Clinical value of BRE-AS1 in myocardial infarction and its role in myocardial infarction-induced cardiac muscle cell apoptosis.

Objectives. The aim of this study was to investigate the expression of long non-coding RNA (lncRNA) brain and reproductive organ-expressed protein (BRE) antisense RNA 1 (BRE-AS1) in patients with acute myocardial infarction (AMI) and its effect on ischemia/reperfusion (I/R)-induced oxidative stress and apoptosis of cardiomyocytes. Methods. Serum BRE-AS1 levels in patients with AMI was detected using quantitative real-time polymerase chain reaction (qRT-PCR). The diagnostic and prognostic values of BRE-AS1 were evaluated. H9c2 cells were treated with hypoxia/reoxygenation to establish an in vitro myocardial infarction cell model. The levels of inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and IL-6 were detected by enzyme-linked immunosorbent assay (ELISA). Levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were determined by commercial kits. Cell counting kit-8 (CCK-8) and flow cytometry were used to evaluate the cell viability and cell apoptosis. Results. The expression of BRE-AS1 in serum of patients with AMI is upregulated, which shows the clinical diagnostic value for AMI. In the I/R injury cell model, the knockout of BRE-AS1 can significantly alleviate the increase in TNF-α, IL-1ß, and IL-6 levels, inhibit the production of LDH and MDA, increase the activities of SOD and GSH-Px, promote the cell viability and suppress cell apoptosis. Conclusions. Abnormally elevated BRE-AS1 has a high diagnostic value for AMI as well as a prognostic value for major adverse cardiovascular events (MACEs). The elevation of BRE-AS1 promoted oxidative stress injury and cell apoptosis in vitro.

Exosomes from uterine fluid promote capacitation of human sperm.

Background: Extracellular vesicles (EVs) are membrane-bound vesicles containing various proteins, lipids, and nucleic acids. EVs are found in many body fluids, such as blood and urine. The release of EVs can facilitate intercellular communication through fusion with the plasma membrane or endocytosis into the recipient cell or through internalization of the contents. Recent studies have reported that EVs isolated from human endometrial epithelial cells (EECs) promote sperm fertilization ability. EVs from uterine flushing fluid more closely resemble the physiological condition of the uterus. However, it is unclear whether EVs derived directly from uterine flushing fluid have the same effect on sperm. This study aimed to research the effect of EVs from uterine flushing fluid on sperm. Methods: EVs were isolated from the uterine flushing fluid. The presence of EVs was confirmed by nanoparticle tracking analysis (NTA), Western blot, and transmission electron microscopy (TEM). EVs were incubated with human sperm for 2 h and 4 h. The effects of EVs on sperm were evaluated by analyzing acrosome reaction, sperm motility, and reactive oxygen species (ROS). Results: The EVs fractions isolated from the uterine fluid were observed in cup-shaped vesicles of different sizes by TEM. All isolated vesicles contained similar numbers of vesicles in the expected size range (30-200 nm) by NTA. CD9 and CD63 were detected in EVs by western blot. Comparing the motility of the two groups incubated sperm motility significantly differed at 4 h. The acrosome reactions were promoted by incubating with EVs significantly. ROS were increased in sperm incubated with EVs. Conclusion: Our results showed EVs present in the uterine fluid. Acrosome reactions and ROS levels increased in human sperm incubated with EVs. EVs from uterine fluid can promote the capacitation of human sperm. The increased capacitation after sperm interaction with EVs suggests a possible physiological effect during the transit of the uterus.

Single-Cell Analysis Reveals Cxcl14+ Fibroblast Accumulation in Regenerating Diabetic Wounds Treated by Hydrogel-Delivering Carbon Monoxide.

Nonhealing skin wounds are a problematic complication associated with diabetes. Therapeutic gases delivered by biomaterials have demonstrated powerful wound healing capabilities. However, the cellular responses and heterogeneity in the skin regeneration process after gas therapy remain elusive. Here, we display the benefit of the carbon monoxide (CO)-releasing hyaluronan hydrogel (CO@HAG) in promoting diabetic wound healing and investigate the cellular responses through single-cell transcriptomic analysis. The presented CO@HAG demonstrates wound microenvironment responsive gas releasing properties and accelerates the diabetic wound healing process in vivo. It is found that a new cluster of Cxcl14+ fibroblasts with progenitor property is accumulated in the CO@HAG-treated wound. This cluster of Cxcl14+ fibroblasts is yet unreported in the skin regeneration process. CO@HAG-treated wound macrophages feature a decrease in pro-inflammatory property, while their anti-inflammatory property increases. Moreover, the TGF-ß signal between the pro-inflammatory (M1) macrophage and the Cxcl14+ fibroblast in the CO@HAG-treated wound is attenuated based on cell-cell interaction analysis. Our study provides a useful hydrogel-mediated gas therapy method for diabetic wounds and new insights into cellular events in the skin regeneration process after gas-releasing biomaterials therapy.

STING activation in cardiomyocytes drives hypertrophy-associated heart failure via NF-κB-mediated inflammatory response.

Accumulating evidence highlights the key importance of innate immunity in heart hypertrophy and failure. Though stimulator of interferon genes (STING) is an integral innate immunity regulator, whether cardiomyocyte-derived STING driving cardiac hypertrophy and failure has rarely been explored, nor has its underlying mechanism been clarified. Herein, we addressed these two questions through several mouse experiments. Our results revealed that cardiac tissues from patients exhibiting cardiac hypertrophy markedly increased STING expression. Myocardial tissues of mice challenged with angiotensin II (Ang II) or transverse aortic constriction (TAC) also showed that STING was consistently upregulated and activated. Activation of STING by cGAMP or DMXAA resulted in cardiomyocyte hypertrophy in vitro, which was abolished by STING knockout. Furthermore, deleting or pharmacologically inhibiting STING attenuated cardiac hypertrophy and dysfunction in TAC or Ang II-treated mice. In contrast, mice with cardiomyocyte-specific STING activation developed cardiac hypertrophy and failure. Mechanistically, NF-κB signaling but not TBK1 or autophagy formation was implicated in STING -induced cardiac hypertrophy and failure. Collectively, we identified that STING-NF-κB axis mediated inflammatory response to drive cardiac hypertrophy-associated heart failure, highlighting its promise as a potential therapeutic target in clinical practice.

MiR-483-5p downregulation alleviates ox-LDL induced endothelial cell injury in atherosclerosis.

BACKGROUND: In light of the abnormal expression of microRNA (miR-483-5p) in patients with atherosclerosis (AS), its role in vascular endothelial cell injury was explored. And the mechanisms related to autophagy were also elucidated. METHODS: Human umbilical vein endothelial cells (HUVECs) were given 100 mg/L ox-LDL to induce endothelial injury. Cell transfection was done to regulate miR-483-5p levels. Cell viability and apoptosis were detected. qRT-PCR was employed for the mRNA levels' detection. RESULTS: Autophagic flux impairment of HUVECs was detected after ox-LDL treatment, along with the upregulation of miR-483-5p. Ox-LDL inhibited cell viability and promoted cell apoptosis, but these influences were changed by miR-483-5p downregulation. MiR-483-5p downregulation decreased the mRNA levels of IL-1ß, IL-6, ICAM-1 and VCAM-1. 3-MA, the autophagy inhibitor, reversed the beneficial role of miR-483-5p downregulation in ox-LDL-induced HUVECs' injury. TIMP2 acts as a target gene of miR-483-5p, and was downregulated in HUVEC models. CONCLUSION: MiR-483-5p downregulation alleviated ox-LDL-induced endothelial injury via activating autophagy, this might be related to TIMP2.

STING/ACSL4 axis-dependent ferroptosis and inflammation promote hypertension-associated chronic kidney disease.

Hypertension is a primary modifiable risk factor for cardiovascular diseases, which often induces renal end-organ damage and complicates chronic kidney disease (CKD). In the present study, histological analysis of human kidney samples revealed that hypertension induced mtDNA leakage and promoted the expression of stimulator of interferon genes (STING) in renal epithelial cells. We used angiotensin II (AngII)- and 2K1C-treated mouse kidneys to elucidate the underlying mechanisms. Abnormal renal mtDNA packing caused by AngII promoted STING-dependent production of inflammatory cytokines, macrophage infiltration, and a fibrogenic response. STING knockout significantly decreased nuclear factor-κB activation and immune cell infiltration, attenuating tubule atrophy and extracellular matrix accumulation in vivo and in vitro. These effects delayed CKD progression. Immunoprecipitation assays and liquid chromatography-tandem mass spectrometry showed that STING and ACSL4 were directly combined at the D53 and K412 amino acids of ACSL4. Furthermore, STING induced renal inflammatory response and fibrosis through ACSL4-dependent ferroptosis. Last, inhibition of ACSL4 using small interfering RNA, rosiglitazone, or Fer-1 downregulated AngII-induced mtDNA-STING-dependent renal inflammation. These results suggest that targeting the STING/ACSL4 axis might represent a potential strategy for treating hypertension-associated CKD.

Activating transcription factor 4 drives the progression of diabetic cardiac fibrosis.

AIMS: Diabetic cardiomyopathy (DC) is one of serious complications of diabetic patients. This study investigated the biological function of activating transcription factor 4 (ATF4) in DC. METHODS AND RESULTS: Streptozotocin-treated mice and high glucose (HG)-exposed HL-1 cells were used as the in vivo and in vitro models of DC. Myocardial infarction (MI) was induced by left coronary artery ligation in mice. Cardiac functional parameters were detected by echocardiography. Target molecule expression was determined by real time quantitative PCR and western blotting. Cardiac fibrosis was observed by haematoxylin and eosin and Masson's staining. Cardiac apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick end labelling. Activities of superoxide dismutase, glutathione peroxidase, and levels of malonic dialdehyde and reactive oxygen species were used to assess oxidative stress damage. Molecular mechanisms were evaluated by chromatin immunoprecipitation, dual luciferase assay, and co-immunoprecipitation. ATF4 was up-regulated in the DC and MI mice (P < 0.01). Down-regulation of ATF4 improved cardiac function as evidenced by changes in cardiac functional parameters (P < 0.01), inhibited myocardial collagen I (P < 0.001) and collagen III (P < 0.001) expression, apoptosis (P < 0.001), and oxidative stress (P < 0.001) in diabetic mice. Collagen I (P < 0.01) and collagen III (P < 0.01) expression was increased in MI mice, which was reversed by ATF4 silencing (P < 0.05). ATF4 depletion enhanced viability (P < 0.01), repressed apoptosis (P < 0.001), oxidative damage (P < 0.001), and collagen I (P < 0.001), and collagen III (P < 0.001) expression of HG-stimulated HL-1 cells. ATF4 transcriptionally activated Smad ubiquitin regulatory factor 2 (Smurf2, P < 0.001) to promote ubiquitination and degradation of homeodomain interacting protein kinase-2 (P < 0.001) and subsequently caused inactivation of nuclear factor erythroid 2-related factor 2/heme oxygenase 1 pathway (P < 0.001). The inhibitory effects of ATF4 silencing on HG-induced apoptosis (P < 0.01), oxidative injury (P < 0.01), collagen I (P < 0.001), and collagen III (P < 0.001) expression were reversed by Smurf2 overexpression. CONCLUSIONS: ATF4 facilitates diabetic cardiac fibrosis and oxidative stress by promoting Smurf2-mediated ubiquitination and degradation of homeodomain interacting protein kinase-2 and then inactivation of nuclear factor erythroid 2-related factor 2/heme oxygenase 1 pathway, suggesting ATF4 as a treatment target for DC.

The innate immune sensor STING accelerates neointima formation via NF-κB signaling pathway.

Vascular smooth muscle cells (VSMCs) proliferation, migration, and phenotypic switching are considered crucial events in the progression of neointima formation. Stimulator of interferon genes (STING), an innate immune sensor of cyclic dinucleotides against pathogens, in neointima formation remains obscure. Here, we observed a significant increase in STING expression on the neointima of injured vessels and mouse aortic VSMCs induced by PDGF-BB. In vivo, global knockout of STING (Sting-/-) attenuated neointima formation after vascular injury. In vitro data showed that STING deficiency significantly alleviated PDGF-BB-induced proliferation and migration in VSMCs. Furthermore, these contractile marker genes were upregulated in Sting-/- VSMCs. Overexpression of STING promoted proliferation, migration, and phenotypic switching in VSMCs. Mechanistically, STING-NF-κB signaling was involved in this process. The pharmacological inhibition of STING induced by C-176 partially prevented neointima formation due to suppression of VSMCs proliferation. Taken together, STING-NF-κB axis significantly promoted proliferation, migration, and phenotypic switching of VSMCs, which may be a novel therapeutic approach to combat vascular proliferative diseases.

Polypyrimidine tract binding protein 1 exacerbates cardiac fibrosis by regulating fatty acid-binding protein 5.

AIMS: The activation of cardiac fibroblasts (CFs) leads to overproduction of collagens and subsequently cardiac fibrosis. However, the regulatory mechanism of CF function in the process of cardiac fibrosis remains unclear. This work investigated the function of polypyrimidine tract binding protein 1 (PTBP1)/nuclear receptor NR4A1 (Nur77)/fatty acid-binding protein 5 (FABP5) axis in myocardial fibrosis. METHODS AND RESULTS: Cardiac fibrosis was induced in mice suffered left anterior descending ligation. In parallel, neonatal mouse CFs were isolated and stimulated with transforming growth factor-ß1 (TGF-ß1). Cardiac fibrosis was evaluated by Masson's trichrome staining. Expression of PTBP1, Nur77, FABP5, collagen I, and collagen III was measured by quantitative real-time PCR and western blotting. Proliferation of CFs was assessed by 5-ethynyl-2'-deoxyuridine assay. Molecular interaction was validated by RNA-binding protein immunoprecipitation, chromatin immunoprecipitation, and dual luciferase reporter assay. PTBP1 was up-regulated (P < 0.05), whereas Nur77 (P < 0.05) and FABP5 (P < 0.05) were down-regulated in the fibrotic hearts of mice and TGF-ß1-exposed CFs. PTBP1 overexpression facilitated proliferation (P < 0.05) and collagen I (P < 0.05) and collagen III (P < 0.05) expression of CFs after stimulation with TGF-ß1. PTBP1 reduced Nur77 stability (P < 0.05) to inhibit Nur77 expression (P < 0.05) in CFs. Nur77 bound to FABP5 promoter to promote the transcription (P < 0.05) and expression (P < 0.05) of FABP5. Silencing of Nur77 or FABP5 abolished the inhibitory effect of PTBP1 knockdown on proliferation (P < 0.05) and collagen I (P < 0.05) and collagen III (P < 0.05) expression of CFs in vitro. PTBP1 depletion ameliorated cardiac fibrosis (P < 0.05), α-smooth muscle actin (P < 0.05), and collagen I (P < 0.05) expression in myocardial infarction mice through regulating Nur77/FABP5 pathway (P < 0.05) in vivo. CONCLUSIONS: PTBP1 contributed to cardiac fibrosis via promoting CF proliferation and collagen deposition through Nur77 mRNA decay and subsequent transcription inhibition of FABP5. Our findings suggest that PTBP1/Nur77/FABP5 axis may be potential targets for cardiac fibrosis therapy.

Hyaluronic Acid-Guided Cerasome Nano-Agents for Simultaneous Imaging and Treatment of Advanced Atherosclerosis.

Early noninvasive screening and regression therapy for vulnerable atherosclerotic plaques remain challenging. In this study, it is aimed to develop a new approach for the active targeting of atherosclerotic plaques with nano-agents to aid imaging and treatment. Biocompatible hyaluronic acid (HA)-guided cerasomes are generated to selectively target CD44-positive cells within the plaque in in vitro studies and in vivo testing in Apoe-/- mice. Rosuvastatin (RST) is encapsulated in the HA-guided cerasome nano-formulation to produce HA-CC-RST, which results in significant plaque regression as compared to treatment with the free drug. Moreover, gadodiamide-loaded HA-CC enhances magnetic resonance images of vulnerable plaques, thereby attaining the goal of improved simultaneous treatment and imaging. Transcriptomic analysis confirms plaque regression with HA-CC-RST treatment, which potentially benefits from the anti-inflammatory effect of RST. In summary, a safe and efficient nano-formulation for the targeted delivery of active agents to atherosclerotic plaques is developed and may be applicable to other diagnostic and therapeutic agents for atherosclerosis treatment.

Whole-crop biorefinery of corn biomass for pullulan production by Aureobasidium pullulans.

In the present study, corn starch, cob, and straw were biorefined and used as feedstocks for the production of pullulan. The titer and molecular weight (Mw) of pullulan significantly decreased when corn cob and straw hydrolysates were utilized by the parental strain Aureobasidium pullulans CCTCC M 2012259 (PS). Based on adaptive laboratory evolution of PS, an evolved strain A. pullulans EV6 with strong adaptability to the whole corn biomass hydrolysate and high capability of pullulan biosynthesis was screened. Batch pullulan fermentation results indicated that EV6 produced an increased titer of pullulan with a higher Mw than PS. The underlying reasons for these increases were revealed by assaying key enzymes activities and measuring intracellular uridine diphosphate glucose levels. Subsequently, whole-crop biorefinery of corn biomass was conducted, and the results confirmed that whole corn crop has immense potential for efficient pullulan production.

Link between sterile inflammation and cardiovascular diseases: Focus on cGAS-STING pathway in the pathogenesis and therapeutic prospect.

Sterile inflammation characterized by unresolved chronic inflammation is well established to promote the progression of multiple autoimmune diseases, metabolic disorders, neurodegenerative diseases, and cardiovascular diseases, collectively termed as sterile inflammatory diseases. In recent years, substantial evidence has revealed that the inflammatory response is closely related to cardiovascular diseases. Cyclic guanosine monophosphate-adenosine monophosphate synthase (cGAS)-stimulator of interferon genes (STING) pathway which is activated by cytoplasmic DNA promotes the activation of interferon regulatory factor 3 (IRF3) or nuclear factor-κB (NF-κB), thus leading to upregulation of the levels of inflammatory factors and interferons (IFNs). Therefore, studying the role of inflammation caused by cGAS-STING pathway in cardiovascular diseases could provide a new therapeutic target for cardiovascular diseases. This review focuses on that cGAS-STING-mediated inflammatory response in the progression of cardiovascular diseases and the prospects of cGAS or STING inhibitors for treatment of cardiovascular diseases.

A long noncoding RNA GTF2IRD2P1 suppresses cell proliferation in bladder cancer by inhibiting the Wnt/ß­catenin signaling pathway.

Background: There is growing evidence that long non-coding RNAs (LncRNAs) are key in the development of a variety of human tumors. However, the role of lncRNA GTF2IRD2P1 has not been well studied in cancer. The impact of GTF2IRD2P1 on the biological function and clinical relevance in bladder cancer is largely unknown. This study aimed to investigate the biological role of GTF2IRD2P1 in bladder evolution and carcinogenesis. Methods: We used bioinformatics to obtain the lncRNA GTF2IRD2P1 from bladder urothelial carcinoma (BLCA) in The Cancer Genome Atlas (TCGA) database. The expression of lncRNA GTF2IRD2P1 was detected by qRT-PCR. The CCK8 assay and flow cytometry were used to detect the lncRNA GTF2IRD2P1 function on the proliferation of bladder cancer cells. A western blot was used to calculate the protein level of cell cycle proteins and Wnt signaling pathway proteins. The effect of lncRNA GTF2IRD2P1 on tumorigenesis of bladder cancer was confirmed by a xenograft nude mouse model. Results: GTF2IRD2P1 expression was found to be lower in both human bladder cancer tissues and cell lines (UM-UC-3, RT4, and 5637), and elevated in T24 compared to the corresponding normal controls. GTF2IRD2P1 expression was also enhanced after transfection of UM-UC-3 cells with the overexpression vector. Meanwhile, overexpression of GTF2IRD2P1 inhibited the proliferation of UM-UC-3 and prolonged the cell cycle. The silencing of GTF2IRD2P1 significantly increased the proliferation and shortened the cell cycle of T24 cells and induced Wnt signaling activity to promote the progression of bladder cancer. Similarly, the transplanted tumor nude mouse model demonstrated that silencing GTF2IRD2P1 strengthens the progression of bladder cancer by targeting the Wnt signaling pathway.

The semenogelin I-derived peptide SgI-52 in seminal plasma participates in sperm selection and clearance by macrophages.

BACKGROUND: Macrophages can phagocytose sperm, especially damaged spermatozoa, in the female genital tract. The semenogelin I-derived peptide SgI-52 in seminal plasma exhibits seminal plasma motility inhibitor (SPMI) activity and can inhibit sperm motility. This raises the question of the role played by SPMIs in macrophage-mediated phagocytosis of sperm. We speculated that SgI-52 promotes sperm clearance by macrophages. Therefore, we investigated the phagocytosis of sperm in different states using this peptide. METHODS: SgI-52 was fluorescently labeled, and its binding site for sperm was observed. The ability of macrophages to phagocytose sperm was observed using fluorescence confocal microscopy. Spermatozoa from different sources were co-cultured with SgI-52 in BWW medium for 4 and 22 h to compare the differences in their phagocytosis by macrophages. Sperm motility, induced acrosome reaction, mitochondrial membrane potential, and ATP content were examined after incubation with SgI-52. RESULTS: SgI-52 could bind to spermatozoa in different states, mainly to the tail, and then spread to the acrosome. This effect was more pronounced in demembranated spermatozoa. SgI-52 promoted phagocytosis of spermatozoa by macrophages, decreased the mitochondrial membrane potential, and increased the average ATP content of spermatozoa (P < 0.05). CONCLUSIONS: We found for the first time that SgI-52 can bind to spermatozoa in different states and promote their phagocytosis by macrophages. Therefore, we speculate that SgI-52 is involved in the screening of sperm in the female reproductive tract and has potential value in improving assisted reproductive technology.

Chronic Stress-Induced Gene Changes In Vitro and In Vivo: Potential Biomarkers Associated With Depression and Cancer Based on circRNA- and lncRNA-Associated ceRNA Networks.

Circular RNAs (circRNAs) and long noncoding RNAs (lncRNAs) have been considered as biomarkers or regulators in many diseases. However, the exact role of circRNA- or lncRNA-mediated competing endogenous RNA (ceRNA) networks in the modulation of depression pathogenesis-relevant processes is not clear. In this study, we profiled whole transcriptome in depression patients' blood samples via microarray analysis. As a result, a total of 340 circRNAs, 398 lncRNAs, 206 miRNAs, and 92 mRNAs were differentially expressed between the depression and control groups. Then, we constructed ceRNA networks according to the differentially expressed genes (DEGs). Using bioinformatics analysis, 89 pairs of circRNA-ceRNA and 49 pairs of lncRNA-ceRNA networks were obtained. Since depression is a broad and heterogeneous condition that is known as promoter for many chronic diseases including cancer, so we further dug out 28 circRNAs, 61 lncRNAs, 26 miRNAs, and 29 mRNAs that are associated with cancer. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that the DEGs were significantly enriched in cancer-related signaling pathways such as MAPK, Wnt, IL-17, Ras, and PI3K-Akt. Genes involved in the above pathways such as S100A9, GATA2, SRFP5, SLC45A3, NTRK1, FRZB, has_circ_0014221, has_circ_0014220, and has_circ_0087100 were dysregulated in various cancer cell lines by stress hormones induced. HDC, GATA2, SLC45A3, and NTRK1 were downregulated in tumor-bearing mice subjected to chronic unpredictable mild stress (CUMS). LncRNA-mediated ceRNA network validation showed that overexpression of miR-4530 declined HDC level. Our findings highlight the potential circRNA- and lncRNA-mediated ceRNA regulatory mechanisms in the pathogenesis of depression and as potential biomarkers in depression cancer comorbidity through the pathways of IL-17 or histidine metabolism.

Activation of STING Pathway Contributed to Cisplatin-Induced Cardiac Dysfunction via Promoting the Activation of TNF-α-AP-1 Signal Pathway.

Cardiovascular complications are a well-documented limitation of conventional cancer chemotherapy. As a notable side effect of cisplatin, cardiotoxicity represents a major obstacle to the treatment of cancer. Recently, it has been reported that cyclic GMP-AMP synthase (cGAS) stimulator of interferon genes (STING) signaling pathway was associated with the occurrence and development of cardiovascular diseases. However, the effect of STING on cardiac damage caused by cisplatin remains unclear. In this study, cisplatin was shown to activate the cGAS-STING signaling pathway, and deficiency of STING attenuated cisplatin-induced cardiotoxicity in vivo and in vitro. Mechanistically, the STING-TNF-α-AP-1 axis contributed to cisplatin-induced cardiotoxicity by triggering cardiomyocyte apoptosis. In conclusion, our results indicated that STING might be a critical regulator of cisplatin-induced cardiotoxicity and be considered as a potential therapeutic target for preventing the progression of chemotherapy-associated cardiovascular complications.

Improved production of ß-glucan by a T-DNA-based mutant of Aureobasidium pullulans.

To improve ß-1,3-1,6-D-glucan (ß-glucan) production by Aureobasidium pullulans, an Agrobacterium tumefaciens-mediated transformation method was developed to screen a mutant A. pullulans CGMCC 19650. Based on thermal asymmetric-interlaced PCR detection, DNA sequencing, BLAST analysis, and quantitative real-time PCR assay, the T-DNA was identified to be inserted in the coding region of mal31 gene, which encodes a sugar transporter involved in pullulan biosynthesis in the mutant. The maximal biomass and ß-glucan production under batch fermentation were significantly increased by 47.6% and 78.6%, respectively, while pullulan production was decreased by 41.7% in the mutant, as compared to the parental strain A. pullulans CCTCC M 2012259. Analysis of the physiological mechanism of these changes revealed that mal31 gene disruption increased the transcriptional levels of pgm2, ugp, fks1, and kre6 genes; increased the amounts of key enzymes associated with UDPG and ß-glucan biosynthesis; and improved intracellular UDPG contents and energy supply, all of which favored ß-glucan production. However, the T-DNA insertion decreased the transcriptional levels of ags2 genes, and reduced the biosynthetic capability to form pullulan, resulting in the decrease in pullulan production. This study not only provides an effective approach for improved ß-glucan production by A. pullulans, but also presents an accurate and useful gene for metabolic engineering of the producer for efficient polysaccharide production. KEY POINTS: • A mutant A. pullulans CGMCC 19650 was screened by using the ATMT method. • The mal31 gene encoding a sugar transporter was disrupted in the mutant. • ß-Glucan produced by the mutant was significantly improved.

Efficient pullulan production by Aureobasidium pullulans using cost-effective substrates.

In this study, cost-effective substrates such as cassava starch, corn steep liquor (CSL) and soybean meal hydrolysate (SMH) were used for pullulan production by Aureobasidium pullulans CCTCC M 2012259. The medium was optimized using response surface methodology (RSM) and artificial neural network (ANN) approaches, and analysis of variance indicated that the ANN model achieved higher prediction accuracy. The optimal medium predicted by ANN was used to produce high molecular weight pullulan in high yield. SMH substrates increased both biomass and pullulan titer, while CSL substrates maintained higher pullulan molecular weight. Results of kinetic parameters, key enzyme activities and intracellular uridine diphosphate glucose contents revealed the physiological mechanism of changes in pullulan titer and molecular weight using different substrates. Economic analysis of batch pullulan production using different substrates was performed, and the cost of nutrimental materials for CSL and SMH substrates was decreased by 46.1% and 49.9%, respectively, compared to the control using glucose and yeast extract as substrates, which could improve the competitiveness of pullulan against other polysaccharides in industrial applications.

A novel affinity peptide-antibody sandwich electrochemical biosensor for PSA based on the signal amplification of MnO2-functionalized covalent organic framework.

This work describes a novel affinity peptide-antibody sandwich electrochemical strategy for the ultrasensitive detection of prostate-specific antigen (PSA). Herein, polydopamine-coated boron-doped carbon nitride (Au@PDA@BCN) was synthesized and used as a sensing platform to anchor gold nanoparticles and immobilize primary antibody. Meanwhile, AuPt metallic nanoparticle and manganese dioxide (MnO2)-functionalized covalent organic frameworks (AuPt@MnO2@COF) was facilely synthesized to serve as a nanocatalyst and ordered nanopore for the enrichment and amplification of signal molecules (methylene blue, MB). PSA affinity peptide was bound to AuPt@MnO2@COF to form Pep/MB/AuPt@MnO2@COF nanocomposites (probe). The peptide-PSA-antibody sandwich biosensor was constructed, and the redox signal of MB was measured with the existence of PSA. The fabricated sensor exhibited a linear response (0.00005-10 ng mL-1) with a low detection limit of 16.7 fg mL-1 under the optimum condition. Additionally, the sensor showed an excellent selectivity, ideal repeatability, and good stability for PSA detection in real samples. Furthermore, the porous structure of COF can enrich more MB molecules and increase the sensitivity of the biosensor. This study provides an efficient and ultrasensitive strategy for PSA detection and broadens the use of organic/inorganic porous nanocomposite in biosensing.

Smooth muscle cell-specific knockout of interferon gamma (IFN-γ) receptor attenuates intimal hyperplasia via STAT1-KLF4 activation.

BACKGROUND: Intimal hyperplasia is a main contributor to in-stent restenosis. Previous researches have shown that interferon-gamma (IFN-γ), a pleiotropic pro-inflammatory factor, plays a pathological role in intimal hyperplasia. However, the specific role and molecular mechanism of vascular smooth muscle cells (VSMCs)-derived IFN-γ receptor in intimal hyperplasia remains unknown. METHODS: We examined the distribution of IFN-γ receptor in human restenosis arteries. Then, the role of IFN-γ receptor in intimal hyperplasia was detected using VSMC-specific IFN-γ receptor-knock out carotid ligation injury models. We performed immunostaining, transwell assay and EdU staining to identify the role of IFN-γ in VSMCs proliferation and migration. The effect of IFN-γ on VSMCs phenotype switching was also investigated. Finally, we evaluated whether the mechanism of IFN-γ on intimal hyperplasia is STAT1-KLF4 dependent. RESULTS: The distribution of IFN-γ receptor in human restenosis arteries with VSMC-rich neointima is eventually upregulated. Specific deletion of IFN-γ receptor exhibits thinner intima and lesser proliferating VSMCs. In vitro, treatment with IFN-γ promotes human aortic VSMC (HAVSMCs) proliferation and migration, whereas specifically knock out IFN-γ receptor results in the opposite effect. Deficiency of IFN-γ receptor regulates VSMCs phenotypic switching, such as upregulated contractile markers and downregulated proliferation markers. Mechanistic studies suggest that ablation of IFN-γ receptor prevents VSMCs proliferation, migration and dedifferentiation via STAT1-KLF4 activation. CONCLUSION: These results reveal that knockout of VSMC-derived IFN-γ receptor potentiates neointimal hyperplasia by preventing VSMCs proliferation, migration and dedifferentiation. Our finding implies that targeting IFN-γ-STAT1-KLF4 signaling could provide a new therapeutic strategy to attenuate vessel restenosis.