Effect of in vitro mechanical compression on Epilysin (matrix metalloproteinase-28) expression in hypertrophic scars

Biochemical markers of postsurgical knee arthrofibrosis: A systematic review

Introduction

Postsurgical knee arthrofibrosis is a common complication associated with pain and limited range of motion. Although the mechanism is unclear, many biochemical and genetic markers have been identified within arthrofibrotic knees. The purpose of this systematic review is to synthesize the many biochemical and genetic markers that have been associated with surgery-induced knee arthrofibrosis in order to better guide future therapeutic endeavors.

Methods

A thorough search of literature was conducted on April 27, 2022. Seventeen studies met inclusion criteria for this systematic review. Inclusion criteria for this study were as follows: title or abstract discussed biochemical and genetic markers associated with postoperative knee arthrofibrosis, study design included human and/or animal subjects.

Results

A wide variety of genetic biomarkers (mRNA), proteins/enzymes, and cytokines were identified in both animal models and human subjects with postsurgical knee arthrofibrosis. These included various extracellular matrix-encoding mRNA sequences, matrix metalloproteinases, proteins and mRNA sequences involved in Transforming Growth Factor-β signaling, and interleukin-family cytokines to name just a few.

Conclusion

There are many biomarkers found in postsurgical arthrofibrotic knees. TGF-β, and mRNA/proteins that participate in TGF-β signaling (i.e., LOX, SERPINE1, PAI-1/Akt/mTOR, BMP-2), appear to be particularly common. Future comparative studies should aim to determine which of these are most relevant, and therefore, worthwhile therapeutic targets.

Clinical Utility of the Portable Pressure-Measuring Device for Compression Garment Pressure Measurement on Hypertrophic Scars by Burn Injury during Compression Therapy

Compression therapy for burn scars can accelerate scar maturation and improve clinical symptoms (pruritus and pain). This study objectively verified the effect of pressure garment therapy in maintaining a therapeutic pressure range for hypertrophic scars. Sixty-five participants (aged 20~70 years) with partial- or full-thickness burns, Vancouver scar scale score of ≥4, and a hypertrophic scar of ≥4 cm × 4 cm were enrolled. Compression pressure was measured weekly using a portable pressure-monitoring device to regulate this pressure at 15~25 mmHg for 2 months. In the control group, the compression garment use duration and all other burn rehabilitation measures were identical except for compression monitoring. No significant difference was noted in the initial evaluations between the two groups (p > 0.05). The improvements in the amount of change in scar thickness (p = 0.03), erythema (p = 0.03), and sebum (p = 0.02) were significantly more in the pressure monitoring group than in the control group. No significant differences were noted in melanin levels, trans-epidermal water loss, or changes measured using the Cutometer® between the two groups. The efficacy of compression garment therapy for burn-related hypertrophic scars can be improved using a pressure-monitoring device to maintain the therapeutic range.

Comparison between the portable pressure measuring device and PicoPress® for garment pressure measurement on hypertrophic burn scar during compression therapy

PURPOSE

The current standard treatment for hypertrophic scars following burn injury is pressure garment therapy. The experimenters developed the novel portable pressure measuring device using silicon piezoresistive sensors. As PicoPress® is the most accurate (i.e., lowest variation and error) manometric sensor for pressure measurement, we sought to compare and examine the accuracy of the novel device regarding in vitro pressure measurements at the hypertrophic scar-pressure garment interface.

METHODS

The novel device was designed to operate in non-corrosive media, such as air. The device can use up to six pressure sensing points and was developed to adjust the number of pressure sensors according to the size of the scar. Pressure measurements were acquired through a readout circuit consisting of an analog-to-digital converter, a microprocessor, and a Bluetooth transmission module for wireless data transmission to an external device. All signals were converted into mean pressure expressed in millimeters of mercury (mmHg). The mean pressure values measured by the sensors were compared to those obtained from PicoPress®. 55 garment pressures recordings were obtained from the sensors over this study conducted in 2018-February 2020. We then analyzed the test-retest reliability using the intraclass correlation coefficients (ICC). PicoPress® was also employed in the same pressure garments for obtaining similar measurements. A two way random effects model ICC with 95% confidence intervals was used to compare the mean pressure values obtained from the silicon piezoresistive sensors to the PicoPress® measurements.

RESULTS

The test-retest reliability of the pressure sensors was close to the acceptable level for clinical use regarding stationary interface pressure measurement (ICC = 0.99, 95% CI 0.990-0.997). The mean pressure obtained from the silicon piezoresistive pressure sensors showed an accordance with the measurements from PicoPress® (ICC = 0.97, 95% CI 0.947-0.985).

CONCLUSION

The novel device may present a viable alternative to PicoPress® for garment pressure measurements. In addition, the novel device improves adaptability to the hypertrophic scar shape and size. Complementary characteristics such as wireless transmission to an external device may allow burn patients to continuously wear the device for real-time measurements during pressure garment therapy, thus improving existing devices including PicoPress®.

Dynamic expression of MMP28 during cranial morphogenesis

Matrix metalloproteinases (MMPs) are a large family of proteases comprising 24 members in vertebrates. They are well known for their extracellular matrix remodelling activity. MMP28 is the latest member of the family to be discovered. It is a secreted MMP involved in wound healing, immune system maturation, cell survival and migration. MMP28 is also expressed during embryogenesis in human and mouse. Here, we describe the detailed expression profile of MMP28 in Xenopus laevis embryos. We show that MMP28 is expressed maternally and accumulates at neurula and tail bud stages specifically in the cranial placode territories adjacent to migrating neural crest cells. As a secreted MMP, MMP28 may be required in neural crest-placode interactions. This article is part of a discussion meeting issue 'Contemporary morphogenesis'.

Nonsurgical Management of Hypertrophic Scars: Evidence-Based Therapies, Standard Practices, and Emerging Methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.

Clinical efficacy of intermittent magnetic pressure therapy for ear keloid treatment after excision

BACKGROUND

Keloids are benign fibro-proliferative lesion, related to excessive inflammatory reactions in certain anatomical areas, including the auricles. Their specific etiology remains unclear; nonetheless they exhibit tumor-like characteristics of significant recurrence and cause emotional distress, even with various treatment strategies. We applied intermittent magnetic pressure therapy on ear keloids in combination with surgical excision, and present its effectiveness herein.

METHODS

Ear keloid patients were treated with surgical excision followed by magnetic pressure therapy. The keloid tissues underwent excision and keloid marginal flaps were utilized for wound closure. Intermittent magnetic pressure therapy was applied 2 weeks after the surgical procedure. The pressure therapy consisted of a 3-hour application and 2-hour resting protocol (9 hr/day), and lasted for 6 months. The results were analyzed 6 months after the therapeutic procedures, using the scar assessment scale.

RESULTS

Twenty-two ear keloids from 20 patients were finally reviewed. Among the keloids that completed the therapeutic course, 20 ear keloids out of 22 in total (90.9%) were successfully eradicated. Two patients (2 keloids) exhibited slight under-correction. Postoperative complications such as wound dehiscence or surgical site infection were not noted. The scar assessment scale demonstrated a significant improvement in each index. The intermittent pressure therapy led to patient compliance, and avoided pressure-related pain and discomfort.

CONCLUSION

Excision followed by intermittent pressure application using a magnet successfully reduced the burden of fibro-proliferative keloids, and had good patient compliance. The role of intermittent pressure application and resting should be studied with regard to keloid tissue remodeling.

Identification of MMP28 as a biomarker for the differential diagnosis of idiopathic pulmonary fibrosis

Background and objective

Idiopathic Pulmonary Fibrosis (IPF) is a progressive disease of unknown etiology. The diagnosis is based on the identification of a pattern of usual interstitial pneumonia either by high resolution computed tomography and/or histology. However, a similar pattern can be observed in other fibrotic lung disorders, and precise diagnosis remains challenging. Studies on biomarkers contributing to the differential diagnosis are scanty, and still in an exploratory phase. Our aim was to evaluate matrix metalloproteinase (MMP)-28, which has been implicated in abnormal wound healing, as a biomarker for distinguishing IPF from fibrotic non-IPF patients.

Methods

The cell localization of MMP28 in lungs was examined by immunohistochemistry and its serum concentration was measured by ELISA in two different populations. The derivation cohort included 82 IPF and 69 fibrotic non-IPF patients. The validation cohort involved 42 IPF and 41 fibrotic non-IPF patients.

Results

MMP28 was detected mainly in IPF lungs and localized in epithelial cells. In both cohorts, serum concentrations of MMP28 were significantly higher in IPF versus non-IPF (mostly with lung fibrosis associated to autoimmune diseases and chronic hypersensitivity pneumonitis) and healthy controls (ANOVA, p<0.0001). The AUC of the derivation cohort was 0.718 (95%CI, 0.635–0.800). With a cutoff point of 4.5 ng/mL, OR was 5.32 (95%CI, 2.55–11.46), and sensitivity and specificity of 70.9% and 69% respectively. The AUC of the validation cohort was 0.690 (95%CI, 0.581–0.798), OR 4.57 (95%CI, 1.76–12.04), and sensitivity and specificity of 69.6% and 66.7%. Interestingly, we found that IPF patients with definite UIP pattern on HRCT showed higher serum concentrations of MMP28 than non-IPF patients with the same pattern (7.8±4.4 versus 4.9±4.4; p = 0.04). By contrast, no differences were observed when IPF with possible UIP-pattern were compared (4.7±3.2 versus 3.9±3.0; p = 0.43).

Conclusion

These findings indicate that MMP28 might be a useful biomarker to improve the diagnostic certainty of IPF.

MicroRNA-125b-1-3p mediates intervertebral disc degeneration in rats by targeting teashirt zinc finger homeobox 3

The present study aimed to investigate the association between Teashirt zinc finger homeobox 3 (TSHZ3) and the nucleus pulposus (NP) of intervertebral discs in rats. TSHZ3 was identified from the differentially expressed micro (mi)RNAs in the expression profile of GSE63492 by identifying the overlapped target genes of microRNA (miR)-125b-1-3p across different databases. TSHZ3 small interfering RNA (siRNA) and an miR-125b-1-3p inhibitor were used for gene silencing and gene silencing efficiency was assessed by reverse transcription-polymerase chain reaction. Western blotting was performed to detect the cell cycle proteins cyclin D1 and B1 and the proteins associated with DNA damage in NP. The results revealed that in normal NPs, the expression of TSHZ3 increased following the inhibition of miR-125b-1-3p and in DNA damaged NPs, the expression of TSHZ3 was associated with the degree of DNA damage. The present study demonstrated that TSHZ3, as a target gene of miR-125b-1-3p, may serve a protective role in intervertebral disc degeneration and that this protective function may be inhibited by high levels of miR-125b-1-3p.

Compression therapy affects collagen type balance in hypertrophic scar

BACKGROUND

The effects of pressure on hypertrophic scar are poorly understood. Decreased extracellular matrix deposition is hypothesized to contribute to changes observed after pressure therapy. To examine this further, collagen composition was analyzed in a model of pressure therapy in hypertrophic scar.

MATERIALS AND METHODS

Hypertrophic scars created on red Duroc swine (n = 8) received pressure treatment (pressure device mounting and delivery at 30 mm Hg), sham treatment (device mounting and no delivery), or no treatment for 2 wk. Scars were assessed weekly and biopsied for histology, hydroxyproline quantification, and gene expression analysis. Transcription levels of collagen precursors COL1A2 and COL3A1 were quantified using reverse transcription-polymerase chain reaction. Masson trichrome was used for general collagen quantification, whereas immunofluorescence was used for collagen types I and III specific quantification.

RESULTS

Total collagen quantification using hydroxyproline assay showed a 51.9% decrease after pressure initiation. Masson trichrome staining showed less collagen after 1 (P < 0.03) and 2 wk (P < 0.002) of pressure application compared with sham and untreated scars. Collagen 1A2 and 3A1 transcript decreased by 41.9- and 42.3-fold, respectively, compared with uninjured skin after pressure treatment, whereas a 2.3- and 1.3-fold increase was seen in untreated scars. This decrease was seen in immunofluorescence staining for collagen types I (P < 0.001) and III (P < 0.04) compared with pretreated levels. Pressure-treated scars also had lower levels of collagen I and III after pressure treatment (P < 0.05) compared with sham and untreated scars.

CONCLUSIONS

These results demonstrate the modulation of collagen after pressure therapy and further characterize its role in scar formation and therapy.

A histological study on the effect of pressure therapy on the activities of myofibroblasts and keratinocytes in hypertrophic scar tissues after burn

Although pressure therapy (PT) has been widely used as the first-line treatment for hypertrophic scars (HS), the histopathological changes involved have seldom been studied. This study aimed to examine the longitudinal effect of PT on the histopathological changes in HS. Ten scar samples were selected from six patients with HS after burn and they were given a standardized PT intervention for 3 months while 16 scar samples were obtained on those without PT. The scar biopsies were collected pre-treatment, 1 and 3 months post-intervention for both clinical and histopathological examinations. Clinical assessments demonstrated significant improvement in the thickness and redness of the scars after PT. Histological examination revealed that cell density in the dermal layer was markedly reduced in the 3-months post-pressurized scar tissues, while the arrangement of the collagen fiber was changed from nodular to wave-like pattern. The α-smooth muscle actin immunoreactivity was significantly decreased after 1-month pressure treatment. There was a significant reduction of myofibroblasts population and a concomitant increase in the apoptotic index in the dermal layer in the 3-months' post-pressurized scars. A significant negative correlation was found between the myofibroblasts population and the apoptotic index. The keratinocyte proliferation was found inhibited after PT. Results demonstrated that PT appeared to promote HS maturation by inhibiting the keratinocyte proliferation and suppressing myofibroblasts population, the latter possibly via apoptosis.

Mechanical compression upregulates MMP9 through SMAD3 but not SMAD2 modulation in hypertrophic scar fibroblasts

PURPOSE

Activation of transforming growth factor-β (TGF-β) signaling and matrix metalloproteinases are involved in hypertrophic scar (HS) formation. Compression therapy is known to be an effective approach for the treatment of hypertrophic scarring; however, the underlying molecular mechanisms remain poorly understood. We investigated the relationship between TGF-β signaling activation and matrix metalloproteinases in HS fibroblasts during mechanical compressive stress.

MATERIALS AND METHODS

Two groups of skin tissue from HS and the nearby normal tissue were obtained from surgical patients and analyzed. Primary fibroblasts from the HS tissue and normal fibroblasts were isolated. Pressure therapy was recapitulated in an in vitro three-dimensional culture model, using mechanical stress produced with the Flexcell FX-4000C Compression Plus System. Quantitative real-time PCR (qPCR) was used to analyze the gene expression profiles in skin tissue and cultured primary cells exposed to compressive stress. Knockdown of SMAD2 and SMAD3 was performed using their specific siRNA in HS and normal fibroblasts subjected to compressive stress, and gene expression was examined by qPCR and Western blot.

RESULTS

There was a significant upregulation of the mRNA expression of matrix metalloproteinase-2 (MMP2) and MMP9 in primary HS fibroblasts in response to mechanical stress. In contrast, the mRNA levels of collagen I and collagen III were downregulated in primary HS fibroblasts compared with those in the control cells. SiRNA-mediated knockdown of SMAD3 in the primary fibroblasts exposed to mechanical stress resulted in a decrease in the expression of MMP9 compared to control cells.

CONCLUSION

These results demonstrate that compressive stress upregulates MMP9 by SMAD3 but not by SMAD2.

Update on hypertrophic scar treatment

Scar formation is a consequence of the wound healing process that occurs when body tissues are damaged by a physical injury. Hypertrophic scars and keloids are pathological scars resulting from abnormal responses to trauma and can be itchy and painful, causing serious functional and cosmetic disability. The current review will focus on the definition of hypertrophic scars, distinguishing them from keloids and on the various methods for treating hypertrophic scarring that have been described in the literature, including treatments with clearly proven efficiency and therapies with doubtful benefits. Numerous methods have been described for the treatment of abnormal scars, but to date, the optimal treatment method has not been established. This review will explore the differences between different types of nonsurgical management of hypertrophic scars, focusing on the indications, uses, mechanisms of action, associations and efficacies of the following therapies: silicone, pressure garments, onion extract, intralesional corticoid injections and bleomycin.

Effect of a gelatin hydrogel incorporating epiregulin on human keratinocyte growth

Ionic hydrogels are biocompatible interesting candidates for tissue-engineering applications, such as the creation of artificial skin, as they can also be used, along with growth factors and cells grown in vitro, for developing bioengineered tissues to be implanted. Among the growth factors that can be used to induce keratinocytes growth in vitro, epiregulin, a broad-specificity epidermal growth factor (EGF) family member, has been shown to be more effective than EGF and transforming growth factor-alpha (TGF-α) in promoting re-epithelization in vitro. To produce a drug-delivery hydrogel for epiregulin, bovine gelatin was cross-linked with poly(glutamic acid) (PLG) in the presence of epiregulin (5-50 ng/ml). Spontaneously immortalized human keratinocytes (HaCaT) were seeded on unloaded and epiregulin-loaded hydrogels and cell adhesion was evaluated after 6 h. Moreover, cell proliferation and stratification, cytokeratins (K5, K10), differentiation markers (filaggrin and transglutaminase-1 (TG-1)) and matrix metalloproteinases (MMP-2, MMP-9 and MMP-28) expression were evaluated after 7 days. The presence of epiregulin induced an increase in cell proliferation, stratification and K5 expression along with MMP-9 and MMP-28 expression, while all differentiation markers expression (K10, filaggrin, TG-1) was decreased. These data indicated that a simple hydrogel loaded with epiregulin could be an effective tool for skin tissue engineering.

Clinical relevance of cyclooxygenase-2 and matrix metalloproteinases (MMP-2 and MT1-MMP) in human breast cancer tissue

Breast cancer (BC) is the most common neoplasm among women in most developed countries, including Egypt. Elevated levels of certain proteins in human BC are associated with unfavorable prognosis and progressive stages of the disease. The aim of our study was to evaluate the protein expression profile and prognostic significance of cyclooxygenase-2 (COX-2), matrix metalloproteinase-2 (MMP-2), MMP-9 and membrane type 1-MMP (MT1-MMP) and their interaction in operable BC patients. The protein expression of COX-2, MMP-2 and MT1-MMP were evaluated by western blot technique, whereas enzymatic activity of MMP-2 and MMP-9 was determined by zymography in 47 breast cancer patients as well as normal adjacent tissues. Also, the correlation between these proteins and age, tumor size, LN stage, TNM stage, estrogen receptor, progesterone receptor, disease-free survival, and overall survival (OS) has been investigated. As compared to adjacent normal tissues, COX-2, MMP-2 and MT1-MMP were over-expressed in 43, 64, and 60 % of tumor tissues, respectively. In the same pattern, the activity of MMP-2 (62 %) and MMP-9 (45 %) was elevated in BC tissues. Multivariate analysis showed a positive correlation between the protein expression of COX-2, MMP-2, and MT1-MMP and the activity of MMP-2 and MMP-9 in BC patients. However, the enzymatic activity showed no correlation with clinicopathological features. This study confirms the preclinical evidence that COX-2 increased the expression of MT1-MMP, which in turn activates MMP-2. The lack of correlation with clinicopathological features, OS or disease-free survival ascertains the complexity of tumor progression and metastasis with many pro- and counter regulatory factors.

Matrix metalloproteinase-28 deletion amplifies inflammatory and extracellular matrix responses to cardiac aging

To determine if matrix metalloproteinase (MMP)-28 mediates cardiac aging, wild-type (WT) and MMP-28-/- young (7 ± 1 months, n = 9 each) and old (20 ± 2 months, n = 7 each) female mice were evaluated. MMP-28 expression in the left ventricle (LV) increased 42% in old WT mice compared to young controls (p < 0.05). By Doppler echocardiography, LV function declined at 20 ± 2 months of age for both groups. However, dobutamine stress responses were similar, indicating that cardiac reserve was maintained. Plasma proteomic profiling revealed that macrophage inflammatory protein (MIP)-1 α, MIP-1β and MMP-9 plasma levels did not change in WT old mice but were significantly elevated in MMP-28-/- old mice (all p < 0.05), suggestive of a higher inflammatory status when MMP-28 is deleted. RT2-PCR gene array and immunoblotting analyses demonstrated that MIP-1α and MMP-9 gene and protein levels in the LV were also higher in MMP-28-/- old mice (all p < 0.05). Macrophage numbers in the LV increased similarly in WT and MMP-28-/- old mice, compared to respective young controls (both p < 0.05). Collagen content was not different among the WT and MMP-28-/- young and old mice. In conclusion, LV inflammation increases with age, and MMP-28 deletion further elevates inflammation and extracellular matrix responses, without altering macrophage numbers or collagen content.

Gelatin-based anionic hydrogel as biocompatible substrate for human keratinocyte growth

Ionic hydrogels are biocompatible candidates for skin tissue engineering. Two hydrogels synthesized by crosslinking gelatin with polylysine (positively charged HG1) or polyglutamic acid (negatively charged HG2) were tested using spontaneously immortalized human keratinocytes (HaCaT). HaCaT cells displayed higher adhesion and proliferation onto HG2, forming a continuous and stratified epithelium after 7 days. Moreover HaCaT cells grown onto HG2 showed a decreased Epilysin and Filaggrin expression, while transglutaminase-1 expression was increased. Those data indicate that human keratinocyte can form a stratified epithelium onto HG2 that could therefore be an useful tool for skin tissue engineering.

Human matrix metalloproteinases: an ubiquitarian class of enzymes involved in several pathological processes

Human matrix metalloproteinases (MMPs) belong to the M10 family of the MA clan of endopeptidases. They are ubiquitarian enzymes, structurally characterized by an active site where a Zn(2+) atom, coordinated by three histidines, plays the catalytic role, assisted by a glutamic acid as a general base. Various MMPs display different domain composition, which is very important for macromolecular substrates recognition. Substrate specificity is very different among MMPs, being often associated to their cellular compartmentalization and/or cellular type where they are expressed. An extensive review of the different MMPs structural and functional features is integrated with their pathological role in several types of diseases, spanning from cancer to cardiovascular diseases and to neurodegeneration. It emerges a very complex and crucial role played by these enzymes in many physiological and pathological processes.

Long-term stent use can prevent postoperative canal stenosis in patients with congenital aural atresia

OBJECTIVE

Postoperative external auditory canal (EAC) stenosis is the most common complication after congenital aural atresia (CAA) surgery. The authors applied an ear mold or hearing aid as an EAC stent following surgery and analyzed the impact on postoperative EAC stenosis.

STUDY DESIGN

Historical cohort study.

SETTING

A tertiary hospital.

SUBJECTS AND METHODS

Ninety-six patients who underwent canaloplasty between 1996 and 2010 were included in this study. To discover factors contributing to postoperative EAC stenosis, clinical parameters, including age, sex, Marx grading, Schuknecht classification, Jahrsdoerfer score, surgical approach, triamcinolone injection, and use of stenting with an ear mold or hearing aid, were reviewed and analyzed. Each stent was used for at least 6 months postoperatively. Pure-tone audiometry was performed preoperatively and 3, 6, and 12 months after canaloplasty.

RESULTS

Postoperative EAC stenosis was the most common postoperative complication, occurring in 8 (8.2%) cases with a mean time interval of 4.1 months. For patients who did not use an ear mold or a hearing aid during the postoperative follow-up period, the relative risk for the development of postoperative EAC stenosis was 5.125 (95% confidence interval, 1.428-18.400; P = .023). Other factors did not show an association with postoperative stenosis. Preoperative air-bone gap (ABG) was 49.00 dB, and closure of the ABG within 30 dB was obtained in 56.9%, 58.1%, and 48.7% of patients at the 3-, 6-, and 12-month follow-up, respectively.

CONCLUSION

Stenting with an ear mold or hearing aid might be a useful method for preventing postoperative EAC stenosis in CAA patients.

Chronic exposure to cigarette smoke increases matrix metalloproteinases and Filaggrin mRNA expression in oral keratinocytes: role of nicotine stimulation

The vegetal alkaloid nicotine has been proved to modify the expression of many keratinocyte markers. In this study, the basal expression of MMP-2, MMP-9, MMP-28, and Filaggrin has been evaluated in oral keratinocytes, in order to collect information about the ability of cigarette smoke to modify the basal expression pattern of these key enzymes in the absence of evident clinical signs in the oral epithelium. MMP-2, MMP-9, MMP-28, and Filaggrin basal expression was investigated by RT-PCR in oral keratinocytes derived from smokers (n=11), non-smokers (n=11), and ex-smokers (n=6) healthy volunteers. Moreover keratinocytes from non-smokers volunteers were stimulated in vitro by a single dose administration of nicotine (10 μM) in order to estimate the effect of nicotinic receptors activation on the basal expression of the studied markers. RT-PCR analysis showed that all the markers studied were overexpressed in keratinocytes from smoker donors compared to control keratinocytes, while a single dose of nicotine was able to induce only Filaggrin expression in keratinocytes from non-smoking donors. Markers expression in ex-smoker donors was similar to that observed in normal non-smoker donors. These data indicate for the first time that cigarette smoking affects basal expression of some important markers in oral mucosa keratinocytes in vivo in the absence of clinical signs and that smoke quitting restores basal expression levels of these markers.

Matrix metalloproteinase 28, a novel matrix metalloproteinase, is constitutively expressed in human intervertebral disc tissue and is present in matrix of more degenerated discs

Introduction

The regulation and elevation in expression of the catabolic matrix metalloproteinases (MMPs) is of high importance in the human intervertebral disc since upregulation of these matrix-degrading enzymes results in matrix destruction associated with disc degeneration. MMP28 (epilysin) is a newly discovered MMP believed to play a role in matrix composition and turnover in skin. It is present in basal keratinocytes where its expression is upregulated with wound repair, and in cartilage and synovium where it is upregulated in osteoarthritis. Recent work has shown that mechanical compression can act to modulate expression of MMP28. The expression of MMP28 is unexplored in the intervertebral disc.

Methods

Following approval by our human subjects institutional review board, we employed microarray analyses to evaluate in vivo expression of MMP28 and the MMP28 precursor in human disc tissue, and utilized immunohistochemistry to determine cellular and extracellular matrix localization of MMP28 in 35 human disc tissue specimens. The percentage of cells positive for MMP28 immunocytochemical localization was also determined.

Results

The present work documents the expression and presence of MMP28 in cells and extracellular matrix (ECM) of the human intervertebral disc. Gene expression levels in human disc tissue were detectable for both MMP28 and the MMP28 precursor. MMP28 cytoplasmic localization was present in cells of the outer annulus; it was also present in some, but not all, cells of the inner annulus and nucleus. MMP28 was not found in the ECM of healthier Grade I to II discs, but was identified in the ECM of 61% of the more degenerated Grade III to V discs (P = 0.0018). There was a significant difference in cellular MMP28 distribution in the disc (P = 0.008): the outer annulus showed the largest percentage of cells positive for MMP28 immunolocalization, followed by the inner annulus and then the nucleus. Herniated discs showed a significantly greater proportion of MMP28-positive cells compared with nonherniated discs (P = 0.034).

Conclusions

Findings presented here show the first documentation of intervertebral disc expression and production of MMP28. MMP28 was found in both disc cell cytoplasm and in the ECM of more degenerated specimens, with greater cellular localization in the outer annulus and in herniated disc specimens. These findings are important because of the key role of MMPs in disc turnover and homeostasis, and previous indications of a role for this MMP in matrix repair and matrix turnover in other tissues. Our data, which show the presence of MMP28 in human disc tissue, suggest that MMP28 may have a potentially important role in ECM modulation in the healthy and degenerating disc.

Hypertrophic scars and keloids--a review of their pathophysiology, risk factors, and therapeutic management

BACKGROUND

Hypertrophic scars and keloids result from an abnormal fibrous wound healing process in which tissue repair and regeneration-regulating mechanism control is lost. These abnormal fibrous growths present a major therapeutic dilemma and challenge to the plastic surgeon because they are disfiguring and frequently recur.

OBJECTIVE

To provide updated clinical and experimental information on hypertrophic scars and keloids so that physicians can better understand and properly treat such lesions.

METHODS

A Medline literature search was performed for relevant publications and for diverse strategies for management of hypertrophic scars and keloids.

CONCLUSION

The growing understanding of the molecular processes of normal and abnormal wound healing is promising for discovery of novel approaches for the management of hypertrophic scars and keloids. Although optimal treatment of these lesions remains undefined, successful healing can be achieved only with combined multidisciplinary therapeutic regimens.

Biomechanical regulation of cell orientation and fate

Biomechanical regulation of tumor phenotypes have been noted for several decades, yet the function of mechanics in the co-evolution of the tumor epithelium and altered cancer extracellular matrix has not been appreciated until fairly recently. In this review, we examine the dynamic interaction between the developing epithelia and the extracellular matrix, and discuss how similar interactions are exploited by the genetically modified epithelium during tumor progression. We emphasize the process of mechanoreciprocity, which is a phenomenon observed during epithelial transformation, in which tension generated within the extracellular microenvironment induce and cooperate with opposing reactive forces within transformed epithelium to drive tumor progression and metastasis. We highlight the importance of matrix remodeling, and present a new, emerging paradigm that underscores the importance of tissue morphology as a key regulator of epithelial cell invasion and metastasis.

Epilysin (MMP-28)--structure, expression and potential functions

Epilysin (MMP-28) is the newest member of the matrix metalloproteinase (MMP) family of extracellular proteases. Together the MMPs can degrade almost all components of the extracellular matrix (ECM). MMPs also regulate cell behaviour by releasing growth factors and biologically active peptides from the ECM by modulating cell surface receptors and adhesion molecules and by regulating the activity of mediators of the inflammatory pathways. Epilysin differs from most other MMPs as it is expressed in a number of normal tissues, suggestive of functions in tissue homeostasis. The epilysin homologue in Xenopus laevis (XMMP-28) is expressed in neural tissues, where it cleaves the neural cell adhesion molecule. Enhanced expression of epilysin has been observed in basal keratinocytes during wound healing and in different forms of cancer. There are, however, also reports on the downregulation of epilysin in malignant cells. The roles of epilysin in cancer seem to vary based on tumor type and stage of the disease. Importantly, epilysin can induce stable epithelial to mesenchymal transition (EMT) when overexpressed in epithelial lung carcinoma cells. Transforming growth factor beta (TGF-beta) is a crucial mediator of this process, which was characterized by the loss of E-cadherin and increased cell migration and invasion. Current results suggest a plausible interaction between epilysin and TGF-beta also under physiological circumstances, where epilysin activity may not induce EMT but, instead, trigger less permanent changes in TGF-beta signalling and cell motility.

Postburn Scars: An Update

Burn wounds give rise to the largest scars we can find in human pathology, influencing patients' quality of life. Despite the improved knowledge on pathophysiology, efficacy of the various treatments remains unsatisfactory. In this short review recent literature is examined with a focus on recent data on postburn pathological scars epidemiology and risk factors, which underline the high prevalence and the long evolution, pointing to identify this illness as a systemic inflammatory one, more frequent in women and in those of younger age, regulated by local factors relevant in wound healing.

Nonsurgical management of hypertrophic scars: evidence-based therapies, standard practices, and emerging methods

Hypertrophic scars, resulting from alterations in the normal processes of cutaneous wound healing, are characterized by proliferation of dermal tissue with excessive deposition of fibroblast-derived extracellular matrix proteins, especially collagen, over long periods, and by persistent inflammation and fibrosis. Hypertrophic scars are among the most common and frustrating problems after injury. As current aesthetic surgical techniques become more standardized and results more predictable, a fine scar may be the demarcating line between acceptable and unacceptable aesthetic results. However, hypertrophic scars remain notoriously difficult to eradicate because of the high recurrence rates and the incidence of side effects associated with available treatment methods. This review explores the various treatment methods for hypertrophic scarring described in the literature including evidence-based therapies, standard practices, and emerging methods, attempting to distinguish those with clearly proven efficiency from anecdotal reports about therapies of doubtful benefits while trying to differentiate between prophylactic measures and actual treatment methods. Unfortunately, the distinction between hypertrophic scar treatments and keloid treatments is not obvious in most reports, making it difficult to assess the efficacy of hypertrophic scar treatment.

In vitro and in vivo MMP gene expression localisation by In Situ-RT-PCR in cell culture and paraffin embedded human breast cancer cell line xenografts

Background

Members of the matrix metalloproteinase (MMP) family of proteases are required for the degradation of the basement membrane and extracellular matrix in both normal and pathological conditions. In vitro, MT1-MMP (MMP-14, membrane type-1-MMP) expression is higher in more invasive human breast cancer (HBC) cell lines, whilst in vivo its expression has been associated with the stroma surrounding breast tumours. MMP-1 (interstitial collagenase) has been associated with MDA-MB-231 invasion in vitro, while MMP-3 (stromelysin-1) has been localised around invasive cells of breast tumours in vivo. As MMPs are not stored intracellularly, the ability to localise their expression to their cells of origin is difficult.

Methods

We utilised the unique in situ-reverse transcription-polymerase chain reaction (IS-RT-PCR) methodology to localise the in vitro and in vivo gene expression of MT1-MMP, MMP-1 and MMP-3 in human breast cancer. In vitro, MMP induction was examined in the MDA-MB-231 and MCF-7 HBC cell lines following exposure to Concanavalin A (Con A). In vivo, we examined their expression in archival paraffin embedded xenografts derived from a range of HBC cell lines of varied invasive and metastatic potential. Mouse xenografts are heterogenous, containing neoplastic human parenchyma with mouse stroma and vasculature and provide a reproducible in vivo model system correlated to the human disease state.

Results

In vitro, exposure to Con A increased MT1-MMP gene expression in MDA-MB-231 cells and decreased MT1-MMP gene expression in MCF-7 cells. MMP-1 and MMP-3 gene expression remained unchanged in both cell lines. In vivo, stromal cells recruited into each xenograft demonstrated differences in localised levels of MMP gene expression. Specifically, MDA-MB-231, MDA-MB-435 and Hs578T HBC cell lines are able to influence MMP gene expression in the surrounding stroma.

Conclusion

We have demonstrated the applicability and sensitivity of IS-RT-PCR for the examination of MMP gene expression both in vitro and in vivo. Induction of MMP gene expression in both the epithelial tumour cells and surrounding stromal cells is associated with increased metastatic potential. Our data demonstrate the contribution of the stroma to epithelial MMP gene expression, and highlight the complexity of the role of MMPs in the stromal-epithelial interactions within breast carcinoma.