Burgeoning evidence has indicated that normal autophagy is required for nuclear factor erythroid 2-related factor (Nrf2)-mediated cardiac protection whereas autophagy inhibition turns on Nrf2-mediated myocardial damage and dysfunction in a setting of pressure overload (PO). However, such a concept remains to be fully established by a careful genetic interrogation in vivo. This study was designed to validate the hypothesis using a mouse model of PO-induced cardiomyopathy and heart failure, in which cardiac autophagy and/or Nrf2 activity are genetically inhibited. Myocardial autophagy inhibition was induced by cardiomyocyte-restricted (CR) knockout (KO) of autophagy related (Atg) 5 (CR-Atg5KO) in adult mice. CR-Atg5KO impaired cardiac adaptations while exacerbating cardiac maladaptive responses in the setting of PO. Notably, it also turned off Nrf2-mediated defense while switching on Nrf2-operated tissue damage in PO hearts. In addition, cardiac autophagy inhibition selectively inactivated extracellular signal regulated kinase (ERK), which coincided with increased nuclear accumulation of Nrf2 and decreased nuclear translocation of activated ERK in cardiomyocytes in PO hearts. Mechanistic investigation revealed that autophagy is required for the activation of ERK, which suppresses Nrf2-driven expression of angiotensinogen in cardiomyocytes. Taken together, these results provide direct evidence consolidating the notion that normal autophagy enables Nrf2-operated adaptation while switching off Nrf2-mediated maladaptive responses in PO hearts partly through suppressing Nrf2-driven angiotensinogen expression in cardiomyocytes.
BackgroundDirect transdifferentiation of adult somatic cells into insulin-producing cells (IPCs) is a promising approach for cell-based therapies for type 1 diabetes mellitus. Liver cells are an ideal source for generating IPCs because they have regenerative ability and a developmental process similar to that of the pancreas. Pancreas versus liver fate is regulated by TALE homeoprotein (TGIF2) during development. Here, we wanted to investigate whether TGIF2 could enhance the efficiency of transdifferentiation of hepatocytes into IPCs induced by three pancreatic transcription factors (pTFs), i.e., Pdx1, NeuroD, and Mafa, which are crucial for pancreatic development in the embryo.MethodsThe in vitro transcribed (IVT) mRNAs of TGIF2 and the three pTFs were synthesized in vitro and sequentially supplemented in hepatocytes. On day 6, the expression of transcription factors was assessed by quantitative real-time polymerase chain reaction (qRT-PCR), and insulin expression was detected by immunofluorescence. Glucose-stimulated insulin secretion was assessed by enzyme-linked immunosorbent assay (ELISA). The key genes controlling cell polarity and the Wnt/PCP signaling pathway were assayed by qRT-PCR, and the level of JNK protein phosphorylation, which regulates the Wnt/PCP signaling pathway, was detected by western blotting.ResultsIVT mRNAs could be efficiently transfected into hepatocytes. Quantitative real-time polymerase chain reaction results revealed that compared with ectopic expression of the three pTFs alone, ectopic expression of the three pTFs plus TGIF2 could strongly reduce hepatic gene expression and subsequently improve the induction of a set of pancreatic genes. Immunofluorescence analysis showed that TGIF2 expression could double the transdifferentiation yield; 30% of the cells were insulin positive if induced by TGIF2 plus the 3 pTFs, while only 15% of the cells were insulin positive if induced by the three pTFs alone. ELISA analysis confirmed that glucose-stimulated insulin secretion was less efficient after transfection with the three pTFs alone. The differentiated cells derived from the addition of TGIF2 mRNA could form islet-like clusters. By contrast, the cells differentiated with the three pTFs did not form clusters under the same conditions. Tgif2 induced transdifferentiation more efficiently by remodeling the expression of genes in the Wnt/PCP pathway. Overexpression of TGIF2 in hepatocytes could activate the expression of key genes controlling cell polarity and genes in the Wnt/PCP signaling pathway, increasing the level of JNK protein phosphorylation.ConclusionsOur study established a novel footprint-free protocol for efficient transdifferentiation of hepatocytes into IPCs using IVT mRNAs of TGIF2 and 3 pTFs, which paved the way toward a clinical application.
Background: Qiliqiangxin (QLQX) is a preparation refined from a traditional Chinese medicine compound. It plays an important role in protecting cardiac function after myocardial infarction (MI). However, the underline mechanism of QLQX action is not clear. The purpose of this study was to detect the effects of QLQX on mitophagy after MI. Methods: Male FVB/NJ mice aged 8-10 weeks were underwent left coronary artery ligation and were orally administered either QLQX (0.25 g/kg/d) or saline. Twenty-eight days after surgical operation, the cardiac function of mice was detected by echocardiography. Electron Microscopy was used to observe the microstructure of cardiomyocytes. Myocardial apoptosis was examined by TdT-mediated dUTP Nick-End Labeling (TUNEL) and western blot. H9c2 cells were cultured in a hypoxic incubator chamber (5% CO2, 1% O-2, 94% N-2) for 12 h and pretreated with or without QLQX (0.5 mg/mL). The cell apoptosis, reactive oxygen species (ROS), mitochondrial membrane potential and mitophagy were detected. Results: When compared to sham group, the cardiac function of MI mice decreased significantly, and their cardiomyocyte apoptosis and mitochondrial damage were more serious. These MI-induced cardiac changes could be reversed by QLQX treatment. In vitro experiments also confirmed that QLQX could protect cardiomyocytes from hypoxia-induced apoptosis and mitochondrial damage. Further study indicated that QLQX could increase the expression of Pink1 and Parkin in cardiomyocytes. Conclusion: Qiliqiangxin could reduce cardiomyocytes apotosis and improved heart function in infarcted heart through Pink1-mediated mitochondrial autophagy.
Cellular senescence, a process whereby cells enter a state of permanent growth arrest, appears to regulate cardiac pathological remodeling and dysfunction in response to various stresses including myocardial infarction (MI). However, the precise role as well as the underlying regulatory mechanism of cardiac cellular senescence in the ischemic heart disease remain to be further determined. Herein we report an inhibitory role of Nrf2, a key transcription factor of cellular defense, in regulating cardiac senescence in infarcted hearts as well as a therapeutic potential of targeting Nrf2-mediated suppression of cardiac senescence in the treatment of MI-induced cardiac dysfunction. MI was induced by left coronary artery ligation for 28 days in mice. Heart tissues from the infarct border zone were used for the analyses. The MI-induced cardiac dysfunction was associated with increased myocardial cell senescence, oxidative stress and apoptosis in adult wild type (WT) mice. In addition, a downregulated Nrf2 activity was associated with upregulated Keap1 levels and increased phosphorylation of JAK and FYN in the infarcted border zone heart tissues. Nrf2 Knockout (Nrf2(-/-)) enhanced the MI-induced myocardial, cardiac dysfunction and senescence. Qiliqiangxin (QLQX), a herbal medicine which could reverse the MI-induced suppression of Nrf2 activity, significantly inhibited the MI-induced cardiac senescence, apoptosis, and cardiac dysfunction in WT mice but not in Nrf2(-/-) mice. These results indicate that MI downregulates Nrf2 activity thus promoting oxidative stress to accelerate cellular senescence in the infarcted heart towards cardiac dysfunction and Nrf2 may be a drug target for suppressing the cellular senescence-associated pathologies in infarcted hearts.
This paper presents a new high power density permanent magnet brushless DC motor structure. It places the Hall element in the motor's slots which ensures the normal operation of the motor and shortens the axial length of the motor. Since the precision of the magnetoelectric encoder in the control unit of mechanical arms is highly required, it is necessary to analyze the magnetic leakage density at its location. Adding magnetic shielding measures at the end of the motor windings can ensure smooth operation of the mechanical arms. It's verified by finite element analysis and calculation.
FAM92A1–289(abbreviated FAM289) is recognized as one of the newly-discovered putative oncogenes. However, its role and molecular mechanisms in promoting cancer progression has not yet been elucidated. This study was performed to reveal its oncogenic functions and molecular mechanisms in human glioblastoma multiforme (GBM) cell models with knockdown or overexpression of FAM289 in vitro and in vivo. To elucidate the molecular mechanisms underlying FAM289-mediated tumor progression, the protein-protein interaction between FAM289 and Galectin-1 was verified by co-immunoprecipitation, followed by an analysis of the expression and activity of Galectin-1-associated signaling molecules. Knockdown and overexpression of FAM289 in glioma cells were applied for investigating the effects of FAM289 on cell growth, migration and invasion. The determination of FAM289 expression was performed in specimens from various stages of human gliomas. FAM289-galectin-1 interaction and concomitant activation of the extracellular signal-regulated kinase (ERK) pathway participated in FAM289-mediated tumor-promoting function. Since the expression of DNA methyl transferase 1 (DNMT1) and DNA methyl transferase 3B (DNMT3B) was regulated by FAM289 in U251 and U87-MG glioma cells, Galectin-1 interaction with FAM289 may promote FAM289 protein into the cell nucleus and activate the ERK pathway, thereby upregulating DNMTs expression. Drug resistance tests indicated that FAM289-mediated TMZ resistance was through stem-like property acquisition by activating the ERK pathway. The correlation between FAM289, Galectin-1 expression and the clinical stage of gliomas was also verified in tissue samples from glioblastoma patients. Our results suggest that high expression of FAM289 in GBM tissues correlated with poor prognosis. FAM289 contributes to tumor progression in malignant glioma by interacting with Galectin-1 thereby promoting FAM289 protein translocation into the cell nucleus. FAM289 in the nucleus activated the ERK pathway, up regulated DNMTs expression and induced stem-like property gene expression which affects drug resistance of glioma cells to TMZ. This study provided functional evidence for FAM289 to be developed as a therapeutic target for cancer treatment.
Most HIV-1-infected patients experience hematopoiesis suppression complications. Bone marrow mesenchymal stem cells (BMSCs) are involved in regulation of hematopoietic homeostasis, so we investigated the role of Tat, a protein released by infected cells in bone marrow and impacted differentiation potential of mesenchymal stem cells, in the BMSC hematopoietic support function. BMSCs were treated with HIV-1 Tat protein (BMSCTat-p), transfected with HIV-1 Tat mRNA (BMSCTat-m) or treated with solvent (PBS) (BMSCcon) for 20 days. Then, the hematopoietic support function of BMSCTat-p, BMSCTat-m and BMSCcon was analyzed via ex vivo expansion of hematopoietic stem cells (HSCs) grown on the BMSCs and via in vivo cotransplantation of HSCs and BMSCs. In addition, the hematopoiesis-supporting gene expression patterns of BMSCTat-p, BMSCTat-m and BMSCcon were compared. The results showed that BMSCTat-p and BMSCTat-m displayed reduced expansion, a decline in the number of colony forming units (CFUs) and a decreased proportion of the primitive subpopulation of hematopoietic stem cells under coculture conditions compared with BMSCcon. The ability of BMSCTat-p to support hematopoietic recovery was also impaired, which was further confirmed by the patterns in gene expression analysis. In conclusion, Tat treatment reduced the function of BMSCs in hematopoietic support, likely by downregulating the expression of a series of hematopoietic cytokines.
Ten-eleven translocation 1 catalyzes the conversion of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), which plays an important role in epigenetics and is related to the malignant biological behavior of tumors. However, its regulatory role in glioma remains unclear. In this study, the levels of 5mC and 5hmC were detected using immunohistochemistry, dot-blot, hMeDIP-chip, and western blot in glioma tissues and normal brain tissues, whereas 5hmC differentially enriched genes were determined and further validated. The level of 5hmC in gliomas was decreased, whereas 5mC was increased. 5hmC highly enriched 10 functional protein-coding genes and 10 signaling pathways were identified using hMeGIP-chip in glioma tissues. Two autophagy-related genes, ATG13 and DNA damage-regulated autophagy modulator protein 1, with low enrichment of 5hmC in glioma tissues were verified in the promoter region, and hMeGIP-PCR further confirmed this result in U251 cells. Immunohistochemistry further confirmed that autophagy level in glioma tissues was lower than that of normal controls, and negatively correlated with WHO grade. This study indicates that ten-eleven translocation 1 may be involved in the development and progression of glioma through demethylation regulating a variety of cellular functions and signaling pathways, and autophagy is one of the regulatory mechanisms.
Cancer stem cells (CSCs) are a rare population of multipotent cells with the capacity to self-renew. It has been reported that there are CSCs in cervical cancer cells. Pluripotency-associated (PA) transcription factors such as Oct4, Sox2, Nanog and CD44 have been used to isolate CSCs subpopulations. In this study, we showed that autophagy plays an important role in the biological behavior of cervical cancer cells. The expression of the autophagy protein Beclin 1 and LC3B was higher in tumorspheres established from human cervical cancers cell lines (and CaSki) than in the parental adherent cells. It was also observed that the basal and starvation-induced autophagy flux was higher in tumorspheres than in the bulk population. Autophagy could regulate the expression level of PA proteins in cervical CSCs. In addition, CRISPR/Cas 9-mediated Beclin 1 knockout enhanced the malignancy of HeLa cells, leading to accumulation of PA proteins and promoted tumorsphere formation. Our findings suggest that autophagy modulates homeostasis of PA proteins, and Beclin 1 is critical for CSC maintenance and tumor development in nude mice. This demonstrates that a prosurvival autophagic pathway is critical for CSC maintenance.
Patients with human immunodeficiency virus-1 (HIV-1) infection often present with hematopoietic failure. As the important hematopoietic support cells in the bone marrow (BM), the BM mesenchymal stem cells (BMSCs) can be impacted by HIV proteins that are released by infected cells within BM. In this study, we tested whether HIV protein p55-gag could induce senescence of BMSCs and reduce their capacity to support expansion of hematopoietic stem cells in vitro. BMSCs were chronically treated with p55-gag (BMSCgag ) for up to 20 days, and their proliferative activity and senescence makers were compared to nontreated cells (BMSCcon ). Then, we analyzed the hematopoietic support function of BMSCcon and BMSCgag by determining cellular proliferation, colony-forming ability, and primitive hematopoietic populations of hematopoietic progenitors grown on the BMSCs. In addition, we compared the gene expression patterns for supporting hematopoiesis of BMSCcon and BMSCgag. The results show that when compared to BMSCcon , BMSCgag reduced their proliferative activity and underwent senescence. The ability of BMSCgag to support the expansion of committed hematopoietic progenitors from umbilical cord blood-derived CD34+ cells may be impaired, while the expression of genes associated with maintaining and enhancing hematopoiesis appeared to be decreased in treated BMSCs compared to control BMSCs. In conclusion, senescence induced by p55-gag resulted in decreased hematopoietic support function of BMSCs through reducing a series of hematopoietic cytokine expression.
The host range of human immunodeficiency virus type 1 (HIV-1) is extremely narrow, which has hampered the establishment of non-human primate models for HIV-1 infection. The species-specific innate immune factor tripartite motif 5 alpha (TRIM5α) is a key molecule that confers potent resistance against HIV-1 infection. In this study, we targeted the TRIM5α gene of rhesus macaques (rhTRIM5α) using the transcription activator-like effector nuclease (TALEN) to study the effect on HIV-1 infection. CD4+ T cells were separated from the peripheral blood of rhesus macaques by magnetic cell sorting, and the positive rate was greater than 99%. TALEN plasmids targeting rhTRIM5α were constructed and introduced into CD4+ T cells by electroporation, with a transfection efficiency of approximately 25%. The genome of the targeted cells was extracted, and the target efficiency was analyzed by T7E1 enzyme digestion. After sorting the positive transductants, the TALENs induced rhTRIM5α mutations at a rate of more than 40%. The ability of the HIV-1 virus to infect the targeted cells was demonstrated by ELISA. The results showed that targeting rhTRIM5α enhanced the susceptibility to HIV-1 infection. This finding will pave the way for further establishment of a new rhesus macaque model for HIV-1 studies.
Objective To construct the Prokaryotic expression vector of human betatrophin(h-betatrophin) gene and induce the expression of betatrophin recombinant protein,and purify target protein,which makes preparation of the production of Betatrophin protein polyclonal antibody and lies a foundation for research this gene's function.Methods Cloned Betatrophin cDNA sequence in vitro was inserted to PET 32 a (+) expression vector through double enzyme digestion and established the recombinant expression vector h-Betatrophin-PET 32 a.h-Betatrophin-PET 32 a vector was then transformed into E.coli BL 21 (DE 3).The expression of Betatrophin protein was induced with Isopropyl β-D-1-thiogalactopyranoside (IPTG) in BL 21,and confirmed by SDS-PAGE-commassie blue fast staining solution and western-blot analysis.In addition,the Betatrophin recombinant protein was purified by Ni-NTA His·Bind(R) Resin.Results The recombinant vector h-Betatrophin-PET 32 a was constructed.The epigenetic molecular weight of induced Betatrophin recombinant protein was correct,and high purity Betatrophin recombinant protein was successfully purified.Conclusion Recombinant expression vector h-Betatrophin-PET 32 a was transformed into BL 21 and could efficiently express h-Betatrophin recombinant protein.A large number of homogeneous h-Betatrophin proteins can be obtained by our purification methods.
CXC chemokine receptor 4 (CXCR4) is associated with poor clinical outcomes and decreased survival in hepatocellular carcinoma (HCC). In the present study, we targeted CXCR4 by CRISPR/Cas9 in HepG2 cells and observed the effects both in vitro and in vivo. The results indicated that after targeting CXCR4 the expression of CXCR4 was significantly decreased and the cell proliferation was inhibited. Clonogenicity and scratch cell migration assays indicated that specific downregulation of CXCR4 inhibited cell migration. This disruption of CXCR4 led to less invasiveness, the genes related to epithelial-mesenchymal transition (EMT) and cell self-renewal were also affected. Moreover, sensitivity to the anticancer drug cisplatin was significantly increased in vitro by the downregulation of CXCR4. The results of the in vivo study showed that the growth volumes were significantly smaller in neoplasms derived from CXCR4-downregulated HepG2 cells compared to those derived from wild-type cells. These results showed that targeting CXCR4 by CRISPR/Cas9 could inhibit proliferation, migration and invasion, reversed EMT, increased chemosensitivity and decrease the malignancy of HCC in vitro and in vivo.
Objective:To study the effect of tripartite motif 5 alpha (TRIM5α) on the HIV-1 infection of CD4 + T cells of Macaca mulatta.Methods:Separation CD4 + T cells from peripheral blood of Macaca mulatta by magnetic cell sorting and the rate of CD4 + T cells was detected by flow cytometry.The transcription activator-like effector nuclease (TALEN) plasmids which targeted TRIM5α gene were constructed and transfected into CD4 + T cells by electroporation.The cells which transfected into TALEN plasmids were separated by flow cytometry.The genome of the targeted cells was extracted and analyzed by T7E1 enzyme digestion.The HIV-1 virus were used to infect the CD4 + T cells which were targeted TRIM5α and the ability of virus infection was detected by ELISA.Results:The CD4 + T cells were successfully separated from the peripheral blood of Macaca mulatta and the positive rate was 99.5%.The TRIM5α TALEN plasmids could enter the CD4 + T cells by electroporation,the infection efficiency was 24.8% and the target efficiency was 40%.The result of ELISA showed that the HIV-1 virus could infect the CD4+ T cells of Macaca mulatta which were targeted TRIM5α.Conclusion:Targeting TRIM5α gene of CD4 + T cells of Macaca mulatta can increase its ability to infect HIV-1 virus.This will lay the foundation for the further establish the Macaca mulatta model for HIV-1 study.
Objective:Recently modification of CCR5 locus for anti-HIV-1 infection was performed by the genome editing methods like TELENs or CRISPR-Cas with the strategies of disruption of CCR5.To obtain the exact mutation of Δ32 deletion at the locus,we employed a novel strategy for developing CCR5Δ32 targeting vector based on Red/ET homologous recombination.Methods:Firstly,a rpsl-neo cassette flanked by two homology arms to CCR5 was amplified by PCR and then electroporated into E.coli DH10B with the BAC bearing CCR5.Through Red/ET homologous recombination,a 52 bp DNA sequences containing Δ32 in CCR5 was replaced by rpsl-neo.Subsequently,a non-selectable fragment was electroporated and replaced the rpsl-neo resulting in Δ32 deletion at CCR5.Furthermore,a loxp-neo-loxp cassette was also introduced into intron 2 within CCR5 through the same machnism,which allows for G418 selection for future targeting human cells and will be cut under the Cre protein only leaving one loxp at the intron region.Results:rpsl-neo cassette was successfully inserted into CCR5 on BAC and replaced by non-selectable fragment and at the same time a loxp-neo-loxp cassette was also introduced into intron 2 of CCR5.Conclusion:CCR5Δ32-loxp-neo-loxp targeting vector was accessed by Red/ET homologous recombination.
Objective:In order to further reveal the mechanism of hematopoietic injury among people infected with HIV-1,The effect of HIV-1 Tat protein on hematopoiesis support function of bone marrow mesenchymal stem cells (BMSC) was researched.Methods:The bone marrow mesenchymal stem cells were primary cultured and their characters were identified by detecting differentiation potential and immune phenotype.Hematopoietic stem cells (HSC) were sorted with immunomagnetic beads and the purity were detected with flow cytometry.As the feeder layer,the control BMSC (BMSCcon) and the experiment BMSC which have been added HIV-1Tat protein into the medium for culturing 20 days (BMSCTat) were respectively co-cultured with HSC and divided into six groups.Then,a series of detections were carried out,the total numbers of hematopoietic cells were counted,hematopoietic cells clonogenic ability were assayed,hematopoietic growth fator mRNA expression of BMSCcon and BMSCTat were detected with RT-PCR,GM-CSF and IL-6 concentration in the condition medium of BMSCcon and BMSCTa,were detected with ELISA.Results:Identification results show that the BMSC were successfully cultured.The purity of HSC sorted by immunomagnetic beads can reach more than 95%.The six groups were compared with each other and the results showed that both the total numbers of hematopoietic cells and the total numbers of hematopoietic cell colony in the groups when BMSCTat were as the feeder layer were significantly less than those in the groups when BMSCcon were as the feeder layer.The hematopoietic growth fator mRNA expression of BMSCTat were significantly weaker than that of BMSCcon.The GM-CSF and IL-6 concentration in the condition medium of BMSCTat were significantly lower than that of BMSCcon.Conclusions:The HIV1 Tat protein was confirmed to inhibit the hematopoiesis support function of bone marrow mesenchymal stem cells.
Introduction: The etiology of diabetes is mainly attributed to insulin deficiency due to the lack of β cells (type 1), or to insulin resistance that eventually results in β cell dysfunction (type 2). Therefore, an ultimate cure for diabetes requires the ability to replace the lost insulin-secreting β cells. Strategies for regenerating β cells are under extensive investigation.Areas covered: Herein, the authors first summarize the mechanisms underlying embryonic β cell development and spontaneous adult β cell regeneration, which forms the basis for developing β cell regeneration strategies. Then the rationale and progress of each β cell regeneration strategy is reviewed. Current β cell regeneration strategies can be classified into two main categories: in vitro β cell regeneration using pluripotent stem cells and in vivo reprogramming of non-β cells into β cells. Each has its own advantages and disadvantages.Expert opinion: Regenerating β cells has shown its potential as a cure for the treatment of insulin-deficient diabetes. Much progress has been made, and β cell regeneration therapy is getting closer to a clinical reality. Nevertheless, more hurdles need to be overcome before any of the strategies suggested can be fully translated from bench to bedside.
DNA methylation and demethylation play a critical role in the regulation of the molecular pathogenesis of gliomas. Tet methylcytosine dioxygenase 1 (TET1) catalyses the sequential oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine, (5hmC) leading to eventual DNA demethylation. It has been reported that TET1 is a tumour suppressor in several cancers. However, whether TET1 plays a role in glioma development is largely unclear. Different glioma specimens and corresponding normal controls were collected to analyse the expression of TET1. At the same time, TET1 of glioma U251 cells was knocked down or overexpressed to observe its effect on glioma cell proliferation and invasion as well as autophagy level. Here, we reported that the expression of TET1 in glioma tissue was significantly lower than the corresponding non-tumour normal tissues, and the concentration of TET1 is negatively correlated with the glioma WHO classification. When TET1 gene in glioma U251 cells was knocked down by CRISPR/Caspase-9 system, the proliferation and invasive ability of U251 increased remarkably. But when TET1 was overexpressed in U251 cells, the proliferation and invasion were impaired. Following the down-expression of TET1, the level of autophagy in U251 cells decreased accordingly.However, when TET1 was overexpressed in U251 cells, the level of autophagy incraesed. Furthermore, bafilomycin A1 (Baf-A1) but not 3-methyladenine (3-MA) could decrease the autophagy level of TET1−/− U251 cells as the wild-type controls. It suggests that the tumour suppressor effect of TET1 seems to be mediated by regulating the level of autophagy, and the regulation of TET1 on autophagy is at an early stage.
Since evidence suggests that transplantation of bone marrow stem cells with the C‑C chemokine receptor type 5 (CCR5)Δ32/Δ32 genotype may cure patients infected with human immunodeficiency virus (HIV)‑1, the present study aimed to reproduce the CCR5Δ32 mutation in cluster of differentiation (CD)4+ U87 cells using genome engineering methods. A modified transcription activator‑like effector nucleases (TALENs) technique, combined with homologous recombination for site‑specific, size‑controlled and homozygous DNA deletions, was used to reproduce the homozygous CCR5Δ32 mutation in CD4+ U87 cells. The results indicated that the frequency of the TALENs‑targeted mutation reached 50.4% without any selection, whereas homologous recombination from CCR5 to CCR5Δ32 occurred in 8.8% of targeted cells. Notably, a HIV‑1 challenge test demonstrated that CCR5Δ32/Δ32 CD4+ U87 cells were resistant to HIV infection. In conclusion, engineered CCR5Δ32/Δ32 mutations endowed CD4+ U87 cells with resistance against HIV‑1 infection; this site‑specific, size‑controlled and homozygous DNA deletion technique was able to induce precise genomic editing, i.e., the deletion or insertion of a predetermined length of DNA sequence at a specific locus throughout the genome.