Promote Fibroblast Proliferation Research Articles

Growth differentiation factor 10 induces angiogenesis to promote wound healing in rats with diabetic foot ulcers by activating TGF-β1/Smad3 signaling pathway.

Diabetic foot ulcer (DFU) represents a highly-prevalent complication of diabetes mellitus (DM). Herein, the current study sought to identify the role of growth differentiation factor 10 (GDF-10) in wound healing in DFU via regulation of the transforming growth factor-beta 1 (TGF-β1)/Smad3 pathway. DM- and DFU-related microarray datasets GSE29221 and GSE134431 were firstly retrieved, and weighted gene co-expression network analysis (WGCNA) was carried out to construct a co-expression network affecting wound healing in DFU, followed by differential analysis. A protein-protein interaction (PPI) network of the DFU-related genes was subsequently constructed, and the core genes and signaling pathways in DFU were screened with the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes functional analyses. A DFU rat model was constructed for mechanism verification of the effect of GDF-10 on wound healing in DFU. WGCNA screened five co-expression modules, and the brown module was most closely-related to DM. Clustering analysis screened 4417 candidate genes, of which 175 differential genes were associated with wound healing, further involved in TGF-β1/Smad3 signaling pathway regulation of wound healing in DFU. The PPI network analysis predicted that GDF-10 might regulate the TGF-β1/Smad3 signaling pathway to participate in DFU development. Results of animal experimentation showed that the wound healing rates of NFU, DFU, DFU + GDF and GDF + SIS3 groups on the 22nd day were (87.66 ± 6.80)%, (56.31 ± 7.29)%, (71.64 ± 9.43)% and (55.09 ± 7.13)%, respectively. Besides, the expression of TGF-β1 in NFU, DFU, DFU + GDF and GDF + SIS3 groups was 0.988 ± 0.086, 0.297 ± 0.036, 0.447 ± 0.044, and 0.240 ± 0.050, respectively, and that of Smad3 was 1.009 ± 0.137, 0.145 ± 0.017, 0.368 ± 0.048, and 0.200 ± 0.028, respectively. Specifically, GDF-10 exerted a significant diminishing effect on fasting blood glucose level, and promoted wound healing in DFU rats, in addition to up-regulation of VEGF, FGF, Ang-1, TGF-β1, Smad3 and enhancement of IL-1b, IL-6, TNF-a and MMP-9, thereby promoting fibroblast proliferation, collagen deposition and angiogenesis. Our findings highlight that GDF-10 may promote angiogenesis by activating TGF-β1/Smad3 signaling, thereby promoting wound healing in DFU rats.

Fibroblast Growth Factor 2 Is Produced By Renal Tubular Cells to Act as a Paracrine Factor in Maladaptive Kidney Repair After Cisplatin Nephrotoxicity

Kidney repair after injury involves the cross-talk of injured kidney tubules with interstitial fibroblasts and immune cells. Although tubular cells produce multiple cytokines, the role and regulation of specific cytokines in kidney repair are largely undefined. In this study, we detected the induction of fibroblast growth factor 2 (FGF2) in mouse kidneys after repeated low-dose cisplatin (RLDC) treatment and in RLDC-treated renal proximal tubule cells in vitro. We further detected FGF2 in the culture medium of RLDC-treated renal tubular cells but not in the medium of control cells, indicating that RLDC induces FGF2 expression and secretion. Compared with the medium of control cells, the medium of RLDC-treated renal tubular cells was twice as effective in promoting fibroblast proliferation. Remarkably, the proliferative effect of the RLDC-treated cell medium was diminished by FGF2-neutralizing antibodies. In addition, the RLDC-treated cell medium induced the expression of fibrosis-related proteins, which was partially suppressed by FGF2-neutralizing antibodies. In mice, FGF2 deficiency partially prevented RLDC-induced decline in kidney function, loss of kidney weight, renal fibrosis, and inflammation. Together, these results indicate that FGF2 is produced by renal tubular cells after kidney injury and acts as an important paracrine factor in maladaptive kidney repair and disease progression.

Osteopontin May Improve Postinjury Muscle Repair Via Matrix Metalloproteinases And tgf-β Activation in Regular Exercise.

Skeletal muscle injuries are commonly observed during sports and trauma. Regular exercise promotes muscle repair; however, the underlying mechanisms require further investigation. In addition to exercise, osteopontin (OPN) contributes to skeletal muscle regeneration and fibrosis following injury. However, whether and how OPN affects matrix proteins to promote post-injury muscle repair remains uncertain. We recruited regular exercise (RE) and sedentary control (SC) groups to determine plasma OPN levels. Additionally, we developed a murine model of muscle contusion injury and compared the extent of damage, inflammatory state, and regeneration-related proteins in OPN knockout (OPN KO) and wild-type (WT) mice. Our results show that regular exercise induced the increase of OPN, matrix metalloproteinases (MMPs), and transforming growth factor-β (TGF-β) expression in plasma. Injured muscle fibers were repaired more slowly in OPN-KO mice than in WT mice. The expression levels of genes and proteins related to muscle regeneration were lower in OPN-KO mice after injury. OPN also promotes fibroblast proliferation, differentiation, and migration. Additionally, OPN upregulates MMP expression by activating TGF-β, which promotes muscle repair. OPN can improve post-injury muscle repair by activating MMPs and TGF-β pathways. It is upregulated by regular exercise. Our study provides a potential target for the treatment of muscle injuries and explains why regular physical exercise is beneficial for muscle repair.

Role of Royal Jelly Treated Adipose‐Derived Stem Cell‐Extracellular Vesicles on Fibroblast Proliferation, Migration, and Collagen Production

Extracellular vesicles (EVs) secreted from adipose‐derived stem cells (ADSCs) are known to exhibit collagen synthesis and migration activity in fibroblasts. These EVs can be used as a regenerative medicine and for cosmetic medicinal materials. Royal jelly (RJ) is produced from the hypopharyngeal and mandibular glands of honeybees (nurse bee), which contains apicin and 10‐hydroxy‐2‐decenoic acid, compounds that promote fibroblast proliferation and collagen and elastin synthesis. Here, we investigated whether RJ could further enhance the physiological function of ADSC‐EVs on fibroblasts. The findings confirmed that lyophilized RJ and enzyme‐treated RJ enhanced the secretion of EVs by ADSCs, increasing the proliferation, migration, and collagen synthesis of fibroblasts compared to those induced by conventional ADSC‐EVs. Bioinformatics analysis was conducted using various software programs, based on the data obtained from comprehensive gene expression and small RNA profiling analyses through next‐generation sequencing; the results suggested that the RJ treatment of ADSC‐EVs significantly enhanced the expression of genes related to extracellular matrix composition. Our findings suggest that the ADSC‐EVs qualitatively altered using RJ could offer a more effective therapeutic material for regenerative and cosmetic medicine than conventional ADSCs‐EVs.

SPARC promotes fibroblast proliferation, migration, and collagen production in keloids by inactivation of p53

BackgroundKeloid, an aggressive fibroproliferative disease of the skin, is usually caused by infectious skin diseases, burns, and trauma. ObjectiveThis study aimed to assess the effect of SPARC on the keloid pathogenesis. MethodsIn normal skin and keloid scar tissues, changes in SPARC expression were analysed by qRT-PCR, western blotting, and immunohistochemistry. Keloid fibroblasts were isolated from human keloid tissue. GSEA was performed to investigate the signalling pathways related to SPARC. Cell Counting Kit-8, 5-Ethynyl-2′-deoxyuridine, transwell assay, and scratching assays were used to assess fibroblast proliferation and migration. Changes in α-SMA, fibronectin, collagen I, and collagen III levels were examined in fibroblasts by western blotting. ResultsSPARC expression was upregulated in keloid scar tissues. In fibroblasts, cell proliferation, migration, collagen production, and extracellular matrix (ECM) synthesis were promoted by SPARC overexpression, whereas SPARC knockdown resulted a converse result. GSEA showed that SPARC regulates the p53 pathway. In keloid scar tissues, there was a negative correlation between SPARC and p53 expression. p53 expression was decreased by SPARC overexpression, whereas SPARC knockdown increased p53 expression. Furthermore, the effects of SPARC on the fibroblast phenotype were reversed by p53 overexpression. ConclusionsFibroblast proliferation, migration, and ECM synthesis were promoted by SPARC overexpression, which was achieved by regulating the p53 pathway. Our findings provide new therapeutic targets for keloids.

Histological evaluation of wound healing by topical phenytoin application on extraction socket: anin vivostudy in albino Wistar rats

Objective:To investigate the effects of topical phenytoin application on wound healing of extraction socket of albino Wistar rats.Materials and methods:Thirty-six albino Wistar rats were randomly divided into Group A (control), B (1% phenytoin mucoadhesive paste), and C (mucoadhesive paste without phenytoin). All animals were anesthetized followed by first molar extraction. Group A did not receive any agent, whereas, Group B and C received daily application of their respective pastes. Four animals from each group were sacrificed on day 7, 14, and 21 and analyzed histologically.Results:No significant difference was found in blood vessel count among the groups. Statistical increase in percentage of fibroblast in Group B was found as compared with other groups at day 7, whereas, no significant difference was found among groups at day 14. Day 21 showed significant decrease in percentage of fibroblasts in Group B (p-value < 0.001) as compared with Group A and C. Increase in percentage of bone trabeculae in Group B was observed on day 7, 14, and 21 with a significant difference (p-value < 0.05) as compared to Group A and C.Conclusion:Topical application of phenytoin promoted fibroblast proliferation and bone trabeculae formation during healing of extraction socket in rats.

M2 macrophages mediate fibrotic scar formation in the early stages after cerebral ischemia in rats.

In the central nervous system, the formation of fibrotic scar after injury inhibits axon regeneration and promotes repair. However, the mechanism underlying fibrotic scar formation and regulation remains poorly understood. M2 macrophages regulate fibrotic scar formation after injury to the heart, lung, kidney, and central nervous system. However, it remains to be clarified whether and how M2 macrophages regulate fibrotic scar formation after cerebral ischemia injury. In this study, we found that, in a rat model of cerebral ischemia induced by middle cerebral artery occlusion/reperfusion, fibrosis and macrophage infiltration were apparent in the ischemic core in the early stage of injury (within 14 days of injury). The number of infiltrated macrophages was positively correlated with fibronectin expression. Depletion of circulating monocyte-derived macrophages attenuated fibrotic scar formation. Interleukin 4 (IL4) expression was strongly enhanced in the ischemic cerebral tissues, and IL4-induced M2 macrophage polarization promoted fibrotic scar formation in the ischemic core. In addition, macrophage-conditioned medium directly promoted fibroblast proliferation and the production of extracellular matrix proteins in vitro. Further pharmacological and genetic analyses showed that sonic hedgehog secreted by M2 macrophages promoted fibrogenesis in vitro and in vivo, and that this process was mediated by secretion of the key fibrosis-associated regulatory proteins transforming growth factor beta 1 and matrix metalloproteinase 9. Furthermore, IL4-afforded functional restoration on angiogenesis, cell apoptosis, and infarct volume in the ischemic core of cerebral ischemia rats were markedly impaired by treatment with an sonic hedgehog signaling inhibitor, paralleling the extent of fibrosis. Taken together, our findings show that IL4/sonic hedgehog/transforming growth factor beta 1 signaling targeting macrophages regulates the formation of fibrotic scar and is a potential therapeutic target for ischemic stroke.

Advances in wound repair and regeneration: Systematic comparison of cell free fat extract and platelet rich plasma.

Background: Previous studies showed Cell free fat extract (CEFFE) and Platelet rich plasma (PRP) could effectively accelerate wound healing. However, the comparative study on curative effect is still lacking. A systematic comparison could provide more theoretical support and laboratory basis for the clinical application of CEFFE and PRP. Objective: To compare the efficacy of CEFFE and PRP in promoting skin wound repair. Methods: CEFFE and PRP were prepared according to the literature. The wound repair related factors were measured and compared. In vitro, the effects of both on cell migration, proliferation and tube formation were compared. In vivo, wound healing rate was measured on the 1st, 3rd, 9th, and 12th days after skin injury and treatment. Then the specimens were cut off for histological analysis. Results: Although the total protein content of PRP was significantly around 19 times higher than that of CEFFE, there was no statistical difference in the content of BDNF, EGF and VEGF between CEFFE and PRP. Even the NT-3 content of CEFFE was just slightly higher than that of PRP. The concentration of b-FGF, HGF and TGF-β and PDGF-BB in PRP is higher than that in CEFFE, but there is only a very small difference between them. In vitro, PRP showed better efficacy than CEFFE in promoting fibroblast proliferation while there was no significant difference in promoting angiogenesis and fibroblast migration. Both PRP and CEFFE could significantly promote wound healing in mice. There was no statistical difference in wound healing between CEFFE and PRP groups in vivo. Immunohistochemical staining of Ki67&CD31 showed that there was no significant difference between PRP and CEFFE groups. Conclusion: The effect of PRP and CEFFE in promoting wound healing was similar. In clinical practice, the acquisition of PRP is relatively more convenient. Containing no cells, CEFFE has the advantage of easier preservation. For patients who have discarded adipose tissue, or contraindications to PRP technology, CEFFE technology may provide a new option for skin wound repair.

Novel Cardiokine GDF3 Predicts Adverse Fibrotic Remodeling After Myocardial Infarction.

Myocardial infarction (MI) induces a repair response that ultimately generates a stable fibrotic scar. Although the scar prevents cardiac rupture, an excessive profibrotic response impairs optimal recovery by promoting the development of noncontractile fibrotic areas. The mechanisms that lead to cardiac fibrosis are diverse and incompletely characterized. We explored whether the expansion of cardiac fibroblasts after MI can be regulated through a paracrine action of cardiac stromal cells. We performed a bioinformatic secretome analysis of cardiac stromal PW1+ cells isolated from normal and post-MI mouse hearts to identify novel secreted proteins. Functional assays were used to screen secreted proteins that promote fibroblast proliferation. The expressions of candidates were subsequently analyzed in mouse and human hearts and plasmas. The relationship between levels of circulating protein candidates and adverse post-MI cardiac remodeling was examined in a cohort of 80 patients with a first ST-segment-elevation MI and serial cardiac magnetic resonance imaging evaluations. Cardiac stromal PW1+ cells undergo a change in paracrine behavior after MI, and the conditioned media from these cells induced a significant increase in the proliferation of fibroblasts. We identified a total of 12 candidates as secreted proteins overexpressed by cardiac PW1+ cells after MI. Among these factors, GDF3 (growth differentiation factor 3), a member of the TGF-β (transforming growth factor-β) family, was markedly upregulated in the ischemic hearts. Conditioned media specifically enriched with GDF3 induced fibroblast proliferation at a high level by stimulation of activin-receptor-like kinases. In line with the secretory nature of this protein, we next found that GDF3 can be detected in mice and human plasma samples, with a significant increase in the days after MI. In humans, higher GDF3 circulating levels (measured in the plasma at day 4 after MI) were significantly associated with an increased risk of adverse remodeling 6 months after MI (adjusted odds ratio, 1.76 [1.03-3.00]; P=0.037), including lower left ventricular ejection fraction and a higher proportion of akinetic segments. Our findings define a mechanism for the profibrotic action of cardiac stromal cells through secreted cardiokines, such as GDF3, a candidate marker of adverse fibrotic remodeling after MI. URL: https://www. gov; Unique identifier: NCT01113268.

Circ004463 promotes fibroblast proliferation and collagen I synthesis by sponging miR-23b and regulating CADM3/MAP4K4 via activation of AKT/ERK pathways

Skin thickness is closely related to the appearance of human skin, such as sagging and wrinkling, which primarily depends on the level of collagen I synthesized by fibroblasts in the dermal layer. To explore the underlying genetics of the development of skin thickness, we used the indigenous Chinese Chenghua pigs, considered to have superior skin thickness, as model animals. We first performed whole transcriptome sequencing analysis to identify significant skin morphological differences between Chenghua pigs and Large White pigs and obtained some differentially expressed coding RNAs (454 mRNAs) and noncoding RNAs (612 circRNAs, 188 miRNAs, and 19 lncRNAs); moreover, some competing endogenous RNA (ceRNA) networks were constructed. Interestingly, we then identified a circRNA, namely circ0044633, which plays an important role in promoting fibroblast proliferation along with myofibroblast transition and collagen I synthesis by sponging miR-23b and regulating CADM3 and MAP4K4 expression via activation of the downstream AKT and ERK pathways in vitro. Furthermore, overexpression of circ004463 increased the mouse skin thickness and collagen I content in vivo. These results revealed a whole transcript profile of skin tissue and identified an important circ0044633-miR-23b-CADM3/MAP4K4 axis related to fibroblast proliferation and collagen I synthesis during the development of skin thickness.

LncRNA FPASL suppresses fibroblast proliferation through its DNA methylation via DNMT3b in hypertrophic scar.

Long noncoding RNAs (lncRNAs) are increasingly being implicated as key regulators of cell proliferation, apoptosis, and differentiation. However, the molecular mechanisms of specific lncRNAs in the context of hypertrophic scar remain largely unclear. Here, we find that the lncRNA FPASL (fibroblast proliferation-associated LncRNA) is downregulated in HS, and FPASL reduces fibroblast proliferation and colony formation and blocks cell cycle progression. Using GO annotation enrichment analysis along with AZC (a specific inhibitor of DNA methylation), we identify that DNA methylation is responsible for downregulating FPASL in hypertrophic scar. Subsequent studies demonstrate that high expression of DNMT3b inhibits FPASL expression in HS. Mechanistic study reveals a significant increase in fibroblast proliferation after transfection with LNA-FPASL, which is further inhibited by knockdown of DNMT3b. Thus, our study reveals that DNMT3b mediates hypermethylation of the lncRNA FPASL promoter and the downregulation of lncRNA FPASL promotes fibroblast proliferation in hypertrophic scar.

Preparation and evaluation of dual drug-loaded nanofiber membranes based on coaxial electrostatic spinning technology

Wound healing is a complicated process consisting of wound bleeding, inflammatory response, cell proliferation and tissue remodeling. During this long-term period, wound is vulnerable to infection by bacteria or microbes. Therefore, we prepared a novel centella total glucoside-ciprofloxacin dual-loaded coaxial nanofiber membrane (CDCNM) by using coaxial electrostatic spinning technique. To satisfy personalized therapeutic demands by adjusting release behaviors, we loaded centella total glucoside (CTG) and ciprofloxacin (CIP) into different positions of the fibers and the morphology and coaxial structure of the nanofiber membranes were analyzed by SEM and TEM. In addition, water contact angle, water absorption capacity, breathability and in vitro drug release were tested. In vitro cell experiments demonstrated that CDCNM can promote fibroblast proliferation. CDCNM demonstrated excellent antimicrobial activity through the agar flat dish diffusion method. Furthermore, rat scald experiments showed that CDCNM significantly accelerated scald healing, meanwhile immunohistochemical staining showed that CDCNM promoted the expression of CD31 and VEGF during early wound healing, which accelerated scald healing by promoting neovascularization and endothelial cell proliferation. As a topical multifunctional wound dressing, this dual drug-loaded nanofiber membrane achieved scald healing effect and continuous bacterial inhibition, which provides new ideas for existing trauma treatment tools and dual drug delivery systems.

In vitro biological activities and preliminary phytochemical screening of different extracts from Achillea sintenisii Hub- Mor

This study was designed to investigate in vitro biological activities and phytochemical composition of aqueous and ethanolic extracts from Achillea sintenisii Hub- Mor. (AS). To determine the chemical composition of AS extracts, phytochemical analyses were performed by using HPLC–ESI-Q-TOF-MS-MS. Afterwards, both extracts were investigated in terms of their effect on fibroblast proliferation, collagen synthesis, and hydrogen peroxide-induced damage. In addition to cell culture analysis, antibacterial, antioxidant, hyaluronidase inhibitory activities and total phenolic contents of the extracts were analyzed in cell-free systems. Our results demonstrated that the aqueous and ethanolic extracts did not show cytotoxic activity on fibroblasts, on the contrary, promoted fibroblast proliferation. Both AS extracts potently inhibited hyaluronidase activity and the inhibitory effect of ethanolic extract was comparable with the positive control, especially at high concentrations. The aqueous extract was the potent stimulator of collagen synthesis at 200 µg/mL concentration. Although the ethanolic extract showed antibacterial activity against all gram-positive bacteria, the aqueous extract was only effective against K. pneumoniae and B. subtilis. The ability of AS extracts, which have a rich phenolic compound content (≥50 mg GAE/g), to scavenge free radicals and protect fibroblasts against hydrogen peroxide-induced damage can be considered as a result of their antioxidant potential. Our findings scientifically support the widespread use of this plant, by demonstrating the pharmacological properties of the extracts.

Modulation of TGF-β Superfamily Signaling to Treat Myelofibrosis and Mitigate JAK Inhibitor Toxicity: A Report on the Phase 2 Study of Ker-050 in Participants with Myelofibrosis

Background: Myelofibrosis (MF) is a disorder characterized by unrestrained proliferation of myeloid precursors and dysfunctional Janus kinase (JAK) signaling. Hyperplastic and dysplastic megakaryocyte expansion in MF releases inflammatory cytokines. These cytokines promote fibroblast proliferation, bone remodeling, and marrow fibrosis, disrupting the osteohematopoietic niche and leading to ineffective and extramedullary hematopoiesis (Vainchenker et al. 2017). Clinical manifestations include splenomegaly, anemia, and often disabling constitutional symptoms. JAK inhibitors, such as ruxolitinib, have been shown to improve spleen size and symptoms, but are associated with dose-limiting anemia and thrombocytopenia, reducing their utility for many patients (Verstovsek et al. 2012). KER-050 is an investigational product designed to alter signaling of TGF-β superfamily ligands, restoring balance to the osteohematopoietic niche and promoting differentiation of erythroid and megakaryocytic precursors. It is a modified activin receptor type IIA ligand trap that inhibits TGF-β superfamily ligands, including activins A and B and growth and differentiation factors (GDFs) 8 and 11. Preclinical studies have demonstrated that KER-050 induces erythropoiesis, increases platelet counts, improves bone mass, and prevents fibrosis. A preclinical study previously presented demonstrated that RKER-050 can reverse ruxolitinib-associated reductions in hemoglobin, hematocrit, and red blood cell count, indicating potential for KER-050 to mitigate ruxolitinib toxicity. In two clinical studies, including an ongoing study in participants with myelodysplastic syndromes (MDS), KER-050 has been well-tolerated. Accumulated clinical data demonstrate that KER-050 can stimulate erythropoiesis and thrombopoiesis in both healthy post-menopausal women and MDS participants with ineffective hematopoiesis. Here we present data from the first clinical study of KER-050 in participants with MF (NCT05037760). The objective of this study is to evaluate the potential of KER-050 as monotherapy and in combination with ruxolitinib to treat the underlying pathology of MF and mitigate JAK inhibitor-associated cytopenias. Methods: This ongoing Phase 2 open-label study is evaluating the safety, tolerability, pharmacokinetics PK), pharmacodynamics (PD), and efficacy of KER-050 administered with or without ruxolitinib in participants with primary myelofibrosis (PMF), post-essential thrombocythemia myelofibrosis (post-ET MF), and post-polycythemia vera myelofibrosis (post-PV MF) who have anemia (hemoglobin ≤ 10 g/dL or receiving transfusions). Part 1 involves parallel dose escalation arms (1A: monotherapy, 1B: combination with ruxolitinib) to evaluate the safety and tolerability of KER-050 and identify the dose(s) of KER-050 to be evaluated in Part 2 (Figure 1). Changes in hemoglobin, transfusion burden, spleen size, the Myelofibrosis Symptom Assessment Form Total Symptom Score (MF-SAF-TSS), PK and incidence of accelerated MF and acute myeloid leukemia are assessed as secondary endpoints. This study is also evaluating markers of multilineage hematopoiesis, bone remodeling, iron metabolism, inflammation, and marrow fibrosis. Frequency of ruxolitinib dose modification and quality of life will be explored. Results: Preliminary results from Part 1 will be presented. At the time of this writing, 5 patients have received KER-050 on study, 3 in Arm 1A and 2 in Arm 1B. Three participants have completed the dose-limiting toxicity (DLT) assessment period and no DLTs have been experienced. Data evaluated to date indicate a PD effect consistent with previous preclinical and clinical studies of KER-050. Summary: KER-050 is designed to alter TGF-β superfamily signaling, restoring balance to the osteohematopoietic niche and promoting multilineage hematopoietic differentiation. Here we present data from the first study of KER-050 in participants with MF evaluating the potential for KER-050 to impact key aspects of the MF disease state (anemia, spleen size, symptoms, progression), as monotherapy and in combination with ruxolitinib. The potential for KER-050 to mitigate ruxolitinib toxicity and related dose-reductions is being investigated. Exploratory analyses of the KER-050 impact on inflammation, bone remodeling, iron metabolism, and marrow fibrosis, as available, will be shared. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Development of tropoelastin-functionalized anisotropic PCL scaffolds for musculoskeletal tissue engineering.

The highly organized extracellular matrix (ECM) of musculoskeletal tissues, encompassing tendons, ligaments and muscles, is structurally anisotropic, hierarchical and multi-compartmental. These features collectively contribute to their unique function. Previous studies have investigated the effect of tissue-engineered scaffold anisotropy on cell morphology and organization for musculoskeletal tissue repair and regeneration, but the hierarchical arrangement of ECM and compartmentalization are not typically replicated. Here, we present a method for multi-compartmental scaffold design that allows for physical mimicry of the spatial architecture of musculoskeletal tissue in regenerative medicine. This design is based on an ECM-inspired macromolecule scaffold. Polycaprolactone (PCL) scaffolds were fabricated with aligned fibers by electrospinning and mechanical stretching, and then surface-functionalized with the cell-supporting ECM protein molecule, tropoelastin (TE). TE was attached using two alternative methods that allowed for either physisorption or covalent attachment, where the latter was achieved by plasma ion immersion implantation (PIII). Aligned fibers stimulated cell elongation and improved cell alignment, in contrast to randomly oriented fibers. TE coatings bound by physisorption or covalently following 200 s PIII treatment promoted fibroblast proliferation. This represents the first cytocompatibility assessment of novel PIII-treated TE-coated PCL scaffolds. To demonstrate their versatility, these 2D anisotropic PCL scaffolds were assembled into 3D hierarchical constructs with an internally compartmentalized structure to mimic the structure of musculoskeletal tissue.

Engineered stem cell exosomes for oral and maxillofacial wound healing.

Wound healing of the oral and maxillofacial area affects the quality of life and mental health of the patient; therefore, effective therapies are required to promote wound healing. However, traditional treatment methods have limited efficacy. Exosomes secreted by stem cells used for oral and maxillofacial wound healing have shown outstanding results. Stem cell-derived exosomes possess the regenerative and repair ability of stem cells. Moreover, they are nontumorigenic and have good biosafety. However, the application of natural stem cell exosomes is limited owing to their low yield, impurity, lack of targeting, and low drug delivery rate. Many modification methods have been developed to engineered stem cell exosomes with beneficial properties, such as modifying parent cells and directly processing stem cell exosomes. These methods include coincubation, genetic engineering, electroporation, ultrasound, and artificial synthesis of engineered stem cell exosomes. These engineered stem cell exosomes can cargo nucleic acids, proteins, and small molecules. This gives them anti-inflammatory and cell proliferation regulatory abilities and enables the targeted promotion of efficient soft tissue repair after trauma. Engineered stem cell exosomes can decrease inflammation, promote fibroblast proliferation, and angiogenesis, and decrease scar formation to promote oral and maxillofacial wound healing, including diabetic and burn wounds. Thus, engineered stem cell exosomes are an effective treatment that has the potential for oral and maxillofacial wound healing.

CCR2 is expressed by tendon resident macrophage and T cells, while CCR2 deficiency impairs tendon healing via blunted involvement of tendon-resident and circulating monocytes/macrophages.

During tendon healing, macrophages are thought to be a key mediator of scar tissue formation, which prevents successful functional restoration of the tendon. However, macrophages are critical for successful tendon healing as they aid in wound debridement, extracellular matrix deposition, and promote fibroblast proliferation. Recent work has sought to better define the multi-faceted functions of macrophages using depletion studies, while other studies have identified a tendon resident macrophage population. To begin to delineate the functions of tendon-resident versus circulation-derived macrophages, we examined the tendon healing phenotype in Chemokine Receptor 2 (CCR2) reporter (CCR2GFP/+ ), and knockout mice. CCR2 is a chemokine receptor primarily found on the surface of circulating bone marrow-derived monocytes, with CCR2 being an important mediator of macrophage recruitment to wound environments. Surprisingly, CCR2GFP/+ cells were present in the tendon during adult homeostasis, and single-cell RNA sequencing identified these cells as tendon-resident macrophages and T cells. During both homeostasis and healing, CCR2 knockout resulted in a substantial decrease in CCR2GFP+ cells and pan-macrophages. Additionally, loss of CCR2 resulted in reduced numbers of myofibroblasts and impeded functional recovery during late healing. This study highlights the heterogeneity of tendon-resident and recruited immune cells and their contributions following injury, and establishes an important role for CCR2 in modulating both the adult tendon cell environment and tendon healing process.

The Signaling Pathways Induced by Exosomes in Promoting Diabetic Wound Healing: A Mini-Review

Impaired healing of diabetic wounds harms patients’ quality of life and even leads to disability and death, which is an urgent issue to be solved clinically. Despite the great progress that has been achieved, it remains a worldwide challenge to develop effective therapeutic treatments for diabetic wounds. Recently, exosomes have attracted special attention because they can be involved in immune response, antigen presentation, cell migration, cell differentiation, tumor invasion and other processes. Meanwhile, exosomes have been proven to hold great potential in the treatment of diabetic wounds. Mechanistic studies of exosomes based on signaling pathways could not only help to uncover the mechanisms by which exosomes promote diabetic wound healing but could also provide a theoretical basis for the clinical application of exosomes. Herein, our mini-review aims to summarize the progress of research on the use of various exosomes derived from different cell types to promote diabetic wound healing, with a focus on the classical signaling pathways, including PI3K/Akt, Wnt, NF-κB, MAPK, Notch, Nrf2, HIF-1α/VEGF and TGF-β/Smad. The results show that exosomes could regulate these signaling pathways to down-regulate inflammation, reduce oxidative stress, increase angiogenesis, promote fibroblast proliferation, induce re-epithelization and inhibit scar formation, making exosomes attractive candidates for the treatment of diabetic wounds.

Chitosan degradation products promote healing of burn wounds of rat skin.

Burns can impair the barrier function of the skin, and small burns can also cause high mortality. The WHO has described that over 180,000 people die of burns worldwide each year. Thus, the treatment of burn wounds is a major clinical challenge. Chitooligosaccharides (COS) are alkaline amino oligosaccharides with small molecular weights obtained by enzyme or chemical degradation of chitosan. With the characteristics of biocompatibility, water solubility and degradability, it has attracted increasing attention in the fields of biomedicine. In the present study, we used COS to treat deep second-degree burn wounds of rat skin and found that COS was able to promote wound healing. We also revealed that COS could promote fibroblast proliferation. Transcriptome sequencing analysis was performed on COS-treated fibroblasts to identify the underlying mechanisms. The results showed that COS was able to promote wound healing through regulation of the mitogen-activated protein kinase (MAPK) pathway and growth factor Hepatocyte Growth Factor (HGF). Our results provide a potential drug for burn wound therapy and the related molecular mechanism.

Food-derived Crassostrea gigas peptides self-assembled supramolecules for scarless healing

Peptides self-assembled materials are considered as excellent candidates for tissue engineering due to their excellent efficacy. However, their development and application are severely restricted on account of their single function, low yield and limited source, so it is urgent to explore new research strategy of self-assembly materials of multifunctional active peptides. In this study, we prepared multifunctional supramolecular materials (CNPs) with randomized peptides self-assemblies from Crassostrea gigas meats utilizing Controllable-hydrolysis (Neutral protease) process to explore their mechanism on dermal wound healing in in vitro and in vivo experiments through two (topical application & oral) administration pathways. Physical and chemical analysis results demonstrated that CNPs were novel supramolecules consisting of peptides with molecular weights of 605–2067 Da and lengths of 5–15 amino acids that randomly self-assemble into nano-structures. Results of in vitro tests suggested that CNPs possessed procoagulant, antioxidant effect and promote the proliferation of HaCaT cells. Results of in vivo studies revealed that two administration pathways of naturally safe CNPs could inhibit inflammation, promote fibroblast proliferation and revascularization, and accelerate the epithelialization process. Thus favoring a balanced repair tissue collagen I/III ratio and the promotion of hair follicle regeneration, with no effect on the intestinal flora structure and having a certain positive effect to achieve scarless healing. Overall, this study presents a simple preparation method of a safe and multifunctional novel self-assembling peptides material and its great potential in soft tissue repair.