OBJECTIVETo probe into the mechanism of fibrillin 1 in pathologic scar, by examining the expressions of fibrillin 1 and TGF-beta1 as well as their correlations in the tissues of keloid, hypertrophic scar and normal skin.

METHODSThe tissues of keloid, hypertrophic scar and normal skin were tested. RT-PCR was used to assess the mRNA expression levels of the aimed genes. The distribution of fibrillin 1 in scars and normal skin was examined by immunohistochemistry staining.

RESULTSThe mRNA level of fibrillin 1 in keloid (0.802 +/- 0.116) was increased by 218.25% (P < 0.01) than that in normal skin (0.252 +/- 0.067). The expression of the gene in hypertrophic scar (0.628 +/- 0.144) was higher by 149.21% (while, P > 0.05) than that in normal skin. The expression of TGF-beta1 in keloid and hypertrophic scar were more than that in normal skin. The expression of fibrillin 1 was related to that of TGF-beta1 positively (r = 0.820, P < 0.01). Fibrillin 1 protein was stained positively in basic membranes, endothelial cells, fibroblasts and extracellular matrix of skin tissues. In dermal, the protein levels of fibrillin 1 in keloid (0.117 +/- 0.042) was decreased than those in normal skin (0.185 +/- 0.043) and hypertrophic scar (0.181 +/- 0.048), the inhibition rates were 36.76%, 35.36% respectively (both P < 0.01).

CONCLUSIONSThe expression of fibrillin 1 in keloid was changed and related to the expression of TGF-beta1 positively, which appears that fibrillin 1 was a cicatrix specific gene. Fibrillin 1 might play an important role in the formation of keloid.

Cicatrix, Hypertrophic ; metabolism ; pathology ; Fibrillin-1 ; Fibrillins ; Humans ; Keloid ; metabolism ; pathology ; Microfilament Proteins ; metabolism ; RNA, Messenger ; genetics ; Transforming Growth Factor beta1 ; genetics ; metabolism

Adolescent ; Child ; Collagen Type I ; metabolism ; Extracellular Matrix ; metabolism ; Female ; Fibrillin-1 ; Fibrillins ; Heart Defects, Congenital ; metabolism ; pathology ; Humans ; Male ; Microfilament Proteins ; metabolism

UNLABELLEDTo investigate the expressions of fibrillin-1, elastin and matrix metalloproteinase-1 and -9 (MMP-1, 9) in chronic actinic dermatitis in elderly patients and explore the pathogenesis of the disease.

METHODSTwenty-three patients with chronic actinic dermatitis were examined for the expressions of fibrillin-1, elastin, MMP-1, and MMP-9 with immunohistochemistry in the skin lesions. Image analysis was carried out to measure MMP-1 and MMP-9 expressions semi-quantitatively.

RESULTSIn the skin lesions of patients with chronic actinic dermatitis, elastin expression was obviously reduced or absent in the papillary dermis. The elastic fibers were disorderly arranged in the reticular dermis with local aggregation in some regions. Obvious fibrillin-1 deposition was found in the reticular dermis. Increased expressions of MMP-1, but not that of MMP-9, was found in the skin lesions of the patients.

CONCLUSIONElastin and fibrillin-1 deposition can be found in the skin lesions in patients with chronic actinic dermatitis, suggesting the association of increased MMP-1 expression with the elastic tissue degeneration in the lesions. MMP-9 does not exhibit an obvious association with the pathogenesis of chronic actinic dermatitis in elderly patients.

Aged ; Elastin ; biosynthesis ; Female ; Fibrillin-1 ; Fibrillins ; Humans ; Immunohistochemistry ; Male ; Matrix Metalloproteinase 1 ; biosynthesis ; Matrix Metalloproteinase 9 ; biosynthesis ; Microfilament Proteins ; biosynthesis ; Middle Aged ; Photosensitivity Disorders ; etiology ; metabolism ; Sunlight ; adverse effects

OBJECTIVE: To identify whether naringenin plays a protective role during thoracic aneurysm formation in Marfan syndrome. METHODS: To validate the effect of naringenin, Fbn1^C1039G/+ mice, the mouse model of Marfan syndrome, were fed with naringenin, and the disease progress was evaluated. The molecular mechanism of naringenin was further investigated via in vitro studies, such as bioluminescence resonance energy transfer (BRET), atomic force microscope and radioligand receptor binding assay. RESULTS: Six-week-old Fbn1^C1039G/+ mice were fed with naringenin for 20 weeks. Compared with the control group, naringenin significantly suppressed the aortic expansion [Fbn1^C1039G/+ vs. Fbn1^C1039G/++naringenin: (2.49±0.47) mm, n=18 vs. (1.87±0.19) mm, n=22, P < 0.05], the degradation of elastin, and the expression and activity of matrix metalloproteinase 2 (MMP2) and MMP9 in the ascending aorta of Fbn1^C1039G/+ mice. Besides, treatment with naringenin for 6 weeks also attenuated the disease progress among the 20-week-old Fbn1^C1039G/+ mice with established thoracic aortic aneurysms [Fbn1^C1039G/+ vs. Fbn1^C1039G/++naringenin: (2.24±0.23) mm, n=8 vs. (1.90±0.17) mm, n=8, P < 0.05]. To understand the underlying molecular mechanisms, we examined the effects of naringenin on angiotensin Ⅱ type 1 receptor (AT1) signaling and transforming growth factor-β (TGF-β) signaling respectively, which were the dominant signaling pathways contributing to aortopathy in Marfan syndrome as previously reported. The results showed that naringenin decreased angiotensin Ⅱ (Ang Ⅱ)-induced phosphorylation of protein kinase C (PKC) and extracellular regulating kinase 1/2 (ERK1/2) in HEK293A cell overexpressing AT1 receptor. Moreover, naringenin inhibited Ang Ⅱ-induced calcium mobilization and uclear factor of activated T-cells (NFAT) signaling. The internalization of AT1 receptor and its binding to β-arrestin-2 with Ang Ⅱ induction were also suppressed by naringenin. As evidenced by atomic force microscope and radioligand receptor binding assay, naringenin inhibited Ang Ⅱ binding to AT1 receptor. In terms of TGF-β signaling, we found that feeding the mice with naringenin decreased the phosphorylation of Smad2 and ERK1/2 as well as the expression of TGF-β downstream genes. Besides, the serum level of TGF-β was also decreased by naringenin in the Fbn1^C1039G/+ mice. Furthermore, we detected the effect of naringenin on platelet, a rich source of TGF-β, both in vivo and in vitro. And we found that naringenin markedly decreased the TGF-β level by inhibiting the activation of platelet. CONCLUSION Our study showed that naringenin has a protective effect on thoracic aortic aneurysm formation in Marfan syndrome by suppressing both AT1 and TGF-β signaling.
Angiotensin II/metabolism* ; Animals ; Aortic Aneurysm, Thoracic/prevention & control* ; Calcium/metabolism* ; Disease Models, Animal ; Elastin/metabolism* ; Fibrillin-1/metabolism* ; Flavanones ; Marfan Syndrome/metabolism* ; Matrix Metalloproteinase 2 ; Matrix Metalloproteinase 9 ; Mice ; Mice, Inbred C57BL ; Protein Kinase C/metabolism* ; Receptor, Angiotensin, Type 1/metabolism* ; Transforming Growth Factor beta/metabolism* ; Transforming Growth Factors/metabolism* ; beta-Arrestins/metabolism*