The Expression Of Caspase-14 In Chronic Actinic Dermatitis And Study The Influence Of Its Mrna And Protein By Ultraviolet B-induced Damage And Demethylation

[Objectives]To understand the clinical and pathological features of CAD,enhance the understanding of it.At the same time,to observe the expression of Caspase-14 in CAD and study the influence of Caspase-14 mRNA and protein by both ultraviolet B-induced damage and demethylation on HaCaT.Study the function and molecular mechanism of Caspase-14 of CAD to provide a further theoretical basis for clinical prevention and treatment of CAD.[Methods]1.Clinical samples from 173 patients with chronic actinic dermatitis diagnosed are collected in the department of dermatology of the First Affiliated Hospital of Kunming Medical University from 2008 to 2016.Statistical analysis is performed by gender,age,location,clinical features,onset seasons,profession and pathological study.2.Select 10 cases diagnosed CAD in the department of dermatology of the First Affiliated Hospital of Kunming Medical University as experimental group and at the same time select 10 cases diagnosed eczema as positive control group;Select 10 cases of normal tissue people in the department of plastic surgery of the First Affiliated Hospital of Kunming Medical University as normal control.Use the method of immunohistochemistry to detect Caspase-14 expression in CAD,eczema and normal tissue.Compare the positive rates of Caspase-14 in CAD,eczema and normal tissue,and analyze the role of Caspase-14 in skin barrier.3.Cultivate HaCaT cells by 96-well plates,take the test into three groups:first,normal control,secondly,UVB exposure group(divide into 30mJ/cm2、60mJ/cm2、90mJ/cm2UVB),thirdly,drug intervention group(plus 1.25umom/L、2.5umom/L、5umom/L concentration 5-azaC).Use MTT to detection the growth situation of HaCaT after giving different does of UVB and 5-azaC,to choose the optimum concentration of 5-azaC.4.Choose the 3-8 generation cells,when 90%cell fusion giving different dose of UVB irradiation and plus 5-azaC of drug intervention group,continue to culture cell.After 24 hours,Using QRT-PCR to detect the transcription of Caspase-14 mRNA and Western blot to detect the expression of Caspase-14 protein.[Results]1.Clinical data analysis results:①Among the 173 CAD patients the male patients is 158 cases(91.33%),females is 15 cases(8.67%).②Age of onset distribution 20 to 85,an average age is 58.26±12.86.Confirmed aged is from 22 to 88,average is 62.94±11.65.There are 8 cases whose age were between the ages of 20 to 39(4.62%),there are 45 cases between the ages of 40 to 59(26.01%),114 cases are 60 to 79 years age(65.90%),6 cases are over the age of 80(3.47%).③Disease happen most is 20 cases in December(11.56%).There is no obvious difference between the four seasons.It is a bit high in Spring for 51(29.48%).④There are 59 cases data complete of Photosensitive experimental,46 cases are sensitive to UVB(77.97%),both sensitive to UVA and UVB for 11(18.64%),42 cases show non-response to UVA(71.19%).⑤Histopathology examination in 126 cases,the epidermal hyperkeratosis 45(35.71%),hyperkeratosis accompanied parakeratosis 73 cases(57.94%).With exudation and crust 12 cases(9.52%),Stratum spinosum edema 77 cases(61.11%),base layer complete 50 cases(39.68%),Base layer liquefaction degeneration 21 cases(16.67%),dermal collagen basophil-degeneration 33 cases(26.19%),with eosinophil infiltration 26 cases(20.63%),inflammatory cell exosmosis 23 cases(18.25%),combine mycosis fungoides 3 cases(2.38%),typical pautrier 2 cases(1.59%).2.Caspase-14 main express above the base layer,corneous layer express significantly,expression positive rate is 90%,it main express in stratum spinosum and granular layer in CAD and eczema,expression positive rate is 50%.Compare to CAD and eczema,had no statistical significance,when compare to normal group,there is statistically significant(P<0.05).3.The result of MTT shows that UVB rays create inhibiting effect to HaCaT,increase exposure dose,cell proliferation activity decline gradually.It does not influence the HaCaT activity when the concentration between 0-5 umom/L of 5-AzaC..4.QRT-PCR and Western blot show that UVB rays decline Caspase-14 expression.After giving 5-AzaC,the mRNA and protein expression of Caspase-14 are both increased,the increasing range has statistically significant(P<0.05).[Conclusions]1.Elderly old male are more likely to acquire CAD.Women compare to men are average age of CAD in advance about 10 years old.There is no significant difference between seasonal.Most persons sensitive to UVB rays and tolerate to UVA.Histopathology examination is similar to chronic eczema and dermatitis,characterized as dermal collagen basophilic,eosinophil infiltration.There is almost no case from PD to AR.2.The causes of CAD have a connection with Caspase-14 expression abnormally.3.UVB radiation inhibition the proliferation of HaCaT,and reduce the expression of Caspase-14mRNA and protein,and participate in the pathogenic mechanism of CAD.4.5-AzaC may up-regulation the expression of Caspase-14 mRNA and protein,own the function of repairing skin barrier,and participate the pathological process of CAD by UVB-induced.