AimsClear cells formed due to depositions of glycogen or lipids in the cytoplasm commonly occur in various tissues. Adipophilin (ADP), a lipid regulatory protein, is closely related to lipid droplets. This study aims to examine adipophilin expression in clear cells of various skin lesions.MethodsADP expression was examined using immunohistochemistry in 108 sections from 15 skin lesion types with clear cell histology, namely, sebaceoma (n=16), sebaceous adenoma (n=3), sebaceous carcinoma (n=12), xanthomata cutis (n=10), xanthogranuloma (n=8), Paget’s disease (n=10), Bowen disease (n=10), hidradenoma (n=9), atypical lipoma (n=5), superficial lipomatous nevus (n=5), metastatic renal cell carcinoma (n=5), squamous cell carcinoma (n=4), seborrheic keratosis (n=4), dermatofibroma (n=4) and clear cell sarcoma (n=3).ResultsADP was not expressed in Bowen disease, hidradenoma or seborrheic keratosis. Four expression patterns, foamy, reticular, granular and punctate, were summarised based on their expression in clear cells. Different expression patterns were related to tissue origin and differentiation degree. Foamy expression was commonly observed in lesions with mature sebaceous glands and xanthomas; reticular expression in adipocytes; granular expression in xanthoma, xanthogranuloma and metastatic renal carcinoma and punctate expression in sebaceoma, sebaceous carcinoma, Paget’s disease, squamous cell carcinoma and clear cell sarcoma. Furthermore, stronger staining with focal vesicular labelling was noted in sebaceoma than in sebaceous carcinoma. Characteristic labelling was noted, including the circular distribution in Touton giant cells of xanthogranulomas and focal distribution in the clear cells along the edge of necrotic tissue in clear cell sarcoma.ConclusionsADP is useful in identifying intracytoplasmic lipids and can be used to diagnose skin lesions with clear cell histology, especially in some lesions with characteristic labelling.

Background:Signal transducer and activator of transcription 3 (STAT3) was strongly expressed and activated in psoriatic keratinocytes (KCs) and correlated with the severity of psoriasis. The study aimed to investigate the effects of STAT3 small interfering RNA (siRNA) combined with ultrasonic irradiation and SonoVue microbubbles on the proliferation and apoptosis in KCs of psoriatic lesions and the relative mechanisms.Methods:Psoriatic KCs were transfected under four experimental conditions: (1) STAT3 siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (LUS group); (2) STAT3 siRNA only carried by Lipofectamine 3000 (L group); (3) the negative control of siRNA carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (siRNA-NC); (4) not treated as Blank. Cell Counting Kit-8 assay was used to evaluate the cell proliferation. Cell cycle analysis was detected with cycle test Plus DNA reagent kit associated with flow cytometer. FITC Annexin V apoptosis detection kit associated with flow cytometer was applied for apoptosis analysis. Fluo calcium indicator associated with flow cytometer was used to analyze intracellular free calcium concentration ([Ca2+]i). The expressions of cyclin D1 and Bcl-xL were detected both at the mRNA level by real-time reverse transcription-polymerase chain reaction (RT-PCR) and at the protein level by Western blotting. The obtained data were statistically evaluated by two-way analysis of variance.Results:STAT3 siRNA inhibited the growth of KCs in a time-dependent manner showing the highest proliferation inhibition in LUS group with proliferation ratio of 45.38% ± 5.85% at 72h (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced an altered cell cycle distribution of KCs showing the highest increases in G2/M-phase population up to 18.06% ± 0.36% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced late apoptosis of KCs with the highest late apoptosis percentage of 22.87% ± 1.28% in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the elevation of [Ca2+]i of KCs with the highest calcium fluorescence intensity mean of 1213.67 ± 60.51 in LUS group (P < 0.05 vs. L group, siRNA-NC, or Blank). STAT3 siRNA induced the downregulation of cyclin D1 and Bcl-xL expressions of KCs at mRNA and protein levels with the lowest expressions in LUS group with cyclin D1 expression of 51.81% ± 9.58% and 70.17% ± 4.22% at mRNA level and at protein level, respectively, and with Bcl-xL expression of 37.58% ± 4.92% and 64.06% ± 7.78% at mRNA level and at protein level, respectively (P < 0.05 vs. L group, siRNA-NC, or Blank).Conclusions:STAT3 siRNA inhibited the growth and induced the apoptosis in psoriatic KCs likely partly through altering cell cycle distribution, elevating [Ca2+]i, and downregulating cyclin D1 and Bcl-xL expressions. Silencing the target gene STAT3 in psoriatic KCs with siRNA combined with ultrasonic irradiation and microbubbles would contribute to a significant i...

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The most effective sequence of small interfering RNA (siRNA) silencing STAT3 of psoriatic keratinocytes (KCs) was screened out, and the effects of the most effective siRNA combined with ultrasonic irradiation and SonoVue microbubbles on the expression of STAT3 of KCs and the dose- and time-response were investigated. Three chemically-synthetic siRNAs targeting STAT3 carried by Lipofectamine 3000 were transfected into KCs, and the effects on STAT3 expression were detected, then the most effective siRNA was selected for the subsequent experiments. The negative controls of siRNA (siRNA-NC) labeled with Cy3 carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles were transfected into KCs, then the optimal parameters of ultrasonic irradiation were determined. The most effective siRNA carried by Li-pofectamine 3000 combined with ultrasonic irradiation at the optimal parameters and SonoVue microbubbles was transfected into KCs, and the dose- and time-response of RNA interference was determined. The effect of RNA interference by the most effective siRNA at the optimal time and dose carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles (LUS group) was compared with that only carried by Li-pofectamine 3000 (L group). The results showed that siRNA-3 achieved the highest silencing efficacy. 0.5 W/cm2 and 30 s were selected as the parameters of ultrasonic irradiation. The siRNA-3 carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles could effectively knock down the STAT3 expression at mRNA and protein levels in dose- and time-dependent manners determined at 100 nmol/L with maximum downregulation on mRNA at 48 h, and on protein at 72 h after transfection. The LUS group achieved the highest silencing efficacy. It was concluded that siRNA-3 carried by Lipofectamine 3000 combined with ultrasonic irradiation and SonoVue microbubbles could effectively knock down the STAT3 expression in psoriatic KCs, and the optimized transfection condition and the sequence of siRNA-3 could serve for further research on gene therapy of psoriasis.