and maintenance of allergic inflammatory diseases, including atopic dermatitis. The present study revealed that UVB radiation exposure could induce TSLP expression in human keratinocytes and a human skin equivalent model. In addition, we investigated the regulatory mechanism of UVB-induced TSLP expression in keratinocytes. TSLP expression was upregulated by transfection with pcDNA3–hypoxia-inducible factor (HIF)-1α (P402A and P564A), which stably expresses HIF-1α protein. UVB-induced TSLP induction in keratinocytes was suppressed in the treatment of mitogen-activated protein kinase inhibitors or small interfering RNAs against HIF-1α. The results of chromatin immunoprecipitation assays indicate the direct involvement of HIF-1α in UVB-mediated TSLP induction. Taken together, these findings indicate that UVB exposure may increase TSLP expression through a HIF-1α-dependent mechanism via the c-JUN N-terminal kinase and extracellular signal-regulated kinase pathways in human keratinocytes. Our data showed that UVB-induced TSLP might increase secretion of the T-helper type 2–attracting chemokine (c–c motif) ligand 17 by human dendritic cells. The present study suggests an important role of HIF-1α in UVB-mediated immune response in keratinocytes

CD24 induced cellular quiescence-like state and chemoresistance in ovarian cancer cells via miR-130a/301a-dependent CDK19 downregulation

Abstract Cancer stem-like cell (CSC) is thought to be responsible for ovarian cancer recurrence. CD24 serves as a CSC marker for ovarian cancer and regulates the expression of miRNAs, which are regulators of CSC phenotypes. Therefore, CD24-regulated miRNAs may play roles in manifesting the CSC phenotypes in ovarian cancer cells. Our miRNA transcriptome analysis showed that 94 miRNAs were up or down-regulated in a CD24-high clone from an ovarian cancer patient compared to a CD24-low one. The CD24-dependent expression trend of the top 7 upregulated miRNAs (miR-199a-3p, 34c, 199a-5p, 130a, 301a, 214, 34b*) was confirmed in other 8 clones (4 clones for each group). CD24 overexpression upregulated the expression of miR-199a-3p, 34c, 199a-5p, 130a, 301a, 214, and 34b* in TOV112D (CD24-low) cells compared to the control, while CD24 knockdown downregulated the expression of miR-199a-3p, 199a-5p, 130a, 301a, and 34b* in OV90 (CD24-high) cells. miR-130a and 301a targeted CDK19, which induced a cellular quiescence-like state (increased G0/G1 phase cell population, decreased cell proliferation, decreased colony formation, and decreased RNA synthesis) and resistance to platinum-based chemotherapeutic agents. CD24 regulated the expression of miR-130a and 301a via STAT4 and YY1 phosphorylation mediated by Src and FAK. miR-130a and 301a were positively correlated in expression with CD24 in ovarian cancer patient tissues and negatively correlated with CDK19. Our results showed that CD24 expression may induce a cellular quiescence-like state and resistance to platinum-based chemotherapeutic agents in ovarian cancer via miR-130a and 301a upregulation. CD24-miR-130a/301a-CDK19 signaling axis could be a prognostic marker for or a potential therapeutic target against ovarian cancer recurrence

Different Chondrogenic Potential among Human Induced Pluripotent Stem Cells from Diverse Origin Primary Cells

Scientists have tried to reprogram various origins of primary cells into human induced pluripotent stem cells (hiPSCs). Every somatic cell can theoretically become a hiPSC and give rise to targeted cells of the human body. However, there have been debates on the controversy about the differentiation propensity according to the origin of primary cells. We reprogrammed hiPSCs from four different types of primary cells such as dermal fibroblasts (DF, n=3), peripheral blood mononuclear cells (PBMC, n=3), cord blood mononuclear cells (CBMC, n=3), and osteoarthritis fibroblast-like synoviocytes (OAFLS, n=3). Established hiPSCs were differentiated into chondrogenic pellets. All told, cartilage-specific markers tended to express more by the order of CBMC > DF > PBMC > FLS. Origin of primary cells may influence the reprogramming and differentiation thereafter. In the context of chondrogenic propensity, CBMC-derived hiPSCs can be a fairly good candidate cell source for cartilage regeneration. The differentiation of hiPSCs into chondrocytes may help develop “cartilage in a dish” in the future. Also, the ideal cell source of hiPSC for chondrogenesis may contribute to future application as well

Intraperitoneal infusion of mesenchymal stem cell attenuates severity of collagen antibody induced arthritis

<div><p>It is unclear how systemic administration of mesenchymal stem cells (MSCs) controls local inflammation. The aim of this study was to evaluate the therapeutic effects of human MSCs on inflammatory arthritis and to identify the underlying mechanisms. Mice with collagen antibody-induced arthritis (CAIA) received two intraperitoneal injections of human bone marrow-derived MSCs. The clinical and histological features of injected CAIA were then compared with those of non-injected mice. The effect of MSCs on induction of regulatory T cells was examined both <i>in vitro</i> and <i>in vivo</i>. We also examined multiple cytokines secreted by peritoneal mononuclear cells, along with migration of MSCs in the presence of stromal cell-derived factor-1 alpha (SDF-1α) and/or regulated on activation, normal T cell expressed and secreted (RANTES). Sections of CAIA mouse joints and spleen were stained for human anti-nuclear antibodies (ANAs) to confirm migration of injected human MSCs. The results showed that MSCs alleviated the clinical and histological signs of synovitis in CAIA mice. Peritoneal lavage cells from mice treated with MSCs expressed higher levels of SDF-1α and RANTES than those from mice not treated with MSCs. MSC migration was more prevalent in the presence of SDF-1α and/or RANTES. MSCs induced CD4+ T cells to differentiate into regulatory T cells <i>in vitro</i>, and expression of FOXP3 mRNA was upregulated in the forepaws of MSC-treated CAIA mice. Synovial and splenic tissues from CAIA mice receiving human MSCs were positive for human ANA, suggesting recruitment of MSCs. Taken together, these results suggest that MSCs migrate into inflamed tissues and directly induce the differentiation of CD4+ T cells into regulatory T cells, which then suppress inflammation. Thus, systemic administration of MSCs may be a therapeutic option for rheumatoid arthritis.</p></div

Intraperitoneal infusion of mesenchymal stem cell attenuates severity of collagen antibody induced arthritis - Fig 2

<p>MSCs migrated to inflamed paws and regulated mouse FOXP3 and IL-17 mRNA expression (A) The joints of CAIA mice were stained with human anti-nuclear antibodies (ANAs) to confirm the presence of human MSCs. Expression of (B) mouse FOXP3 mRNA and (C) IL-17 in forepaws of mice from each group. To evaluate <i>in vivo</i> expression of mFOXP3 and mIL-17, mRNA was extracted from the homogenized forepaws of CAIA mice from each group. Data are expressed as the mean ± SEM. ** <i>p</i> < 0.01; *** <i>p</i> < 0.001.</p

MSCs migrate to the spleen of CAIA mice.

<p>(A) Splenic tissues were stained with antibodies specific for mouse FOXP3 to detect FOXP3+ Treg cells. Images of FOXP3+ cells and human ANA+ cells were merged to evaluate the spatial relationship between MSCs and Treg cells. The original magnification is shown in the right panel of each figure. Flow cytometry analysis of CD4+ T cells isolated from splenocytes of control CAIA mice cultured under (B) Treg and (C) Th17 differentiation conditions. Representative images and percentages of each cell types are shown are shown in the graph on the right.</p

Treatment with MSCs alleviates inflammatory arthritis in mice.

<p>(A) Time schedule for induction of CAIA and treatment with MSCs. CAIA mice received two intraperitoneal injections of MSCs (5 × 10⁶ cells each), with a 3-day interval in between. (B) Clinical photographs of the hind paws of wild-type DBA/1J (WT) mice, control CAIA mice (CAIA), and CAIA mice treated with MSCs (CAIA+MSC) at Day 14. (C) Clinical severity of CAIA in each group after injection of a collagen antibody cocktail. Arthritis severity in each paw was scored from 0 (no swelling) to 4 (erythema and severe swelling of entire tarsal joint) and expressed as the mean of the sum of three paws (0–12) ± the standard error of the mean (SEM). (D) Histologic analysis of hind paws from each group at Day 14. Tarsal joints were stained with haematoxylin and eosin (H&E), safranin O, and toluidine blue. Synovial inflammation and bone erosion were evaluated on a scale from 0 to 3. The histological score was expressed as the mean of the scores determined by three independent examiners (± SEM). *** <i>p</i> < 0.001.</p