Downregulation of Ebp1Khib210 promotes keratinocyte proliferation through induction of TIF-IA-mediated rRNA synthesis.

BACKGROUND: Psoriasis is a prevalent chronic inflammatory dermatosis characterized by excessive proliferation of keratinocytes. Protein lysine 2-hydroxyisobutyrylation (Khib) is a newly identified post-translational modification that regulates various biological processes. Abnormal Khib modification has been closely associated with the development of autoimmune diseases. OBJECTIVE: To investigate the abnormal Khib profile and its pathogenic role in psoriasis. METHODS: We utilized liquid chromatography-tandem mass spectrometry to analyze Khib-modified proteins in the epidermis of psoriasis and healthy controls. Mutated cells and mice with downregulated Ebp1Khib210 were generated to investigate its functional effects in psoriasis. RESULTS: The omic analysis revealed dysregulation of Khib modification in psoriatic lesions, exhibiting a distinct profile compared to controls. We observed the downregulation of Ebp1Khib210 in psoriatic lesions and IMQ-induced psoriatic mice. Notably, the expression of Ebp1Khib210 was upregulated in psoriatic patients following effective treatment. Decreased Ebp1Khib210 enhanced keratinocyte viability, proliferation, and survival while inhibiting apoptosis in vitro. Additionally, Pa2g4K210A mice with downregulated Ebp1Khib210 exhibited more severe psoriatic lesions and enhanced keratinocyte proliferation. Moreover, we found that Ebp1K210A mutation increased the interaction between Ebp1 and nuclear Akt, thereby inhibiting MDM2-mediated TIF-IA ubiquitination, and resulting to increased rRNA synthesis and keratinocyte proliferation. The downregulation of Ebp1Khib210 was attributed to inflammation-induced increases in HDAC2 expression. CONCLUSION: Our findings demonstrate that downregulation of Ebp1Khib210 promotes keratinocyte proliferation through modulation of Akt signaling and TIF-IA-mediated rRNA synthesis. These insights into Khib modification provide a better understanding of the pathogenesis of psoriasis and suggest potential therapeutic targets.

The structure and function of multifunctional protein ErbB3 binding protein 1 (Ebp1) and its role in diseases.

ErbB3-binding protein 1(Ebp1) has two isoforms, p42 Ebp1 and p48 Ebp1, both of which can regulate cell growth and differentiation. But these isoforms often have opposite effects, including contradictory roles in regulation of cell growth in different tissues and cells. P48 Ebp1 belongs to the full-length sequence, while conformational changes in the crystal structure of p42 Ebp1 reveals a lack of an α helix at the amino terminus. Due to the differences in the structures of these two isoforms, they have different binding partners and protein modifications. Ebp1 can function as both an oncogene and a tumor suppressor factor. However, the underlying mechanisms by which these two isoforms exert opposite functions are still not fully understood. In this review, we summarize the genes and the structures of protein of these two isoforms, protein modifications, binding partners and the association of different isoforms with diseases.

The effects of human dermal-derived mesenchymal stem cells on the keratinocyte proliferation and apoptosis in psoriasis.

Psoriasis is a common chronic inflammatory skin disease, characterized by epidermal hyperproliferation. Mesenchymal stem cells (MSCs) regulate inflammation and vascular proliferation in the psoriasis lesions. Whether dermal-derived mesenchymal stem cells (DMSCs), the main MSCs in the dermis, regulate keratinocyte proliferation and apoptosis remains unknown. In the present study, we assessed the proliferation and apoptosis of keratinocytes cocultured with DMSCs isolated from either normal or psoriatic involved skin. Cell growth and apoptotic rates were determined using Cell Count Kit-8 and annexin V-FITC staining, respectively. In addition, EDU kit was also used to measure the rate of keratinocyte proliferation. Our results showed that psoriatic DMSCs (pDMSCs) were more potent than normal DMSCs (nDMSCs) in stimulating keratinocyte proliferation. In contrast, the apoptotic rate and expression levels of caspase-3 protein were lower in pDMSC-treated than nDMSC-treated keratinocytes (p < 0.001). Moreover, significantly higher contents of IL-6, IL-8, TNF-α and IFN-γ were found in the culture medium of pDMSCs than in that of nDMSCs. In conclusion, pDMSCs were more potent than nDMSCs in stimulation of keratinocyte proliferation and secretion of proinflammatory cytokines, but weaker in promoting apoptosis.

The regulation of dermal mesenchymal stem cells on keratinocytes apoptosis.

Dermal mesenchymal stem cells (DMSCs) are progenitor cells with the capacity of self-renewal, multilineage differentiation, and immunomodulation, which were reported to induce the proliferation of keratinocytes, however the regulation on keratinocytes apoptosis was unknown. In this study, we isolated DMSCs from normal skin and co-cultured with keratinocytes, and then detected apoptosis of keratinocytes by flow cytometry and expression of apoptosis associated proteins by western blot. The mRNA expression profile of normal DMSCs was investigated by RNA sequencing. The results of our study presented that the DMSCs promoted HaCaT cells apoptosis both in early apoptotic state (13.8 vs. 2.9, p < 0.05) and late apoptotic state (4.2 vs. 0.7, p < 0.05). The expression of apoptosis associated proteins caspase-3 (3.51 vs. 1.99, p < 0.05) and lymphoid enhancer-binding factor 1 (3.10 vs. 0.83, p < 0.05) were upregulated. However, the cell cycle protein cyclin E1 was similar (9.38 vs. 9.05, p > 0.05). Moreover, 33 genes with the function of induced cell apoptosis were highly expressed in DMSCs, including insulin-like growth factor-binding protein 4 (2828.13), IGFBP7 (1805.69), cathepsin D (1694.34), cathepsin B (CTSB, 1641.40) and dickkopf WNT signaling pathway inhibitor 1 (DKK1, 384.79). This study suggested DMSCs induce the apoptosis of keratinocytes through non-G1/S phase blockade via highly expression of apoptosis inducer.

Multi-omics study in monozygotic twins confirm the contribution of de novo mutation to psoriasis.

BACKGROUND: Genome-wide association studies have identified over 120 risk loci for psoriasis. However, most of the variations are located in non-coding region with high frequency and small effect size. Pathogenetic variants are rarely reported except HLA-C*0602 with the odds ratio being approximately 4.0 in Chinese population. Although rare variations still account for a small proportion of phenotypic variances in complex diseases, their effect on phenotypes is large. Recently, more and more studies focus on the low-frequency functional variants and have achieved a certain amount of success. METHOD: Whole genome sequencing and sanger sequencing was performed on 8 MZ twin pairs discordant for psoriasis to scan and verified the de novo mutations (DNMs). Additionally, 665 individuals with about 20 years' medical history versus 2054 healthy controls and two published large population studies which had about 8 years' medical history (including 10,727 cases versus 10,582 controls) were applied to validate the enrichment of rare damaging mutations in two DNMs genes. Besides, to verify the pathogenicity of candidate DNM in C3, RNA-sequencing for CD4+, CD8+ T cells of twins and lesion, non-lesion skin of psoriasis patients were carried out. Meanwhile, the enzyme-linked immunosorbent assay kit was used to detect the level of C3, C3b in the supernatant of peripheral blood. RESULT: A total of 27 DNMs between co-twins were identified. We found six of eight twins carry HLA-C∗0602 allele which have large effects on psoriasis. And it is interesting that a missense mutation in SPRED1 and a splice region mutation in C3 are found in the psoriasis individuals in the other two MZ twin pairs without carrying HLA-C*0602 allele. In the replication stage, we found 2 loss-of-function (LOF) variants of C3 only in 665 cases with about 20 years' medical history and gene-wise analysis in 665 cases and 2054 controls showed that the rare missense mutations in C3 were enriched in cases (OR = 1.91, P = 0.0028). We further scanned the LOF mutations of C3 in two published studies (about 8 years' medical history), and found one LOF mutation in the case without carrying HLA-C*0602. In the individual with DNM in C3, RNA sequencing showed the expression level of C3 in skin was significant higher than healthy samples in public database (TPM fold change = 1.40, P = 0.000181) and ELISA showed protein C3 in peripheral blood was higher (~2.2-fold difference) than the other samples of twins without DNM in C3. CONCLUSION: To the best of our knowledge, this is the first report that DNM in C3 is the likely pathological mutations, and it provided a better understanding of the genetic etiology of psoriasis and additional treatments for this disease.

Cross-sectional study reveals that HLA-C*07:02 is a potential biomarker of early onset/lesion severity of psoriasis.

Psoriasis is a common chronic autoimmune skin disease, with T cells playing a predominant role in its pathogenesis. Here, we aimed to investigate the relation of T-cell repertoires (TCR) and major histocompatibility complex (MHC) in psoriatic patients to further understand mechanisms in disease pathogenesis. We conducted a cross-sectional study involving nine pairs of monozygotic twins with inconsistent psoriasis and examined the TCR diversity and MHC haplotype of the individuals using multiple-PCR and high-throughput sequencing. Additionally, 665 psoriatic patients were applied to validate the relation of human leucocyte antigen (HLA) class I allele HLA-C*07:02 and early onset or lesion severity of psoriasis. The immune diversity was lower in psoriatic patients compared with unaffected individuals within the twin pairs, although the difference was not significant. The clonotypes of TCR significantly decreased in psoriatic patients with high PASI score and early onset. HLA-C*07:02, a haplotype associated with psoriasis, was positively correlated with the diversity of the TCRV gene. Moreover, HLA-C*07:02 clustered in patients with high PASI and early onset. In the replication stage, we found that the PASI and onset age in psoriasis with HLA-C*07:02 were significantly different from those without HLA-C*07:02 and without HLA-C*06:02. Our observations indicate that HLA-C*07:02 is positively correlated with the diversity of TCRV gene in psoriasis and maybe a potential biomarker of early onset/severe lesions of psoriasis.

Psoriatic Dermal-derived Mesenchymal Stem Cells Reduce Keratinocyte Junctions, and Increase Glycolysis.

Although it is known that psoriatic dermal-derived mesenchymal stem cells (DMSCs) dysregulate keratinocyte proliferation, the biological activity profile of keratinocytes influenced by psoriatic DMSCs remain unknown. In the present study, we assessed the impact of psoriatic DMSCs on keratinocyte proliferation, differentiation, and glucose metabolism in normal human epidermal keratinocytes co-cultured with or without psoriatic DMSCs. Co-culture of normal human epidermal keratinocytes with psoriatic DMSCs downregulated expression levels of proteins associated with cell junction assembly (alpha-actinin-1, catenin beta-1, poliovirus receptor-related protein 4 and procollagen-lysine, 2-oxoglutarate 5-dioxygenase 2), while upregulating proteins associated with keratinocyte proliferation and differentiation (involucrin, isoform 2 of Histone-binding protein, isoform 3 of Telomeric repeat-binding factor 2 and keratin 13). Moreover, co-culture of normal human epidermal keratinocytes with psoriatic DMSCs stimulated keratinocyte proliferation and glycolysis, but reduced keratinocyte junctions. Taken together, these results demonstrate that psoriatic DMSCs increase keratinocyte proliferation and glycolysis, and reduce cell junctions, suggesting a pathogenic role of psoriatic DMSCs in epidermal hyperplasia, aberrant differentiation, and reduction in turnover time of keratinocytes in psoriasis.

Different epigenome regulation and transcriptome expression of CD4+ and CD8+ T cells from monozygotic twins discordant for psoriasis.

OBJECTIVES: Psoriasis is an immunodeficient skin disorder, and its exact pathogenesis is unclear. Monozygotic twins are presumed to be genetically identical, and their phenotypic differences may be due to transcriptional regulation or epigenome factors. To explain the inconsistency between twins, we have collected 3 pairs of monozygotic twins who are discordant for psoriasis. METHODS: Reduced representation of bisulfite sequencing and RNA sequencing was conducted using the peripheral blood of the twins to find the genes playing important roles in psoriasis pathogenesis. RESULTS: As a result, we found methylation diversity in four genes (MAST3, MTOR, PM20D1 and ZNF99), and we also found 9 differentially expressed genes (PPAN-P2RY11, PIGV, RPS18, TMEM121, KIF21A, KCNH2, WNT10B, PRX and CDH24) by RNA sequencing. According to the conjoint analysis of methylation and the mRNA results, PTPN6, CCL5, NFATC1 and PRF1 were found to be closely related to psoriasis. We then annotated the genes to explore the associations between these genes and psoriasis. CONCLUSIONS: These findings provide a better understanding of psoriasis that can improve the diagnosis and treatment of the disease.

Comparison of two commonly used methods for stimulating T cells.

OBJECTIVE: Although several methods have been reported and used for in vitro T cell amplification, there are no consistent reports on the optimal stimulation conditions and the characterization of these stimulated T cells. The current study aimed to determine the optimal conditions for efficient T cell amplification by two commonly used methods involving CD3/CD28 antibody and phytohemagglutinin (PHA), respectively. RESULTS: Orthogonal design and CCK8 assay showed that 5 µg/mL CD3, 5 µg/mL CD28, and 100 ng/mL IL2 for the first method and 50 µg/mL PHA for the second method was optimal for T cell stimulation. Flow cytometry demonstrated that the percentage of CD8+ in the stimulated groups significantly increased, while the percentage of CD4+/CD8+ was significantly decreased compared with the unstimulated group. The percentage of CD4+ showed no significant difference among the three groups. Notably, there was no significant difference between the two stimulated groups. In addition, the percentage of apoptotic cells was significantly increased in the stimulated groups compared with the unstimulated group, but showed no remarkable difference between the PHA and CD3/CD28 stimulation groups. Glycolysis analysis showed that the glycolytic capacity and glycolytic reserve were both significantly increased in the PHA and CD3/CD28 groups compared with the unstimulated group, with no significant difference noted between the stimulated groups. CONCLUSIONS: Although both stimulation methods showed similar efficacies, we suggest the PHA method might be better considering its easy application and cost-effective nature.

The mRNA Expression Profile of Psoriatic Lesion Distinct from Non-Lesion.

Purpose: Psoriasis is a chronic recurring autoimmune skin disease with a complex etiology and chronic progression; however, its molecular mechanisms remain unclear. Patients and Methods: We performed transcriptomic analysis to profile the mRNA expression of psoriatic lesions (PL) and non-lesion (NL) tissues from psoriasis patients along with normal skin from healthy donors. RT-qPCR was used to validate the mRNA expression profiles. Results: A total of 237 differentially expressed genes were screened and identified by RNA sequencing. GO and KEGG analysis indicated that these DEGs were enriched in the PPAR signaling pathway and intermediate filament cytoskeleton. For PPAR signaling pathway, the expression of five genes, including ADIPOQ, AQP7, PLIN1, FABP4 and LPL, were all significantly decreased in psoriatic lesions compared to normal skin by RT-qPCR. There is a clear difference between psoriatic lesions and non-lesion in the expression of ADIPOQ, AQP7 and LPL. For intermediate filament cytoskeleton, including KRT27, KRT25, KRT71, KRT86 and KRT85 were significantly decreased in the psoriasis lesions, showing agreement with the RNA-seq data. Conclusion: This study revealed a significant difference between the mRNA expression profiles of PL, NL tissue and normal skin.

Variants in PRKCE and KLC1, Potential Regulators of Type I Psoriasis.

Purpose: Psoriasis is a multifactorial disease with a complex genetic predisposition. The pathophysiology of psoriasis is associated with genetic variants. To better characterize gene variants in psoriasis and identify the relationship between clinical characteristics and variant genes in its pathogenesis. Patients and Methods: DNA was extracted and purified from eight pairs of monozygotic twins with psoriasis discordance and 282 type I psoriasis patients. Thirteen variable genes were amplified and sequenced using the Sanger method after whole genome sequencing. Results: Thirteen genes were found to be variable in eight pairs of monozygotic twins with psoriasis discordance. Among the 13 genes, the variant frequencies of protein kinase C epsilon (PRKCE) (c.240T>C, 35.9% vs 47.7%, P < 0.05) and kinesin light chain 1 (KLC1) (c.216A>G, 2.9% vs 98.1%, P< 0.01) were significantly lower in psoriasis than in normal Asian individuals. Additionally, we found considerable differences in the relationship between variants in genes CADM2, JPH2, SPTLC3 and clinical characteristics stratified by medical history and family history. Moreover, the variants in MEGF6 (39.52% vs 22.50%, χ 2=3.83, p < 0.05) showed a stronger association with the mild group (PASI ≤10) than the heavy group. Conclusion: Our results provide a comprehensive correlation analysis of regulatory genes that are regulated in psoriasis. This integrated analysis offers novel insight into the pathogenic mechanisms involved in psoriasis.

Psoriatic Dermal-Derived Mesenchymal Stem Cells Induced C3 Expression in Keratinocytes.

Purpose: Our recent studies found a splice region mutation in C3 accompanied by a significantly increased C3 in psoriatic peripheral blood. Mesenchymal stem cells (MSCs) are a key immunological suppression cell. We further investigate the regulation of MSCs on C3 in psoriasis. Patients and Methods: We analyzed the C3 and its upstream S100A9, S100A8 and downstream MCP1 in psoriatic and control skin, and in normal human epidermal keratinocytes (NHEKs) co-cultured with psoriatic versus control dermal-derived mesenchymal stem cells (DMSCs) by mRNA, iTRAQ (isobaric tags for relative and absolute quantitative) and simple Western analysis. Results: The mRNA and Simple Western analysis showed that the expression of C3, S100A8 and S100A9 are upregulated in psoriatic lesion (C3: mRNA, 9.23-fold, p = 0.0092; protein, 3.56-fold, p = 0.0244. S100A8: mRNA, 28.35-fold, p = 0.0015; protein, 4.68-fold, p = 0.0215. S100A9: mRNA, 79.45-fold, p = 0.0066; protein, 12.42-fold, p > 0.05). Moreover, the iTRAQ showed that C3 and S100A9 were significantly increased in NHEKs after co-cultured with psoriatic DMSCs compared to that of control DMSCs (C3: 3.40-fold, p = 0, FDR = 0; S100A9: 2.30-fold, p = 9.86E-241, FDR = 6.50E-239), verified by Simple Western. However, the expression of S100A8 and MCP1 was slightly different between the two groups. Conclusion: Our results suggest that psoriatic DMSCs contribute to the increased C3 expression in psoriatic lesion via upregulating S100A9, providing the theoretical basis for the role of C3 and DMSCs in the pathogenesis of psoriasis.

Normal mesenchymal stem cells can improve the abnormal function of T cells in psoriasis via upregulating transforming growth factor-ß receptor.

Psoriasis, a chronic inflammatory skin disease, is a refractory disorder. Previous studies have shown that the imbalance of the T-helper (Th)17/regulatory T cells (Treg) results in the immune imbalance of T cells in psoriatic patients, and that mesenchymal stem cells display an immunosuppressive role by promoting the differentiation of T cells into Treg, leading to a reduction in the proportion of Th17/Treg. Utility of mesenchymal stem cells is becoming a new approach for the treatment of immune disorders. Following co-culture of dermal mesenchymal stromal cells (DMSC) and CD3+ T cells with or without transforming growth factor (TGF)-ß receptor inhibitor, the biological function and relative signal pathway of CD3+ T cells were assessed by flow cytometry, transwell, real-time polymerase chain reaction and western blotting, respectively. Normal DMSC were more potent than psoriatic DMSC in inhibition of CD3+ T-cell proliferation, and stimulation of CD3+ T-cell apoptosis than psoriasis DMSC. Moreover, normal DMSC decreased the ratio of Th17/Treg, while enhancing the immunosuppressive effect of Tregs on effector T cells. However, TGF-ß receptor (TGF-ßR) inhibitor attenuated the effect of normal DMSC on CD3+ T cells and Th17/Treg ratio. Additionally, the normal DMSC were more potent than the psoriatic DMSC in increasing TGF-ß receptors and activation of TGF-ß/SMAD pathway in psoriatic CD3+ T cells. In conclusion, normal DMSC can partially improve the biological function and immunosuppressive ability of psoriatic CD3+ T cells, possibly via upregulating the TGF-ß receptors.

Dysregulated Dermal Mesenchymal Stem Cell Proliferation and Differentiation Interfered by Glucose Metabolism in Psoriasis.

BACKGROUND AND OBJECTIVES: Psoriasis is a chronic inflammatory skin disease, which the mechanisms behind its initiation and development are related to many factors. DMSCs (dermal mesenchymal stem cells) represent an important member of the skin microenvironment and play an important role in the surrounding environment and in neighbouring cells, but they are also affected by the microenvironment. We studied the glucose metabolism of DMSCs in psoriasis patients and a control group to reveal the relationship among glucose metabolism, cell proliferation activity，and VEC (vascular endothelial cell) differentiation in vitro, we demonstrated the biological activity and molecular mechanisms of DMSCs in psoriasis. METHODS AND RESULTS: We found that the OCR of DMSCs in psoriatic lesions was higher than that in the control group, and mRNA of GLUT1 and HK2 were up-regulated compared with the control group. The proliferative activity of DMSCs in psoriasis was reduced at an early stage, and mRNA involved in proliferation, JUNB and FOS were expressed at lower levels than those in the control group. The number of blood vessels in psoriatic lesions was significantly higher than that in the control group (p<0.05), which the mRNA of VEC differentiation, CXCL12, CXCR7, HEYL and RGS5 tended to be increased in psoriatic lesions compared to the control group, in addition to Notch3. CONCLUSIONS: We speculated that DMSCs affected local psoriatic blood vessels through glucose metabolism, and the differentiation of VECs, which resulted in the pathophysiological process of psoriasis.

Role of SPRED1 in keratinocyte proliferation in psoriasis.

Psoriasis is a recurrent inflammatory skin disease, affecting approximately 2% of the population. Previous studies have demonstrated that psoriatic dermal mesenchymal stem cells (DMSC) stimulated keratinocyte (KC) proliferation and that psoriasis exhibited missense SPRED1 mutations. To further investigate the molecular mechanism by which psoriatic DMSC stimulate KC proliferation, and the role of missense SPRED1 mutations in psoriasis, we assessed expression levels of miRNA, and both mRNA and protein of SPRED1 in normal human epidermal keratinocyte cells (NHEK) cocultured with either psoriatic or control DMSC. Expression levels of miRNA and mRNA were determined by RNA sequencing. Expression levels of spred1 protein were assessed using western blot analysis. Moreover, the variation in SPRED1 was also examined by whole-genome sequencing in 665 psoriatic patients, and verified by Sanger sequencing. Our results showed that coculture of NHEK with psoriatic DMSC induced 32 differentially expressed miRNA, in which expression levels of miR-1 increased approximately 16-fold over control DMSC-treated NHEK (P < 0.05). Likewise, expression levels of miR-21-3p increased over twofold (P < 0.05). Moreover, coculture of NHEK with psoriatic DMSC induced marked increase in expression levels of mRNA for MAPK3, CDC25B and CDC25C, while decreasing expression levels of SPRED1 mRNA and protein in comparison with control DMSC treatment (P < 0.05 for all between cocultured with control and psoriatic DMSC). Furthermore, psoriasis displayed non-synonymous mutation of SPRED1 enriched in exon 7: c.A881T:p.Y294F (chr15:38351210). These results suggest that dysregulation and mutations of SPRED1 may participate in the pathogenesis of psoriasis, including epidermal hyperproliferation.

Variation at ACOT12 and CT62 locus represents susceptibility to psoriasis in Han population.

BACKGROUND: Psoriasis is a chronic inflammatory disorder of the skin, and genetic factors are reported to be involved in the disease pathogenesis. Many studies have named psoriasis candidate genes. OBJECTIVE: In this study, we determined the mutation frequency of 7 variable genes in 1,027 psoriatic patients and investigated its possible mechanism associated with psoriasis. METHOD: A total of 7 variable genes from 1,027 psoriatic patients were amplified and sequenced using the Sanger method. The mutation frequency was compared to that of non-psoriatic individuals in Asia using information from databases. RESULTS: Among the 7 investigated genes, the mutation frequency of ACOT12 (c.80A>G, 9.98% vs. 5.85%, p < .05) and CT62 (c.476C>T,15.8% vs. 9.93%, p < .05) was found to be significantly higher than among non-psoriatic Asian individuals. The mutation frequencies of CASZ1(c.599T>G), SPRED1(c.155A>G), and ACOT12 (c.80A>G) differed significantly between the groups organized by medical history, PASI, and family history. SPRED1 gene variants (17.25% vs. 7.78%, p < .01) showed a stronger association with the family history group at the onset of psoriasis than with the no family history group. CONCLUSIONS: Our results provide a comprehensive correlation analysis of susceptibility genes in psoriasis patients. Clinical characteristics of patients play important roles in the development of psoriatic skin.

Expression and functional regulation of gap junction protein connexin 43 in dermal mesenchymal stem cells from psoriasis patients.

BACKGROUND: Psoriasis is a chronic recurrent inflammatory disease. Mesenchymal stem cells (MSCs) can regulate the inflammatory microenvironment, thereby controlling the proliferation, differentiation, and migration of immune cells. Connexin 43(Cx43), a key gap junction protein, has been shown to form gap junctions for communication between neighboring cells. OBJECTIVE: We investigated the expression of Cx43 in dermal mesenchymal stem cells (DMSCs) derived from psoriasis patients and explored the relationship between the Cx43-mediated gap junction intercellular communication (GJIC) and DMSCs. METHODS: Human DMSCs were isolated and propagated in adherent culture. Quantitative real-time reverse transcription PCR and western blot and immunofluorescence were used to detect the expression and localization of Cx43 in DMSCs. Fluorescence redistribution after photobleaching was performed to assess adjacent DMSCs GJIC. CCK8 was used to detect the proliferation of DMSCs before and after gap junction blocker (18α-glycyrrhetinic acid; AGA) treatment. Cell energy metabolism was analyzed with an energy metabolism analyzer. RESULTS: Cx43 was located in the cytoplasm and cytomembrane, as well as partially in the nucleus of DMSCs. The expression of Cx43 in psoriasis DMSCs was higher than that in control samples and the gap junction function was enhanced. In addition, the glycolysis and mitochondrial respiration of psoriasis DMSCs were also enhanced. However, AGA inhibited the expression of Cx43, attenuated GJIC function, and inhibited the proliferation of DMSCs. CONCLUSIONS: Our results indicated that the expression of Cx43 in DMSCs from psoriasis lesions is increased and that the inhibition of Cx43 leads to the inhibition of both GJIC and DMSCs proliferation.