Purpurogallin Protects Keratinocytes from Damage and Apoptosis Induced by Ultraviolet B Radiation and Particulate Matter 2.5

Purpurogallin, a natural phenol obtained from oak nutgalls, has been shown to possess antioxidant, anticancer, and anti-inflammatory effects. Recently, in addition to ultraviolet B (UVB) radiation that induces cell apoptosis via oxidative stress, particulate matter 2.5 (PM(2.5)) was shown to trigger excessive production of reactive oxygen species. In this study, we observed that UVB radiation and PM(2.5) severely damaged human HaCaT keratinocytes, disrupting cellular DNA, lipids, and proteins and causing mitochondrial depolarization. Purpurogallin protected HaCaT cells from apoptosis induced by UVB radiation and/or PM(2.5). Furthermore, purpurogallin effectively modulates the pro-apoptotic and anti-apoptotic proteins under UVB irradiation via caspase signaling pathways. Additionally, purpurogallin reduced apoptosis via MAPK signaling pathways, as demonstrated using MAPK-p38, ERK, and JNK inhibitors. These results indicate that purpurogallin possesses antioxidant effects and protects cells from damage and apoptosis induced by UVB radiation and PM(2.5).

Knockdown of lncRNA MIR31HG inhibits cell proliferation in human HaCaT keratinocytes

BACKGROUND: Psoriasis is a complex, chronic inflammatory skin disease with substantial negative effects on patient quality of life. Long non-coding RNAs (lncRNAs) are able to be involved in multitudes of cellular processes in diverse human diseases. This study aimed to investigate the potential involvement of lncRNA MIR31HG in HaCaT keratinocytes proliferation. RESULTS: The study showed that MIR31HG was significantly elevated in the lesional psoriatic skin compared with normal individuals' skin. Knockdown of MIR31HG inhibited HaCaT keratinocytes proliferation. Flow cytometry analysis showed that siRNA-mediated MIR31HG depletion induced cell cycle arrest in the G2/M phase. In addition, MIR31HG expression was found to be dependent on NF-κB activation. CONCLUSIONS: NF-κB activation mediated MIR31HG upregulation plays an important role in the regulation of HaCaT keratinocytes proliferation. It could be a potential diagnostic biomarker and therapeutic target for psoriasis.

Scavenging effect of crude polysaccharides extracted from Lycium barbarum on reactive oxygen species in ultraviolet radiation-induced HaCaT cells / 中华皮肤科杂志

Objective To evaluate the scavenging effect of crude polysaccharides extracted from Lycium barbarum (LBP) on reactive oxygen species in ultraviolet radiation-induced HaCaT cells,and to explore its possible mechanism.Methods Cultured immortalized human keratiuocyte HaCaT cells were divided into 6 groups:blank control group receiving no treatment,LBP group treated with crude LBP alone,ultraviolet A (UVA) group treated with UVA radiation alone,ultraviolet B (UVB) group treated with UVB radiation alone,UVA + LBP group treated with crude LBP for 24 hours followed by UVA radiation,and UVB + LBP group treated with crude LBP for 24 hours followed by UVB radiation.MTT colorimetry was performed to evaluate the cellular proliferative activity,UV spectrophotometric method to measure the UVA and UVB absorption of crude LBP,dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescent probe assay to detect the level of ROS,enzymatic-biochemical method to estimate the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px),as well as to detect the leakage of lactate dehydrogenase (LDH).Results Crude LBP at different concentrations of 0,100,200,300,400,500,600,1 500,2 000 mg/L had no obvious effects on the proliferative activity of HaCaT cells.Crude LBP had a high transmittance of ultraviolet rays at 280-400 nm.Compared with the blank control group,the UVA group and UVB group both showed significantly higher LDH leakage and ROS level,lower activities of SOD and GSH-Px (P ＜ 0.001 or 0.05).Pretreatment with crude LBP before the ultraviolet radiation could significantly increase the activities of SOD and GSH-Px,decrease the LDH leakage and ROS level in the UVA + LBP group and UVB + LBP group compared with the UVA group or UVB group (P ＜ 0.05).Conclusion Crude LBP have no effect of sunscreening agents,but can effectively scavenge ROS,decrease LDH leakage,inhibit ultraviolet radiation-induced photodamage in HaCaT cells,which may be associated with the enhancement of antioxidant enzyme activity.

Mechanism of Macrophage-Derived Chemokine/CCL22 Production by HaCaT Keratinocytes

BACKGROUND: CC chemokine ligand 17 (CCL17) and CCL22 are the functional ligands for CCR4. We previously reported that inhibitors of nuclear factor-kappa B and p38 mitogen-activated protein kinase (p38 MAPK), but not of extracellular signal-related kinase (ERK), inhibited tumor necrosis factor (TNF)-alpha- and interferon (IFN)-gamma-induced production of CCL17 by the human keratinocyte cell line, HaCaT. Further, an inhibitor of epidermal growth factor receptor (EGFR) enhanced the CCL17 production by these keratinocytes. OBJECTIVE: To identify the mechanism underlying CCL22 production by HaCaT cells. METHODS: We investigated the signal transduction pathways by which TNF-alpha and IFN-gamma stimulate HaCaT cells to produce CCL22 by adding various inhibitors. RESULTS: TNF-alpha- and IFN-gamma-induced CCL22 production was inhibited by PD98059, PD153035, Bay 11-7085, SB202190, c-Jun N-terminal kinase (JNK) inhibitor II, and Janus kinase (JAK) inhibitor 1. CONCLUSION: Our results indicate that CCL22 production in HaCaT cells is dependent on ERK, EGFR, p38 MAPK, JNK, and JAK and is mediated by different signal pathways from those regulating CCL17 production. Altogether, our previous and present results suggest that EGFR activation represses CCL17 but enhances CCL22 production by these cells.

The Chloroform Fraction of Carpinus tschonoskii Leaves Inhibits the Production of Inflammatory Mediators in HaCaT Keratinocytes and RAW264.7 Macrophages

Inflammation is the immune system's response to infection and injury-related disorders, and is related to pro-inflammatory factors (NO, PGE2, cytokines, etc.) produced by inflammatory cells. Atopic dermatitis (AD) is a representative inflammatory skin disease that is characterized by increasing serum levels of inflammatory chemokines, including macrophage-derived chemokine (MDC). Carpinus tschonoskii is a member of the genus Carpinus. We investigated the anti-inflammatory activity of C. tschonoskii by studying the effects of various solvent fractions prepared from its leaves on inflammatory mediators in HaCaT and RAW264.7 cells. We found that the chloroform fraction of C. tschonoskii inhibited MDC at both the protein and mRNA levels in HaCaT cells, acting via the inhibition of STAT1 in the IFN-gamma signaling pathway. In addition, the chloroform fraction significantly suppressed the expression of inflammatory factors induced by lipopolysaccharide stimulation, except COX-2 and TNF-alpha. These results suggest that the chloroform fraction of C. tschonoskii leaves may include a component with potential anti-inflammatory activity.

Inhibition of UVA-induced apoptosis by the polypeptide from Chlamys farreri via regulation of c-jun and COX-2 expression in HaCaT cells / 中国药理学通报

Aim A UVA-induced apoptotic model of HaCaT cells was established to investigate the impact of UVA on c-jun/cyclooxygenase-2(COX-2)and explore related molecular mechanism of the polypeptide from Chlamys farreri(PCF)protecting HaCaT cells from UVA-induced apoptosis.Methods Cells were divided into five groups:control group,UVA model group,UVA+5.69 mmol?L-1 PCF group,UVA+2.84 mmol?L-1 PCF group,UVA+1.42 mmol?L-1 PCF group.Expression level of c-jun was assayed by Real-Time PCR and Western blot.RT-PCR and Western blot analysis were used to determine the mRNA and protein levels of COX-2.Using agarose gel electrophoresis,the effects of PCF and COX-2 inhibitor celecoxib on UVA-induced apoptosis were also investigated.Results PCF and celecoxib had inhibitory effect on 8 J?cm-2 UVA-induced apoptosis of HaCaT cells.COX-2 mRNA and protein levels increased after UVA radiation and the discrepancy was significant compared with control group(P