CD201+ fascia progenitors choreograph injury repair.

Optimal tissue recovery and organismal survival are achieved by spatiotemporal tuning of tissue inflammation, contraction and scar formation1. Here we identify a multipotent fibroblast progenitor marked by CD201 expression in the fascia, the deepest connective tissue layer of the skin. Using skin injury models in mice, single-cell transcriptomics and genetic lineage tracing, ablation and gene deletion models, we demonstrate that CD201+ progenitors control the pace of wound healing by generating multiple specialized cell types, from proinflammatory fibroblasts to myofibroblasts, in a spatiotemporally tuned sequence. We identified retinoic acid and hypoxia signalling as the entry checkpoints into proinflammatory and myofibroblast states. Modulating CD201+ progenitor differentiation impaired the spatiotemporal appearances of fibroblasts and chronically delayed wound healing. The discovery of proinflammatory and myofibroblast progenitors and their differentiation pathways provide a new roadmap to understand and clinically treat impaired wound healing.

A Closer Look at the Cellular and Molecular Components of the Deep/Muscular Fasciae.

The fascia can be defined as a dynamic highly complex connective tissue network composed of different types of cells embedded in the extracellular matrix and nervous fibers: each component plays a specific role in the fascial system changing and responding to stimuli in different ways. This review intends to discuss the various components of the fascia and their specific roles; this will be carried out in the effort to shed light on the mechanisms by which they affect the entire network and all body systems. A clear understanding of fascial anatomy from a microscopic viewpoint can further elucidate its physiological and pathological characteristics and facilitate the identification of appropriate treatment strategies.

Injury triggers fascia fibroblast collective cell migration to drive scar formation through N-cadherin.

Scars are more severe when the subcutaneous fascia beneath the dermis is injured upon surgical or traumatic wounding. Here, we present a detailed analysis of fascia cell mobilisation by using deep tissue intravital live imaging of acute surgical wounds, fibroblast lineage-specific transgenic mice, and skin-fascia explants (scar-like tissue in a dish - SCAD). We observe that injury triggers a swarming-like collective cell migration of fascia fibroblasts that progressively contracts the skin and form scars. Swarming is exclusive to fascia fibroblasts, and requires the upregulation of N-cadherin. Both swarming and N-cadherin expression are absent from fibroblasts in the upper skin layers and the oral mucosa, tissues that repair wounds with minimal scar. Impeding N-cadherin binding inhibits swarming and skin contraction, and leads to reduced scarring in SCADs and in animals. Fibroblast swarming and N-cadherin thus provide therapeutic avenues to curtail fascia mobilisation and pathological fibrotic responses across a range of medical settings.

Sensitivity of the fasciae to sex hormone levels: Modulation of collagen-I, collagen-III and fibrillin production.

Although it is now recognized that women suffer from myofascial pain to a greater extent than men, and that the muscular fasciae can respond to hormonal stimuli, thanks to the expression of sex hormone receptors, how the fasciae can modify their structure under hormonal stimulation is not clear. In this work, an immunocytochemical analysis of collagen-I, collagen-III and fibrillin were carried out on fibroblasts isolated from human fascia lata after in vitro treatment with various levels of sex hormones ß-estradiol and/or relaxin-1, according to the phases of a woman's period (follicular, periovulatory, luteal, post-menopausal phases and pregnancy). This study demonstrates for the first time that fascial cells can modulate the production of some components of the extracellular matrix according to hormone levels, when treated with ß-estradiol: collagen-I falls from 6% of positivity in the follicular phase to 1.9 in the periovulatory phase. However, after the addition of relaxin-1 to the cell culture, the production of extracellular matrix decreased and remained at the same level (1.7% of collagen-I, at both follicular and periovulatory levels of hormones). These results confirm the antifibrotic function of relaxin-1, thanks to its ability to reduce matrix synthesis. They are also a first step in our understanding of how some hormonal dysfunctions in women can cause a dysregulation of extracellular matrix production in fasciae.

Spatial distribution and correlation of adipocytes and mast cells in superficial fascia in rats.

Superficial fascia has abundant preadipocytes capable of spontaneous and induced differentiation and is thought to be a novel origin of adipocytes. This study aimed to quantitatively evaluate the spatial distribution and correlation of adipocytes and mast cells in rat superficial fascia. Panoramic images were obtained from whole-mounted fascia stained by toluidine blue. Adipocytes increased gradually in superficial fascia of growing rats. Abundant mast cells, with the degranulation and exocytosis of abundant secretory granules, appeared in fascia where partially differentiating adipocytes and mature adipocytes occurred. Quantitative histological analysis by variance-mean ratio and Morisita index of dispersion indicated that both mast cells and adipocytes in fascia were distributed individually in cluster, but not random or uniform. Spearman's correlation coefficient revealed that the spatial cluster distributions of mast cells and adipocytes positively correlated with each other and correlated with increased number and size of adipocytes and adipogenic areas in fascia. Morphometry analysis indicated the strong correlation between fascial adipocytes and mast cells during the periods of rat growth. The correlation coefficient increased significantly at 8 weeks compared to 4 weeks, consistent with the increasing trend of the number and size of fascia adipocytes in growing rats. This finding provided the first quantitative histological analysis for the spatial distribution and correlation of fascia adipocytes and mast cells, which could be the histocytological basis for further exploring spatial and functional interactions between fascial mast cells and adipocytes. Also, the present data were informative for the research on physiologies and pathologies of fascia and fascia-related connective tissues.

Investigating the effects of Pirfenidone on TGF-ß1 stimulated non-SMAD signaling pathways in Dupuytren's disease -derived fibroblasts.

BACKGROUND: Dupuytren's disease (DD) is a progressive, debilitating condition of the hand that can eventually cause contractures of the affected fingers. Transforming growth factor- ß1 (TGF-ß1) has been reported to play a key role in DD pathology. Increased expression of TGF-ß1 has shown to be the main stimulator of myofibroblast activity and in DD contractures. Pirfenidone (PFD), a small active molecule possess the ability to inhibit TGF-ß1-mediated action in various fibrotic disorders. Our recent published findings show that PFD reduced TGF-ß1-mediated cellular functions implicated in DD through SMAD signaling pathways. In the present study, the effect of PFD on TGF-ß1-mediated non-SMAD signaling pathways were investigated in both carpal tunnel (CT) - and DD-derived fibroblasts. METHODS: Fibroblasts harvested from Dupuytren's disease (DD) and carpal tunnel (CT) tissues were cultured in the presence or absence of TGF-ß1 (10 ng/ml) and/or PFD (800 µg/ml). Cell lysates were analyzed using Western blots. Equal amounts of proteins were loaded to determine the phosphorylation levels of phosphatidylinositol-3 kinase (PI3K/AKT), extracellular regulated kinases (ERK1/2), p38 mitogen-activated protein kinase and Rho family related myosin light chain (MLC). RESULTS: We show that the TGF-ß1-induced phosphorylation of AKT was significantly decreased by the addition of PFD (800 µg/mL) in both CT- and DD-derived fibroblasts. Interestingly, there was no significant difference in the phosphorylation levels of both ERK and p38 on TGF-ß1- induced cells in both CT-and DD-derived fibroblasts. But, PFD significantly decreased the TGF- ß1-induced phosphorylation levels of ERK1/2 in both CT- and DD- cells. In contrast, PFD significantly decreased the basal and TGF- ß1-induced phosphorylation levels of p38 in DD-derived fibroblasts. TGF- ß1-induced phosphorylation levels of MLC was decreased by PFD in DD-derived fibroblasts. CONCLUSIONS: These in-vitro results indicate for the first time that PFD has the potential to inhibit TGF-ß1-induced non-SMAD signaling pathways in both CT- and DD-derived fibroblasts but pronounced statistically significant inhibition on all molecules was observed only in DD-derived fibroblasts. Our previous studies show that PFD can inhibit TGF-ß1- induced SMAD signaling pathway proteins, namely p- SMAD2/SMAD3. These broad and complementary actions suggest PFD as a promising candidate to inhibit the TGF-ß1- mediated molecular mechanisms leading to DD fibrosis.

Group A Streptococcal DNase Sda1 Impairs Plasmacytoid Dendritic Cells' Type 1 Interferon Response.

Group A Streptococcus causes severe invasive infections, including necrotizing fasciitis. The expression of an array of virulence factors targeting specific host immune functions impedes successful bacterial clearance. The virulence factor streptococcal DNase Sda1 was previously shown to interfere with the entrapment of bacteria through neutrophil extracellular traps and TLR9 signaling. In this study, we showed that plasmacytoid dendritic cells are recruited to the infected tissue during group A streptococcal necrotizing fasciitis. We found that the streptococcal DNase Sda1 impairs plasmacytoid dendritic cell recruitment by reducing IFN-1 levels at the site of infection. We found that streptococcal DNase Sda1 interferes with stabilization of the DNA by the host molecule HMGB1 protein, which may account for decreased IFN-1 levels at the site of infection.

Extracellular matrix particle-glycosaminoglycan composite hydrogels for regenerative medicine applications.

Tissue extracellular matrix (ECM) is a complex material made up of fibrous proteins and ground substance (glycosaminoglycans, GAGs) that are secreted by cells. ECM contains important biological cues that modulate cell behaviors, and it also serves as a structural scaffold to which cells can adhere. For clinical applications, where immune rejection is a constraint, ECM can be processed using decellularization methods intended to remove cells and donor antigens from tissue or organs, while preserving native biological cues essential for cell growth and differentiation. In this study, a decellularized ECM-based composite hydrogel was formulated by using modified GAGs that covalently bind tissue particles. These GAG-ECM composite hydrogels combine the advantages of solid decellularized ECM scaffolds and pepsin-digested ECM hydrogels by facilitating ECM hydrogel formation without a disruptive enzymatic digestion process. Additionally, engineered hydrogels can contain more than one type of ECM (from bone, fat, liver, lung, spleen, cartilage, or brain), at various concentrations. These hydrogels demonstrated tunable gelation kinetics and mechanical properties, offering the possibility of numerous in vivo and in vitro applications with different property requirements. Retained bioactivity of ECM particles crosslinked into this hydrogel platform was confirmed by the variable response of stem cells to different types of ECM particles with respect to osteogenic differentiation in vitro, and bone regeneration in vivo. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 147-159, 2018.

Donor mesenchymal stem cells home to maternal wounds after transamniotic stem cell therapy (TRASCET) in a rodent model.

PURPOSE: Transamniotic stem cell therapy (TRASCET) with amniotic fluid-derived MSCs (afMSCs) has emerged experimentally as a practical treatment strategy for congenital anomalies. In this study, we sought to determine whether afMSCs migrate to the mother following TRASCET. METHODS: Pregnant rat dams were divided into three groups. Two groups received volume-matched injections into all amniotic cavities of either a suspension of afMSCs labeled with a luciferase reporter gene or the luciferase protein alone. In a third group, a suspension of labeled cells was aliquoted onto the serosal surface of the uterus. Maternal samples from the laparotomy scar (fascia and skin separately), bone marrow, and peripheral blood were procured, along with placenta and umbilical cord. Specimens were screened for luminescence via microplate luminometry. RESULTS: Luminescence was detected in 60% (9/15) of the fascial scars from the group receiving intraamniotic injection of afMSCs, but in none of the other groups (P<0.001). There was a direct correlation between the presence of donor cells in the placenta and their presence in maternal fascia (Wald test=10.2; P=0.001). CONCLUSIONS: Amniotic mesenchymal stem cells migrate to maternal sites of injury after intraamniotic injection. Maternal homing of donor cells must be considered in the setting of transamniotic stem cell therapy. LEVEL OF EVIDENCE: N/A (animal and laboratory study).

Impact of the nature of the temporalis fascia graft on the outcome of type I underlay tympanoplasty.

OBJECTIVES: Temporalis fascia has become the most widely used graft for tympanoplasty, as it is strong, durable, and easy to procure and handle. However, the type of temporalis fascia graft to use (i.e. dry or wet) remains controversial. The present review aimed to evaluate the success rates of dry and wet temporalis fascia grafts in type I underlay tympanoplasty. METHODS: A literature search was performed, using PubMed up to August 2016, to identify all studies of dry and wet temporalis fascia grafts in type I underlay tympanoplasty. The initial search using the key words 'temporalis fascia' and 'tympanoplasty' identified 130 articles; these were screened by reviewing the titles or abstracts based on the inclusion and exclusion criteria. Ultimately, this review included seven articles. RESULTS AND CONCLUSION: A dry or wet temporalis fascia graft did not affect the outcome of type I underlay tympanoplasty. However, using wet temporalis fascia could shorten the duration of surgery in type I underlay tympanoplasty. Concerns that the fibroblast count of temporalis fascia may beneficially affect success rate have not been substantiated in clinical reports thus far.

Expression of the endocannabinoid receptors in human fascial tissue.

Cannabinoid receptors have been localized in the central and peripheral nervous system as well as on cells of the immune system, but recent studies on animal tissue gave evidence for the presence of cannabinoid receptors in different types of tissues. Their presence was supposed also in myofascial tissue, suggesting that the endocannabinoid system may help resolve myofascial trigger points and relieve symptoms of fibromyalgia. However, until now the expression of CB1 (cannabinoid receptor 1) and CB2 (cannabinoid receptor 2) in fasciae has not yet been established. Small samples of fascia were collected from volunteers patients during orthopedic surgery. For each sample were done a cell isolation, immunohistochemical investigation (CB1 and CB2 antibodies) and real time RT-PCR to detect the expression of CB1 and CB2. Both cannabinoid receptors are expressed in human fascia and in human fascial fibroblasts culture cells, although to a lesser extent than the control gene. We can assume that the expression of mRNA and protein of CB1 and CB2 receptors in fascial tissue are concentrated into the fibroblasts. This is the first demonstration that the fibroblasts of the muscular fasciae express CB1 and CB2. The presence of these receptors could help to provide a description of cannabinoid receptors distribution and to better explain the role of fasciae as pain generator and the efficacy of some fascial treatments. Indeed the endocannabinoid receptors of fascial fibroblasts can contribute to modulate the fascial fibrosis and inflammation.

Fascial hierarchies and the relevance of crossed-helical arrangements of collagen to changes in the shape of muscles.

Muscles are composite structures consisting of contractile myofibres surrounded by complex hierarchies of collagen-reinforced fascial sheaths. They are essentially flexible cylinders that change in shape, with the particular alignment of collagen fibres within their myofascial walls reflecting the most efficient distribution of mechanical stresses and coordinating these changes. However, while the functional significance of this crossed-helical fibre arrangement is well established in other species and in different parts of the body, relatively little attention has been given to this within the fascia of humans; and the relevance of this geometric configuration to muscles and surrounding fascial tissues is described.

Fascia Origin of Adipose Cells.

Adipocytes might arise from vascular stromal cells, pericytes and endothelia within adipose tissue or from bone marrow cells resident in nonadipose tissue. Here, we identified adipose precursor cells resident in fascia, an uninterrupted sheet of connective tissue that extends throughout the body. The cells and fragments of superficial fascia from the rat hindlimb were highly capable of spontaneous and induced adipogenic differentiation but not myogenic and osteogenic differentiation. Fascial preadipocytes expressed multiple markers of adipogenic progenitors, similar to subcutaneous adipose-derived stromal cells (ASCs) but discriminative from visceral ASCs. Such preadipocytes resided in fascial vasculature and were physiologically active in vivo. In growing rats, adipocytes dynamically arose from the adventitia to form a thin adipose layer in the fascia. Later, some adipocytes appeared to overlay on top of other adipocytes, an early sign for the formation of three-dimensional adipose tissue in fascia. The primitive adipose lobules extended invariably along blood vessels toward the distal fascia areas. At the lobule front, nascent capillaries wrapped and passed ahead of mature adipocytes to form the distal neovasculature niche, which might replenish the pool of preadipocytes and supply nutrients and hormones necessary for continuous adipogenesis. Our findings suggest a novel model for the origin of adipocytes from the fascia, which explains both neogenesis and expansion of adipose tissue. Fascial preadipocytes generate adipose cells to form primitive adipose lobules in superficial fascia, a subcutaneous nonadipose tissue. With continuous adipogenesis, these primitive adipose lobules newly formed in superficial fascia may be the rudiment of subcutaneous adipose tissue. Stem Cells 2016;34:1407-1419.

[Effects of acupuncture with different filiform needles on tissues, cells and collagenous fiber of fascia in acupoint area of rats].

OBJECTIVE: To explore the effects of acupuncture with different filiform needles on structure of fascial connective tissues, cellular activity, arrangement and content of collagen fibers in acupoint area of rats. METHODS: A total of 32 SD rats were randomly divided into a blank group, a thin needle group, a medium needle group and a thick needle group, 8 rats in each one. Except for the blank group, rats in the remaining groups were treated with horizontal acupuncture at "Zhongwan" (CV 12) towards Conception Vessel with different filiform needles, and twirling mild reinforcing-reducing method was applied, once a day. Rats in the blank group were treated with identical anesthesia, grasping and fixation. After 3-day intervention, the fascial connective tissue of acupoint area was collected. HE staining, immumohistochemical staining of proliferating cell nuclear antigen (PCNA) and MASSON staining were adopted to observe the morphology of fascial connective tissues, expression of PCNA in cells and arrangement and expression of collagenous fiber. RESULTS: After acupuncture in each group, the consistency of morphology of fascial connective tissues and arrangement of collagenous fiber were changed; the expression of PCNA protein in the fascial connective tissue in each group was significantly increased (P<0. 01, P<0. 05). The area distribution of collagenous fiber were changed, and that in the thin needle group was insignificantly increased compared with that in the blank group (P>0. 05), and that in the medium needle group and thick needle group were reduced compared with that in the blank group (both P<0. 05). CONCLUSIONS: Acupuncture with different filiform needles can change the local tissue morphology of acupoints, strengthen cell activity and adjust the exyression of collagenous fiber protein, which may be one of the cellular biomechanics principles of the acupuncture therapy's "regulating meridians" effects. However, the stimulation is produced by different fifiform needles, and the complex relationships exist between cells and collagen fibers.

Whole mount microscopic sections reveal that Denonvilliers' fascia is one entity and adherent to the mesorectal fascia; implications for the anterior plane in total mesorectal excision?

BACKGROUND: Excellent anatomical knowledge of the rectum and surrounding structures is essential for total mesorectal excision (TME). Denonviliers' fascia (DVF) has been frequently studied, though the optimal anterior plane in TME is still disputed. The relationship of the lateral edges of DVF to the autonomic nerves and mesorectal fascia is unclear. We studied whole mout microscopic sections of en-bloc cadaveric pelvic exenteration and describe implications for TME. METHODS: Four donated human adult cadaveric specimens (two males, two females) were obtained from the Leeds GIFT Research Tissue Programme. Paraffin-embedded mega blocks were produced and serially sectioned at 50 and 250 µm intervals. Sections were stained with haematoxylin & eosin, Masson's trichrome and Millers' elastin. Additionally, a series of eleven human fetal specimens (embryonic age of 9-20 weeks) were studied. RESULTS: DVF consisted of multiple fascial condensations of collagen and smooth muscle fibres and was indistinguishable from the anterior mesorectal fascia and the prostatic fascia or posterior vaginal wall. The lateral edges of DVF appeared fan-shaped and the most posterior part was continuous with the mesorectal fascia. Fasciae were not identified in fetal specimens. CONCLUSION: DVF is adherent to and continuous with the mesorectal fascia. Optimal surgical dissection during TME should be carried out anterior to DVF to ensure radical removal, particularly for anterior tumours. Autonomic nerves are at risk, but can be preserved by closely following the mesorectal fascia along the anterolateral mesorectum. The lack of evident fasciae in fetal specimens suggested that these might be formed in later developmental stages.

Induction of endometrial mesenchymal stem cells into tissue-forming cells suitable for fascial repair.

Pelvic organ prolapse is a major hidden burden affecting almost one in four women. It is treated by reconstructive surgery, often augmented with synthetic mesh. To overcome the growing concerns of using current synthetic meshes coupled with the high risk of reoperation, a tissue engineering strategy has been developed, adopting a novel source of mesenchymal stem cells. These cells are derived from the highly regenerative endometrial lining of the uterus (eMSCs) and will be delivered in vivo using a new gelatin-coated polyamide scaffold. In this study, gelatin properties were optimized by altering the gelatin concentration and extent of crosslinking to produce the desired gelation and degradation rate in culture. Following cell seeding of uncoated polyamide (PA) and gelatin-coated meshes (PA+G), the growth rate of eMSCs on the PA+G scaffolds was more than that on the PA alone, without compromising cell shape. eMSCs cultured on the PA+G scaffold retained their phenotype, as demonstrated by W5C5/SUSD2 (eMSC-specific marker) immunocytochemistry. Additionally, eMSCs were induced to differentiate into smooth muscle cells (SMC), as shown by immunofluorescence for smooth muscle protein 22 and smooth muscle myosin heavy chain. eMSCs also differentiated into fibroblast-like cells when treated with connective tissue growth factor with enhanced detection of Tenascin-C and collagen type I as well as new tissue formation, as seen by Masson's trichrome. In summary, it was demonstrated that the PA+G scaffold is an appropriate platform for eMSC delivery, proliferation and differentiation into SMC and fibroblasts, with good biocompatibility and the capacity to regenerate neo-tissue.

Fascia tissue engineering with human adipose-derived stem cells in a murine model: Implications for pelvic floor reconstruction.

BACKGROUND/PURPOSE: Mesh-augmented vaginal surgery for treatment of pelvic organ prolapse (POP) does not meet patients' needs. This study aims to test the hypothesis that fascia tissue engineering using adipose-derived stem cells (ADSCs) might be a potential therapeutic strategy for reconstructing the pelvic floor. METHODS: Human ADSCs were isolated, differentiated, and characterized in vitro. Both ADSCs and fibroblastic-differentiated ADSCs were used to fabricate tissue-engineered fascia equivalents, which were then transplanted under the back skin of experimental nude mice. RESULTS: ADSCs prepared in our laboratory were characterized as a group of mesenchymal stem cells. In vitro fibroblastic differentiation of ADSCs showed significantly increased gene expression of cellular collagen type I and elastin (p < 0.05) concomitantly with morphological changes. By contrast, ADSCs cultured in control medium did not demonstrate these changes. Both of the engrafted fascia equivalents could be traced up to 12 weeks after transplantation in the subsequent animal study. Furthermore, the histological outcomes differed with a thin (111.0 ± 19.8 µm) lamellar connective tissue or a thick (414.3 ± 114.9 µm) adhesive fibrous tissue formation between the transplantation of ADSCs and fibroblastic-differentiated ADSCs, respectively. Nonetheless, the implantation of a scaffold without cell seeding (the control group) resulted in a thin (102.0 ± 17.1 µm) fibrotic band and tissue contracture. CONCLUSION: Our results suggest the ADSC-seeded implant is better than the implant alone in enhancing tissue regeneration after transplantation. ADSCs with or without fibroblastic differentiation might have a potential but different role in fascia tissue engineering to repair POP in the future.

Response of dupuytren fibroblasts to different oxygen environments.

PURPOSE: It is thought that local ischemia and oxygen radicals are responsible for fibroblast-to-myofibroblast cell transformation and proliferation. We hypothesized that hypoxia could differentially activate the contractility of fibroblasts from normal human palmar fascia and from fibroblasts-myofibroblasts of Dupuytren cords. METHODS: Normal palmar fascia from 5 patients with carpal tunnel syndrome and Dupuytren cords from 5 patients were harvested. Cells were cultured from all tissue samples, and collagen lattices were prepared containing these cells. Oxygen treatment subgroups were created and incubated under hypoxic (1% O(2), 5% CO(2), and 94% N(2)), normoxic (21% O(2), 5% CO(2), and 74% N(2)), and hyperoxic (100% oxygen using 2.4 atm pressure twice a day for 7 d) conditions. After 7 days, each subgroup was photographed, and lattices were released from dishes. Postrelease photographs were taken immediately, 5 minutes after release, and after 1 hour. Areas of the lattices at each time point were calculated using MetaMorph software. Actin staining and live/dead cell analysis was performed. Linear repeated measures analysis of variance was used for data analysis given that contraction levels were measured over 3 distinct time points. RESULTS: We found a statistically significant difference between normal samples and Dupuytren samples in mean contraction levels over time. There was no statistically significant difference between tissue groups over the 3 time periods based on the oxygen treatment received. CONCLUSIONS: Our results showed a greater degree of contractility in Dupuytren disease cells than normal fibroblasts. However, the contraction in either group was not affected by oxygen level. Future in vivo research is needed to better understand the nature of pathophysiology of Dupuytren disease.

Nociception originating from the crural fascia in rats.

Little is documented in the literature as to the function of muscle fascia in nociception and pain. The aim of this study was to examine the distribution of presumptive nociceptive nerve fibers, to characterize fascial thin-fiber sensory receptors, and to examine the spinal projection of nociceptive input from the rat crural fascia (CF). Nerve fibers labeled with specific antibodies to calcitonin gene-related peptide (CGRP) and peripherin were found to be densely distributed in the distal third of the CF. Thin-fiber receptors (Aδ- and C-fibers) responding to pinching stimuli to the CF with sharpened watchmaker's forceps, identified in vivo with the teased fiber technique from the common peroneal nerve, exist in the CF. Forty-three percent of the mechano-responsive fascial C-fibers were polymodal receptors (nociceptors) responding to mechanical, chemical (bradykinin), and heat stimuli, whereas almost all Aδ-fibers were responsive only to mechanical stimuli. Repetitive pinching stimulus to the CF induced c-Fos protein expression in the middle to medial part of superficial layers ie, laminae I-II of the spinal dorsal horn at segments L2 to L4, peaking at L3. These results clearly demonstrate the following: 1) peptidergic and non-peptidergic axons of unmyelinated C-fibers with nerve terminals are distributed in the CF; 2) peripheral afferents responding to noxious stimuli exist in the fascia, and 3) nociceptive information from the CF is mainly processed in the spinal dorsal horn at the segments L2 to L4. These results together indicate that the "muscle fascia," a tissue often overlooked in pain research, can be an important source of nociception under normal conditions.

Experimental biological research on stem cells in fascia tissue.

The fascia tissue, derived from the mesoderm, is distributed in all parts of the human body. It consists of connective tissues and stem cells. The fascia tissue is also believed to be a functional system, like the digestive system, in the human body, controlling self-inspection, self-maintenance, support, and storage. In addition, much of the research relevant to fascia tissue has focused on adipose-derived stem cells (ADSCs), which mainly exist in adipose tissues. The aim of this review is to summarize the current research on ADSCs, including a brief introduction of their biological characteristics, the isolation and expansion methods, a conclusion on their multidifferentiation potential, new clinical applications, and the therapeutic strategies for treating tumors.