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Objective:To evaluate the effect of niraparib, the poly (ADP-ribose) polymerase (PARP) inhibitor, on the radiosensitivity of esophageal squamous cell carcinoma (ESCC) and to preliminarily investigate its mechanism.Methods:Human esophageal squamous cell carcinoma cells ECA-109 and KYSE-150 were divided into the control, niraparib, single irradiation, combined (niraparib+irradiation) groups. Cell proliferation was measured by CCK-8 assay. The changes of cell survival rate were detected by colony formation assay. The changes of cell cycle and apoptosis were analyzed by flow cytometry. The number of γH2AX foci was detected by immunofluorescence, and the expression levels of PARP-1, cleaved-PARP, RAD51, mitogen-activated protein kinase (MAPK) [extracellular signal-regulated kinase 1 and 2 (ERK1/2) ] and p-MAPK (ERK1/2) proteins were determined by Western blot. All data were expressed as Mean±SD. Data between two groups conforming to normal distribution through the normality test were subject to independent sample t-test and multiple groups were analyzed using one-way ANOVA. Results:In human ESCC cells ECA-109 and KYSE-150, the proliferation of ESCC cells was significantly inhibited by niraparib combined with irradiation, and the values of average lethal dose (D 0), quasi-threshould dose(D q), survival fraction after 2 Gy irradiation (SF 2) in the combined group were decreased compared with those in the single irradiation group. The effect of irradiation alone on apoptosis of ECA-109 and KYSE-150 cells was limited. Compared to single irradiation group, irradiation combined with niraparib further increased the apoptosis rate in ESCC cells ( P=0.015, P=0.006). In ECA-109 cells, G 2/M phase arrest was significantly increased in combined group compared with irradiation alone group ( P<0.001). In ECA-109 cells, the number of γH2AX foci in combined group was higher than that in the single irradiation group after 2 h, and showed a significantly slower decay of γH2AX foci ( P<0.001). Moreover, niraparib combined with irradiation enhanced the radiation-induced cleavage of PARP-1 and down-regulated the expression of Rad51 and p-MAPK(ERK1/2). Conclusion:Niraparib can increase the radiosensitivity of esophageal cancer cells by inhibiting cell proliferation, promoting cell apoptosis, inhibiting the repair of DNA damage and regulating the MARK-ERK signaling pathway.
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BACKGROUND@#Radiotherapy is one of the most common treatments for lung cancer, and about 40%-50% of patients after radiotherapy will appear uncontrolled or recurrence in the case of local tumors. Radioresistance is the predominant cause of local therapeutic failure. Nevertheless, the lack of in vitro radioresistance models is an influential factor obstructing the study of its mechanism. Therefore, the establishment of radioresistant cell lines, H1975DR and H1299DR, was beneficial to explore the mechanism of radioresistance in lung adenocarcinoma.@*METHODS@#The radioresistant cell lines of H1975DR and H1299DR were obtained from H1975 and H1299 cells irradiated with equal doses of X-rays; Clonogenic assays were performed to compare the clone-forming ability of H1975 vs H1975DR cells, H1299 vs H1299DR cells, then fitting cell survival curve by linear quadratic model; The comet assay was employed to examine DNA damage repair and calculate the percentage of DNA tails; The optical microscopy, CCK-8, flow cytometry, Transwell invasion assays were used to compare biological characteristics such as cell morphology, cell proliferation, apoptosis level, cycle distribution, cell migration and invasion; Western blot was carried out to measure the protein expression of DNA damage repair factors, such as DNA-PKcs, 53BP1, RAD51, and p-ATM.@*RESULTS@#After five months of continuous irradiation and stable culture, radioresistant cell lines H1975DR and H1299DR were obtained. The cell proliferation activity, clone formation ability and DNA damage repair ability of the two radioresistant cell lines were significantly improved under X-ray irradiation. The proportion of the G2/M phase was markedly decreased and the proportion of the G0/G1 phase was increased. Cell migration and invasion ability were significantly enhanced. Relative expression levels of p-DNA-PKcs (Ser2056), 53BP1 in the nonhomologous end-joining (NHEJ) repair pathway and p-ATM (Ser1981), RAD51 in the homologous recombination (HR) repair pathway were higher than those in H1975 and H1299.@*CONCLUSIONS@#H1975 and H1299 cell lines can be able to differentiate into lung adenocarcinoma radioresistant cell lines H1975DR and H1299DR by equal dose fractional irradiation, which provided an in vitro cytological model for the study of radiotherapy resistance mechanism of lung cancer patients.
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Humans , Lung Neoplasms , Adenocarcinoma of Lung , Apoptosis , Cell Movement , Cell ProliferationABSTRACT
AIM: To investigate the changes of protein expressions in human lens epithelial cells(SRA01/04)undergoing oxidative damage, hoping to provide new protein target for the pathogenesis of age-related cataract(ARC).METHODS: SRA01/04 cells were divided into experimental group and control group. In the experimental group, cells were irradiated with ultraviolet-B(UVB)for 10min to establish the model of oxidative damage, whereas cells in the control group were untreated. Protein expression profile from the two groups was sequenced by isobaric tags for relative and absolute quantitation(iTRAQ). The filtering criteria that fold change &#x003E;1.2 and p&#x003C;0.05 was used to determine the differentially expressed proteins(DEPs). Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)database were utilized for functional enrichment analysis of the top 50 DEPs with either up-regulated or down-regulated significance. Furthermore, Pathway commons software was used to establish the protein-protein interaction(PPI)network.RESULTS: Overall, 552 DEPs were screened out. A total of 176 DEPs were up-regulated in the experimental group compared with the control group, including HMGB1 and USP1, while 376 DEPs were down-regulated, including POLR2A and POLR2B. GO and KEGG enrichment analysis indicated that the top 50 DEPs with up-regulated or down-regulated significance were involved in various crucial biological processes and signaling pathways. PPI network revealed that oxidative damage repair(ODR)-related proteins might play a key role in UVB-induced oxidative damage.CONCLUSIONS: The expressions of multiple proteins, especially ODR-related proteins, can be altered in SRA01/04 cells via UVB irradiation. These findings may provide cellular-related insights into the pathogenesis of ARC and into proteins or pathways associated with therapeutic targets.
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OBJECTIVE@#Immunotherapy has brought significant clinical benefits to a subset of patients, but has thus far been disappointing in the treatment of immunologically "cold" tumors. Existing biomarkers that can precisely identify these populations are insufficient. In this context, a potential cold tumor microenvironment (TME) marker FARSB was investigated to reveal its impact on TME and patients' response to immunotherapy across pan-cancer.@*METHODS@#The expression levels and mutational landscape of FARSB in pan-cancer were investigated. Kaplan-Meier and univariate Cox regression analyses were applied to analyze the prognostic significance of FARSB. Pathways affected by FARSB were investigated by gene set enrichment and variation analysis. The relationship between FARSB expression and immune infiltration was examined using the TIMER2 and R packages. Single-cell RNA sequencing (scRNA-seq) data of several cancer types from GSE72056, GSE131907, GSE132465, GSE125449 and PMID32561858 were analyzed to validate the impact of FARSB on the TME. The predictive effect of FARSB on immunotherapy efficacy was explored in 3 immune checkpoint inhibitors (ICIs)- treated cohorts (PMID32472114, GSE176307, and Riaz2017).@*RESULTS@#FARSB expression was significantly higher in 25 tumor tissues than in normal tissues and was associated with poor prognosis in almost all tumor types. FARSB expression exhibited a strong association with several DNA damage repair pathways and was significantly associated with TP53 mutation in lung adenocarcinoma (P < 0.0001, OR=2.25). FARSB characterized a typical immune desert TME and correlated with impaired expression of chemokines and chemokines receptors. Large-scale scRNA-seq analysis confirmed the immunosuppressive role of FARSB and revealed that FARSB potentially shapes the cold TME by impeding intercellular interactions. In 3 ICI-treated cohorts, FARSB demonstrated predictive value for immunotherapy.@*CONCLUSION@#This study provides a pan-cancer landscape of the FARSB gene by integrated single-cell and bulk DNA sequencing analysis and elucidates its biological function to promote DNA damage repair and construct the immune desert TME, suggesting the potential value of FARSB as a novel marker for stratifying patients with poor immunotherapeutic benefits and "cold" TME.
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Humans , Tumor Microenvironment , Prognosis , Adenocarcinoma of Lung/genetics , Lung Neoplasms/genetics , Sequence Analysis, RNAABSTRACT
OBJECTIVES@#To investigate the prevalence of pathogenic germline mutations of mismatch repair (MMR) genes in prostate cancer patients and its relationship with clinicopathological characteristics.@*METHODS@#Germline sequencing data of 855 prostate cancer patients admitted in Fudan University Shanghai Cancer Center from 2018 to 2022 were retrospectively analyzed. The pathogenicity of mutations was assessed according to the American College of Medical Genetics and Genomics (ACMG) standard guideline, Clinvar and Intervar databases. The clinicopathological characteristics and responses to castration treatment were compared among patients with MMR gene mutation (MMR+ group), patients with DNA damage repair (DDR) gene germline pathogenic mutation without MMR gene (DDR+MMR－ group) and patients without DDR gene germline pathogenic mutation (DDR－ group).@*RESULTS@#Thirteen (1.52%) MMR+ patients were identified in 855 prostate cancer patients, including 1 case with MLH1 gene mutation, 6 cases with MSH2 gene mutation, 4 cases with MSH6 gene mutation and 2 cases with PMS2 gene mutation. 105 (11.9%) patients were identified as DDR gene positive (except MMR gene), and 737 (86.2%) patients were DDR gene negative. Compared with DDR－ group, MMR+ group had lower age of onset (P<0.05) and initial prostate-specific antigen (PSA) (P<0.01), while no significant differences were found between the two groups in Gleason score and TMN staging (both P>0.05). The median time to castration resistance was 8 months (95%CI: 6 months-not achieved), 16 months (95%CI: 12-32 months) and 24 months (95%CI: 21-27 months) for MMR+ group, DDR+MMR－ group and DDR－ group, respectively. The time to castration resistance in MMR+ group was significantly shorter than that in DDR+MMR－ group and DDR－ group (both P<0.01), while there was no significant difference between DDR+MMR－ group and DDR－ group (P>0.05).@*CONCLUSIONS@#MMR gene mutation testing is recommended for prostate cancer patients with early onset, low initial PSA, metastasis or early resistance to castration therapy.
Subject(s)
Male , Humans , Prostate-Specific Antigen/genetics , Germ-Line Mutation , Retrospective Studies , DNA Mismatch Repair/genetics , DNA-Binding Proteins/metabolism , China , Prostatic Neoplasms/pathologyABSTRACT
Triple negative breast cancer (TNBC) is prone to recurrence and metastasis, which is the subtype of poorest prognosis. Chemotherapy is the main treatment, although there is lack of effective adjuvant chemotherapy regimens. The unsatisfactory efficacy of chemotherapy has been a bottleneck in improving the outcome of TNBC. Platinum compounds act directly on DNA to kill tumor cells, and they have a stronger killing effect on tumor cells carrying DNA damage repair (DDR) defects, which is an important entry point to improve the efficacy of TNBC. Biomarkers for predicting the efficacy of platinum drugs in TNBC treatment have always been a hot topic. The DDR pathway contains a large number of related genes, and recent studies have shown that deficiencies in the DDR pathway may be associated with the efficacy of platinum drugs, which is expected to be a biomarker for predicting the efficacy of platinum drugs in breast cancer treatment.
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Humans , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , DNA Damage , DNA Repair , Pharmaceutical Preparations , Platinum/therapeutic use , Platinum Compounds/therapeutic use , Triple Negative Breast Neoplasms/geneticsABSTRACT
DNA damage repair (DDR) defects occurred in 8%-16% of metastatic castration resistant prostate cancer (mCRPC). DDR gene mutation was related to poorer prognosis. Patients with DDR gene mutation, especially BRCA1/2 mutation, showed high sensitivity to poly ADP-ribose polymerase inhibitor (PARPi) and platinum.
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Objective:To investigate the role of SUMO E3 ligase ZNF451 in DNA damage repair and explore the underlying mechanism in non-small cell lung cancer A549 cells and cervical cancer HeLa cells.Methods:A549 cells and HeLa cells were irradiated with γ-ray irradiation or treated with etoposide. Cell proliferation viability was detected by the cell counting kit-8 assay. Protein expression was detected by Western blot assay. DNA damage repair level was detected by DR-GFP plasmid system, and the spatial positioning was detected by immunofluorescence.Results:Etoposide decreased the expression level of ZNF451 in a dose- and time- dependent manner. After treatment with 30, 50, 80 μmol/L etoposide, the cell viability were reduced after the knockdown of ZNF451 in A549 and HeLa cells(A549: t = 27.62, 25.61, 5.32, P<0.01; HeLa: t = 30.77, 21.28, 4.18, P<0.01). Furthermore, ZNF451 was recruited at DNA damage sites. A co-localization and endogenous interaction were found between ZNF451 and γ-H2AX after the treatment of irradiation or etoposide. Moreover, the expression level of γ-H2AX was significantly increased after treatment with 30, 50, 80 μmol/L etoposide(A549: t = 6.12, 10.67, 4.68, P<0.01; HeLa: t = 7.94, 9.81, 15.12, P<0.01)and the repair efficiency of NHEJ was reduced in ZNF451 knockdown cells( t = 18.60, P<0.05). Finally, the immunofluorescence assay showed that ZNF451 was co-localizated with 53BP1 and MDC1 after irradiation or etoposide treatment. Conclusions:Knockdown of ZNF451 inhibits cell proliferation and increases the level of DNA damage in A549 and HeLa cells. ZNF451 was recruited to DNA damage sites after DSBs and participated in NHEJ repair by co-localizing with DNA damage repair factor 53BP1/MDC1.
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The cyclic GMP-AMP (cGAMP) synthase (cGAS) has been identified as a cytosolic double stranded DNA sensor that plays a pivotal role in the type I interferon and inflammation responses via the STING-dependent signaling pathway. In the past several years, a growing body of evidence has revealed that cGAS is also localized in the nucleus where it is associated with distinct nuclear substructures such as nucleosomes, DNA replication forks, the double-stranded breaks, and centromeres, suggesting that cGAS may have other functions in addition to its role in DNA sensing. However, while the innate immune function of cGAS is well established, the non-canonical nuclear function of cGAS remains poorly understood. Here, we review our current understanding of the complex nature of nuclear cGAS and point to open questions on the novel roles and the mechanisms of action of this protein as a key regulator of cell nuclear function, beyond its well-established role in dsDNA sensing and innate immune response.
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Humans , Cell Nucleus/immunology , Immunity, Innate , Nucleotidyltransferases/immunology , Signal Transduction/immunologyABSTRACT
Objective: To detect of gene expression and genotype of the ataxia telangiectasia mutated (ATM) from coal workers' pneumoconiosis (CWP) , It is explored whether CWP is related to ATM gene. Methods: In October 2020, the relevant information of 264 subjects who received physical examination or medical treatment in the Department of occupational diseases of Guiyang public health treatment center from January 2019 to September 2020 was collected. Through the occupational health examination, 67 healthy people with no history of exposure to occupational hazards were selected as the healthy control group; The coal miners with more than 10 years of coal dust exposure history and small shadow in the lung but not up to the diagnostic criteria were the dust exposure control group, a total of 66 people; The patients with the same history of coal dust exposure and confirmed stage I were coal worker's pneumoconiosis stage I group, a total of 131 people. The expression of ATM was detected by QRT PCR. ATM rs189037 and rs1801516 were genotyped by massarray. Results: There was significant difference in the expression of ATM among the groups (P<0.05) ; Compared with the healthy control group, the expression of ATM in the dust exposed control group was significantly increased (P<0.05) . With the occurrence and development of CWP, the GG of rs189037 wild type decreased, the GA of mutant heterozygote and AA of homozygote increased, but the difference was not statistically significant (P>0.05) ; Rs1801516 wild type GG and mutant heterozygote GA had no significant changes (P>0.05) . There were significant differences in age, neutrophils and basophils among rs189037 groups (all P<0.05) . There were no significant differences in blood pressure, eosinophils, lymphocytes, monocytes, smoking and drinking history among rs189037 groups (all P>0.05) . Compared with wild-type GG, the or of mutant heterozygotes and homozygotes increased, but the differences were not statistically significant (P>0.05) . Conclusion: ATM gene may be one of the early activation genes of CWP and rs189037 may be the functional loci which affects gene expression. ATM gene is related to inflammatory response, Neutrophils and basophils have an impact on the development of CWP.
Subject(s)
Humans , Anthracosis/genetics , Ataxia Telangiectasia , Ataxia Telangiectasia Mutated Proteins/genetics , China , Coal , Coal Mining , Miners , Pneumoconiosis/epidemiology , Polymorphism, Single NucleotideABSTRACT
The production efficiency of microbial cell factory is determined by the growth performance, product synthetic capacity, and stress resistance of the strain. Strengthening the stress resistance is the key point to improve the production efficiency of microbial cell factory. Tolerance engineering is based on the response mechanism of microbial cell factory to resist stress. Specifically, it consolidates the cell wall-cell membrane barrier to enhance the defense against stress, accelerates the stress response to improve the damage repair, and creates tolerance evolutionary tools to screen industrial microorganisms with enhanced robustness. We summarize the regulation strategies and forecast the prospects of tolerance engineering, which plays an important role in the microbial cell factories for sustainable production of natural products and bulk chemicals.
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Cell Membrane , Metabolic EngineeringABSTRACT
Mesenchymal stem cells(MSCs) have functions such as immune regulation and tissue damage repair, but the specific mechanisms of their effects need to be further studied. Paracrine effect is an important mechanism for MSCs to achieve immune regulation, relieve inflammation and repair tissue damage. Tumor necrosis factor α(TNF-α) stimulated protein 6(TSG-6) is one of the paracrine factors of MSCs, which has significant inflammation inhibitory capability and tissue repair ability. It is an important cytokine of MSCs to exert their anti-inflammatory and anti-fibrotic effects. The MSCs can repair tissue damage in kidney, peritonea, skin, liver, lung, cornea, nervous system, and colon by secreting TSG-6. This powerful repair ability could be attributed to the ability of TSG-6 to inhibit the secretion of pro-inflammatory cytokines and pro-fibrogenic factors, such as TNF-α, interleukin(IL)-6, IL-1β and transforming growth factor-β1, thereby reducing the inflammatory response and fibrosis of the body.
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Genome stability can be threatened by both endogenous and exogenous agents. Organisms have evolved numerous mechanisms to repair DNA damage, including homologous recombination (HR) and non-homologous end joining (NHEJ). Among the factors associated with DNA repair, the MRE11-RAD50-NBS1 (MRN) complex (MRE11-RAD50-XRS2 in
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Adenosine diphosphate (ADP)-ribosylation is a unique post-translational modification that regulates many biological processes, such as DNA damage repair. During DNA repair, ADP-ribosylation needs to be reversed by ADP-ribosylhydrolases. A group of ADP-ribosylhydrolases have a catalytic domain, namely the macrodomain, which is conserved in evolution from prokaryotes to humans. Not all macrodomains remove ADP-ribosylation. One set of macrodomains loses enzymatic activity and only binds to ADP-ribose (ADPR). Here, we summarize the biological functions of these macrodomains in DNA damage repair and compare the structure of enzymatically active and inactive macrodomains. Moreover, small molecular inhibitors have been developed that target macrodomains to suppress DNA damage repair and tumor growth. Macrodomain proteins are also expressed in pathogens, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, these domains may not be directly involved in DNA damage repair in the hosts or pathogens. Instead, they play key roles in pathogen replication. Thus, by targeting macrodomains it may be possible to treat pathogen-induced diseases, such as coronavirus disease 2019 (COVID-19).
Subject(s)
Humans , ADP-Ribosylation , COVID-19/metabolism , DNA Repair/physiology , Evolution, Molecular , Models, Biological , Models, Molecular , N-Glycosyl Hydrolases/metabolism , Poly(ADP-ribose) Polymerases/metabolism , Protein Domains , SARS-CoV-2/pathogenicityABSTRACT
Radiotherapy kills tumor cells by radiation-induced DNA double-strand breaks (DSB), however, abnormal DSB repair in tumor cells often leads to radioresistance, in which epigenetics plays an important role. Targeting aberrant epigenetic markers may be a potential means of cancer radiosensitization, but the clinical application of the combination of epigenetic drugs and radiotherapy requires further investigation. This article reviews the latest research progress the role of epigenetics in the repair of radiation-induced DNA damage in tumors.
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Objective:To clarify the role of classic Wnt signaling pathway in the radioresistance of esophageal cancer cells (ECC), and investigate the underlying mechanism, aiming to identify critical molecular targets for clinically enhancing the radiosensitivity of esophageal cancer.Methods:The radiosensitivity of four types of ECCs (EC9706, ECA109, KYSE70 and KYSE150) were assessed by colony formation assay. Western blot and RT-PCR were used to detect the activation of classical Wnt signaling pathway after irradiation. Classic Wnt signaling pathway activator (AZD2858) and inhibitor (XAV-939) were utilized to comprehensively evaluate the effect of classic Wnt signaling pathway on the radiosensitivity of ECCs. Cellular immunofluorescence staining was performed to detect the production and repair of DNA double-strand breaks (DSB), as well as the foci formation of DSB repair proteins after irradiation.Results:The results of colony formation assay showed that the radiosensitivity of four types of ECCs from high to low was EC9706, ECA109, KYSE70 and KYSE150. In KYSE150, a radioresistant cell type, the level of nuclear β-catenin and the transcription of c-Myc gene were significantly increased after irradiation (both P<0.05). However, in EC9706, a radiosensitive cell type, the level of nuclear β-catenin and c-Myc gene transcription were not affected by irradiation (both P>0.05). Moreover, EC9706 cells showed enhanced radioresistance in the presence of AZD2858( P<0.05), whereas XAV-939 treatment decreased the radioresistance in KYSE150 cells ( P<0.05). AZD2858 accelerated the DSB repair in EC9706 cells ( P<0.05), whereas XAV-939 delayed the DSB repair in KYSE150 cells ( P<0.05). Furthermore, the results of immunofluorescence staining showed that XAV-939 reduced the DSB repair capacity by inhibiting homologous recombination repair-related proteins (BRCA1 and RAD51) rather than non-homologous end junction repair-related proteins (Ku80 and XRCC4). Conclusions:The classic Wnt signaling pathway participates in the regulation of radiosensitivity in ECCs by regulating the homologous recombination repair of DSB after irradiation. Inhibition of the classic Wnt signaling pathway can counteract the radioresistance of ECCs and enhance the killing effect of irradiation on ECCs.
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Objective:To evaluate the skin development and repair process of X-ray radiation damage in rat with non-invasive two-photon excitation fluorescence (TPEF) imaging technology in vivo. Methods:Totally 24 SD rats were randomly divided into four groups including X-ray irradiated group (25, 35 and 45 Gy) and non-irradiation control group. At different times after irradiation, the degree of skin injury was evaluated, and the pathological changes of nicotinamide adenine dinucleotide (phosphate) [NAD(P)H] and collagen fiber fluorescence signals in epidermal cells were detected in vivo by TPEF imaging technology. Results:At 10 d post-irradiation, the skin of irradiation groups showed erythema and desquamation. At 15-20 d post-irradiation, the skin of radiation groups developed progressive exudation, edema and ulcers with increasing radiation dose. On day 25, the skin began to repair in the 25 Gy group, however, the skin of other groups still had exudation and ulcers. On day 10, NAD(P)H fluorescence signal in epidermal cells of irradiation groups decreased and the fluorescence signal of collagen fibers in papillary layer and reticular layer of irradiation groups reduced, which were significantly lower than that of normal control group ( t=24.145, 28.303, 26.989, 6.654, 7.510, 7.997, P<0.05). On day 30, fluorescence signal of NAD(P)H and collagen fibers in epidermal cells and dermis began to repair, the cell from stratum granulosum, stratum spinosum, and stratum basale in the 25 Gy group showed fluorescence signal, the other groups did not show. The fluorescence signal of collagen fibers in the 25 Gy group were gradually increased in papillary layer and reticular layer, however, they were significantly lower than normal control group ( t=115.133, 17.431, P<0.05), the skin of 45 Gy group did not show fluorescence signal of collagen fibers. Conclusions:The damage and repair process of epidermal cells and dermal collagen fiber can be detected noninvasively by TPEF imaging technology after X-ray irradiation in vivo.
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Objective To study bone remodeling behavior under different damage conditions. Methods A bone remodeling model under fatigue mechanism was proposed. By establishing a three-dimensional (3D) finite element model of the proximal femur and combining with the finite element method, the bone remodeling under three loading conditions was simulated, and the mechanical properties and density changes of the proximal femur were analyzed. Results The damage increased with the number of loading cycles increasing. Under different damage conditions, bone showed different remodeling behaviors. As a kind of repair mechanism, bone remodeling could make up for the loss of bone mass due to fatigue damage within a certain range. Conclusions The damage adaptive remodeling model proposed in this study can simulate the bone remodeling behavior under different damage conditions, and the overload absorption caused by excessive loading cycles. The study on the behavior of bone remodeling under fatigue damage can provide references for fracture prevention and postoperative rehabilitation treatment.
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Desmoplastic small round cell tumor (DSRCT) is a rare and highly malignant soft tissue sarcoma. Most patients are diagnosed at advanced stage unless DSRCT happens to be discovered accidentally. DSRCT mainly occurs in the abdomen and pelvis, spreading along the peritoneal surface. At the time of diagnosis, most patients have passed the operable stage. The diagnosis of DSRCT is based on the histological analysis of a biopsy. It typically manifests as small round blue cells in the nest, separated by a large number of fibroproliferative stroma. A stable cytogenetic feature of DSRCT is that the characteristic t(11; 22) (P13; Q12) chromosome produces the EWSWT1 fusion gene. The prognosis of patients with DSRCT is very poor, and the 5-year survival rate is about 15%. Despite the use of active treatment methods, such as chemotherapy, surgery, and total abdominal radiotherapy, about 60% 70% of patients with DSRCT die within 2- 3 years. Targeted therapy, immunotherapy, and other methods have been trialed recently in the treatment of DSRCT due to the development of DSRCT molecular genetics.
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Respiratory infectious diseases are important diseases causing major public safety events, posing a great threat to life, health, and social development. Effective control and scientific treatment of the diseases is the key basis for ensuring the stability and long-term development of the community of a shared future for human health. Although the pathogens of respiratory viral infectious diseases are diverse and the process is complex, the common pathological basis of their pathogenesis is characterized by the "damage-repair" functional imbalance of the immune microenvironment of the lesions, which leads to the subsequent structural and functional destruction of important organs. Therefore, the treatment should focus on antivirus and immunological regulation, strengthen the protection against immune injury, and promote the functional repair of damaged tissues. The above conclusions are the scientific core of host-directed therapies(HDT), which coincides with "human-disease co-treatment and healthy qi and pathogen interaction" in traditional Chinese medicine(TCM) theories. Under the support of TCM and western medicine theories, the complete pathological chain "infection-immunity-injury" of respiratory viral infectious diseases is integrated with dynamic change in "healthy qi-pathogen" in TCM to transform the treatment focus from the diseases to the patients. It is possible to fundamentally correct the "damage-repair" imbalance in the disease state, change the environment for disease development, and bring benefits to patients by strengthening human intervention, maintaining immune homeostasis, enhancing the protection of tissues and organs, and promoting the repair and regeneration of damaged tissues. This study focused on the common and key pathological processes of respiratory infectious diseases, especially the immune damage caused by the viral infection, to seek effective prevention and treatment strategies, review relevant theoretical progress, summarize effective drug candidates, prospect future research and development, and highlight the therapeutic characteristics of TCM.