Fasciola hepatica is refractory to complement killing by preventing attachment of mannose binding lectin (MBL) and inhibiting MBL-associated serine proteases (MASPs) with serpins.

The complement system is a first-line innate host immune defence against invading pathogens. It is activated via three pathways, termed Classical, Lectin and Alternative, which are mediated by antibodies, carbohydrate arrays or microbial liposaccharides, respectively. The three complement pathways converge in the formation of C3-convertase followed by the assembly of a lethal pore-like structure, the membrane attack complex (MAC), on the pathogen surface. We found that the infectious stage of the helminth parasite Fasciola hepatica, the newly excysted juvenile (NEJ), is resistant to the damaging effects of complement. Despite being coated with mannosylated proteins, the main initiator of the Lectin pathway, the mannose binding lectin (MBL), does not bind to the surface of live NEJ. In addition, we found that recombinantly expressed serine protease inhibitors secreted by NEJ (rFhSrp1 and rFhSrp2) selectively prevent activation of the complement via the Lectin pathway. Our experiments demonstrate that rFhSrp1 and rFhSrp2 inhibit native and recombinant MBL-associated serine proteases (MASPs), impairing the primary step that mediates C3b and C4b deposition on the NEJ surface. Indeed, immunofluorescence studies show that MBL, C3b, C4b or MAC are not deposited on the surface of NEJ incubated in normal human serum. Taken together, our findings uncover new means by which a helminth parasite prevents the activation of the Lectin complement pathway to become refractory to killing via this host response, in spite of presenting an assortment of glycans on their surface.

Current Approaches to Wound Repair in Burns: How far Have we Come From Cover to Close? A Narrative Review.

Burn injuries are a significant global health concern, with more than 11 million people requiring medical intervention each year and approximately 180,000 deaths annually. Despite progress in health and social care, burn injuries continue to result in socioeconomic burdens for victims and their families. The management of severe burn injuries involves preventing and treating burn shock and promoting skin repair through a two-step procedure of covering and closing the wound. Currently, split-thickness/full-thickness skin autografts are the gold standard for permanent skin substitution. However, deep burns treated with split-thickness skin autografts may contract, leading to functional and appearance issues. Conversely, defects treated with full-thickness skin autografts often result in more satisfactory function and appearance. The development of tissue-engineered dermal templates has further expanded the scope of wound repair, providing scar reductive and regenerative properties that have extended their use to reconstructive surgical interventions. Although their interactions with the wound microenvironment are not fully understood, these templates have shown potential in local infection control. This narrative review discusses the current state of wound repair in burn injuries, focusing on the progress made from wound cover to wound closure and local infection control. Advancements in technology and therapies hold promise for improving the outcomes for burn injury patients. Understanding the underlying mechanisms of wound repair and tissue regeneration may provide new insights for developing more effective treatments in the future.

The Lectin Pathway of the Complement System-Activation, Regulation, Disease Connections and Interplay with Other (Proteolytic) Systems.

The complement system is the other major proteolytic cascade in the blood of vertebrates besides the coagulation-fibrinolytic system. Among the three main activation routes of complement, the lectin pathway (LP) has been discovered the latest, and it is still the subject of intense research. Mannose-binding lectin (MBL), other collectins, and ficolins are collectively termed as the pattern recognition molecules (PRMs) of the LP, and they are responsible for targeting LP activation to molecular patterns, e.g., on bacteria. MBL-associated serine proteases (MASPs) are the effectors, while MBL-associated proteins (MAps) have regulatory functions. Two serine protease components, MASP-1 and MASP-2, trigger the LP activation, while the third component, MASP-3, is involved in the function of the alternative pathway (AP) of complement. Besides their functions within the complement system, certain LP components have secondary ("moonlighting") functions, e.g., in embryonic development. They also contribute to blood coagulation, and some might have tumor suppressing roles. Uncontrolled complement activation can contribute to the progression of many diseases (e.g., stroke, kidney diseases, thrombotic complications, and COVID-19). In most cases, the lectin pathway has also been implicated. In this review, we summarize the history of the lectin pathway, introduce their components, describe its activation and regulation, its roles within the complement cascade, its connections to blood coagulation, and its direct cellular effects. Special emphasis is placed on disease connections and the non-canonical functions of LP components.

Complement MASP-1 Modifies Endothelial Wound Healing.

Endothelial wound-healing processes are fundamental for the maintenance and restoration of the circulatory system and are greatly affected by the factors present in the blood. We have previously shown that the complement protein mannan-binding lectin-associated serine protease-1 (MASP-1) induces the proinflammatory activation of endothelial cells and is able to cooperate with other proinflammatory activators. Our aim was to investigate the combined effect of mechanical wounding and MASP-1 on endothelial cells. Transcriptomic analysis showed that MASP-1 alters the expression of wound-healing-related and angiogenesis-related genes. Both wounding and MASP-1 induced Ca2+ mobilization when applied individually. However, MASP-1-induced Ca2+ mobilization was inhibited when the treatment was preceded by wounding. Mechanical wounding promoted CREB phosphorylation, and the presence of MASP-1 enhanced this effect. Wounding induced ICAM-1 and VCAM-1 expression on endothelial cells, and MASP-1 pretreatment further increased VCAM-1 levels. MASP-1 played a role in the subsequent stages of angiogenesis, facilitating the breakdown of the endothelial capillary network on Matrigel®. Our findings extend our general understanding of endothelial wound healing and highlight the importance of complement MASP-1 activation in wound-healing processes.

Five-year prognosis of patients with acute myocardial infarction and out-of-hospital cardiac arrest.

OBJECTIVES: This study aimed to assess the mortality and prognosis of acute myocardial infarction (AMI) patients with out-of-hospital cardiac arrest (OHCA) initially admitted to Department of Anesthesiology and Intensive Care in comparison with patients initially admitted to Cardiac Centre (CC). BACKGROUND: Global acute coronary syndrome (ACS) registries often omit patients with OHCA initially admitted to anaesthesiology and intensive care units. This exclusion may lead to underestimated mortality rates in patients following acute MI worldwide. METHODS: A retrospective analysis was conducted in patients admitted in 2014 to the (Department of Anesthesiology and Intensive Care) at a single center, J.A. Reiman Teaching Hospital in Presov, Slovakia. Survival rates were evaluated in-hospital, at 30 days, and annually over a five-year period. Patients with STEMI and NSTEMI were analyzed separately, particularly during the early in-hospital phase. RESULTS: In the OHCA group, 52% of STEMI patients experienced in-hospital mortality, whereas the CC group reported only 3% mortality. The total hospital mortality for STEMI patients was 6.69%. Among NSTEMI patients in the OHCA group, in-hospital mortality reached 50%, compared to 4.33% in the CC group. The total center mortality for all NSTEMI patients was 6.09%. CONCLUSION: Although the short-term prognosis for MI patients with OHCA is unfavorable, with a 30-day mortality rate of 54.9%, for those who survive the initial 30 days following cardiac arrest and are successfully discharged from the hospital, the long-term prognosis aligns with MI patients without OHCA. In light of these findings, the inclusion of all patients with MI (from both OHCA and CC groups) in global ACS registries could significantly raise in-hospital and 30-day mortality rates (Tab. 3, Fig. 4, Ref. 21).

Synergy of protease-binding sites within the ecotin homodimer is crucial for inhibition of MASP enzymes and for blocking lectin pathway activation.

Ecotin is a homodimeric serine protease inhibitor produced by many commensal and pathogenic microbes. It functions as a virulence factor, enabling survival of various pathogens in the blood. The ecotin dimer binds two protease molecules, and each ecotin protomer has two protease-binding sites: site1 occupies the substrate-binding groove, whereas site2 engages a distinct secondary region. Owing to the twofold rotational symmetry within the ecotin dimer, sites 1 and 2 of a protomer bind to different protease molecules within the tetrameric complex. Escherichia coli ecotin inhibits trypsin-like, chymotrypsin-like, and elastase-like enzymes, including pancreatic proteases, leukocyte elastase, key enzymes of blood coagulation, the contact and complement systems, and other antimicrobial cascades. Here, we show that mannan-binding lectin-associated serine protease-1 (MASP-1) and MASP-2, essential activators of the complement lectin pathway, and MASP-3, an essential alternative pathway activator, are all inhibited by ecotin. We decipher in detail how the preorganization of site1 and site2 within the ecotin dimer contributes to the inhibition of each MASP enzyme. In addition, using mutated and monomeric ecotin variants, we show that site1, site2, and dimerization contribute to inhibition in a surprisingly target-dependent manner. We present the first ecotin:MASP-1 and ecotin:MASP-2 crystal structures, which provide additional insights and permit structural interpretation of the observed functional results. Importantly, we reveal that monomerization completely disables the MASP-2-inhibitory, MASP-3-inhibitory, and lectin pathway-inhibitory capacity of ecotin. These findings provide new opportunities to combat dangerous multidrug-resistant pathogens through development of compounds capable of blocking ecotin dimer formation.

Heterogeneous response to TGF-ß1/3 isoforms in fibroblasts of different origins: implications for wound healing and tumorigenesis.

Identification of therapeutic targets for treating fibrotic diseases and cancer remains challenging. Our study aimed to investigate the effects of TGF-ß1 and TGF-ß3 on myofibroblast differentiation and extracellular matrix deposition in different types of fibroblasts, including normal/dermal, cancer-associated, and scar-derived fibroblasts. When comparing the phenotype and signaling pathways activation we observed extreme heterogeneity of studied markers across different fibroblast populations, even within those isolated from the same tissue. Specifically, the presence of myofibroblast and deposition of extracellular matrix were dependent on the origin of the fibroblasts and the type of treatment they received (TGF-ß1 vs. TGF-ß3). In parallel, we detected activation of canonical signaling (pSMAD2/3) across all studied fibroblasts, albeit to various extents. Treatment with TGF-ß1 and TGF-ß3 resulted in the activation of canonical and several non-canonical pathways, including AKT, ERK, and ROCK. Among studied cells, cancer-associated fibroblasts displayed the most heterogenic response to TGF-ß1/3 treatments. In general, TGF-ß1 demonstrated a more potent activation of signaling pathways compared to TGF-ß3, whereas TGF-ß3 exhibited rather an inhibitory effect in keloid- and hypertrophic scar-derived fibroblasts suggesting its clinical potential for scar treatment. In summary, our study has implications for comprehending the role of TGF-ß signaling in fibroblast biology, fibrotic diseases, and cancer. Future research should focus on unraveling the mechanisms beyond differential fibroblast responses to TGF-ß isomers considering inherent fibroblast heterogeneity.

Proprotein Convertase Is the Highest-Level Activator of the Alternative Complement Pathway in the Blood.

Factor D (FD) is an essential element of the alternative pathway of the complement system, and it circulates predominantly in cleaved, activated form in the blood. In resting blood, mannose-binding lectin-associated serine protease 3 (MASP-3) is the exclusive activator of pro-FD. Similarly to FD, MASP-3 also circulates mainly in the active form. It was not clear, however, how zymogen MASP-3 is activated. To decipher its activation mechanism, we followed the cleavage of MASP-3 in human hirudin plasma. Our data suggest that neither lectin pathway proteases nor any protease controlled by C1-inhibitor are required for MASP-3 activation. However, EDTA and the general proprotein convertase inhibitor decanoyl-RVKR-chloromethylketone completely prevented activation of exogenous MASP-3 added to blood samples. In this study, we show that proprotein convertase subtilisin/kexin (PCSK) 5 and PCSK6 are able to activate MASP-3 in vitro. Unlike PCSK5, PCSK6 was detected in human serum and plasma, and previously PCSK6 had also been shown to activate corin in the circulation. In all, PCSK6 emerges as the MASP-3 activator in human blood. These findings clarify the very first step of the activation of the alternative pathway and also connect the complement and the proprotein convertase systems in the blood.

Cooperation of Complement MASP-1 with Other Proinflammatory Factors to Enhance the Activation of Endothelial Cells.

Endothelial cells play an important role in sensing danger signals and regulating inflammation. Several factors are capable of inducing a proinflammatory response (e.g., LPS, histamine, IFNγ, and bradykinin), and these factors act simultaneously during the natural course of the inflammatory reaction. We have previously shown that the complement protein mannan-binding lectin-associated serine protease-1 (MASP-1) also induces a proinflammatory activation of the endothelial cells. Our aim was to investigate the possible cooperation between MASP-1 and other proinflammatory mediators when they are present in low doses. We used HUVECs and measured Ca2+ mobilization, IL-8, E-selectin, VCAM-1 expression, endothelial permeability, and mRNA levels of specific receptors. LPS pretreatment increased the expression of PAR2, a MASP-1 receptor, and furthermore, MASP-1 and LPS enhanced each other's effects in regulating IL-8, E-selectin, Ca2+ mobilization, and changes in permeability in a variety of ways. Cotreatment of MASP-1 and IFNγ increased the IL-8 expression of HUVECs. MASP-1 induced bradykinin and histamine receptor expression, and consequently, increased Ca2+ mobilization was found. Pretreatment with IFNγ enhanced MASP-1-induced Ca2+ mobilization. Our findings highlight that well-known proinflammatory mediators and MASP-1, even at low effective doses, can strongly synergize to enhance the inflammatory response of endothelial cells.

[Replantation of a traumatically amputated tongue]. / Gjenfesting av traumatisk amputert tungedel.

BACKGROUND: We describe a successful composite graft of a 4.5 cm piece of an amputated tongue, performed without microvascular technique. CASE PRESENTATION: A young adult fell off his bicycle, resulting in a traumatic amputation of part of his tongue, approximately 4.5 cm from the tip. Microvascular expertise was not available but the otolaryngologist on duty was advised to proceed with non-vascular composite graft surgery. Postoperatively the tongue was ischaemic. Marginal blood flow was assessed with ultrasound and pulse oximetry, and surgical reamputation was deferred. Several treatments were initiated to facilitate tongue revitalisation and circulation, including hyperbaric oxygen. Five months postoperatively, the patient was able to protrude his tongue to his teeth, had no problems swallowing, had improved pronunciation, and had regained some sensibility and taste. INTERPRETATION: We strongly recommend microvascular surgery reimplantation when such competency is available, but in locations without this option we have demonstrated that a non-vascular approach with a composite graft can be attempted as a last resort.

Autoimmunity, cancer and COVID-19 abnormally activate wound healing pathways: critical role of inflammation.

Recent evidence indicates that targeting IL-6 provides broad therapeutic approaches to several diseases. In patients with cancer, autoimmune diseases, severe respiratory infections [e.g. coronavirus disease 2019 (COVID-19)] and wound healing, IL-6 plays a critical role in modulating the systemic and local microenvironment. Elevated serum levels of IL-6 interfere with the systemic immune response and are associated with disease progression and prognosis. As already noted, monoclonal antibodies blocking either IL-6 or binding of IL-6 to receptors have been used/tested successfully in the treatment of rheumatoid arthritis, many cancer types, and COVID-19. Therefore, in the present review, we compare the impact of IL-6 and anti-IL-6 therapy to demonstrate common (pathological) features of the studied diseases such as formation of granulation tissue with the presence of myofibroblasts and deposition of new extracellular matrix. We also discuss abnormal activation of other wound-healing-related pathways that have been implicated in autoimmune disorders, cancer or COVID-19.

Aesculus hippocastanum L. extract differently modulates normal human dermal fibroblasts and cancer-associated fibroblasts from basal/squamous cell carcinoma.

Fibroblasts are actively involved in the formation of granulation tissue and/or tumor stroma. These cells possess the potential to differentiate into myofibroblasts acquiring a highly contractile phenotype characterized by the expression of α-smooth muscle actin (SMA). Considering TGF-ß1 as the main inducer of myofibroblast differentiation and horse chestnut extract (HCE) as an effective modulator of the wound healing, we have new evidence to demonstrate canonical TGF-ß1/SMAD and non-canonical/non-SMAD signaling in normal fibroblasts, isolated from healthy human skin (human dermal fibroblasts - HDFs), and their malignant counterparts (CAFs) isolated from basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) using western blot and immunofluorescence. Our study revealed that HCE stimulated the deposition of fibronectin by BCC fibroblasts (BCCFs), an effect not seen in other studied fibroblasts. Moreover, HCE in combination with TGF-ß1 showed a synergic effect on the presence of polymerized SMA-stress fibers, particularly visible in CAFs. Interestingly, the TGF-ß1 exposure led to activation of the canonical SMAD signaling in HDFs and BCCFs, whereas treatment of SCC fibroblasts (SCCFs) resulted in activation of the non-canonical AKT and/or ERK1/2 signaling. In conclusion, we observed specific differences in signaling between HDFs and CAFs that should be considered when developing new therapeutic approaches targeting wound/tumor microenvironments.

Molecular Changes Underlying Genistein Treatment of Wound Healing: A Review.

Estrogen deprivation is one of the major factors responsible for many age-related processes including poor wound healing in postmenopausal women. However, the reported side-effects of estrogen replacement therapy (ERT) have precluded broad clinical administration. Therefore, selective estrogen receptor modulators (SERMs) have been developed to overcome the detrimental side effects of ERT on breast and/or uterine tissues. The use of natural products isolated from plants (e.g., soy) may represent a promising source of biologically active compounds (e.g., genistein) as efficient alternatives to conventional treatment. Genistein as natural SERM has the unique ability to selectively act as agonist or antagonist in a tissue-specific manner, i.e., it improves skin repair and simultaneously exerts anti-cancer and chemopreventive properties. Hence, we present here a wound healing phases-based review of the most studied naturally occurring SERM.

Ecotin, a microbial inhibitor of serine proteases, blocks multiple complement dependent and independent microbicidal activities of human serum.

Ecotin is a serine protease inhibitor produced by hundreds of microbial species, including pathogens. Here we show, that ecotin orthologs from Escherichia coli, Yersinia pestis, Pseudomonas aeruginosa and Leishmania major are potent inhibitors of MASP-1 and MASP-2, the two key activator proteases of the complement lectin pathway. Factor D is the key activator protease of another complement activation route, the alternative pathway. We show that ecotin inhibits MASP-3, which is the sole factor D activator in resting human blood. In pathway-specific ELISA tests, we found that all ecotin orthologs are potent lectin pathway inhibitors, and at high concentration, they block the alternative pathway as well. In flow cytometry experiments, we compared the extent of complement-mediated opsonization and lysis of wild-type and ecotin-knockout variants of two E. coli strains carrying different surface lipopolysaccharides. We show, that endogenous ecotin provides significant protections against these microbicidal activities for both bacteria. By using pathway specific complement inhibitors, we detected classical-, lectin- and alternative pathway-driven complement attack from normal serum, with the relative contributions of the activation routes depending on the lipopolysaccharide type. Moreover, in cell proliferation experiments we observed an additional, complement-unrelated antimicrobial activity exerted by heat-inactivated serum. While ecotin-knockout cells are highly vulnerable to these activities, endogenous ecotin of wild-type bacteria provides complete protection against the lectin pathway-related and the complement-unrelated attack, and partial protection against the alternative pathway-related damage. In all, ecotin emerges as a potent, versatile self-defense tool that blocks multiple antimicrobial activities of the serum. These findings suggest that ecotin might be a relevant antimicrobial drug target.

Molecular Changes Underlying Hypertrophic Scarring Following Burns Involve Specific Deregulations at All Wound Healing Stages (Inflammation, Proliferation and Maturation).

Excessive connective tissue accumulation, a hallmark of hypertrophic scaring, results in progressive deterioration of the structure and function of organs. It can also be seen during tumor growth and other fibroproliferative disorders. These processes result from a wide spectrum of cross-talks between mesenchymal, epithelial and inflammatory/immune cells that have not yet been fully understood. In the present review, we aimed to describe the molecular features of fibroblasts and their interactions with immune and epithelial cells and extracellular matrix. We also compared different types of fibroblasts and their roles in skin repair and regeneration following burn injury. In summary, here we briefly review molecular changes underlying hypertrophic scarring following burns throughout all basic wound healing stages, i.e. during inflammation, proliferation and maturation.

Novel MASP-2 inhibitors developed via directed evolution of human TFPI1 are potent lectin pathway inhibitors.

The lectin pathway (LP) of the complement system is an important antimicrobial defense mechanism, but it also contributes significantly to ischemia reperfusion injury (IRI) associated with myocardial infarct, stroke, and several other clinical conditions. Mannan-binding lectin-associated serine proteinase 2 (MASP-2) is essential for LP activation, and therefore, it is a potential drug target. We have previously developed the first two generations of MASP-2 inhibitors by in vitro evolution of two unrelated canonical serine proteinase inhibitors. These inhibitors were selective LP inhibitors, but their nonhuman origin rendered them suboptimal lead molecules for drug development. Here, we present our third-generation MASP-2 inhibitors that were developed based on a human inhibitor scaffold. We subjected the second Kunitz domain of human tissue factor pathway inhibitor 1 (TFPI1 D2) to directed evolution using phage display to yield inhibitors against human and rat MASP-2. These novel TFPI1-based MASP-2 inhibitor (TFMI-2) variants are potent and selective LP inhibitors in both human and rat serum. Directed evolution of the first Kunitz domain of TFPI1 had already yielded the potent kallikrein inhibitor, Kalbitor® (ecallantide), which is an FDA-approved drug to treat acute attacks of hereditary angioedema. Like hereditary angioedema, acute IRI is also related to the uncontrolled activation of a specific plasma serine proteinase. Therefore, TFMI-2 variants are promising lead molecules for drug development against IRI.

Cutting Edge: A New Player in the Alternative Complement Pathway, MASP-1 Is Essential for LPS-Induced, but Not for Zymosan-Induced, Alternative Pathway Activation.

The complement system is a sophisticated network of proteases. In this article, we describe an unexpected link between two linear activation routes of the complement system: the lectin pathway (LP) and the alternative pathway (AP). Mannose-lectin binding-associated serine protease (MASP)-1 is known to be the initiator protease of the LP. Using a specific and potent inhibitor of MASP-1, SGMI-1, as well as other MASP-1 inhibitors with different mechanisms of action, we demonstrated that, in addition to its functions in the LP, MASP-1 is essential for bacterial LPS-induced AP activation, whereas it has little effect on zymosan-induced AP activation. We have shown that MASP-1 inhibition prevents AP activation, as well as attenuates the already initiated AP activity on the LPS surface. This newly recognized function of MASP-1 can be important for the defense against certain bacterial infections. Our results also emphasize that the mechanism of AP activation depends on the activator surface.

Complex approach to skin repair in an extensively burned child: a case study.

The limited amount of donor sites and loss of dermis are major challenges in the therapy of extensively burned patients. Here, we present a complex treatment approach of an eight-year-old boy with full-thickness burns on 90% of the total body surface area, using simple and efficient techniques of tissue engineering. To obtain sufficient skin for grafting we repeatedly harvested the same anatomical areas. Acceleration of donor site healing was achieved by treatment with a suspension of noncultured autologous skin cells (NASC) and acellular porcine dermis (Xe-Derma (XD), Czech Republic). Moreover, such wound management allowed up to six reharvestings, compared with one-to-three procedures following routine treatment. Bilayer Integra template (Integra LifeSciences Corp., US) was used as the dermal substitute in over 60% of full-thickness burns. Following successful vascularisation of the neodermis in 3-4 weeks, the templates were covered with meshed split-thickness skin grafts (STSG), or Meek autografts, and facilitated by NASC/XD. We may conclude that such a 'sandwich' technique approach, combining four biological covers (Integra, STSG, NASC and XD), significantly contributed to the successful skin repair of the patient.

Association between deficient cesarean delivery scar and cesarean scar syndrome.

INTRODUCTION: The aim of our study was to compare long-term morbidity after elective and emergency cesarean delivery (CD). METHODS: A prospective cohort study was conducted in 200 women delivered by CD. Ultrasound examinations were performed transvaginally at 6 weeks and 18 months after CD. Clinical data were collected at the time of CD and after 18 months. RESULTS: In the group of 200 women, 29% underwent emergency and 71% elective CD. Then, 6 weeks and 18 months after CD, a severe scar defect was present in 7% and 5%, respectively (P = .4). After 18 months of CD, 17% (34/200) of women had evidence of adhesions of the vesicouterine pouch. Severe CD scar defects were significant predictors for adhesion formation in vesicouterine pouch (OR 3.14, 95% CI, 1.54-4.74), pelvic pain (OR 1.68, 95% CI, 0.22-3.14), dysmenorrhea (OR 2.12, 95% CI, 0.74-3.50), and dyspareunia (OR 1.38, 95% CI, 0.09-2.67). Uterine scar defects detected at 6 weeks after elective CD were detectable at 18 months in only 40% of cases, whereas uterine scar defects after emergency CD were still detectable in 87% of cases. CONCLUSION: Uterine scar defects are more frequent at 18 weeks after emergency CD, than after elective CD (40% vs 87%). Women with severe scar defects have higher risk of adhesion formation, dysmenorrhea, dyspareunia, and chronic pelvic pain.

Aesculus hippocastanum L. Extract Does Not Induce Fibroblast to Myofibroblast Conversion but Increases Extracellular Matrix Production In Vitro Leading to Increased Wound Tensile Strength in Rats.

The ability of horse chestnut extract (HCE) to induce contraction force in fibroblasts, a process with remarkable significance in skin repair, motivated us to evaluate its wound healing potential in a series of experiments. In the in vitro study of the ability of human dermal fibroblasts to form myofibroblast-like cells was evaluated at the protein level (Western blot and immunofluorescence). The in vivo study was conducted on male Sprague-Dawley rats with inflicted wounds (one open circular and one sutured incision) on their backs. Rats were topically treated with two tested HCE concentrations (0.1% and 1%) or sterile water. The control group remained untreated. The incisions were processed for wound tensile strength (TS) measurement whereas the open wounds were subjected to histological examination. On the in vitro level the HCE extract induced fibronectin-rich extracellular matrix formation, but did not induced α-smooth muscle actin (SMA) expression in dermal fibroblasts. The animal study revealed that HCE increased wound TS and improved collagen organization. In conclusion, the direct comparison of both basic wound models demonstrated that the healing was significantly increased following HCE, thus this extract may be found useful to improve healing of acute wounds. Nevertheless, the use of an experimental rat model warrants a direct extrapolation to the human clinical situation.