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Theranostics 2023Safe and effective wound healing can be a major clinical challenge. Inflammation and vascular impairment are two main causes of inadequate wound healing. Here, we...
Safe and effective wound healing can be a major clinical challenge. Inflammation and vascular impairment are two main causes of inadequate wound healing. Here, we developed a versatile hydrogel wound dressing, comprising a straightforward physical mixture of royal jelly-derived extracellular vesicles (RJ-EVs) and methacrylic anhydride modified sericin (SerMA), to accelerate wound healing by inhibiting inflammation and promoting vascular reparation. The RJ-EVs showed satisfactory anti-inflammatory and antioxidant effects, and significantly promoted L929 cell proliferation and migration . Meanwhile, the photocrosslinked SerMA hydrogel with its porous interior structure and high fluidity made it a good candidate for wound dressing. The RJ-EVs can be gradually released from the SerMA hydrogel at the wound site, ensuring the restorative effect of RJ-EVs. In a full-thickness skin defect model, the SerMA/RJ-EVs hydrogel dressing accelerated wound healing with a healing rate of 96.8% by improving cell proliferation and angiogenesis. The RNA sequencing results further revealed that the SerMA/RJ-EVs hydrogel dressing was involved in inflammatory damage repair-related pathways including recombinational repair, epidermis development, and Wnt signaling. This SerMA/RJ-EVs hydrogel dressing offers a simple, safe and robust strategy for modulating inflammation and vascular impairment for accelerated wound healing.
Topics: Humans; Wound Healing; Inflammation; Hydrogels; Extracellular Vesicles
PubMed: 37284440
DOI: 10.7150/thno.84665 -
Cold Spring Harbor Perspectives in... Aug 2014DNA is subject to many endogenous and exogenous insults that impair DNA replication and proper chromosome segregation. DNA double-strand breaks (DSBs) are one of the... (Review)
Review
DNA is subject to many endogenous and exogenous insults that impair DNA replication and proper chromosome segregation. DNA double-strand breaks (DSBs) are one of the most toxic of these lesions and must be repaired to preserve chromosomal integrity. Eukaryotes are equipped with several different, but related, repair mechanisms involving homologous recombination, including single-strand annealing, gene conversion, and break-induced replication. In this review, we highlight the chief sources of DSBs and crucial requirements for each of these repair processes, as well as the methods to identify and study intermediate steps in DSB repair by homologous recombination.
Topics: Animals; Cell Cycle; Chromosomes; DNA Breaks, Double-Stranded; DNA Replication; DNA, Cruciform; Genes, Mating Type, Fungal; Humans; Recombination, Genetic; Recombinational DNA Repair; Saccharomyces cerevisiae
PubMed: 25104768
DOI: 10.1101/cshperspect.a016428 -
Microbiology and Molecular Biology... Dec 1999Although homologous recombination and DNA repair phenomena in bacteria were initially extensively studied without regard to any relationship between the two, it is now... (Review)
Review
Although homologous recombination and DNA repair phenomena in bacteria were initially extensively studied without regard to any relationship between the two, it is now appreciated that DNA repair and homologous recombination are related through DNA replication. In Escherichia coli, two-strand DNA damage, generated mostly during replication on a template DNA containing one-strand damage, is repaired by recombination with a homologous intact duplex, usually the sister chromosome. The two major types of two-strand DNA lesions are channeled into two distinct pathways of recombinational repair: daughter-strand gaps are closed by the RecF pathway, while disintegrated replication forks are reestablished by the RecBCD pathway. The phage lambda recombination system is simpler in that its major reaction is to link two double-stranded DNA ends by using overlapping homologous sequences. The remarkable progress in understanding the mechanisms of recombinational repair in E. coli over the last decade is due to the in vitro characterization of the activities of individual recombination proteins. Putting our knowledge about recombinational repair in the broader context of DNA replication will guide future experimentation.
Topics: Bacteriophage lambda; DNA Damage; DNA Repair; DNA Replication; DNA, Bacterial; DNA, Viral; Escherichia coli; Nucleic Acid Conformation; Rec A Recombinases; Recombination, Genetic; SOS Response, Genetics
PubMed: 10585965
DOI: 10.1128/MMBR.63.4.751-813.1999 -
Microbiological Reviews Mar 1985
Review
Topics: Alleles; Crossing Over, Genetic; DNA Repair; Fungi; Gene Conversion; Meiosis; Mitosis; Models, Genetic; Mutation; Plasmids; Recombination, Genetic
PubMed: 3884994
DOI: 10.1128/mr.49.1.33-58.1985 -
Scientific Reports May 2023Many factors regulate scar formation, which yields a modified extracellular matrix (ECM). Among ECM components, microfibril-associated proteins have been minimally...
Many factors regulate scar formation, which yields a modified extracellular matrix (ECM). Among ECM components, microfibril-associated proteins have been minimally explored in the context of skin wound repair. Microfibril-associated protein 5 (MFAP5), a small 25 kD serine and threonine rich microfibril-associated protein, influences microfibril function and modulates major extracellular signaling pathways. Though known to be associated with fibrosis and angiogenesis in certain pathologies, MFAP5's role in wound healing is unknown. Using a murine model of skin wound repair, we found that MFAP5 is significantly expressed during the proliferative and remodeling phases of healing. Analysis of existing single-cell RNA-sequencing data from mouse skin wounds identified two fibroblast subpopulations as the main expressors of MFAP5 during wound healing. Furthermore, neutralization of MFAP5 in healing mouse wounds decreased collagen deposition and refined angiogenesis without altering wound closure. In vitro, recombinant MFAP5 significantly enhanced dermal fibroblast migration, collagen contractility, and expression of pro-fibrotic genes. Additionally, TGF-ß1 increased MFAP5 expression and production in dermal fibroblasts. Our findings suggest that MFAP5 regulates fibroblast function and influences scar formation in healing wounds. Our work demonstrates a previously undescribed role for MFAP5 and suggests that microfibril-associated proteins may be significant modulators of wound healing outcomes and scarring.
Topics: Animals; Mice; Cicatrix; Fibroblasts; Fibrosis; Microfibrils; Skin; Wound Healing; Intercellular Signaling Peptides and Proteins; Contractile Proteins
PubMed: 37253753
DOI: 10.1038/s41598-023-35558-x -
Acta Medica Okayama Feb 2005DNA damage causes chromosomal instability leading to oncogenesis, apoptosis, and severe failure of cell functions. The DNA repair system includes base excision repair,... (Review)
Review
DNA damage causes chromosomal instability leading to oncogenesis, apoptosis, and severe failure of cell functions. The DNA repair system includes base excision repair, nucleotide excision repair, mismatch repair, translesion replication, non-homologous end-joining, and recombinational repair. Homologous recombination performs the recombinational repair. The RAD51 gene is an ortholog of Esherichia coli recA, and the gene product Rad51 protein plays a central role in the homologous recombination. In mammals, 7 recA-like genes have been identified: RAD51, RAD51L1/B, RAD51L2/C, RAD51L3/D, XRCC2, XRCC3, and DMC1. These genes, with the exception of meiosis-specific DMC1, are essential for development in mammals. Disruption of the RAD51 gene leads to cell death, whereas RAD51L1/B, RAD51L2/C, RAD51L3/D, XRCC2, and XRCC3 genes (RAD51 paralogs) are not essential for viability of cells, but these gene-deficient cells exhibit a similar defective phenotype. Yeast two-hybrid analysis, co-immunoprecipitation, mutation analysis, and domain mapping of Rad51 and Rad51 paralogs have revealed protein-protein interactions among these gene products. Recent investigations have shown that Rad51 paralogs play a role not only in an early step, but also in a late step of homologous recombination. In addition, identification of alternative transcripts of some RAD51 paralogs may reflect the complexity of the homologous recombination system.
Topics: Animals; DNA-Binding Proteins; Escherichia coli; Humans; Mammals; Multigene Family; Rad51 Recombinase; Rec A Recombinases; Recombination, Genetic
PubMed: 15902993
DOI: 10.18926/AMO/31987 -
Clinics in Dermatology 2007Wound repair involves the sequential interaction of various cell types, extracellular matrix molecules, and soluble mediators. During the past 10 years, much new... (Review)
Review
Wound repair involves the sequential interaction of various cell types, extracellular matrix molecules, and soluble mediators. During the past 10 years, much new information on signals controlling wound cell behavior has emerged. This knowledge has led to a number of novel therapeutic strategies. In particular, the local delivery of pluripotent growth factor molecules to the injured tissue has been intensively investigated over the past decade. Limited success of clinical trails indicates that a crucial aspect of the growth factor wound healing strategy is the effective delivery of these polypeptides to the wound site. A molecular approach in which genetically modified cells synthesize and deliver the desired growth factor in regulated fashion has been used to overcome the limitations associated with the (topical) application of recombinant growth factor proteins. We have summarized the molecular and cellular basis of repair mechanisms and their failure, and we give an overview of techniques and studies applied to gene transfer in tissue repair.
Topics: Genetic Therapy; Humans; Skin; Skin Ulcer; Soft Tissue Injuries; Wound Healing; Wounds, Penetrating
PubMed: 17276205
DOI: 10.1016/j.clindermatol.2006.09.011 -
Chromosomal Location Determines the Rate of Intrachromosomal Homologous Recombination in Salmonella.MBio Jun 2021Homologous recombination is an important mechanism directly involved in the repair, organization, and evolution of prokaryotic and eukaryotic chromosomes. We developed a...
Homologous recombination is an important mechanism directly involved in the repair, organization, and evolution of prokaryotic and eukaryotic chromosomes. We developed a system, based on two genetic cassettes, that allows the measurement of recombinational repair rates between different locations on the chromosome. Using this system, we analyzed 81 different positional combinations throughout the chromosome to answer the question of how the position and orientation of sequences affect intrachromosomal homologous recombination. Our results show that recombination was possible between any two locations tested in this study and that recombinational repair rates varied by just above an order of magnitude. The observed differences in rate do not correlate with distance between the recombination cassettes or with distance from the origin of replication but could be explained if each location contributes individually to the recombination event. The relative levels of accessibility for recombination vary 5-fold between the various cassette locations, and we found that the nucleoid structure of the chromosome may be the major factor influencing the recombinational accessibility of each chromosomal site. Furthermore, we found that the orientation of the recombination cassettes had a significant impact on recombination. Recombinational repair rates for the cassettes inserted as direct repeats are, on average, 2.2-fold higher than those for the same sets inserted as inverted repeats. These results suggest that the bacterial chromosome is not homogenous with regard to homologous recombination, with regions that are more or less accessible, and that the orientation of genes affects recombination rates. Bacterial chromosomes frequently carry multiple copies of genes at separate chromosomal locations. In Salmonella, these include the 7 operons and the duplicate genes. Genes within these families coevolve by homologous recombination, but it is not obvious whether their rates of recombination reflect general rates of intrachromosomal recombination or are an evolved property particularly associated with these conserved genes and locations. Using a novel experimental system, we show that recombination is possible between all tested pairs of locations at rates that vary by just above 1 order of magnitude. Differences in rate do not correlate with distance between the sites or distance to the origin of replication but may be explained if each location contributes individually to the recombination event. Our results suggest the existence of bacterial chromosomal domains that are differentially available for recombination and that gene orientation affects recombination rates.
Topics: Chromosomes, Bacterial; DNA Repair; Homologous Recombination; Salmonella
PubMed: 34061591
DOI: 10.1128/mBio.01151-21 -
Clinical Cancer Research : An Official... Sep 2010Cancer chemotherapy exploits limitations in repairing DNA damage in order to kill proliferating malignant cells. Recent evidence suggests that cancers within and across... (Review)
Review
Cancer chemotherapy exploits limitations in repairing DNA damage in order to kill proliferating malignant cells. Recent evidence suggests that cancers within and across tissue types have specific defects in DNA repair pathways, and that these defects may predispose for sensitivity and resistance to various classes of cytotoxic agents. Poly (ADP-ribose) polymerase (PARP) and BRCA proteins are central to the repair of DNA strand breaks and, when defective, lead to the accumulation of mutations introduced by error-prone DNA repair. Breast, ovarian, and other cancers develop in the setting of BRCA deficiency, and these cancers may be more sensitive to cytotoxic agents that induce DNA strand breaks, as well as inhibitors of PARP activity. A series of recent clinical trials has tested whether PARP inhibitors can achieve synthetic lethality in BRCA-pathway-deficient tumors. Future studies must seek to identify sporadic cancers that harbor genomic instability, rendering susceptibility to agents that induce additional and lethal DNA damage.
Topics: Animals; Antineoplastic Agents; DNA Repair; Enzyme Inhibitors; Genetic Diseases, Inborn; Humans; Models, Biological; Molecular Targeted Therapy; Neoplasms; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Recombination, Genetic
PubMed: 20823142
DOI: 10.1158/1078-0432.CCR-10-0526 -
Epigenomics Dec 2009The integrity of a eukaryotic genome is often challenged by DNA double-strand breaks (DSBs). Even a single, unrepaired DSB can be a lethal event, or such unrepaired... (Review)
Review
The integrity of a eukaryotic genome is often challenged by DNA double-strand breaks (DSBs). Even a single, unrepaired DSB can be a lethal event, or such unrepaired damage can result in chromosomal instability and loss of genetic information. Furthermore, defects in the pathways that respond to and repair DSBs can lead to the onset of several human pathologic disorders with pleiotropic clinical features, including age-related diseases and cancer. For decades, studies have focused on elucidating the enzymatic mechanisms involved in recognizing, signaling and repairing DSBs within eukaryotic cells. The majority of biochemical and genetic studies have used simple, DNA substrates, whereas only recently efforts have been geared towards understanding how the repair machinery deals with DSBs within chromatin fibers, the nucleoprotein complex that packages DNA within the eukaryotic nucleus. The aim of this review is to discuss our recent understanding of the relationship between chromatin structure and the repair of DSBs by homologous recombination. In particular, we discuss recent studies implicating specialized roles for several, distinct ATP-dependent chromatin remodeling enzymes in facilitating multiple steps within the homologous recombination process.
Topics: Cell Cycle Proteins; Chromatin; Chromosomal Instability; Chromosomal Proteins, Non-Histone; DNA Breaks, Double-Stranded; Histones; Humans; Recombinational DNA Repair; Transcription Factors
PubMed: 20495614
DOI: 10.2217/epi.09.22