Reduction of scar formation in full-thickness wounds with topical celecoxib treatment

Comparative Gene-Expression Analysis of the Ligamentum Flavum of Patients with Lumbar Spinal Canal Stenosis: Comparison between the Dural and Dorsal Sides of the Thickened Ligamentum Flavum

Thickening of the ligamentum flavum is the main factor in the development of lumbar spinal canal stenosis (LSCS). Although previous studies have reported factors related to ligamentum flavum thickening, its etiology has not been clarified. Furthermore, it is often difficult to set proper controls to investigate the pathologies of thickening due to differences in patient characteristics, such as age, sex, obesity, and comorbidities. This study aimed to elucidate the pathologies of ligamentum flavum thickening by comparing the dural and dorsal sides of the thickened ligamentum flavum in patients with LSCS. Ligamentum flavum samples were collected from 19 patients with LSCS. The samples were divided into the dural and dorsal sides. The dural side was used as a control to assess the pathologies occurring on the dorsal side. Elastic Masson staining was used to assess the elastic fibres. Gene expression levels were comprehensively assessed using quantitative reverse transcription polymerase chain reaction and DNA microarray analyses. Gene ontology analysis was used to identify biological processes associated with differentially expressed genes. The elastic fibres were significantly decreased on the dorsal side of the thickened ligamentum flavum. Genes related to fibrosis, inflammation, tissue repair, remodeling, and chondrometaplasia, such as COL1A2, COL3A1, COL5A1, TGFB1, VEGFA, TNFA, MMP2, COL10A1, and ADAMTS4, were highly expressed on the dorsal side of the thickened ligamentum flavum. The biological processes occurring on the dorsal side of the thickened ligamentum flavum were extracellular matrix organization, cell adhesion, extracellular matrix disassembly, and proteolysis.These are considered important pathologies of ligamentum flavum thickening.

Prevented Cell Clusters' Migration Via Microdot Biomaterials for Inhibiting Scar Adhesion

Cluster-like collective cell migration of fibroblasts is one of the main factors of adhesion in injured tissues. In this research, a microdot biomaterial system is constructed using α-helical polypeptide nanoparticles and anti-inflammatory micelles, which are prepared by ring-opening polymerization of α-amino acids-N-carboxylic anhydrides (NCAs) and lactide, respectively. The microdot biomaterial system slowly releases functionalized polypeptides targeting mitochondria and promoting the influx of extracellular calcium ions under the inflammatory environment, thus inhibiting the expression of N-cadherin mediating cell-cell interaction, and promoting apoptosis of cluster fibroblasts, synergistically inhibiting the migration of fibroblast clusters at the site of tendon injury. Meanwhile, the anti-inflammatory micelles are celecoxib (Cex) solubilized by PEG/polyester, which can improve the inflammatory microenvironment at the injury site for a long time. In vitro, the microdot biomaterial system can effectively inhibit the migration of the cluster fibroblasts by inhibiting the expression of N-cadherin between cell-cell and promoting apoptosis. In vivo, the microdot biomaterial system can promote apoptosis while achieving long-acting anti-inflammation effects, and reduce the expression of vimentin and α-smooth muscle actin (α-SMA) in fibroblasts. Thus, this microdot biomaterial system provides new ideas for the prevention and treatment of tendon adhesion by inhibiting the cluster migration of fibroblasts.

Parecoxib decreases cellular growth and Bcl-2 protein levels in primary cultures of keloid fibroblasts

Keloids seem to overexpress cyclo-oxygenase-2 (COX-2), suggesting a role in its deregulated pathway in inducing an altered epithelial-mesenchymal interaction, which may be responsible for the overgrowth of dermal components resulting in scars or keloid lesions. This study aimed to evaluate the effect of Parecoxib, a COX-2 inhibitor, on cell growth in fibroblast primary cultures obtained from human keloid tissues. Tissue explants were obtained from patients who underwent intralesional excision of untreated keloids; central fractions were isolated from keloid tissues and used for establishing distinct primary cultures. Appropriate aliquots of Parecoxib, a COX-2 inhibitor were diluted to obtain the concentration used in the experimental protocols in vitro (1, 10 or 100 μM). Treatment with Parecoxib (at all concentrations) caused a significant decrease in cellular growth from 24 hours onwards, and with a maximum at 72 hours (P < .02). Moreover, at 72 hours Parecoxib significantly reduced cellular vitality. Parecoxib treatment also induced an increase in fragmented nuclei with a maximum effect at 100 μM and a significant decrease in Bcl-2 and an increase in activated caspase-3 protein levels at 72 hours compared with control untreated cultures. Our findings suggest a potential use of the COX-2 inhibitor, Parecoxib, as the therapy for keloids.

Investigating Inflammatory Markers in Wound Healing: Understanding Implications and Identifying Artifacts

Understanding the complex interplay of pro-inflammatory and anti-inflammatory cytokines is crucial in the field of wound healing, as it holds the key to developing effective therapeutics. In the initial stages of wound healing, pro-inflammatory cytokines like IL-1β, IL-6, TNF-α, and various chemokines play vital roles in recruiting cells for debris clearance and the recruitment of growth factors. Careful regulation and timely resolution of this early inflammation are essential for optimal wound repair. As the healing process progresses, anti-inflammatory proteins such as IL-10 and IL-4 become instrumental in facilitating the transition to later stages where pro-inflammatory cytokines promote angiogenesis and wound remodeling. This Perspective underscores the complexity of inflammatory cytokines in wound healing research and emphasizes the need for comprehensive and unbiased methodologies in their evaluation. For robust and reliable results in wound-healing research, a more holistic approach is necessary-one that considers the roles, interactions, and timing of biological molecules, alongside careful sampling and evaluation strategies.

In Vitro, Ex Vivo, and In Vivo Approaches for Investigation of Skin Scarring: Human and Animal Models

Significance: The cutaneous repair process naturally results in different types of scarring that are classified as normal or pathological. Affected individuals are often affected from an esthetic, physical (functional), and psychosocial perspective. The distinct nature of scarring in humans, particularly the formation of pathological scars, makes the study of skin scarring a challenge for researchers in this area. Several established experimental models exist for studying scar formation. However, the increasing development and validation of newly emerging models have made it possible to carry out studies focused on different variables that influence this unique process. Recent Advances: Experimental models such as in vitro, ex vivo, and in vivo models have obtained different degrees of success in the reproduction of the scar formation in its native milieu and true environment. These models also differ in their ability to elucidate the molecular, cellular, and structural mechanisms involved in scarring, as well as for testing new agents and approaches for therapies. The models reviewed here, including cells derived from human skin and in vivo animal models, have contributed to the advancement of skin scarring research. Critical Issues and Future Directions: The absence of experimental models that faithfully reproduce the typical characteristics of the different types of human skin scars makes the improvement of validated models and the establishment of new ones a critical unmet need. The fields of wound healing research combined with tissue engineering have offered newer alternatives for experimental studies with the potential to provide clinically useful knowledge about scar formation.

Identification of ferroptosis-related genes and predicted overall survival in patients with burns

Introduction

Burns are a common trauma associated with considerable mortality and morbidity. Although a lot is known regarding burns' pathogenesis, the involvement of ferroptosis is uncertain. Here, we aimed to explore vital ferroptosis-related genes and molecules in burns, through bioinformatics analysis, to uncover new effective therapeutic targets.

Methods

The FerrDb database was used to acquire ferroptosis-related genes and GSE19743 was downloaded from Gene Expression Omnibus (GEO), a dataset with analysis of control and burned individuals. Hub genes were selected with Cytoscape software, and Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were conducted. Cox proportional hazard function and Kaplan-Meier survival analyses were implemented to screen prognosis-related genes. Additionally, the miRWalk database was used to acquire the miRNAs relevant to our hub genes function and analyzed for enrichment.

Result

We identified 64 differentially expressed genes and through the intersection with ferroptosis-related genes, 10 were selected as hub genes. GO analysis revealed that the hub genes' most enriched activities were response to oxidative stress, pyridine-containing compound metabolic processes, and reactive oxygen species metabolic processes. KEGG pathways' analysis showed that these overlapped genes were enriched in several pathways, namely, in VEGF signaling. Furthermore, the molecular miRNA functions significantly enriched were signal transduction and cell communication, namely, the biological pathways of the glypican pathway and the ErbB receptor signaling network. SLC40A1 and GPT2 genes were found to be associated with overall survival, suggesting an important role in burn prognosis.

Discussion

This study may improve our understanding of the underlying burn mechanisms and provide a new direction for the prevention of poor outcomes, advances in burns treatment, and drug development.

Investigation on wound healing effect of Mediterranean medicinal plants and some related phenolic compounds: A review

ETHNOPHARMACOLOGICAL RELEVANCE

The human skin constitutes a biological barrier against external stress and wounds can reduce the role of its physiological structure. In medical sciences, wounds are considered a major problem that requires urgent intervention. For centuries, medicinal plants have been used in the Mediterranean countries for many purposes and against wounds.

AIM OF THIS REVIEW

Provides an outlook on the Mediterranean medicinal plants used in wound healing. Furthermore, the wound healing effect of polyphenolic compounds and their chemical structures are also summarized. Moreover, we discussed the wound healing process, the structure of the skin, and the current therapies in wound healing.

MATERIALS AND METHODS

The search was performed in several databases such as ScienceDirect, PubMed, Google Scholar, Scopus, and Web of Science. The following Keywords were used individually and/or in combination: the Mediterranean, wound healing, medicinal plants, phenolic compounds, composition, flavonoid, tannin.

RESULTS

The wound healing process is distinguished by four phases, which are respectively, hemostasis, inflammation, proliferation, and remodeling. The Mediterranean medicinal plants are widely used in the treatment of wounds. The finding showed that eighty-nine species belonging to forty families were evaluated for their wound-healing effect in this area. The Asteraceae family was the most reported family with 12 species followed by Lamiaceae (11 species). Tunisia, Egypt, Morocco, and Algeria were the countries where these plants are frequently used in wound healing. In addition to medicinal plants, results showed that nineteen phenolic compounds from different classes are used in wound treatment. Tyrosol, hydroxytyrosol, curcumin, luteolin, chrysin, rutin, kaempferol, quercetin, icariin, morin, epigallocatechin gallate, taxifolin, silymarin, hesperidin, naringin, isoliquiritin, puerarin, genistein, and daidzein were the main compounds that showed wound-healing effect.

CONCLUSION

In conclusion, medicinal plants and polyphenolic compounds provide therapeutic evidence in wound healing and for the development of new drugs in this field.

Pharmaceutical Prophylaxis of Scarring with Emphasis on Burns: A Review of Preclinical and Clinical Studies

Significance: The worldwide estimate of burns requiring medical attention each year is 11 million. Each year in the United States, ∼486,000 burn injuries receive medical attention, including 40,000 hospitalizations. Scars resulting from burns can be disfiguring and impair functions. The development of prophylactic drugs for cutaneous scarring could improve the outcomes for burns, traumatic lacerations (>6 million/year treated in U.S. emergency rooms), and surgical incisions (∼250 million/year worldwide). Antiscar pharmaceuticals have been estimated to have a market of $12 billion. Recent Advances: Many small molecules, cells, proteins/polypeptides, and nucleic acids have mitigated scarring in animal studies and clinical trials, but none have received Food and Drug Administration (FDA) approval yet. Critical Issues: The development of antiscar pharmaceuticals involves the identification of the proper dose, frequency of application, and window of administration postwounding for the indicated wound. Risks of infection and impaired healing must be considered. Scar outcome needs to be evaluated after scars have matured. Future Directions: Once treatments have demonstrated safety and efficacy in rodent and/or rabbit and porcine wound models, human testing can begin, such as on artificially created wounds on healthy subjects and on bilateral-surgical wounds, comparing treatments versus vehicle controls on intrapatient-matched wounds, before testing on separate cohorts of patients. Given the progress made in the past 20 years, FDA-approved drugs for improving scar outcomes may be expected.

Thioctamer: a novel thioctic acid-glatiramer acetate nanoconjugate expedites wound healing in diabetic rats

The current work aims to design thioctic acid (TA) and glatiramer acetate (GA) nanoconjugate (thioctamer) loaded hydrogel formula as well as evaluation of thioctamer preclinical efficacy in expediting wound healing in a rat model of the diabetic wound. Thioctamer was prepared by conjugation of GA and TA in a 1:1 molar ratio. Particle size, zeta potential, and thermodynamic stability of the prepared thioctamer were assessed. Thioctamer was loaded in hydroxypropyl methylcellulose-based hydrogel and in vitro release study was investigated. The ability of thioctamer to enhance the process of wound healing in diabetic rats was investigated by assessing wound contraction and immunohistochemical assessment of the inflammation markers IL-6 and TNF-α. The results demonstrated that thioctamer showed particle size of 137 ± 21.4 nm, polydispersity index (PDI) of 0.235, and positive zeta potential value of 7.43 ± 4.95 mV. On day 7 of making a skin excision, diabetic rat wounds administered thioctamer preparation showed almost complete healing (95.6 ± 8.6%). Meanwhile, % of wound contraction in animals treated with TA or GA groups exhibited values amounting to 56.5 ± 5.8% and 62.6 ± 7.1%, respectively. Histological investigation showed that the highest healing rate was noted in the thioctamer group animals, as the surface of the wound was nearly fully protected by regenerated epithelium with keratinization, with few inflammatory cells noticed. Thioctamer significantly (p<.05) inhibited IL-6 and TNF-α expression as compared with sections obtained from the negative control, TA, GA, or positive control group animals on day 7. The evidence of the ability of thioctamer to significantly expedite wound healing in the diabetic rats is presented.

Sprayable methacrylic anhydride-modified gelatin hydrogel combined with bionic neutrophils nanoparticles for scar-free wound healing of diabetes mellitus

Hard-to-healing or nonhealing diabetic wounds caused by hyperglycemia, bacterial infection and chronic inflammation are becoming a challenge globally. In this study, a novel hydrogel for diabetic wound healing composed of methacrylic anhydride-modified gelatin (GelMA) hydrogel and mimicking neutrophil nanoparticles was originally created. The prepared GelMA hydrogel has good sprayability and film-formation ability under blue light illumination (wavelength = 435-480 nm). Nanoparticles mimicking neutrophils belong to a double enzyme system that are encapsulated in ZIF-8 nanoparticles, which can consume glucose to produce HClO, ensuring a decrease in the glucose concentration of the wound and growth inhibition in bacteria. The hydrogel also has excellent biocompatibility, which can promote the growth and proliferation of fibroblasts. More importantly, the hydrogel can accelerate wound healing in type I diabetic rats owing to the downregulation of proinflammatory cytokines, and the wound with an area of 1 cm² can be almost fully healed with no formation of the scar on the 21st day, as verified by histochemistry and immunohistochemistry. All these combinations indicate its potential in diabetic wound treatment.

Adipose-derived stem cells inhibit dermal fibroblast growth and induce apoptosis in keloids through the arachidonic acid-derived cyclooxygenase-2/prostaglandin E2 cascade by paracrine

Background

The clinical features of keloids consist of aberrant proliferation, secretion, differentiation and apoptosis of keloid dermis-derived fibroblasts (KFBs). Notably, the apoptosis rate of KFBs is lower than the proliferation rate. Though the anti-fibrotic effect of adipose-derived stem cells (ADSCs) on keloids has become a hot topic of research, the exact anti-fibrotic mechanism of the paracrine effect remains unclear. This study aimed to find out how the conditioned medium of ADSCs (ADSC-CM) exerts an anti-fibrotic effect in KFBs.

Methods

KFBs and ADSCs were extracted and cultured. Then, ADSC-CM was prepared. Whether ADSC-CM could inhibit KFB growth and induce apoptosis was verified by the use of a cell counting kit-8, an 5-Ethynyl-2-deoxyuridine (Edu) kit and flow cytometry. The expressions of cyclooxygenase-1 (COX-1), COX-2, caspase 3 and B-cell lymphoma-2 (Bcl-2) in ADSC-CM-cultured KFBs were tested by real-time PCR and western blotting. To clarify the role of COX-2 in ADSC-CM-induced KFB apoptosis, a specific COX-2 inhibitor, celecoxib, was applied to KFBs cultured in ADSC-CM. Moreover, we tested the production of arachidonic acid (AA) and prostaglandin E2 (PGE2) by ELISA. Then, we established a keloid transplantation model in a nude mouse to validate the therapeutic effect in vivo.

Results

The proliferation ability of KFBs cultured in ADSC-CM was found to be weakened and apoptosis was significantly increased. Caspase 3 expression was significantly upregulated and Bcl-2 was downregulated in ADSC-CM-cultured KFBs. Furthermore, ADSC-CM strikingly elevated COX-2 mRNA and protein expressions, but COX-1 expression was unaltered. COX-2 inhibitors reduced ADSC-CM-induced apoptosis. Additionally, COX-2 inhibition blocked the elevation of caspase 3 and reversed the decrease in Bcl-2 expression. ADSC-CM increased PGE2 levels by 1.5-fold and this effect was restrained by COX-2 inhibition. In the nude mouse model, expressions of AA, COX-2 and PGE2 were higher in the translated keloid tissues after ADSC-CM injection than in the controls.

Conclusions

We showed activation of the COX-2/PGE2 cascade in KFBs in response to ADSC-CM. By employing a specific COX-2 inhibitor, COX-2/PGE2 cascade activation played a crucial role in mediating the ADSC-CM-induced KFB apoptosis and anti-proliferation effects.

Celecoxib alleviates pathological cardiac hypertrophy and fibrosis via M1-like macrophage infiltration in neonatal mice

Cardiac hypertrophy is an adaptive response to all forms of heart disease, including hypertension, myocardial infarction, and cardiomyopathy. Cyclooxygenase-2 (COX-2) overexpression results in inflammatory response, cardiac cell apoptosis, and hypertrophy in adult heart after injury. However, immune response-mediated cardiac hypertrophy and fibrosis have not been well documented in injured neonatal heart. This study showed that cardiac hypertrophy and fibrosis are significantly attenuated in celecoxib (a selective COX-2 inhibitor)-treated P8 ICR mice after cryoinjury. Molecular and cellular profiling of immune response shows that celecoxib inhibits the production of cytokines and the expression of adhesion molecular genes, increases the recruitment of M1-like macrophage at wound site, and alleviates cardiac hypertrophy and fibrosis. Furthermore, celecoxib administration improves cardiac function at 4 weeks after injury. These results demonstrate that COX-2 inhibition promotes the recruitment of M1-like macrophages during early wound healing, which may contribute to the suppression of cardiac hypertrophy and fibrosis after injury.

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Cryoinjury successfully induces cardiac hypertrophy and fibrosis in P8 ICR mice

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COX-2 inhibition alleviates cardiac hypertrophy and fibrosis after cryoinjury

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MCP-1 significantly increases in COX-2 inhibition

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COX-2 inhibition improves cardiac repair in P8 ICR mice by recruiting M1-like macrophages

Identification of drug compounds for keloids and hypertrophic scars: drug discovery based on text mining and DeepPurpose

Background

Keloids (KL) and hypertrophic scars (HS) are forms of abnormal cutaneous scarring characterized by excessive deposition of extracellular matrix and fibroblast proliferation. Currently, the efficacy of drug therapies for KL and HS is limited. The present study aimed to investigate new drug therapies for KL and HS by using computational methods.

Methods

Text mining and GeneCodis were used to mine genes closely related to KL and HS. Protein-protein interaction analysis was performed using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) and Cytoscape. The selection of drugs targeting the genes closely related to KL and HS was carried out using Pharmaprojects. Drug-target interaction prediction was performed using DeepPurpose, through which candidate drugs with the highest predicted binding affinity were finally obtained.

Results

Our analysis using text mining identified 69 KL- and HS-related genes. Gene enrichment analysis generated 25 genes, representing 7 pathways and 130 targeting drugs. DeepPurpose recommended 14 drugs as the final drug list, including 2 phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) inhibitors, 10 prostaglandin-endoperoxide synthase 2 (PTGS2) inhibitors and 2 vascular endothelial growth factor A (VEGFA) antagonists.

Conclusions

Drug discovery using in silico text mining and DeepPurpose may be a powerful and effective way to identify drugs targeting the genes related to KL and HS.

Petite miracles: insight into the nano-management of scarless wound healing

Scars affect millions of patients worldwide, yet their treatment efficacy and options clinically remain limited. In recent years, increased understanding of scar formation pathways leading to developments in nanotechnology have opened many opportunities for scar detection, prevention, and treatment due to the nanoscale features and therapeutic delivery capabilities of such technologies. Led by nanoparticles (NPs) and nanofibers, these novel strategies can aid in reducing scar contracture, improving wound-healing efficacy, and advancing progress towards scarless wound healing.

Pirfenidone regulates LPS mediated activation of neutrophils

Excessive inflammation or its absence may result in impaired wound healing. Neutrophils are among the first innate immune cells to arrive at the injury site. They participate in infection control and debris removal to initiate healing. If not timely resolved, neutrophils can cause excessive tissue inflammation and damage. Drugs with anti-inflammatory and anti-fibrotic effects are of promise for improving healing by balancing the primary defensive functions and excessive tissue damage actions. Of interest, pirfenidone (Pf), an FDA approved anti-fibrotic drug to treat idiopathic pulmonary fibrosis, has been shown to ameliorate inflammation in several animal models including mouse deep partial-thickness burn wounds. However, there is a lack of mechanistic insights into Pf drug action on inflammatory cells such as neutrophils. Here, we examined the treatment effects of Pf on LPS-stimulated neutrophils as a model of non-sterile inflammation. Firstly, Pf reduced chemotaxis and production of pro-inflammatory ROS, cytokines, and chemokines by LPS-activated neutrophils. Secondly, Pf increased anti-inflammatory IL-1RA and reduced neutrophil degranulation, phagocytosis, and NETosis. Thirdly, Pf affected downstream signaling kinases which might directly or indirectly influence neutrophil responses to LPS. In conclusion, the results suggest that Pf lessens the inflammatory phenotypes of LPS-activated neutrophils.

Inflammation as an orchestrator of cutaneous scar formation: a review of the literature

Inflammation is a key phase in the cutaneous wound repair process. The activation of inflammatory cells is critical for preventing infection in contaminated wounds and results in the release of an array of mediators, some of which stimulate the activity of keratinocytes, endothelial cells, and fibroblasts to aid in the repair process. However, there is an abundance of data suggesting that the strength of the inflammatory response early in the healing process correlates directly with the amount of scar tissue that will eventually form. This review will summarize the literature related to inflammation and cutaneous scar formation, highlight recent discoveries, and discuss potential treatment modalities that target inflammation to minimize scarring.

COX2 is induced in the ovarian epithelium during ovulatory wound repair and promotes cell survival†

The ovarian surface epithelium (OSE) is a monolayer of cells surrounding the ovary that is ruptured during ovulation. After ovulation, the wound is repaired, however, this process is poorly understood. In epithelial tissues, wound repair is mediated by an epithelial-to-mesenchymal transition (EMT). Transforming Growth Factor Beta-1 (TGFβ1) is a cytokine commonly known to induce an EMT and is present throughout the ovarian microenvironment. We, therefore, hypothesized that TGFβ1 induces an EMT in OSE cells and activates signaling pathways important for wound repair. Treating primary cultures of mouse OSE cells with TGFβ1 induced an EMT mediated by TGFβRI signaling. The transcription factor Snail was the only EMT-associated transcription factor increased by TGFβ1 and, when overexpressed, was shown to increase OSE cell migration. A polymerase chain reaction array of TGFβ signaling targets determined Cyclooxygenase-2 (Cox2) to be most highly induced by TGFβ1. Constitutive Cox2 expression modestly increased migration and robustly enhanced cell survival, under stress conditions similar to those observed during wound repair. The increase in Snail and Cox2 expression with TGFβ1 was reproduced in human OSE cultures, suggesting these responses are conserved between mouse and human. Finally, the induction of Cox2 expression in OSE cells during ovulatory wound repair was shown in vivo, suggesting TGFβ1 increases Cox2 to promote wound repair by enhancing cell survival. These data support that TGFβ1 promotes ovulatory wound repair by induction of an EMT and activation of a COX2-mediated pro-survival pathway. Understanding ovulatory wound repair may give insight into why ovulation is the primary non-hereditary risk factor for ovarian cancer.

Complex Tissue Regeneration in Mammals Is Associated With Reduced Inflammatory Cytokines and an Influx of T Cells

While mammals tend to repair injuries, other adult vertebrates like salamanders and fish regenerate damaged tissue. One prominent hypothesis offered to explain an inability to regenerate complex tissue in mammals is a bias during healing toward strong adaptive immunity and inflammatory responses. Here we directly test this hypothesis by characterizing part of the immune response during regeneration in spiny mice (Acomys cahirinus and Acomys percivali) vs. fibrotic repair in Mus musculus. By directly quantifying cytokines during tissue healing, we found that fibrotic repair was associated with a greater release of pro-inflammatory cytokines (i.e., IL-6, CCL2, and CXCL1) during acute inflammation in the wound microenvironment. However, reducing inflammation via COX-2 inhibition was not sufficient to reduce fibrosis or induce a regenerative response, suggesting that inflammatory strength does not control how an injury heals. Although regeneration was associated with lower concentrations of many inflammatory markers, we measured a comparatively larger influx of T cells into regenerating ear tissue and detected a local increase in the T cell associated cytokines IL-12 and IL-17 during the proliferative phase of regeneration. Taken together, our data demonstrate that a strong adaptive immune response is not antagonistic to regeneration and that other mechanisms likely explain the distribution of regenerative ability in vertebrates.

The in vivo effect of Lacto-N-neotetraose (LNnT) on the expression of type 2 immune response involved genes in the wound healing process

Lacto-n-neotatraose (LNnT) oligosaccharide shows properties such as anti-inflammatory, type 2 immune response induction, induced angiogenesis, and anti-bacterial effects. Here, we hypothesized that the application of LnNT in the skin full-thickness wound can accelerate the healing process through its anti-inflammatory effect as well as induction of type 2 immune responses. In this study, we evaluated the cell viability of fibroblasts in the presence of LNnT. The full-thickness wound model was created by punch biopsy. The mice were treated intradermaly with LNnT at the concentrations of 100 and 200 µg or PBS as a control group. The wounds samples were compared based on the macroscopic and histological evaluations. The amount of collagen deposition and expression of genes involved in type 2 immunity were measured by the hydroxyproline assay and real time PCR method, respectively. Our results showed that LNnT had no negative effect on the cell viability of fibroblasts. LNnT increased the wound closure rate on day 7 post-wounding. H&E stain analysis revealed that mice treated with 200 µg LNnT exhibited better healing score, follicle formation, and lower epidermal thickness index. The mice treated with LNnT exhibited a lower collagen deposition on day 21 and higher collagen content on days 7 and 14 post-treatment. The LNnT groups also exhibited a lower number of neutrophils and a higher number of basal cells and fibroblasts. The expression rate of IL-10, IL-4, and IL-13 was higher in the LNnT groups. These results showed the high potential of LNnT for use in treatment of full-thickness wounds.

Complex Tissue Regeneration in Mammals Is Associated With Reduced Inflammatory Cytokines and an Influx of T Cells

While mammals tend to repair injuries, other adult vertebrates like salamanders and fish regenerate damaged tissue. One prominent hypothesis offered to explain an inability to regenerate complex tissue in mammals is a bias during healing toward strong adaptive immunity and inflammatory responses. Here we directly test this hypothesis by characterizing part of the immune response during regeneration in spiny mice (Acomys cahirinus and Acomys percivali) vs. fibrotic repair in Mus musculus. By directly quantifying cytokines during tissue healing, we found that fibrotic repair was associated with a greater release of pro-inflammatory cytokines (i.e., IL-6, CCL2, and CXCL1) during acute inflammation in the wound microenvironment. However, reducing inflammation via COX-2 inhibition was not sufficient to reduce fibrosis or induce a regenerative response, suggesting that inflammatory strength does not control how an injury heals. Although regeneration was associated with lower concentrations of many inflammatory markers, we measured a comparatively larger influx of T cells into regenerating ear tissue and detected a local increase in the T cell associated cytokines IL-12 and IL-17 during the proliferative phase of regeneration. Taken together, our data demonstrate that a strong adaptive immune response is not antagonistic to regeneration and that other mechanisms likely explain the distribution of regenerative ability in vertebrates.

Topically Applied Cross-Linked Hyaluronan Attenuates the Formation of Spinal Epidural Fibrosis in a Swine Model of Laminectomy

Epidural fibrosis is an inevitable aspect of the postoperative healing process which is one of the causes of failed back surgery syndrome following spinal surgery. The aim of the present study was to examine the inhibitory effect of 1,4-butanediol diglycidyl ether-crosslinked hyaluronan (cHA) on spinal epidural fibrosis in a swine model. Epidural fibrosis was induced through conduction of hemi-laminotomy (L2 and L3) or laminectomy (L4 and L5), while L1 was assigned as the control group in six pigs. The cHA was applied to L3 and L5 surgical sites. MRI evaluation, histologic examination, expressions of matrix metalloproteinases (MMPs), and cytokines in scar tissue were assessed four months after surgery. cHA treatment significantly decreased the scar formation in both hemi-laminotomy and laminectomy sites. cHA also significantly increased MMP-3 and MMP-9 expression in scar tissue. Further, the epithelial-mesenchymal transition -related factors (transforming growth factor-β and vimentin) were suppressed and the anti-inflammatory cytokines (CD44 and interleukin-6) were increasingly expressed in cHA-treated sites. The current study demonstrated that cHA may attenuate spinal epidural fibrosis formation after laminectomy surgery by enhancing the expression of MMPs and anti-inflammatory pathways.

Effect of Relaxin Expression from an Alginate Gel-Encapsulated Adenovirus on Scar Remodeling in a Pig Model

PURPOSE

Relaxin (RLX) is a transforming growth factor-β1 (TGF-β1) antagonist that is believed to function as a potent collagen re-arranger and a major suppressor of extracellular matrix components. Adenoviruses (Ads) are accepted vectors for cancer gene therapy. However, repeated treatments of Ad are limited by short-term biological activity in vivo. The efficacy of sustained RLX expression to scar remodeling was assessed using an injectable alginate gel-matrix system.

MATERIALS AND METHODS

Pig scar tissue was treated with relaxin-expressing Ad loaded in alginate gel (gel/Ad-RLX). Surface areas, color, and pliability of scars were compared, and various factors influencing scar formation and collagen arrangement were analyzed.

RESULTS

Gel/Ad-RLX decreased scar size, color index, and pliability. Immunohistochemistry showed decreased levels of major extracellular matrix proteins in the gel/Ad-RLX-treated group. Furthermore, treatment with gel/Ad-RLX reduced expression of tissue inhibitor of metalloproteinase-1 and alpha-smooth muscle actin and markedly increased expression of matrix metalloproteinase-1 in pig scar tissues. Gel/Ad-RLX also significantly downregulated TGF-β1 and upregulated TGF-β3 mRNAs in pig scar tissues.

CONCLUSION

These results support a prominent role for RLX in scar remodeling and suggest that gel/Ad-RLX may have therapeutic effects on scar formation.

Current and upcoming therapies to modulate skin scarring and fibrosis

Skin is the largest organ of the human body. Being the interface between the body and the outer environment, makes it susceptible to physical injury. To maintain life, nature has endowed skin with a fast healing response that invariably ends in the formation of scar at the wounded dermal area. In many cases, skin remodelling may be impaired, leading to local hypertrophic scars or keloids. One should also consider that the scarring process is part of the wound healing response, which always starts with inflammation. Thus, scarring can also be induced in the dermis, in the absence of an actual wound, during chronic inflammatory processes. Considering the significant portion of the population that is subject to abnormal scarring, this review critically discusses the state-of-the-art and upcoming therapies in skin scarring and fibrosis.

Tissue specific human fibroblast differential expression based on RNAsequencing analysis

Background

Physical forces, such as mechanical stress, are essential for tissue homeostasis and influence gene expression of cells. In particular, the fibroblast has demonstrated sensitivity to extracellular matrices with assumed adaptation upon various mechanical loads. The purpose of this study was to compare the vocal fold fibroblast genotype, known for its unique mechanically stressful tissue environment, with cellular counterparts at various other anatomic locales to identify differences in functional gene expression profiles.

Results

By using RNA-seq technology, we identified differentially expressed gene programs (DEseq2) among seven normal human fibroblast primary cell lines from healthy cadavers, which included: vocal fold, trachea, lung, abdomen, scalp, upper gingiva, and soft palate. Unsupervised gene expression analysis yielded 6216 genes differentially expressed across all anatomic sites. Hierarchical cluster analysis revealed grouping based on anatomic site origin rather than donor, suggesting global fibroblast phenotype heterogeneity. Sex and age-related effects were negligible. Functional enrichment analyses based on separate post-hoc 2-group comparisons revealed several functional themes within the vocal fold fibroblast related to transcription factors for signaling pathways regulating pluripotency of stem cells and extracellular matrix components such as cell signaling, migration, proliferation, and differentiation potential.

Conclusions

Human fibroblasts display a phenomenon of global topographic differentiation, which is maintained in isolation via in vitro assays. Epigenetic mechanical influences on vocal fold tissue may play a role in uniquely modelling and maintaining the local environmental cellular niche during homeostasis with vocal fold fibroblasts distinctly specialized related to their anatomic positional and developmental origins established during embryogenesis.

Electronic supplementary material

The online version of this article (10.1186/s12864-019-5682-5) contains supplementary material, which is available to authorized users.

Immunohistochemical Expression of Cyclooxygenases in Hypertrophic Scars and Keloids

Background:

There are studies demonstrating an increased expression of cyclooxygenase (COX) in keloids and hypertrophic scars, suggesting that anti-inflammatory drugs could be used in their treatment. However, a precise relationship between COX and pathological scarring has not been established in the literature yet. This study aims to evaluate the immunohistochemical expression of COXs in these scars.

Methods:

Prospective study, including 54 patients (aged 18–60 years) undergoing scar excision: 18 normal scars (group 1), 18 hypertrophic scar (group 2), and 18 keloids (group 3). The group classification was performed by clinical criteria. Scars samples were collected and anatomopathological examination (through hematoxylin-eosin method) was performed to confirm the scar type. Immunohistochemistry was performed to assess the expression of COX1 and COX2 in epidermis and dermis. Results were compared among all groups and between group I versus II and III together (abnormal scars).

Results:

For COX1, in the epidermis, there was no significant difference in the immunohistochemical expression when comparing the 3 groups. In the dermis, groups 2 and 3 had greater expression than group 1, with a significant difference being found when comparing all groups (P = 0.014), and in the comparison between normal versus abnormal scars (P = 0.004). For COX2, there was no significant difference between the groups in both the epidermis and dermis.

Conclusions:

The immunohistochemical expression of COX1 was greater in the dermis of abnormal scars when compared with normal scars. Future studies can be performed involving COX blockade as a perspective of these scars treatment.

Photodynamic therapy induces antifibrotic alterations in primary human vocal fold fibroblasts

OBJECTIVES/HYPOTHESIS

Photodynamic therapy (PDT) is a promising treatment modality for laryngeal dysplasia, early-stage carcinoma, and papilloma, and was reported to have the ability to preserve laryngeal function and voice quality without clinical fibrotic response. We aimed to investigate the mechanism behind the antifibrotic effects of PDT on primary human vocal fold fibroblasts (VFFs) in vitro.

STUDY DESIGN

In vitro analysis from one human donor.

METHODS

Cell viability of VFFs in response to varying doses of PDT was investigated by the Cell Counting Kit-8 method. Sublethal-dose PDT (SL-PDT) was used for the following experiments. Expression of genes related to vocal fold extracellular matrix formation was analyzed by real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and Western blotting. Effects of PDT on cell migration, collagen contraction, and transforming growth factor β-1 (TGF-β1)-induced myofibroblast differentiation were also analyzed.

RESULTS

PDT affects the viability of VFFs in a dose-dependent manner. SL-PDT significantly changed the expression profile of VFFs with antifibrotic effects. It also inhibited cell migration, reduced collagen contraction, and reversed the fibroblast-myofibroblast differentiation induced by TGF-β1.

CONCLUSIONS

SL-PDT induces antifibrotic alterations in VFFs. This could explain the low incidence of vocal fold scar associated with PDT. Moreover, PDT may be useful in treating existing vocal fold scars. Further studies should focus on the in vivo effect of PDT on vocal fold wound healing and scar remodeling.

LEVEL OF EVIDENCE

NA Laryngoscope, 128:E323-E331, 2018.

Partners in crime: neutrophils and monocytes/macrophages in inflammation and disease

Neutrophils are becoming recognized as highly versatile and sophisticated cells that display de novo synthetic capacity and potentially prolonged lifespan. Emerging concepts such as neutrophil heterogeneity and plasticity have revealed that, under pathological conditions, neutrophils may differentiate into discrete subsets defined by distinct phenotypic and functional characteristics. Indeed, these newly described neutrophil subsets will undoubtedly add to the already complex interactions between neutrophils and other immune cell types for an effective immune response. The interactions between neutrophils and monocytes/macrophages enable the host to efficiently defend against and eliminate foreign pathogens. However, it is also becoming increasingly clear that these interactions can be detrimental to the host if not tightly regulated. In this review, we will explore the functional cooperation of neutrophil and monocytes/macrophages in homeostasis, during acute inflammation and in various disease settings. We will discuss this in the context of cardiovascular disease in the form of atherosclerosis, an autoimmune disease mainly occurring in the kidneys, as well as the unique intestinal immune response of the gut that does not conform to the norms of the typical immune system.

Comparative regenerative mechanisms across different mammalian tissues

Stimulating regeneration of complex tissues and organs after injury to effect complete structural and functional repair, is an attractive therapeutic option that would revolutionize clinical medicine. Compared to many metazoan phyla that show extraordinary regenerative capacity, which in some instances persists throughout life, regeneration in mammalians, particularly humans, is limited or absent. Here we consider recent insights in the elucidation of molecular mechanisms of regeneration that have come from studies of tissue homeostasis and injury repair in mammalian tissues that span the spectrum from little or no self-renewal, to those showing active cell turnover throughout life. These studies highlight the diversity of factors that constrain regeneration, including immune responses, extracellular matrix composition, age, injury type, physiological adaptation, and angiogenic and neurogenic capacity. Despite these constraints, much progress has been made in elucidating key molecular mechanisms that may provide therapeutic targets for the development of future regenerative therapies, as well as previously unidentified developmental paradigms and windows-of-opportunity for improved regenerative repair.

Embryonic skin development and repair

Fetal cutaneous wounds have the unique ability to completely regenerate wounded skin and heal without scarring. However, adult cutaneous wounds heal via a fibroproliferative response which results in the formation of a scar. Understanding the mechanism(s) of scarless wound healing leads to enormous clinical potential in facilitating an environment conducive to scarless healing in adult cutaneous wounds. This article reviews the embryonic development of the skin and outlines the structural and functional differences in adult and fetal wound healing phenotypes. A review of current developments made towards applying this clinical knowledge to promote scarless healing in adult wounds is addressed.

Cox-2 inhibition and the composition of inflammatory cell populations during early and mid-time tendon healing

Background

During early tendon healing, the cells within the regenerating tissue are, to a large part, inflammatory leukocytes (CD45⁺). In a rat Achilles tendon healing model, the inflammation resolves between 5 and 10 days. In the same model, Cox inhibitors (NSAIDs) impair healing when given during the first 5 days, but have a positive effect if given later. We tested the hypothesis that a Cox inhibitor would exert these effects by influencing inflammation, and thereby the composition of the inflammatory cell subpopulations.

Methods

Achilles tendon transection was performed in 44 animals. Animals were randomized to either parecoxib or saline injections. Healing was evaluated by mechanical testing day 7 after surgery and by flow cytometry day 3 and 10.

Results

Cross-sectional area, peak force and stiffness were reduced by parecoxib 31, 33, and 25% respectively (p=0.005, p=0.002, and p=0.005). By flow cytometry, there was a strong effect of time (p<0.001) on virtually all inflammatory cell subpopulations (CD45, CD11b, CD68, CCR7, CD163, CD206, CD3, CD4), but no significant effect of parecoxib at any time point.

Conclusion

The results suggest that the negative effects of Cox inhibitors on tendon healing might be exerted mainly via mechanisms not directly related to inflammatory cells.

Effect of Relaxin Expressing Adenovirus on Scar Remodeling: A Preliminary Study

Background

Relaxin is a transforming growth factor β1 antagonist. To determine the effects of relaxin on scar reduction, we investigated the scar remodeling process by injecting relaxin-expressing adenoviruses using a pig scar model.

Methods

Scars with full thickness were generated on the backs of Yorkshire pigs. Scars were divided into two groups (relaxin [RLX] and Control). Adenoviruses were injected into the RLX (expressing relaxin) and Control (not expressing relaxin) groups. Changes in the surface areas, color index and pliability of scars were compared.

Results

Fifty days after treatment, the surface areas of scars decreased, the color of scars was normalized, and the pliability of scars increased in RLX group.

Conclusion

Relaxin-expressing adenoviruses improved the surface area, color, and pliability of scars. The mechanism of therapeutic effects on scar formation should be further investigated.

Lipoxin A4 encapsulated in PLGA microparticles accelerates wound healing of skin ulcers

Lipoxin A₄ (LXA₄) is involved in the resolution of inflammation and wound healing; however, it is extremely unstable. Thus, to preserve its biological activities and confer stability, we encapsulated LXA₄ in poly-lactic-co-glycolic acid (PLGA) microparticles (LXA₄-MS) and assessed its application in treating dorsal rat skin lesions. Ulcers were sealed with fibrin adhesive and treated with either LXA₄-MS, unloaded microparticles (Un-MS), soluble LXA₄, or PBS/glue (vehicle). All groups were compared at 0, 2, 7, and 14 days post-lesions. Our results revealed that LXA₄-MS accelerated wound healing from day 7 and reduced initial ulcer diameters by 80%. Soluble LXA₄, Un-MS, or PBS closed wounds by 60%, 45%, and 39%, respectively. LXA₄-MS reduced IL-1β and TNF-α, but increased TGF-β, collagen deposition, and the number of blood vessels. Compared to other treatments, LXA₄-MS reduced inflammatory cell numbers, myeloperoxidase (MPO) concentration, and metalloproteinase-8 (MMP8) mRNA in scar tissue, indicating decreased neutrophil chemotaxis. In addition, LXA₄-MS treatment increased macrophages and IL-4, suggesting a positive impact on wound healing. Finally, we demonstrated that WRW4, a selective LXA₄ receptor (ALX) antagonist, reversed healing by 50%, indicating that LXA₄ must interact with ALX to induce wound healing. Our results show that LXA₄-MS could be used as a pharmaceutical formulation for the treatment of skin ulcers.

Theoretical and practical aspects of using fetal fibroblasts for skin regeneration

Cutaneous wounding in late-gestational fetal or postnatal humans results in scar formation without any skin appendages. Early or mid- gestational skin healing in humans is characterized by the absence of scaring in a process resembling regeneration. Tremendous cellular and molecular mechanisms contribute to this distinction, and fibroblasts play critical roles in scar or scarless wound healing. This review discussed the different repair mechanisms involved in wound healing of fibroblasts at different developmental stages and further confirmed that fetal fibroblast transplantation resulted in reduced scar healing in vivo. We also discussed the possible problem in fetal fibroblast transplantation for wound repair. We proposed the use of small molecules to improve the regenerative potential of repairing cells in the wound given that remodeling of the wound microenvironment into a regenerative microenvironment in adults might improve skin regeneration.

Macrophages and fibroblasts during inflammation and tissue repair in models of organ regeneration

This review provides a concise summary of the changing phenotypes of macrophages and fibroblastic cells during the local inflammatory response, the onset of tissue repair, and the resolution of inflammation which follow injury to an organ. Both cell populations respond directly to damage and present coordinated sequences of activation states which determine the reparative outcome, ranging from true regeneration of the organ to fibrosis and variable functional deficits. Recent work with mammalian models of organ regeneration, including regeneration of full‐thickness skin, hair follicles, ear punch tissues, and digit tips, is summarized and the roles of local immune cells in these systems are discussed. New investigations of the early phase of amphibian limb and tail regeneration, including the effects of pro‐inflammatory and anti‐inflammatory agents, are then briefly discussed, focusing on the transition from the normally covert inflammatory response to the initiation of the regeneration blastema by migrating fibroblasts and the expression of genes for limb patterning.

Cox-2 inhibition potentiates mouse bone marrow stem cell engraftment and differentiation-mediated wound repair

BACKGROUND

Engraftment of transplanted stem cells is often limited by cytokine and noncytokine proinflammatory mediators at the injury site. We examined the role of Cyclooxygenase-2 (Cox-2)-induced cytokine-mediated inflammation on engraftment of transplanted bone marrow stem cells (BMSCs) at the wound site.

METHODS

BMSCs isolated from male C57/BL6J mice were transplanted onto excisional splinting wounds in syngenic females in presence or absence of celecoxib, Cox-2 specific inhibitor (50 mg/kg, body weight [b wt]), to evaluate engraftment and wound closure. Inflammatory cell infiltration and temporal expression of inflammatory cytokines at the wound bed were determined using immunohistochemical and quantitative-real time polymerase chain reaction (qPCR) analysis, respectively. Mechanistic studies were performed on a murine macrophage cell line (J774.2) to evaluate the effect of interleukin (IL)-17A.

RESULTS

Celecoxib administration led to a significantly high percent of wound closure, cellular proliferation, collagen deposition, BMSCs engraftment and re-epithelialization at the wound site. Interestingly, recruitment of CD4⁺T cells and F4/80⁺ macrophages as well as BMSC transplantation induced up-regulation of Cox-2 and IL-17A gene expression levels were reverted by celecoxib administration. Exogenous supplementation of recombinant interleukin (rIL)-17 to J774.2 cells significantly increased proliferation and gene expression of cytokines -IL-1β, IL-6, IL-8, IL-18 and tumor necrosis factor (TNF)-α via nuclear translocation of nuclear factor kappa B (NFκB)p65/50 subunit. Conditioned media of rIL-17 treated J774.2 cells when supplemented to BMSCs depicted a dose-dependent increase in the number of apoptotic cells and proapoptotic protein expression that was perturbed by celecoxib or IL-17 neutralizing antibody. Finally, celecoxib led to a dose-dependent increase in BMSC differentiation into keratinocyte-like cells in vitro.

CONCLUSION

Celecoxib protects transplanted BMSCs from Cox-2/IL-17-induced inflammation and increases their engraftment, differentiation into keratinocytes and re-epithelialization thereby potentiating wound tissue repair.

Analysis of the Relationship between Ligamentum Flavum Thickening and Lumbar Segmental Instability, Disc Degeneration, and Facet Joint Osteoarthritis in Lumbar Spinal Stenosis

Study Design

Cross-sectional study.

Purpose

To investigate the relationship between ligamentum flavum (LF) thickening and lumbar segmental instability and disc degeneration and facet joint osteoarthritis.

Overview of Literature

Posterior spinal structures, including LF thickness, play a major role in lumbar spinal canal stenosis pathogenesis. The cause of LF thickening is multifactorial and includes activity level, age, and mechanical stress. LF thickening pathogenesis is unknown.

Methods

We examined 419 patients who underwent computed tomography (CT) myelography and magnetic resonance imaging after complaints of clinical symptoms. To investigate LF hypertrophy, 57 patients whose lumbar vertebra had normal disc heights at L4–5 were selected to exclude LF buckling as a hypertrophy component. LF thickness, disc space widening angulation in flexion, segmental angulation, presence of a vacuum phenomenon, and lumbar lordosis at T12–S1 were investigated. Disc and facet degeneration were also evaluated. Facet joint orientation was measured via an axial CT scan.

Results

The mean LF thickness in all patients was 4.4±1.0 mm at L4–5. There was a significant correlation between LF thickness and disc degeneration; LF thickness significantly increased with severe disc degeneration and facet joint osteoarthritis. There was a tendency toward increased LF thickness in more sagittalized facet joints than in coronalized facet joints. Logistic regression analysis showed that LF thickening was influenced by segmental angulation and facet joint osteoarthritis. Patient age was associated with LF thickening.

Conclusions

LF hypertrophy development was associated with segmental instability and severe disc degeneration, severe facet joint osteoarthritis, and a sagittalized facet joint orientation.

Drug repurposing: a new front in the war against Staphylococcus aureus

Staphylococcus aureus continues its domination of worldwide bacterial infection rates, thereby remaining a pathogen of significant public health interest. A major reason for its continued success is its ability to acquire and maintain diverse drug resistance mechanisms, leading to a paucity of antimicrobials active against it, concomitantly leading to a continuous search for new antimicrobial agents. However, with the withdrawal of the major pharmaceutical firms from the anti-infective area, drug repurposing has provided a potential boost to the drug pipeline. In this review, we provide an overview of the currently approved drugs with repurposing potential against Staphylococcus aureus, thus augmenting the classical drug discovery pathway.

Analysis of the Relationship between Hypertrophy of the Ligamentum Flavum and Lumbar Segmental Motion with Aging Process

Study Design

Retrospective cross-sectional study.

Purpose

To investigate the relationship between ligamentum flavum (LF) hypertrophy and lumbar segmental motion.

Overview of Literature

The pathogenesis of LF thickening is unclear and whether the thickening results from tissue hypertrophy or buckling remains controversial.

Methods

296 consecutive patients underwent assessment of the lumbar spine by radiographic and magnetic resonance imaging (MRI). Of these patients, 39 with normal L4–L5 disc height were selected to exclude LF buckling as one component of LF hypertrophy. The study group included 27 men and 12 women, with an average age of 61.2 years (range, 23–81 years). Disc degeneration and LF thickness were quantified on MRI. Lumbar segmental spine instability and presence of a vacuum phenomenon were identified on radiographic images.

Results

The distribution of disc degeneration and LF thickness included grade II degeneration in 4 patients, with a mean LF thickness of 2.43±0.20 mm; grade III in 10 patients, 3.01±0.41 mm; and grade IV in 25 patients, 4.16±1.12 mm. LF thickness significantly increased with grade of disc degeneration and was significantly correlated with age (r=0.55, p<0.01). Logistic regression analysis identified predictive effects of segmental angulation (odds ratio [OR]=1.55, p=0.014) and age (OR=1.16, p=0.008).

Conclusions

Age-related increases in disc degeneration, combined with continuous lumbar segmental flexion-extension motion, leads to the development of LF hypertrophy.

Immediate postoperative evaluation of enteric anastomosis after the use of meloxicam in rats

PURPOSE

To compare ileal anastomoses in the immediate postoperative healing period after meloxicam use.

METHODS

Forty two male Wistar rats were randomly divided into two groups of 21, COX and control group. To COX meloxicam in combination with morphine was given in 3 days period. Control group received only morphine during the same period. Each group was divided into three sub-groups of 7, which were euthanized at 5, 10, and 21 days postoperatively. Comparison was based in histological evaluation of collagen type I and III using sirius red, immunohistochemical through vascular endothelial growth factor and matrix metalloproteinase-9.

RESULTS

Healing process in scheduled periods did not show significant differences (p>0.05) between the COX and control groups during any of the periods.

CONCLUSION

The use of meloxicam in the postoperative period following ileal anastomosis did not affect healing.

Healthy human second-trimester fetal skin is deficient in leukocytes and associated homing chemokines

The lack of immune cells in mid-gestational fetal skin is often mentioned as a key factor underlying scarless healing. However, the scarless healing ability is conserved until long after the immune system in the fetus is fully developed. Therefore, we studied human second-trimester fetal skin and compared the numbers of immune cells and chemokine levels from fetal skin with adult skin. By using immunohistochemistry, we show that healthy fetal skin contains significant lower numbers of CD68(+) -macrophages, Tryptase(+) -mast cells, Langerin(+) -Langerhans cells, CD1a(+) -dendritic cells, and CD3(+) -T cells compared to adult skin. Staining with an early lineage leukocyte marker, i.e., CD45, verified that the number of CD45(+) -immune cells was indeed significantly lower in fetal skin but that sufficient numbers of immune cells were present in the fetal lymph node. No differences in the vascular network were observed between fetal and adult skin. Moreover, significant lower levels of lymphocyte chemokines CCL17, CCL21, and CCL27 were observed in fetal skin. However, levels of inflammatory interleukins such as IL-6, IL-8, and IL-10 were undetectable and levels of CCL2 were similar in healthy fetal and adult skin. In conclusion, this study shows that second-trimester fetal skin contains low levels of immune cells and leukocyte chemokines compared to adult skin. This immune cell deficiency includes CD45(+) leukocytes, despite the abundant presence of these cells in the lymph node. The immune deficiency in healthy second-trimester fetal skin may result in reduced inflammation during wound healing, and could underlie the scarless healing capacities of the fetal skin.

Ibuprofen-conjugated hyaluronate/polygalacturonic acid hydrogel for the prevention of epidural fibrosis

The formation of fibrous tissue is part of the natural healing response following a laminectomy. Severe scar tissue adhesion, known as epidural fibrosis, is a common cause of failed back surgery syndrome. In this study, by combining the advantages of drug treatment with a physical barrier, an ibuprofen-conjugated crosslinkable polygalacturonic acid and hyaluronic acid hydrogel was developed for epidural fibrosis prevention. Conjugation was confirmed and measured by 1D 1H NMR spectroscopy. In vitro analysis showed that the ibuprofen-conjugated polygalacturonic acid–hyaluronic acid hydrogel showed low cytotoxicity. In addition, the conjugated ibuprofen decreased prostaglandin E2 production of the lipopolysaccharide-induced RAW264.7 cells. Histological data in in vivo studies indicated that the scar tissue adhesion of laminectomized male adult rats was reduced by the application of our ibuprofen-conjugated polygalacturonic acid-hyaluronic acid hydrogel. Its use also reduced the population of giant cells and collagen deposition of scar tissue without inducing extensive cell recruitment. The results of this study therefore suggest that the local delivery of ibuprofen via a polygalacturonic acid-hyaluronic acid-based hydrogel reduces the possibility of epidural fibrosis.

The Burn Wound Microenvironment

Significance: While the survival rate of the severely burned patient has improved significantly, relatively little progress has been made in treatment or prevention of burn-induced long-term sequelae, such as contraction and fibrosis. Recent Advances: Our knowledge of the molecular pathways involved in burn wounds has increased dramatically, and technological advances now allow large-scale genomic studies, providing a global view of wound healing processes. Critical Issues: Translating findings from a large number of in vitro and preclinical animal studies into clinical practice represents a gap in our understanding, and the failures of a number of clinical trials suggest that targeting single pathways or cytokines may not be the best approach. Significant opportunities for improvement exist. Future Directions: Study of the underlying molecular influences of burn wound healing progression will undoubtedly continue as an active research focus. Increasing our knowledge of these processes will identify additional therapeutic targets, supporting informed clinical studies that translate into clinical relevance and practice.

Self-assembling ultrashort NSAID-peptide nanosponges: multifunctional antimicrobial and anti-inflammatory materials

This paper outlines the design, synthesis and characterisation of innovative NSAID-peptide gelators which demonstrate antimicrobial and anti-inflammatory properties and have potential use as multifunctional materials for biomedical applications.

A Comparative Analysis of Gene Expression Profiles during Skin Regeneration in Mus and Acomys

The African spiny mouse (Acomys spp.) can heal full thickness excisional skin wounds in a scar-free manner with regeneration of all dermal components including hair and associated structures. Comparing Acomys scar-free healing from Mus scarring identifies gene expression differences that discriminate these processes. We have performed an extensive comparison of gene expression profiles in response to 8mm full-thickness excisional wounds at days 3, 5, 7 and 14 post-wounding between Acomys and Mus to characterize differences in wound healing, and identify mechanisms involved in scar-free healing. We also identify similarities with scar-free healing observed in fetal wounds. While wounding in Mus elicits a strong inflammatory response, wounding in Acomys produces a moderated immune response and little to no increase in expression for most cytokines and chemokines assayed. We also identified differences in the ECM profiles of the Acomys wounds, which appear to have a collagen profile more similar to fetal wounds, with larger increases in expression of collagen types III and V. In contrast, Mus wounds have very high levels of collagen XII. This data suggests that an overall lack of induction of cytokines and chemokines, coupled with an ECM profile more similar to fetal wounds, may underlie scar-free wound healing in Acomys skin. These data identify candidate genes for further testing in order to elucidate the causal mechanisms of scar-free healing.