Rosemary extract and rosmarinic acid accelerate elastic fiber formation by increasing the expression of elastic fiber components in dermal fibroblasts

Ultraviolet (UV)-induced skin photoaging is caused by qualitative and quantitative degradation of dermal extracellular matrix components such as collagen and elastic fibers. Elastic fibers are important for maintaining cutaneous elasticity, despite their small amount in the skin. Previously, microfibril-associated protein 4 (MFAP-4), which is downregulated in photoaging dermis, has been found to be essential for elastic fiber formation by interaction with both fibrillin-1 and elastin, which are core components of elastic fiber. In addition, enhanced cutaneous MFAP-4 expression in a human skin-xenografted murine photoaging model protects against UV-induced photodamage accompanied by the prevention of elastic fiber degradation and aggravated elasticity. We therefore hypothesized that the upregulation of MFAP-4 in dermal fibroblasts may more efficiently accelerate elastic fiber formation. We screened botanical extracts for MFAP-4 expression-promoting activity in normal human dermal fibroblasts (NHDFs). We found that rosemary extract markedly promotes early microfibril formation and mature elastic fiber formation along with a significant upregulation of not only MFAP-4 but also fibrillin-1 and elastin in NHDFs. Furthermore, rosmarinic acid, which is abundant in rosemary extract, accelerated elastic fiber formation via upregulation of transforming growth factor β-1. This was achieved by the induction of cAMP response element-binding protein phosphorylation, demonstrating that rosmarinic acid represents one of the active ingredients in rosemary extract. Based on the findings in this study, we conclude that rosemary extract and rosmarinic acid represent promising materials that exert a preventive or ameliorative effect on skin photoaging by accelerating elastic fiber formation.

Ciprofloxacin accelerates aortic enlargement and promotes dissection and rupture in Marfan mice

OBJECTIVE

Aortic aneurysm and dissection are major life-threatening complications of Marfan syndrome. Avoiding factors that promote aortic damage is critical in managing the care of these patients. Findings from clinical and animal studies raise concerns regarding fluoroquinolone use in patients at risk for aortic aneurysm and dissection. Therefore, we examined the effects of ciprofloxacin on aortic aneurysm and dissection development in Marfan mice.

METHODS

Eight-week-old Marfan mice (Fbn1C1041G/+) were given ciprofloxacin (100 mg/kg/d; n = 51) or vehicle (n = 59) for 4 weeks. Mice were monitored for 16 weeks. Aortic diameters were measured by using ultrasonography, and aortic structure was examined by using histopathologic and immunostaining analyses.

RESULTS

Vehicle-treated Fbn1C1041G/+ mice showed progressive aortic enlargement, with aortic rupture occurring in 5% of these mice. Compared with vehicle-treated Fbn1C1041G/+ mice, ciprofloxacin-treated Fbn1C1041G/+ mice showed accelerated aortic enlargement (P = .01) and increased incidences of aortic dissection (25% vs 47%, P = .03) and rupture (5% vs 25%, P = .005). Furthermore, ciprofloxacin-treated Fbn1C1041G/+ mice had higher levels of elastic fiber fragmentation, matrix metalloproteinase expression, and apoptosis than did vehicle-treated Fbn1C1041G/+ mice.

CONCLUSIONS

Ciprofloxacin accelerates aortic root enlargement and increases the incidence of aortic dissection and rupture in Marfan mice, partially by suppressing lysyl oxidase expression and further compromising the inherited defect in aortic elastic fibers. Our findings substantiate that ciprofloxacin should be avoided in patients with Marfan syndrome.

Intraluminal infusion of Penta-Galloyl Glucose reduces abdominal aortic aneurysm development in the elastase rat model

BACKGROUND

An abdominal aortic aneurysm (AAA) is a progressive chronic dilatation of the abdominal aorta with terminally rupture when the aortic wall is so weakened that aortic wall stress exceeds wall strength. No effective medical treatment exists so far. We aimed to test whether intraluminal admission of Penta-Galloyl Glucose (PGG) treatment in a rodent AAA model could hold the potential to inhibit aneurysmal progression.

METHOD

Male Sprague Dawley rats had either intraluminal elastase infused for AAA induction or saline to serve as controls. In two independent experimental series, elastase was used to induce AAA followed by an intraluminal PGG (directly or by a drug eluting balloon) treatment. All rats were followed for 28 days and euthanized. In both series, maximal infrarenal aortic diameter was measured at baseline and at termination as a measure of AAA size. In series 2, maximal internally AAA diameter was followed by ultrasound weekly. AAA tissues were analyzed for elastin integrity by millers stain, collagen deposition by masson trichrome staining. In other AAA tissue samples the mRNA level of CD45, lysyloxidase (LOX), lysyloxidase like protein 1 (LOXL1) were determined by qPCR.

RESULTS

Direct administration of PGG significantly reduced AAA expansion when compared to controls. PGG treatment resulted in a higher number and more preserved elastic fibers in the aneurysmal wall, while no significant difference was seen in the levels of CD45 and LOX mRNA levels. The drug eluting balloon (DEB) experiment showed no significant difference in AAA size observed neither macroscopically nor ultrasonically. Also the aneurysmal mRNA levels of CD45, LOX and LOXL1 were unchanged between groups.

CONCLUSION

A significant reduced expansion of AAAs was observed in the PGG group, suggesting PGG as a drug to inhibit aneurysmal progression, while administration through a DEB did not show a promising new way of administration.

Effects of tadalafil to prevent injury on corpus cavernosum after vascular or nervous peri-prostatic bundle injury. Experimental model in rats

PURPOSE

To evaluate the effects of tadalafil (TD) in preventing histological alterations of the corpus cavernosum caused by isolated lesions of cavernous nerve (ILCN) and artery (ILCA) in rats.

METHODS

Fifty male Wistar rats were randomly assigned in five groups: G1: control; G2: bilateral ILCN; G3: bilateral ILCA; G4: ILCN+TD; G5: ILCA+TD. The cavernous bodies were submitted to histomorphometry, immunohistochemistry and biochemical analysis.

RESULTS

Nerve density was significantly higher in G2 and G4 compared to control (22.62±2.84 and 19.53±3.47 vs. 15.72±1.82; respectively, p<0.05). Smooth muscle density was significantly lower in G2 and G3 in comparison to G1 (12.87±1.90 and 18.93±1.51 vs. 21.78±1.81, respectively; p<0.05). A significant decrease in the sinusoidal lumen area was observed in G2 compared to controls (5.01±1.62 vs. 9.88±3.66, respectively; p<0.05) and the blood vessel density was increased in G2 and G3 (29.32±4.13 e 20.80±2.47 vs. 10.13±2.71, p<0.05). Collagen density was higher in G3 compared to G1 (93.76±15.81 vs. 64.59±19.25; p<0.05).

CONCLUSIONS

Histomorphometric alterations caused by ILCN were more intense than those produced by vascular injury, but the collagen analyses showed more fibrosis in animals with ILCA. TD was effective in preventing the majority of the alterations induced by the periprostatic bundle injury.

A reproducible swine model of proximal descending thoracic aortic aneurysm created with intra-adventitial application of elastase

OBJECTIVE

Animal models are required to explore the mechanisms of and therapy for proximal descending thoracic aortic aneurysm (TAA). This study aimed to establish a reproducible swine model of proximal descending TAA that can further explain the occurrence and progression of proximal descending TAA.

METHODS

Eighteen Chinese Wuzhishan miniature pigs (30.32 ± 1.34 kg) were randomized into the elastase group (n = 12) and the control group (n = 6). The elastase group received intra-adventitial injections of elastase (5 mL, 20 mg/mL), and the control group received injections of physiologic saline solution. A 4-cm descending thoracic aortic segment proximal to the left subclavian artery was isolated. The distance between the left subclavian artery and the injection starting point of the descending thoracic aorta was 0.5 cm. Elastic protease was circumferentially injected intra-adventitially into the isolated segment of the aortic wall in the elastase group by a handmade bent syringe. The length of the elastic protease injection was 2 cm. An average of 12 injection points were distributed in this 2-cm aortic segment. Each injection point used about 0.4 mL of elastic protease. The distance between two injection points was about 1.5 cm. All animals underwent digital subtraction angiography preoperatively and 3 weeks after operation. Three weeks after TAA induction, aortas were harvested for biochemical and histologic measurements.

RESULTS

All animals in the elastase group developed TAAs. No aneurysms were observed in the control group. The distance between the left subclavian artery and the TAA was 8.00 ± 4.19 mm. Preoperative and postoperative aortic diameters of the elastase group were 15.42 ± 0.43 mm and 24.53 ± 1.41 mm, respectively (P < .0001). Preoperative and postoperative aortic diameters of the control group were 15.31 ± 0.33 mm and 15.57 ± 0.40 mm, respectively (P = .5211). The changes of aortic structure and composition included reduction of smooth muscle cells and degradation of elastic fibers. Levels of matrix metalloproteinases 2 and 9 were increased in TAA tissue.

CONCLUSIONS

This study established a reproducible large animal model of proximal descending TAA. This model has the same biochemical characteristics as human aneurysms in the aspects of aortic expansion, aortic middle-level degeneration, and changes in the levels of matrix metalloproteinases and provides a platform for further study.

Understanding Solar Skin Elastosis-Cause and Treatment

Photoageing, also called actinic ageing, is the main cause of prematurely aged skin. Our expertise in elastic fibers has led us to discover a process triggered in response to ultraviolet (UV) light and which upsets the balance of elastin fibers: there is too much elastin and insufficient lysyl oxidase (LOXL1) enzyme to form functional elastic fibers. This imbalance then leads to an accumulation of nonfunctional elastin, which forms aggregates. In addition to this imbalance, UV rays also induce elafin synthesis by fibroblasts. Known to be a marker of elastotic aggregates, elafin crystallizes the elastin fibers and stimulates the formation of aggregates that cannot be naturally eliminated by the skin. We developed a Hamamelis virginiana leaf extract that was able to restore both the balance between elastin and LOXL1 and to decrease the elafin synthesis to fight and correct the damage. This specific Hamamelis virginiana extract increased LOXL1 expression by twofold and decreased elafin synthesis. As a consequence, elastic fibers became functional and aggregates of unfunctional fibers decreased. The specific Hamamelis extract activity was confirmed in vivo with decreasing wrinkles and improving skin firmness.

Treatment of Annular Elastolytic Giant Cell Granuloma With Topical Tretinoin

<p>Annular elastolytic giant cell granuloma, also known as actinic granuloma, is a rare skin condition with a chronic course that is often resistant to treatment. Literature is sparse, and only a handful of case reports are available to guide treatment decisions. Typical first line treatment options include topical and intralesional steroids, topical pimecrolimus, and cryotherapy. Resistant cases have been treated with cyclosporine, systemic steroids, antimalarials, and oral retinoids. In particular, acitretin and isotretinoin have shown success in three cases. However, these medications can have side effects and require frequent lab monitoring. We present a case of a 47-year-old woman with bilateral forearm lesions consistent with annular elastolytic giant cell granuloma who was successfully treated with topical tretinoin.</p> <p><em>J Drugs Dermatol. 2017;16(7):699-700.</em></p>.

Steroid Hormones Are Key Modulators of Tissue Mechanical Function via Regulation of Collagen and Elastic Fibers

The extracellular matrix (ECM) plays an active and dynamic role that both reflects and facilitates the functional requirements of a tissue. The mature ECM of the nonpregnant cervix is drastically reorganized during pregnancy to drive changes in tissue mechanics that ensure safe birth. In this study, our research on mice deficient in the proteoglycan decorin have led to the finding that progesterone and estrogen play distinct and complementary roles to orchestrate structural reorganization of both collagen and elastic fibers in the cervix during pregnancy. Abnormalities in collagen and elastic fiber structure and tissue mechanical function evident in the cervix of nonpregnant and early pregnant decorin-null mice transiently recover for the remainder of pregnancy only to return 1 month postpartum. Consistent with the hypothesis that pregnancy levels of progesterone and estrogen may regulate ECM organization and turnover, expressions of factors required for assembly and synthesis of collagen and elastic fibers are temporally regulated, and the ultrastructure of collagen fibrils and elastic fibers is markedly altered during pregnancy in wild-type mice. Finally, utilizing ovariectomized nonpregnant decorin-null mice, we demonstrate structural resolution of collagen and elastic fibers by progesterone or estrogen, respectively, and the potential for both ECM proteins to contribute to mechanical function. These investigations advance understanding of regulatory factors that drive specialized ECM organization and contribute to an understanding of the cervical remodeling process, which may provide insight into potential complications associated with preterm birth that impact 9.6% of live births in the United States.

Synergistic Effect of Hydrogen Peroxide and Elastase on Elastic Fiber Injury In Vitro

This laboratory has previously shown that hyperoxia enhances airspace enlargement in a hamster model of elastase-induced emphysema. To further understand the mechanism responsible for this finding, the effect of oxidants on elastase activity was studied in vitro, using a radiolabeled elastic fiber matrix derived from rat pleural mesothelial cells. Matrix samples were treated with either 0.1%, 1%, 3%, or 10% hydrogen peroxide (H2O2) for 1 hr, then incubated with 1.0 μg/ml porcine pancreatic elastase for 2 hrs. Radioactivity released from the matrix was used as a measure of elastolysis. Results indicate that sequential exposure to H2O2 and elastase markedly enhanced elastolysis compared to enzyme treatment alone. A 22% increase in elastolysis was seen with 0.1% H2O2 (325 vs. 396 cpm; P < 0.05), whereas samples pretreated with 1%, 3%, and 10% H2O2 showed increases of 53% (274 vs. 420 cpm; P < 0.05), 71% (381 vs. 653 cpm; P < 0.01), and 38% (322 vs. 443 cpm; P < 0.01), respectively. Exposure to various concentrations of H2O2 alone (0.1% to 10%) produced only minimal elastolysis (<20 cpm). However, 1% H2O2 was capable of degrading peptide-free desmosine and isodesmosine, suggesting that exposure to this oxidant may reduce the stability of the elastic fiber matrix. With regard to lung diseases such as emphysema, H2O2 and other oxidants derived from inflammatory cells or the environment could possibly act as priming agents for elastase-mediated breakdown of elastic fibers, resulting in amplification of lung injury.

The effects of elastic fiber protein insufficiency and treatment on the modulus of arterial smooth muscle cells

Elastic fibers are critical for the mechanical function of the large arteries. Mechanical effects of elastic fiber protein deficiency have been investigated in whole arteries, but not in isolated smooth muscle cells (SMCs). The elastic moduli of SMCs from elastin (Eln-/-) and fibulin-4 (Fbln4-/-) knockout mice were measured using atomic force microscopy. Compared to control SMCs, the modulus of Eln-/- SMCs is reduced by 40%, but is unchanged in Fbln4-/- SMCs. The Eln-/- SMC modulus is rescued by soluble or α elastin treatment. Altered gene expression, specifically of calponin, suggests that SMC phenotypic modulation may be responsible for the modulus changes.

Elastin in large artery stiffness and hypertension

Large artery stiffness, as measured by pulse wave velocity, is correlated with high blood pressure and may be a causative factor in essential hypertension. The extracellular matrix components, specifically the mix of elastin and collagen in the vessel wall, determine the passive mechanical properties of the large arteries. Elastin is organized into elastic fibers in the wall during arterial development in a complex process that requires spatial and temporal coordination of numerous proteins. The elastic fibers last the lifetime of the organism but are subject to proteolytic degradation and chemical alterations that change their mechanical properties. This review discusses how alterations in the amount, assembly, organization, or chemical properties of the elastic fibers affect arterial stiffness and blood pressure. Strategies for encouraging or reversing alterations to the elastic fibers are addressed. Methods for determining the efficacy of these strategies, by measuring elastin amounts and arterial stiffness, are summarized. Therapies that have a direct effect on arterial stiffness through alterations to the elastic fibers in the wall may be an effective treatment for essential hypertension.

Therapeutic effects of hyaluronan on smoke-induced elastic fiber injury: does delayed treatment affect efficacy?

Aerosolized hyaluronan (HA) has been previously shown to prevent cigarette smoke-induced airspace enlargement and elastic fiber injury in mice when given concurrently with smoke. In the present study, a more stringent test of the therapeutic potential of HA was performed by delaying treatment with this agent for 1 month. After treatment with cigarette smoke for 3 h per day for 5 days per week for 1 month, mice (DBA/2J) began receiving aerosolized HA (0.1%) for 1 h prior to smoke exposure (controls were given aerosolized water). The results indicate that much of the damage to the lung elastic fibers occurred within the first several months of smoke exposure, as measured by levels of desmosine and isodesmosine (DID) in bronchoalveolar lavage fluid (BALF). In contrast to previously published studies, where concurrent administration of aerosolized HA significantly reduced BALF DID levels within 3 months of smoke exposure, the same effect was not seen until 6 months when HA treatment was delayed. However, despite the prolonged breakdown of elastic fibers in the current study, a significant reduction in airspace enlargement was observed after only 2 months of HA treatment. These findings provide further support for testing this agent in patients with pre-existing chronic obstructive pulmonary disease.

Structural analysis of gubernaculum testis in cryptorchid patients submitted to treatment with human chorionic gonadotrophin

OBJECTIVES

To make a histological and stereological analysis of gubernaculum testis elastic system fibers, collagen and striated muscle cells in patients with cryptorchidism treated with human chorionic gonadotrophin (hCG).

MATERIALS AND METHODS

Gubernacula tissue samples were obtained from 12 patients with cryptorchidism. Patients' ages ranged from 1 to 3 years (mean 1.8). Of the 12 patients, 6 were treated with hCG. The samples were stained with Masson's trichrome to highlight muscle fibers and collagen, and Weigert's resorcin-fuchsin to highlight the elastic system fibers. The volumetric density of these components was determined by stereological methods.

RESULTS

The volumetric density of collagen was increased in patients treated with hCG, ranging from 85.62% to 94.48%, while in patients not submitted to hCG treatment the volume density ranged from 52.12% to 89.46% (p=0.0052). The volumetric density of the elastic system fibers was higher in patients treated with hCG, ranging from 9.62% to 19.62%, while patients not submitted to hCG treatment the volume density of elastic system fibers was between 10.38% and 12.38% (p=0.0030). The volume density of striated muscle fibers in patients treated with hCG ranged from 4.76% to 39.16%, while and in patients not treated hCG it ranged from 3.24% to 11.14% (p=0.0052).

CONCLUSION

Gubernacular components alter significantly when submitted to treatment with hCG. Patients who underwent hCG treatment and had no complete testicular migration had an increase in the concentration of elastic and striated muscle fibers and a decrease in the volumetric density of collagen.

The development of abdominal aortic aneurysms in mice is enhanced by benzo(a)pyrene

Cigarette smoking has been strongly associated with abdominal aortic aneurysm (AAA), but the components of tobacco smoke involved in AAA have not been identified. Benzo(a)pyrene (BaP) is an important constituent in cigarette smoke capable of induction of alterations strikingly similar to the pathological changes seen during AAA development. We therefore hypothesized that BaP exposure contributes to the development of AAA. In this study, C57/B6J mice were treated with vehicle, angiotensin II (AngII) (0.72 mg/kg/day), BaP (10 mg/kg/week), or the combination of AngII and BaP, for 5 weeks, and then examined for incidence of AAA and pathological changes of the aortic wall. Results showed that incidence of AAA formation in C57/B6J mice treated with BaP and AngII was significantly higher than that in AngII-treated mice (7 of 12 compared to 2 of 12). Further, five mice in the group treated with AngII/BaP and one in the group treated with AngII exhibited AAA rupture and hematoma. BaP caused macrophage infiltration, disarray of elastic lamella, and loss of vascular smooth muscle cells (VSMCs). We conclude that BaP aggravates AAA formation and rupture in C57/B6J mice by promoting macrophage infiltration, degeneration of elastic lamella, and loss of VSMCs in the aortic wall.

Dietary iron deficiency compromises normal development of elastic fibers in the aorta and lungs of chicks

Elastic fibers play a key role in the structure and function of numerous organs that require elasticity. Elastogenesis is a complex process in which cells first produce a microfibrillar scaffold, composed of numerous structural proteins, upon which tropoelastin assembles to be cross-linked into polymeric elastin. Recently, it was demonstrated that low concentrations of free iron upregulate elastin gene expression in cultured fibroblasts. The present studies were conducted to assess whether low-iron diets would affect the deposition of elastic fibers in an in vivo model. One-day-old chicks were fed semipurified diets containing 1.3 (low), 12 (moderate), and 24 (control) mg/kg of iron. After 3 wk, chicks in the low-iron group were underweight and anemic. Their aortas were smaller with significantly thinner walls than control chicks, yet elastin or collagen content did not decrease relative to total protein. They also demonstrated a significantly lower stress-strain resistance than the controls. Electron microscopy demonstrated that aortic and lung smooth muscle cells were vacuolated and surrounded by loose extracellular matrix and disorganized elastic lamellae with diffuse and fragmented networks of elastic fibers and microfibrils. Immunohistology demonstrated that fibrillin-3 (FBN3) was disorganized and markedly reduced in amount in aortas of the low-iron chicks. Elastin messenger RNA levels were not downregulated in the tissues from the low-iron-fed chicks; however, there was a significant reduction in expression of the FBN1 and FBN3 genes compared with control chicks. The studies indicate that iron deficiency had a pronounced negative effect on elastic fiber development and suggests that fibrillin may have an important role in this pathology.

Sequelae from inadvertent long-term use of potent topical steroids

We report a case of a 53-year-old African American woman with an unusual example of striae caused by topical steroid usage and discuss the widespread usage of these products.

Versican, a major hyaluronan-binding component in the dermis, loses its hyaluronan-binding ability in solar elastosis

Versican interacts with hyaluronan (HA) at its N-terminus and with fibrillin-1 at its C terminus. As versican in the dermis connects microfibrils to the HA-rich matrix for viscoelasticity, dermal diseases may involve destruction of these complexes. A recombinant versican protein, rVN, covering the HA binding region (HABR) of human versican and a polyclonal antibody, 6084, against rVN were prepared and characterized. Blotting analyses of skin extracts with 6084 and biotin-conjugated HA revealed that versican was a major HA-binding component in the dermis. Matrix metalloprotease-12, which is expressed in areas of solar elastosis, degraded versican and abrogated its HA-binding ability. Immunohistochemical analyses revealed that the elastic materials in solar elastosis lesions were negative for 6084, but positive for 2B1, an antibody recognizing the C-terminus of versican, indicating loss of the HABR in the aggregated elastic fibers. This loss of the HA-binding ability of versican followed by HA exclusion may be responsible for the pathological and phenotypical changes observed in solar elastosis.

Remodeling of the human dermis after application of salicylate silanol

Recently, a controlled double-blind study in patients with photo-aged facial skin demonstrated the beneficial role of oral intake of silanol for skin, hair and nails. The aim of our pilot study was to investigate histologic alterations in human skin after injection of silanol. Seven healthy female caucasian volunteers with a moderate degree of photoaged skin received ten sessions of weekly injections of 0.1% salicylate silanol in the left ventral lateral forearm. The histologic features of punch biopsies of the treated area and the nontreated contralateral arm were compared and the collagen and elastic fibers quantified. Texture analysis was performed on digitalized microscopic images by analyzing the Sarkar fractal dimension or amplitudes (inertia values) after Fast Fourier transformation. The treated area revealed a statistically significant increase of the density of both collagen and elastic fibers. Texture analysis showed more compact and homogeneously distributed collagen fibers after silicon injection. Our results suggest that the application of silicon may stimulate the production of collagen and elastic fibers leading to remodeling of the dermal fiber architecture, which may explain the improvement of the skin surface observed in clinical studies.

Action of topical thyroid hormone analogue, triiodothyroacetic acid in reversing glucocorticoid-induced skin atrophy in humans

The present study concerns the effect of topical treatment with a cream formulation of triiodothyroacetic acid (TRIAC) in comparison with a placebo preparation in producing a reversal of skin atrophy induced by long-term employment of topical glucocorticoid therapy in humans. A total of 39 patients with clinically verified skin atrophy due to long-term use of topical potent glucocorticoids were randomized. The changes in skin thickness, elastic fibers, and hyaluronic acid were evaluated by means of sonography and histology. After 8 weeks' treatment, the skin thickness measured by sonography increased by 16% in the epidermis, 8% in the dermis, and epidermis + dermis in the placebo group. In the TRIAC 0.1% group, the corresponding values were 24% ( p=0.063) in the epidermis, 28% ( p=0.042) in the dermis, and 25% ( p=0.039) in the epidermis + dermis. After 8 weeks, in the placebo group, the skin thickness measured by biopsy increased by 5% in the epidermis, epidermis + dermis, and 6% in the dermis. In the TRIAC 0.1% group, the corresponding values were 31% ( p=0.041) in the epidermis, 46% ( p=0.041) in the dermis and 44% ( p=0.043) in the epidermis + dermis. After 8 weeks, the elastic fibers of moderately irregular and thickened fibers increased by 56% in the placebo group and 100% ( p=0.043) in the TRIAC 0.1 group. This study indicates that topical treatment with TRIAC appears to reverse glucocorticoid-induced skin atrophy under the narrow conditions tested.

Effects of ethanol on intracorporeal structures of the rat

OBJECTIVE

Previous studies demonstrated that acute in vitro exposure of corpus cavernosal tissue to ethanol decreased its response to field stimulation and pharmacological stimulation. In the present study we investigated the effects of chronic ethanol consumption on the ultrastructure of cavernosal smooth muscle cells, elastic fibres and collagen content.

MATERIAL AND METHODS

Fourteen adult wistar rats were divided into a control group (n = 7, fed a standard diet and tap water) and an alcoholic group (n = 7, fed a standard diet and 5% (v/v) ethanol in drinking water and by increasing the ethanol concentration for every week, at the end of 6th week 30% (v/v) ethanol concentration was attained. Same dose was given until 12th week. At the end of 12th week blood samples were obtained and the ethanol concentrations were determined. The cavernosal tissues were obtained and immunohistochemical examinations were performed.

RESULTS

Immunohistochemical analysis revealed that chronic ethanol exposure markedly decreased the content of smooth muscle cells, elastic fibres and collagen type 4.

CONCLUSION

Our findings suggest that in this animal model chronic ethanol exposure decreases the percentage of staining for smooth muscle actin, elastin, and collagen type 4 which are the key structures fundamental for erection.

Ellagic and tannic acids protect newly synthesized elastic fibers from premature enzymatic degradation in dermal fibroblast cultures

Progressive proteolytic degradation of cutaneous elastic fibers, that cannot be adequately replaced or repaired by adult dermal fibroblasts, constitutes a major feature of aging skin. Our present investigations, employing monolayer cultures of human dermal fibroblasts and organ cultures of skin biopsies, were aimed at testing whether the hydrophilic tannic acid (TA) and lipophilic ellagic acid (EA) would protect dermal elastin from exogenous and endogenous enzymatic degradation. Results from both culture systems indicated that dermal fibroblasts, maintained with TA or EA, deposit significantly more elastic fibers than untreated control cultures despite the fact that neither polyphenol enhanced transcription of elastin mRNA or cellular proliferation. Results of a pulse and chase experiment showed that pretreatment with both polyphenols enhanced biostability of tropoelastin and newly deposited elastin. Results of in vitro assays indicated that both polyphenols bound to purified elastin and significantly decreased its proteolytic degradation by elastolytic enzymes belonging to the serine proteinase, cysteine proteinase, and metallo-proteinase families. Importantly, both polyphenols also synergistically enhanced elastogenesis induced by selected elastogenic compounds in cultures of dermal fibroblasts. We propose that EA and TA may be useful for preventing proteolytic degradation of existing dermal elastic fibers and for enhancing more efficient elastogenesis in aged skin.

Mouse strain dependence of lung tissue mechanics: Role of specific extracellular matrix composition

This study analyses the differences between C57BL/10 and BALB/c mice in lung tissue micromechanical behaviour and whether specific histological characteristics are related to the mechanical profile. C57BL/10 and BALB/c subpleural lung strips were submitted to multisinusoidal deformation with frequencies ranging between 0.2 and 3.1 Hz. Tissue resistance (R), elastance (E), and hysteresivity (eta) at each frequency were determined before and 30s, 1, 2, and 3 min after acetylcholine (ACh) treatment. BALB/c mice showed higher E and R, at baseline, as well as greater amount of collagen and elastic fibres, and alpha-actin than C57BL/10 mice. However, E, R, and eta augmented with the same magnitude after ACh treatment in both strains. Baseline R was correlated with collagen fibre content and with the volume proportion of alpha-actin, while E was correlated with elastic and collagen fibres, and alpha-actin contents. In conclusion, BALB/c and C57BL/10 mice present distinct tissue mechanical properties that are accompanied by specific extracellular matrix composition and contractile structures.