UVA1 vs. narrowband UVB phototherapy in the treatment of palmoplantar pustulosis: a pilot randomized controlled study.

UVA1 phototherapy, a new therapeutic approach, has recently been shown good efficacy in the treatment of palmoplantar pustulosis (PPP). The purpose of this study was to compare the efficacy of UVA1 and narrowband UVB (NB-UVB) therapy in the treatment of PPP. Patients with PPP were randomly assigned to either UVA1 or NB-UVB therapy according to a left-right randomization table. Both treatments were performed three times weekly for up to 30 sessions. Clinical evaluation was based on the Palmoplantar Pustular Psoriasis Area and Severity Index (PPPASI) score. Totally 64 patients completed the study. Both UVA1 and NB-UVB therapy showed a statistically significant reduction of PPPASI score compared with the baseline value at the end of the treatment period (P < 0.05). There was a significantly greater mean reduction of PPPASI score in the UVA1 treated group when compared to the NB-UVB treated patients at 30 sessions (6.0 ± 2.4 vs. 4.4 ± 1.4, P < 0.05). No phototoxic reaction or bullous changes were observed in either group. Both NB-UVB and UVA1 phototherapy of PPP resulted in significant improvement. UVA1 phototherapy was more effective than NB-UVB irradiation in the treatment of PPP.

O-GlcNAcylation of the Signaling Scaffold Protein, GNB2L1 Promotes its Degradation and Increases Metastasis of Gastric Tumours.

GNB2L1 is an intercellular scaffold protein of the Trp-Asp (WD) repeat protein family, and has been reported to play suppressive roles in the progression of gastric cancer. However, the regulatory mechanisms of GNB2L1 in gastric cancer still remain largely elusive. In the present study, we found that OGT was capable to interact with GNB2L1 directly and modify GNB2L1 with O-GlcNAcylation in gastric cancer, and this O-GlcNAcylation hindered the inhibition of GNB2L1 on migration of gastric cancer cells. Moreover, O-GlcNAcylation regulated the degradation instead of the synthesis of GNB2L1 in gastric cancer, and our data suggested the O-GlcNAcylation on GNB2L1 influenced its stability directly. In addition, the clinical data revealed the negative correlation of the protein level instead of the mRNA level of GNB2L1 with OGT expression, and showed that OGT reversed the inhibition of GNB2L1 on metastasis, and worsened the prognosis of GNB2L1(High) patients. In summary, this study indicated the O-GlcNAcylation on GNB2L1 reversed its inhibition on gastric tumour metastasis via promoting its degradation.

PHD finger protein 2 (PHF2) represses ribosomal RNA gene transcription by antagonizing PHF finger protein 8 (PHF8) and recruiting methyltransferase SUV39H1.

Regulation of rDNA transcription is central to cell growth and proliferation. PHF2 and PHF8 belong to a subfamily of histone demethylases that also possess a PHD domain-dependent di-/trimethylated histone 3 lysine 4 (H3K4me2/3) binding activity and are known to be enriched in the nucleolus. In this study, we show that, unlike PHF8 that activates rDNA transcription, PHF2 inhibits rDNA transcription. Depletion of PHF2 by RNA interference increases and overexpression of PHF2 decreases rDNA transcription, respectively, whereas simultaneous depletion of PHF8 and PHF2 restores the level of rDNA transcription. The inhibition of rDNA transcription by PHF2 depends on its H3K4me2/3 binding activity that is also required for PHF2 association with the promoter of rDNA genes but not its demethylase activity. We provide evidence that PHF2 is likely to repress rDNA transcription by competing with PHF8 for binding of rDNA promoter and by recruiting H3K9me2/3 methyltransferase SUV39H1. We also provide evidence that, whereas PHF8 promotes, PHF2 represses the transcriptional activity of RARα, Oct4, and KLF4 and a few PHF8 target genes tested. Taken together, our study demonstrates a repressive role for PHF2 in transcription by RNA polymerase I and II.

Exendin-4 promotes proliferation of adipose-derived stem cells through PI3K/Akt-Wnt signaling pathways.

Adipose-derived stem cell (ADSC) transplantation has emerged as a potential tool for the treatment of cardiovascular disease and skin wounds. However, with a limited renewal capacity and the need for mass cells during the engraftment, strategies are needed to enhance ADSC proliferative capacity. In this study, we explored the effects of Exendin-4, a glucagon-like peptide-1 analog, on the growth of ADSCs, focusing in particular on phosphatidylinositol 3-kinase (PI3K)-protein kinase B (Akt) and Wnt signaling pathways. Firstly, ADSCs were isolated and cultured in vitro. Then, flow cytometry demonstrated that ADSCs were positive for CD44, CD90 and CD29 but negative for CD31, CD34, and CD45. Exendin-4 (0-200 nM) treatment increased ADSC proliferation. In order to examine specific signaling pathways, a western blotting assay was performed. Our results demonstrate that after treated with 50 nM Exendin-4 for 48 h, the phosphorylation of PI3K, Akt, and GSK3ß were increased and phosphorylation of ß-catenin was decreased. From these results, we concluded that PI3K-Akt and Wnt-ß-catenin signaling pathways mediate Exendin-4 induced ADSC proliferation, the function of which might contribute to the regulation of ADSC proliferation. Our findings provided new insights into the function of the mechanisms underlying Exendin-4 of ADSCs.

Human adipose tissue-derived stem cells inhibit the activity of keloid fibroblasts and fibrosis in a keloid model by paracrine signaling.

BACKGROUND: Human adipose tissue-derived mesenchymal stem cells (ASCs) have potential utility as modulators of the regeneration of tissue that is inflamed or scarred secondary to injuries such as burns or trauma. However, the effect of ASCs on one particular type of scarring, keloidal disease, remains unknown. The absence of an optimal model for investigation has hindered the development of an effective therapy using ASCs for keloids. OBJECTIVE: To investigate the influence of ASCs on angiogenesis, extracellular matrix deposition, and inflammatory cell influx in keloids. METHODS: We analyzed the proliferation, migration, and apoptosis of human keloid-derived fibroblasts treated with a starvation-induced, conditioned medium from ASCs (ASCs-CM). This was achieved by Brdu proliferation assay, a validated co-culture migration assay, and flow cytometry, respectively. To assess the change in phenotype to a pro-fibrotic state, fibroblasts were analyzed by real-time PCR and contraction assay. A keloid implantation animal model was used to assess the paracrine effect of ASCs histochemically and immunohistochemically on scar morphology, collagen deposition, inflammatory cell composition, and blood vessel density. In tandem, an antibody-based array was used to identify protein concentration in the presence of ASCs-CM at time point 0, 24, and 48h. RESULTS: ASCs-CM inhibited the proliferation and collagen synthesis of human keloid-derived fibroblasts. ASCs-CM was associated with reduced inflammation and fibrosis in the keloid implantation model. Thirty-four cytokines were differentially regulated by ASCs-CM at 24h. These included molecules associated with apoptosis, matrix metalloproteases, and their inhibitors. The same molecules were present at relatively higher concentrations at the 48h timepoint. CONCLUSION: These results suggest that ASCs are associated with the inhibition of fibrosis in keloids by a paracrine effect. This phenomenon may have utility as a therapeutic approach in the clinical environment.

SUMO suppresses and MYC amplifies transcription globally by regulating CDK9 sumoylation.

Regulation of transcription is fundamental to the control of cellular gene expression and function. Although recent studies have revealed a role for the oncoprotein MYC in amplifying global transcription, little is known as to how the global transcription is suppressed. Here we report that SUMO and MYC mediate opposite effects upon global transcription by controlling the level of CDK9 sumoylation. On one hand, SUMO suppresses global transcription via sumoylation of CDK9, the catalytic subunit of P-TEFb kinase essential for productive transcriptional elongation. On the other hand, MYC amplifies global transcription by antagonizing CDK9 sumoylation. Sumoylation of CDK9 blocks its interaction with Cyclin T1 and thus the formation of active P-TEFb complex. Transcription profiling analyses reveal that SUMO represses global transcription, particularly of moderately to highly expressed genes and by generating a sumoylation-resistant CDK9 mutant, we confirm that sumoylation of CDK9 inhibits global transcription. Together, our data reveal that SUMO and MYC oppositely control global gene expression by regulating the dynamic sumoylation and desumoylation of CDK9.

GNB2L1 and its O-GlcNAcylation regulates metastasis via modulating epithelial-mesenchymal transition in the chemoresistance of gastric cancer.

GNB2L1 and its O-GlcNAcylation has been reported to play roles in gastric cancer metastasis. However, the roles of GNB2L1 in chemoresistance of gastric cancer has never been determined. In the present study, we found that GNB2L1 was downregulated in chemoresistant patients of gastric cancer, and observed the decrease of GNB2L1 in protein levels instead of mRNA levels in different chemoresistant gastric cancer cell lines. Further we proved that this downregulation of GNB2L1 was resulted from its elevated O-GlcNAcylation catalyzed by OGT in both cell lines and patients. Next, we investigate the function of GNB2L1 and its O-GlcNAcylation on gastric cancer metastasis during chemoresistance, and confirmed Ser124 as the major O-GlcNAcylation site on GNB2L1 that regulated its function on metastasis. Furthermore, our data demonstrated that GNB2L1 modulated EMT via regulating the translation of EMT-related proteins in the process of chemoresistance. In summary, this study indicated that GNB2L1 and its O-GlcNAcylation regulated metastasis via modulating the translation of EMT-related proteins in the chemoresistance of gastric cancer.

Common genetic heterogeneity of human interleukin-37 leads to functional variance.

Interleukin-37 (IL-37) is an inhibitory member of the IL-1 family of cytokines. We previously found that balanced selection maintains common variations of the human IL37 gene. However, the functional consequences of this selection have yet to be validated. Here, using cells expressing exogenous IL-37 variants, including IL-37 Ref and IL-37 Var1 and Var2, we found that the three variants of IL-37 exhibited different immunoregulatory potencies in response to immune stimulation. The protein level of IL-37 Var2 was found to be significantly less than that of IL-37 Ref or Var1, despite the comparable mRNA levels of all three variants. Further study showed that IL-37 Var2 was rapidly degraded by a proteasome-dependent mechanism mediated by enhanced polyubiquitination, leading to a transient upregulation of IL-37 Var2 after immune stimulation. Finally, when ectopically expressed in cells, human IL-37 Var2 exerted less inhibition on proinflammatory cytokine production than did other IL-37 variants. Conversely, purified extracellular IL-37 variant proteins demonstrated comparable inhibitory abilities in vitro. In conclusion, our study reveals that common genetic variants of IL37 lead to different immune-inhibitory potencies, primarily as a result of differences in IL-37 protein stability, suggesting the possible involvement of these variants in various human diseases.

Interleukin-37 gene variants segregated anciently coexist during hominid evolution.

IL37 is a member of IL-1 cytokine family but conveys anti-inflammatory functions. The biological characteristic and genetic heterogeneity of IL37 are not fully understood yet. Here using the whole-genome sequencing data from 1000 Genomes Project, we performed population and evolutionary genetic analysis of human IL37 gene. First, 2184 IL37 gene sequences from different human populations were retrieved. The IL37 protein sequences were inferred from the coding DNA sequences and multiple species alignment was made. Then, the phylogenetic tree of IL37 was built and dN/dS ratios were calculated for each evolutionary branch, the classic McDonald and Kreitman test was also performed. Next, we conducted intraspecific evolutionary genetic analysis and built the genealogy network of 116 unique IL37 haplotypes through median-joining network analysis. Finally, we compared IL37 sequences between the modern and archaic humans. Our results for the first time provide solid evidence that common IL37 variants other than NCBI reference sequence are present worldwide. Our data also supports that IL37 variants are shaped and maintained by selection instead of neutral evolution. We further identified that human IL37 variants consist of two major haplogroups and their presence in archaic humans corroborates its ancient origin in hominid evolution. In conclusion, these data indicate that common IL37 variants are maintained among human populations by selective force, suggesting their potential involvements in immune regulation and human diseases. In addition, the ancient history of IL37 variants reveals interesting insight into the complicated human evolutionary history.