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Neutrophil/lymphocyte ratio (NLR) is a inflammatory indicator, which can be easily calculated from the results of complete blood cell count. More and more studies have shown that NLR has its unique value in the diagnosis, and evaluation of severity, complications, treatment efficacy and prognosis of skin diseases. This article reviews the recent progress on the application of NLR in clinical management of skin diseases, such as psoriasis, systemic lupus erythematosus and Behcet disease.
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Transient receptor potential (TRP) channels are a special type of non-selective cationic channel family located on the cell membrane or organelle membrane, and notably expressed in melanocytes. This review summarizes recent research progress in biological functions of TRP channels in melanocytes and their involvement in the pathological process of pigmented skin diseases and melanoma, so as to provide a new theoretical basis for the prevention and treatment of melanin-related diseases.
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Tranexamic acid can treat melasma through multiple steps, such as inhibiting dermal angiogenesis, reducing the number of mast cells and inhibiting their activity, reducing damage to the basement membrane zone, inhibiting melanin synthesis and transport in the epidermis, and promoting the recovery of skin barrier function. This review summarizes the action mechanism and efficacy of tranexamic acid in the treatment of melasma, providing more evidence for its clinical application.
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Metabolic syndrome (MS) is a set of clinical symptoms characterized by multiple concurrent metabolic disorders, and is an important risk factor for type 2 diabetes and cardiovascular diseases in individuals. Its pathogenesis is still unclear, and may be associated with insulin resistance, chronic inflammatory reactions and oxidative stress. Studies have shown that MS is closely related to papulosquamous skin diseases, skin adnexal diseases, dermatitis and eczematous skin diseases, pigmentary skin disorders and so on. This review summarizes the relationship between MS and related skin diseases.
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Objective:To analyze dermoscopic and reflectance confocal microscopic characteristics of acanthosis nigricans, and to assess the value of dermoscopy and reflectance confocal microscopy (RCM) in the auxiliary diagnosis of acanthosis nigricans.Methods:A total of 63 patients with acanthosis nigricans were collected from Department of Dermatology, the Third People′s Hospital of Hangzhou from January 2018 to December 2019, and 5 healthy individuals served as controls. Two lesions on the neck and axilla were examined with dermoscopy and RCM separately in each patient. Biopsies were carried out at the sites evaluated by dermoscopy and RCM in 3 patients, followed by routine histopathological examination.Results:Dermoscopy showed papilloma-like hyperplasia in 126 (100%) lesions, "fat finger" structures in 119 (94.4%) , and "gully" structures in 120 (95.2%) . RCM showed hyperpigmentation in the basal layers, downward extension and twisting of dermal papillary rings and "gully" structures in 126 (100%) lesions, moderately to highly refractive particles in the dermal papillary rings in 87 (69.0%) .Conclusion:Acanthosis nigricans has typical dermoscopic and reflectance confocal microscopic characteristics, which can provide a basis for its diagnosis and differential diagnosis.
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Tissue-resident memory T (T RM) cells are derived from stimulated naive T cells and reside in peripheral tissues, mediating rapid immune responses of the host to similar stimuli. Although this immune response helps protect the host against local infections, long-term residence of T RM cells in the skin can lead to repeated attacks of autoimmune-related skin diseases such as vitiligo. This review summarizes the relationship between T RM cells and vitiligo as well as potential therapeutic targets.
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Skin color is regulated by the change of melanin. Previous studies have shown that there are 4 modes of melanin transfer, including exocytosis-endocytosis, shedding-phagocytosis, cell phagocytosis and membrane fusion, and melanosomes are the main carrier for melanin transfer. Recent studies have shown that melanocores depending on the exocytosis-endocytosis pathway play an important role in melanin transfer. This review summarizes the melanocyte exocytosis and keratinocyte endocytosis processes in melanocore transfer, as well as the melanocore degradation process in keratinocytes after melanocore transfer, providing a new therapeutic direction for refractory pigmentory diseases.
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NOD-like receptor protein 3 (NLRP3) inflammasomes play an important role in innate immunity.It can induce the maturation and release of cytokines interleukin (IL)-1β and IL-18 by activating caspase-1,and participate in a variety of host immunoinflammatory responses.Once the regulation of NLRP3 inflammasomes is unbalanced,excessive IL-1β and IL-18 may be produced,triggering a series of inflammatory diseases.NLRP3 inflammasome activation plays important roles in skin diseases such as acne,psoriasis,pyoderma gangrenosum,polymyositis/dermatomyositis and bullous pemphigoid.This review summarizes research progress in NLRP3 inflammasomes in skin diseases.
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There is a high incidence of hepatitis B virus (HBV) infection in China,and dermatologists often encounter patients with skin diseases complicated by HBV infection in clinic.With the widespread use of systemic glucocorticoids in dermatology,HBV reactivation has become a constant problem to face in the treatment process.Attention should be given to risk factors of HBV reactivation,including HBV DNA replication,positive hepatitis B surface antigens (HBsAg) and positive hepatitis B core antibodies (HBcAb).According to HBV serological markers,risk stratification of HBV reactivation induced by glucocorticoids needs to be grasped,and treatment measures should be taken timely to prevent HBV reactivation.In this way,liver function impairment induced by HBV reactivation during the course of glucocorticoid therapy may be avoided to the greatest extent,which is of great benefit to clinical work.
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Objective To analyze the clinocopathological characteristics of infectious granulomas.Methods The clinical features,histopathological manifestations of 39 patients with infectious granulomas were analyzed retrospectively.Results Among 39 cases of infectious granulomas,there were 15 males and 24 females,and 17 cases of fungal granuloma and 22 cases of tuberculous granuloma.There was no statistically significant difference in gender and age between fungal granulomas and tuberculous granulomas.The mean course of tuberculous granuloma aud tuberculous granuloma was (0.88 ± 0.67) years and (5.54 ± 3.49) years,respectively (t =4.51,P =0.00);there was no significant difference in mean age of onset in fungal granuloma patients and tuberculous granuloma patients [(54.6 ± 19.6) vs.(47.6 ± 18.1) years,P ＞0.05)].There were 4 and 18 cases of fungal and tuberculous granulomatosis at the face,and 13 and 3 cases at the extremities (all P =0.00);the lesions occurred in the trunk in one case of tuberculous granuloma.The clinical manifestations of fungal and tuberculous granulomas as plaques/nodules were in 14 cases aud 22 cases (P =0.08);as ulcers and pus exudates were in 10 and 2 cases,respectively (P =0.00).The histopathological features showed epidermal hyperplasia in 12 and 4 cases,infiltrative patterns in 4 and 21 cases,infiltration of neutrophils in 14 and 3 cases,infiltration of plasma cells in 15 and 5 cases,infiltration of eosinophils in 10 and 0 cases,necrosis in 1 and 10 cases in fungal granulomas and tuberculous granulomas,respectively (P =0.00,0.00,0.00,0.00,0.00,0.01).Conclusion Fungal granuloma and tuberculous granuloma are different in the lesion sites,clinical manifestations and histopathological features.
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Objective To evaluate the effect of narrow-band ultraviolet (NB-UVB) radiation on the autophagy of cultured human melanocytes in vitro,and to explore possible mechanisms underlying the treatment of vitiligo by NB-UVB.Methods In vitro cultured human melanocytes were divided into 4 groups to be irradiated with NB-UVB at different irradiation doses of 0 (control group),50,100 and 200 mJ/cm2 (50-,100-and 200-mJ/cm2 NB-UVB groups) respectively.After 24-hour treatment,the cells were collected,and monodansylcadaverin (MDC) staining was conducted to detect changes of autophagosomes in melanocytes.Western blot analysis was performed to determine the protein expression of autophagy signals including phosphorylated AMP-activated protein kinase (p-AMPK),phosphorylated mammalian target of rapamycin (p-mTOR),microtubule-associated protein 1 light chain 3 Ⅱ/Ⅰ (LC3 Ⅱ/Ⅰ) and P62,and transmission electron microscopy to observe ultrastructural changes of autophagosomes and melanosomes in the melanocytes.Statistical analysis was done by using one-way analysis of variance (ANOVA) for the comparison of Western blot results,and by Kruskal-Wallis H test for the comparison of the number of melanosomes,autophagosomes and autolysosomes.Results MDC staining showed that the percentages of autophagosome-positive melanocytes were significantly higher in the 100-,200-mJ/cm2 NB-UVB groups (38.08％ ± 4.10％,40.23％ ± 1.45％,respectively) than in the control group (21.83％ ± 3.50％,both P ＜ 0.05) and 50 mJ/cm2 NB-UVB group (23.66％ ± 4.12％,both P ＜ 0.05).As Western blot analysis revealed,the 100-,200-mJ/cm2 NB-UVB groups showed significantly increased expression of p-AMPK and LC3 Ⅱ/Ⅰ,but significantly decreased expression of p-mTOR and P62 compared with the control group (all P ＜ 0.05).Transmission electron microscopy showed that the number of autophagosomes and autolysosomes was significantly higher in the 100-,200-mJ/cm2 NB-UVB groups (5.12 ± 1.13,5.25 ± 1.04) than in the control group (1.88 ± 1.18,both P ＜ 0.05).Meanwhile,the number of melanosomes was significantly higher in the 50-,100-and 200-mJ/cm2 NB-UVB groups (39.12 ± 9.42,57.38 ± 7.11,59.75 ± 15.15,all P ＜ 0.05) than in the control group (18.50 ± 4.18,all P ＜ 0.05).Conclusion NB-UVB radiation can not only promote the formation of melanosomes,but also activate the autophagy signal pathways in the melanocytes and promote the formation of autophagosomes and autolysosomes,which may be one of the mechanisms underlying the treatment of vitiligo by NB-UVB.
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Objective To investigate clinical and histopathological features of cutaneous epithelioid hemangioma (EH).Methods Clinical and histological data were collected from 22 patients with EH and analyzed.Results Of the 22 EH patients,10 were male,and 12 were female.The age at onset ranged from 16 to 62 years,with an average age of 45.91 years.The duration of disease varied from 1 month to 20 years,with an average disease duration of 37 months.Skin lesions most frequently occurred on the scalp in 14 cases (63.6％),followed by the ear in 6 cases (27.3％),the forehead in 2 cases (9.1％),and the thigh in 1 case (4.5％).Lesions affected both the scalp and forehead in 1 case.Histopathological examination of the 22 cases revealed vascular proliferation.The blood vessels were lined with epithelioid endothelial cells,and a large number of lymphocytes and eosinophils infiltrated around the vessels.The dermis were involved in all cases,and subcutaneous tissues were involved in 8 cases (36.4％).Immunohistochemical examination of 6 cases showed positive staining for CD31,CD34 and factor Ⅷ in blood vessel walls.Conclusion EH is an uncommon disease characterized by vascular proliferation and inflammatory infiltration,and clinical manifestations in combination with histopathological examination facilitate its diagnosis.
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Objective To investigate risk factors for and clinical features of steroid-induced diabetes mellitus due to glucocorticoid treatment.Methods Clinical data were collected from 798 patients who received systemic glucocorticoid treatment in Department of Dermatology of Hangzhou Third People's Hospital from 2013 to 2016,and analyzed retrospectively.Logistic regression analysis was performed to analyze the factors influencing the occurrence of steroid-induced diabetes mellitus (SDM),repeatedmeasures analysis of variance to compare peripheral blood glucose levels of patients with SDM after breakfast,lunch and dinner,and t test to compare the levels of fasting blood glucose and glycosylated hemoglobin (HbA1 c) between patients with SDM and those with type 2 diabetes mellitus.Results Of the 798 patients,38 developed SDM due to glucocorticoid treatment.The average age was significantly older in the patients with SDM ([66.86 ± 13.30] years,n =38) than in those without SDM ([39.95 ± 17.01] years,n =760;t =8.86,P ＜ 0.01),but there was no significant difference in the gender ratio between the patients with and thhose without SDM (x2 =1.61,P =0.20).The prevalence of fatty liver,hyperlipidemia,hypertension,abnormal liver function and family history of diabetes mellitus was significantly higher in the patients with SDM than in those without SDM (x2 =12.25,19.25,32.69,21.47,16.70 respectively,all P ＜0.01).Logistic regression analysis showed that age,fatty liver,hyperlipidemia,hypertension,abnormal liver function,dosage of glucocorticoids,duration of glucocorticoid therapy,use of immunosuppressive agents and family history of diabetes mellitus were risk factors for SDM (all P ＜ 0.05).There were no significant differences in fasting blood glucose levels or postprandial peripheral blood glucose levels among the SDM patients receiving glucocorticoid therapy at different dosages of 0.50-0.74,0.75-0.99,1.00-1.25 mg·kg-1· d-1 (P ＞ 0.05).The peripheral blood glucose levels after breakfast,lunch and dinner were (11.50 ± 2.90),(16.02 ± 5.81) and (16.81 ± 4.52) mmol/L respectively in the patients with SDM.The levels of fasting blood glucose and glycosylated HbA 1 c were both significantly lower in the patients with SDM than in those with type 2 diabetes mellitus (t =3.74,9.92 respectively,both P ＜ 0.001).Conclusions The risk factors for SDM are age,dosage of glucocorticoids,duration of glucocorticoid therapy,fatty liver,hyperlipidemia,hypertension,abnormal liver function,use of immunosuppressive agents and family history of diabetes mellitus.The patients with SDM showed obviously elevated blood glucose levels mostly after lunch and dinner,but slightly increased levels of fasting blood glucose and glycosylated HbA 1c,which can be used to distinguish between SDM and type 2 diabetes mellitus.
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Objective To evaluate the effect of tea polyphenol epigallocatechin gallate (EGCG)on ultraviolet B (UVB)-induced skin pigmentation,transfer and degradation of melanosomes in mice,and to explore the role of autophagy in the mechanism of melanosome degradation.Methods A total of 32 ears from 16 female C57/BL6 mice were randomly and equally divided into 4 groups:acetone control group topically treated with acetone solution daily,EGCG group topically treated with 10 g/L EGCG acetone solution daily,UVB irradiation group irradiated with 500 mJ/cm2 UVB once a day and 2 hours later topically treated with acetone solution,UVB + EGCG group irradiated with 500 mJ/cm2 UVB once a day and 2 hours later topically treated with EGCG acetone solution.Ten days later,all the mice were sacrificed,and skin tissue samples were collected from the ears.Transmission electron microscopy was performed to observe ultrastructural changes of melanosomes and autophagosomes,immunohistochemical study to measure expression of protease-activated receptor 2 (PAR2) and microtubule-associated protein light chain 3 (LC3) in the epidermis,and Western blot analysis to determine the protein expression of PAR2,Rasrelated protein Rab27a and LC3 in the epidermis.Results There was a significant difference in the number of melanosomes and autophagosomes among the acetone control group,EGCG group,UVB irradiation group and UVB + EGCG group (H =12.249,13.888,respectively,both P ＜ 0.05).Compared with the acetone control group,the UVB irradiation group showed significantly increased number of melanosomes (1.85 ± 0.32 vs.1.00 ± 0.41,P ＜ 0.05)and autophagosomes (1.94 ± 0.64 vs.1.00 ± 0.46,P ＜ 0.05) in epidermal keratinocytes in mouse skin.Compared with the UVB irradiation group,the UVB + EGCG group showed significantly decreased number of melanosomes (1.30 ± 0.44,P ＜ 0.05),but significantly increased number of autophagosomes (3.03 ± 0.75,P ＜ 0.05).Immunohistochemical study showed a significant difference in the level of PAR2 in the epidermis among the 4 groups (H =18.700,P ＜ 0.05),and the expression of PAR2 was significantly lower in the UVB + EGCG group than in the UVB irradiation group (7.94 ± 4.57 vs.12.54 ± 3.07,Z =2.143,P ＜ 0.05).However,the 4 groups all showed a low level of LC3,and there was no significant difference among the 4 groups (H =5.051,P ＞ 0.05).Western blot analysis revealed significant differences in the protein expression of PAR2 and Rab27a,as well as in the LC3-Ⅱ/LC3-Ⅰ ratio,among the 4 groups (F =18.739,25.967,24.022,respectively,all P ＜ 0.05).Compared with the UVB irradiation group,the UVB + EGCG group showed significantly decreased expression of PAR2 (0.91 ± 0.54 vs.3.12 ± 0.61,P ＜ 0.05) and Rab27a (0.99 ± 0.16 vs.1.42 ± 0.07,P ＜ 0.05),but significantly increased LC3-Ⅱ/LC3-Ⅰ ratio (1.67 ± 0.08 vs.1.24 ± 0.07,P ＜ 0.05).Conclusion Topical EGCG treatment can effectively suppress UVB-induced skin pigmentation,which may be related to the inhibition of melanosome transfer and promotion of melanosome autophagy.
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Objective To evaluate the effect of green tea polyphenol epigallocatechin-3-gallate (EGCG)and ultraviolet B (UVB) on the expression of aquaporin 3 and epidermal growth factor receptor (EGFR)/extracellular signal-regulated protein kinase (ERK) signaling pathway in keratinocytes.Methods Twenty healthy human subjects were enrolled in this study.Both legs of each subjects were separated into 4 areas to remain untreated (control area),be topically treated with 3％ and 1％ EGCG cream and the vehicle of EGCG cream respectively once a day for 2 weeks followed by the measurement of skin moisture content and transepidermal water loss (TEWL).Cultured keratinocytes were classified into various groups to be irradiated with different doses (10,20 and 30 mJ/cm2) of UVB,or be pretreated with different concentrations of EGCG (10-7,10-6,10-5 mol/L) or EGFR/ERK phosphorylation inhibitors for 1 hour followed by irradiation with UVB of 30 mJ/cm2.After various durations of additional culture,Western blot was conducted to quantify the expression of AQP3 and phosphorylated-EGFR (p-EGFR) and-ERK (p-ERK) of keratinocytes.Data were processed by SPSS 10.0 software,and statistical analysis was carried out by t test.Results Skin moisture content was significantly increased,while TEWL was decreased in healthy skin after treatment with 1％ and 3％ EGCG cream compared with vehicle-treated skin areas and untreated skin areas.Increased AQP3 expression was observed in keratinocytes pretreated with EGCG of 10-7,10-6,10-5 mol/L (172.36 ± 12.42,320.66 ± 15.51 and 368.10 ± 11.39 vs.100.00,t =12.16,26.75 and 38.62 respectively,all P ＜ 0.05) and in those pretreated with the EGFR inhibitor PD153035 of 1.0 μmol/L and ERK inhibitor U0126 of 10 μmol/L (413.85 ± 25.27 and 268.85 ± 16.33 vs.100.00,t =35.16,19.25 respectively,both P ＜ 0.05)compared with those irradiated with UVB of 30 mJ/cm2 alone.UVB irradiation stimulated the phosphorylation of EGFR/ERK in keratinocytes,and the stimulation was markedly inhibited by the pre-treatment with EGCG of 10-7,10-6 and 10-5 mol/L (all P ＜ 0.05).Conclusions EGCG can enhance skin barrier function.AQP3 expression is down-regulated by UVB irradiation in keratinoctyes,while EGCG can inhibit the downregulation likely by suppressing the UVB-induced activation of EGFR and ERK.
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ObjectiveTo assess the relationship of interleukin-17(IL-17) and transforming growth factor-β(TGF-β) with the development of vitiligo.MethodsEnzyme-linked immunosorbent assay (ELISA) was carried out to measure the levels of IL-17 and TGF-β in sera from 120 patients with vitiligo and 60 healthy controls.The correlations of serum IL-17 and TGF-β levels with patients' gender,stage and duration of disease,involved body area and presence of family history were assessed.ResultsThe level of serum IL-17 was significantly higher in patients with active vitiligo than in the controls and patients with stable vitiligo (both P ＜0.05).With the rise in involved body area,the level of serum IL-17 gradually increased (x2 =12.656,P ＜0.05).The level of TGF-β in patients with active vitiligo was a little higher than that in the controls and patients with stable vitiligo,with no significant difference between these groups(both P ＞ 0.05).Conclusions The levels of serum IL-17 and TGF-β are somewhat correlated with the activity of vitiligo,and both of them may play a certain role in the pathogenesis of vitiligo.
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ObjectiveTo study the roles of aquaporin 3(AQP3),Caspase 14 and bleomycin hydrolase(BH) in skin barrier in patients with chronic eczema and to tackle the mechanisms underlying the therapeutic effect of narrow-band ultraviolet B(NB-UVB) on eczema.MethodsTransepidermal water loss (TEWL)and water content of skin were detected by a muhi-functional skin tester in lesions and non-lesional skin of 30 patients with chronic eczema.The protein expressions of AQP3,Caspase 14 and BH were detected by immunohistochemistry in tissue specimens from lesioual and non-lesional skin of these patients.Cultured keratinocytes were irradiated with 3 different doses(400,800,1200 mJ/cm2) of UVB,and Western blot was performed to quantify the protein expressions of AQP3,Caspase 14 and BH at 24 hours after the irradiation.ResultsThere was a significant decrease in water content of skin(11.32 ± 5.25 vs.49.68 ± 8.62) but an increase in TEWL (86.28 ± 16.35 vs.14.62 ± 6.68) in lesional skin compared with non-lesional skin from the patients with chronic eczema(both P ＜ 0.05).The protein expression levels of AQP3,Caspase 14 and BH in lesional skin were 5.3 times,4.2 times and one-third of,those in non-lesional skin from the patients,respectively,and significant differences existed between the lesional and non-lesional skin in the 3 parameters (all P ＜ 0.05 ).After irradiation with NB-UVB at 400,800 and 1200 mJ/cm2,the expression level of AQP3 in keratinocytes was decreased by 52％,77％ and 84％,respectively,and that of Caspase 14 was decreased by 18％,22％ and 78％,respectively,compared with unirradiated keratinocytes (all P ＜ 0.05).A marked decrease(by 66％) was also observed in the expression of Caspase 14 in keratinocytes after irradiation with NB-UVB at 1200 mJ/cm2(P ＜ 0.05).ConclusionsThe impairment of skin barrier function in chronic eczema may be related to the downregulated expression of BH and upregulated expression of Caspase 14 and AQP3.The therapeutic effect of NB-UVB on chronic eczema may be partly attributed to the diminished expression of AQP3,Caspase 14 and BH.
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Objective To assess the clinical features and diagnostic index of progressive macular hypomelanosis(PMH).Methods Eight patients with PMH were recruited into this study.Wood's lamp and in vivo confocal laser scanning microscopy(CLSM)were utilized to observe the lesions of all patients.Microbiological culture of lesion specimens from 2 patients was performed.Tissue specimens from 4 patients underwent immunohistochemieal staining with anti-S-100 and anti-TRP-1 antibodies for the detection of melanocyte quantity.Electron microscopy wag utilized to observe ultrastructural features of lesions.Primary culture of melanocytes was carried out with lesional epidermis.Resnits Under Wood's lamp.the lesions of PMH showed punctiform red fluorescence.CLSM revealed complete pigmented tings in lesions with decreased melanin granules compamd with those surrounding normal skin.Microbiological culture grew red fluorescence-producing,gram-positive bacillus which was identified as Propionibacterium acnes.Immunohistochemistry showed no significant difference in the number of S-100-postive cells or TRP-1-positive cells per high power field (× 400)between lesions and surrounding normal skin (8.25±0.96 vs 8.75±1.71,4.25±0.96 vs 4.50±1.29,both P>0.05).Ultrastructural studies showed a large reduction in the number of type Ⅳ melanosomes in lesions of PMH,along with numemus membrane bound bodies and clusteredly distributed,small type Ⅱ-Ⅳ melanosomes.Melanocytes,with morphological similarity to normal melanocytes,were successfully isolated from the lesional tissue,cuhured and identified.Conclusion A primary diagnostic criteria is pro-posed for PMH according to the clinical and experimental studies.
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Objective To explore the influences of extracellular matrices (ECM) secreted by ultraviolet B (UVB)-induced senescent fibroblasts on the proliferation of and extracellular signal-regulated kinase (ERK) signaling in HaCaT cells. Methods Fibroblasts were irradiated with UVB of 15 mJ/cm2 once daily for 5 days to induce premature senescence, which was identified by SA-β-gal staining 72 hours after the last irradiation.HaCaT cells were divided into 3 groups and inoculated into plates coated with extracellular matrices secreted by non-senescent (PRE-ECM) or senescent fibroblasts (SIPS-ECM) or into uncoated plates (NON-ECM), fol-lowed by additional culture. U0126, an inhibitor of ERK1/2, was used to treat the HaCaT cells 1 hour before inoculation. Then, MTT assay was carried out to detect the proliferation of HaCaT cells after a 3-day culture,Western blot to assess the phosphorylation of ERK at 0.5, 1, 2 and 4 hours after the inoculation, flow cytometry to analyse cell cycle and apoptosis after 24 hours of culture. Results The most rapid and intense phosphory-lation of ERK was observed in SIPS-ECM group. Inhibiting the activation of ERK pathway with U0126 could completely suppress the promoting effect of ECM from senescent fibroblasts on the proliferation of HaCaT cells.After the blocking of ERK activation, the proportion of HaCaT cells in S and G2/M phase decreased from 37.40%, 41.34% and 43.31% to 29.41%, 36.48% and 39.96%, respectively, in NON-ECM, PRE-ECM and SCIP-ECM group. Conclusion The ECM produced by UVB-induced senescent fibroblasts promote the prolifera-tion of HaCaT cells via inducing the phosphorylation of ERK.
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Objective To investigate the role of activation of Akt/mTOR pathway in denfense against UVB-induced apoptosis in cultured human skin keratinocyte cell line HaCaT. Methods HaCaT cells were irradiated with UVB at different doses for various durations. Western blotting was performed to detect dynamic changes of Akt/mTOR pathway-related signaling molecule, such as phosphorylated-epidermal growth factor receptor (EGFR), -Akt, -4EBP1, etc; apoptosis was estimated by staining with DNA dye Hoechst 33342. To evaluate the role of signaling molecules in defense against UVB-induced apoptosis, HaCaT cells were pretreated before irradiation with EGFR inhibitor (PD153035), PI3K inhibitor (LY294002), mTOR inhibitor (rapamycin) followed by the detection of expressions of signaling molecule and apoptosis. Results UVB could activate Akt/mTOR pathway in a dose- (5 ～ 30 mJ/cm2) and time- (5 ～ 30 min) dependent manner. PD153035,LY 294002 and rapamycin could inhibit UVB-induced activation of the Akt/mTOR pathway. The apoptosis rate in HaCaT cells was upregulated by pretreatment with rapamycin and LY294002. Conclusion The activation of Akt/mTOR signaling pathway could inhibit the UVB-induced apoptosis in cultured HaCaT cells.
