Multimodal Mass Spectrometry Identifies a Conserved Protective Epitope in S. pyogenes Streptolysin O.

An important element of antibody-guided vaccine design is the use of neutralizing or opsonic monoclonal antibodies to define protective epitopes in their native three-dimensional conformation. Here, we demonstrate a multimodal mass spectrometry-based strategy for in-depth characterization of antigen-antibody complexes to enable the identification of protective epitopes using the cytolytic exotoxin Streptolysin O (SLO) from Streptococcus pyogenes as a showcase. We first discovered a monoclonal antibody with an undisclosed sequence capable of neutralizing SLO-mediated cytolysis. The amino acid sequence of both the antibody light and the heavy chain was determined using mass-spectrometry-based de novo sequencing, followed by chemical cross-linking mass spectrometry to generate distance constraints between the antibody fragment antigen-binding region and SLO. Subsequent integrative computational modeling revealed a discontinuous epitope located in domain 3 of SLO that was experimentally validated by hydrogen-deuterium exchange mass spectrometry and reverse engineering of the targeted epitope. The results show that the antibody inhibits SLO-mediated cytolysis by binding to a discontinuous epitope in domain 3, likely preventing oligomerization and subsequent secondary structure transitions critical for pore-formation. The epitope is highly conserved across >98% of the characterized S. pyogenes isolates, making it an attractive target for antibody-based therapy and vaccine design against severe streptococcal infections.

Multienzyme deep learning models improve peptide de novo sequencing by mass spectrometry proteomics.

Generating and analyzing overlapping peptides through multienzymatic digestion is an efficient procedure for de novo protein using from bottom-up mass spectrometry (MS). Despite improved instrumentation and software, de novo MS data analysis remains challenging. In recent years, deep learning models have represented a performance breakthrough. Incorporating that technology into de novo protein sequencing workflows require machine-learning models capable of handling highly diverse MS data. In this study, we analyzed the requirements for assembling such generalizable deep learning models by systemcally varying the composition and size of the training set. We assessed the generated models' performances using two test sets composed of peptides originating from the multienzyme digestion of samples from various species. The peptide recall values on the test sets showed that the deep learning models generated from a collection of highly N- and C-termini diverse peptides generalized 76% more over the termini-restricted ones. Moreover, expanding the training set's size by adding peptides from the multienzymatic digestion with five proteases of several species samples led to a 2-3 fold generalizability gain. Furthermore, we tested the applicability of these multienzyme deep learning (MEM) models by fully de novo sequencing the heavy and light monomeric chains of five commercial antibodies (mAbs). MEMs extracted over 10000 matching and overlapped peptides across six different proteases mAb samples, achieving a 100% sequence coverage for 8 of the ten polypeptide chains. We foretell that the MEMs' proven improvements to de novo analysis will positively impact several applications, such as analyzing samples of high complexity, unknown nature, or the peptidomics field.

Confounded association between proton pump inhibitor use and risk of biliary tract cancer: Result from three cohorts.

Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.

Separator with Nitrogen-Phosphorus Flame-Retardant for LiNix Coy Mn1- x - y O2 Cathode-Based Lithium-Ion Batteries.

With the pursuit of high-energy-density for lithium-ion batteries (LIBs), the hidden safety problems of batteries have gradually emerged. LiNix Coy Mn1- x - y O2 (NCM) is considered as an ideal cathode material to meet the urgent needs of high-energy-density batteries. However, the oxygen precipitation reaction of NCM cathode at high temperature brings serious safety concerns. In order to promote high-safety lithium-ion batteries, herein, a new type of flame-retardant separator is prepared using flame-retardant (melamine pyrophosphate, MPP) and thermal stable Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP). MPP takes the advantage of nitrogen-phosphorus synergistic effect upon the increased internal temperature of LIBs, including the dilution effect of noncombustible gas and the rapidly suppression of undesirable thermal runaway. The developed flame-retardant separators show negligible shrinkage over 200 °C and it takes only 0.54 s to extinguish the flame in the ignition test, which are much superior to commercial polyolefin separators. Moreover, pouch cells are assembled to demonstrate the application potential of PVDF-HFP/MPP separators and further verify the safety performance. It is anticipated that the separator with nitrogen-phosphorus flame-retardant can be extensively applied to various high-energy-density devices owing to simplicity and cost-effectiveness.

The associations between diode laser (810 nm) therapy and chronic wound healing and pain relief: Light into the chronic wound patient's life.

Chronic wounds have become one of the major issues in medicine today, the treatments for which include dressing changes, negative pressure wound therapy, hyperbaric oxygen, light irradiation, surgery and so forth. Nevertheless, the application of diode lasers in chronic wounds has rarely been reported. This retrospective cohort study aimed to evaluate the therapeutic effect of diode laser (810 nm) irradiation on chronic wounds. Eighty-nine patients were enrolled in the study. The control group (41 patients) received traditional dressing change therapy, while the diode laser treatment group (48 patients) were patients received additional treatment with diode laser (810 nm) irradiation for 10 min at each dressing change. Wound healing time was compared between two groups, while the pain relief index was creatively introduced to evaluate the effect of relieving wound pain, which was calculated by the difference in pain scores between the first and last dressing changes divided by the number of treatment days. The wound healing time of the diode laser treatment group was 22.71 ± 8.99 days, which was significantly shorter than that of the control group (37.44 ± 23.42 days). The pain relief index of the diode laser treatment group was 0.081 ± 0.055, which was significantly increased compared with that of the control group (0.057 ± 0.033). Our findings suggest that diode laser irradiation has the potential to promote healing in chronic wounds and relieve wound pain.

Siam Deep Feature KCF Method and Experimental Study for Pedestrian Tracking.

The tracking of a particular pedestrian is an important issue in computer vision to guarantee societal safety. Due to the limited computing performances of unmanned aerial vehicle (UAV) systems, the Correlation Filter (CF) algorithm has been widely used to perform the task of tracking. However, it has a fixed template size and cannot effectively solve the occlusion problem. Thus, a tracking-by-detection framework was designed in the current research. A lightweight YOLOv3-based (You Only Look Once version 3) mode which had Efficient Channel Attention (ECA) was integrated into the CF algorithm to provide deep features. In addition, a lightweight Siamese CNN with Cross Stage Partial (CSP) provided the representations of features learned from massive face images, allowing the target similarity in data association to be guaranteed. As a result, a Deep Feature Kernelized Correlation Filters method coupled with Siamese-CSP(Siam-DFKCF) was established to increase the tracking robustness. From the experimental results, it can be concluded that the anti-occlusion and re-tracking performance of the proposed method was increased. The tracking accuracy Distance Precision (DP) and Overlap Precision (OP) had been increased to 0.934 and 0.909 respectively in our test data.

The relationship between internal migration and the likelihood of high-risk pregnancy: Hukou system and high-risk pregnancies in China.

BACKGROUND: China has one of the world's largest internal migrant populations. The Chinese Hukou system is a unique household registration system that limits internal migrants in their access to basic urban public services, such as public health insurance and social assistance of their host city. In the case of female internal migrants, this may lead to high-risk pregnancies. The objective of this study is to assess the relationship between internal migrant status (Hukou) and the likelihood of high-risk pregnancies that occur in one large municipal-level obstetrics hospital in Shanghai, China. METHODS: Medical records data from the Shanghai First Maternity and Infant Hospital from January 1, 2013, to May 31, 2018, were used to analyze 133,358 live births for Shanghai natives (n = 83,872) and internal migrant women (n = 49,486). A propensity score matching approach was used in conjunction with logistic regression analysis to identify the role of internal migrant status (Hukou) on the likelihood of high-risk pregnancies. RESULTS: A greater likelihood of high-risk pregnancies were found among internal migrant women who moved from other parts of China to Shanghai. This effect was more obvious for women who gave birth for the first time and internal migrant women who were employed. CONCLUSION: The results show the effects of internal migrant status (Hukou) and the elevated likelihood of high-risk pregnancies among internal migrant women relative to their urban counterparts in Shanghai even after accounting for self-selection by employing the propensity score matching method. China's unique Hukou household registration system limits access to public services for internal migrant women and accordingly may account for the elevated likelihood of high-risk pregnancies.

Ring size changes in the development of class I HDAC inhibitors.

Five pathways involving different ring structures led to generation of fourteen thienylbenzamides (7-20) which display the structure-activity relationships of class I HDAC inhibitors. All the synthesised compounds inhibit HDAC1 and HDAC2 selectively over other isoforms and many inhibit DLD1 and HCT116 cells more effectively than a parent compound. Compounds 8 and 16 inhibit HCT116 cells by activation of the apoptosis pathway.

Pathogenic and antimicrobial resistance genes in Streptococcus oralis strains revealed by comparative genome analysis.

Streptococcus oralis is an early colonizer bacterium in dental plaques and is considered a potential pathogen of infective endocarditis (IE) disease. In this study, we built a complete genome map of Streptococcus oralis strain SOT, Streptococcus oralis strain SOD and Streptococcus infantis strain SO and performed comparative genomic analysis among these three strains. The results showed that there are five genomic islands (GIs) in strain SOT and one CRISPR in strain SOD. Each genome harbors various pathogenic genes related to diseases and drug resistance, while the antibiotic resistance genes in strains SOT and SOD were quite similar but different from those in strain SO. In addition, we identified 17 main virulence factors and capsule-related genes in three strains. These results suggest the pathogenic potential of Streptococcus strains, which lay a foundation for the prevention and treatment of a Streptococcus oralis infection.

The safety, feasibility, and cost-effectiveness of early laparoscopic cholecystectomy for patients with mild acute biliary pancreatitis: A meta-analysis.

BACKGROUND: It remains controversial on the optimal timing of cholecystectomy for patients with mild acute biliary pancreatitis. This study aimed at comparing the safety, feasibility, and cost-effectiveness of early laparoscopic cholecystectomy (ELC, within 72 h after admission) versus delayed laparoscopic cholecystectomy (DLC, beyond 72 h after admission) for patients with mild acute biliary pancreatitis. METHODS: We performed a systematic search in the following databases: PubMed, Embase, Web of Science, and Cochrane library. We only included articles from RCTs which designed to evaluate the complications, conversion to open cholecystectomy, recurrence of acute pancreatitis, the length of hospital stay, and costs between patients undergoing ELC and those undergoing DLC. We schemed to analyze data using STATA 15.0 with both the random-effects and the fixed-effect models. We computed relative risk (RR) and weighted mean difference (WMD) with 95% confidence intervals (CI) based on the intention-to-treat (ITT) analysis. RESULTS: A total of 4 studies involving 439 (215 vs 224) patients were included. The difference of complication rate [3.3% vs 3.2%; RR 1.03 (0.35, 3.01), P = 0.961] and rate of conversion to open cholecystectomy [3.8% vs 3.3%; RR 1.13 (0.37, 3.43), P = 0.830] are insignificant between patients who underwent ELC and ones who underwent DLC. The difference of rate of recurrence of acute pancreatitis is significant between ELC and DLC (2.17% vs 8.99%; RR 0.24 (0.08-0.70), P = 0.009). ELC does not shorten the length of hospital stay (random-effects model analysis: WMD -1.09 days (-2.67, 0.48), P = 0.173; fixed-effect model analysis: WMD -0.62 days (-1.00, -0.24), P = 0.001). CONCLUSION: Compared to DLC, ELC is equally safe and feasible both in complication rate and rate of conversion to open procedure, and significantly reduces the recurrence rate of acute pancreatitis. PROSPERO REGISTRATION NUMBER: CRD42018116239.

TRPV1 activation mitigates hypoxic injury in mouse cardiomyocytes by inducing autophagy through the AMPK signaling pathway.

Autophagy is a highly conserved self-protection mechanism that plays a crucial role in cardiovascular diseases. Cardiomyocyte hypoxic injury promotes oxidative stress and pathological alterations in the heart, although the interplay between these effects remains elusive. The transient receptor potential vanilloid 1 (TRPV1) ion channel is a nonselective cation channel that is activated in response to a variety of exogenous and endogenous physical and chemical stimuli. Here, we investigated the effects and mechanisms of action of TRPV1 on autophagy in hypoxic cardiomyocytes. In this study, primary cardiomyocytes isolated from C57 mice were subjected to hypoxic stress, and their expression of TRPV1 and adenosine 5'-monophosphate-activated protein kinase (AMPK) was regulated. The autophagy flux was assessed by Western blotting and immunofluorescence staining, and the cell viability was determined through Cell counting kit-8 assay and Lactate dehydrogenase assays. In addition, the calcium influx after the upregulation of TRPV1 expression in cardiomyocytes was examined. The results showed that the number of autophagosomes in cardiomyocytes was higher under hypoxic stress and that the blockade of autophagy flux aggravated hypoxic damage to cardiomyocytes. Moreover, the expression of TRPV1 was induced under hypoxic stress, and its upregulation by capsaicin improved the autophagy flux and protected cardiomyocytes from hypoxic damage, whereas the silencing of TRPV1 significantly attenuated autophagy. Our observations also revealed that AMPK signaling was activated and involved in TRPV1-induced autophagy in cardiomyocytes under hypoxic stress. Overall, this study demonstrates that TRPV1 activation mitigates hypoxic injury in cardiomyocytes by improving autophagy flux through the AMPK signaling pathway and highlights TRPV1 as a novel therapeutic target for the treatment of hypoxic cardiac disease.

Autophagy is required for the directed motility of keratinocytes driven by electric fields.

Endogenous wound electric fields (EFs), an important and fundamental occurrence of wound healing, profoundly influence the directed migration of keratinocytes. Although numerous studies have unveiled the signals responsible for EF-biased direction, the mechanisms by which EFs promote keratinocyte motility remains to be elucidated. In our study, EFs enhanced the directed migratory speed of keratinocytes by inducing autophagic activity, thereby facilitating skin barrier restoration. Initially, we found that electrical signals directed keratinocytes to the cathode with enhanced motility parameters [ i.e., trajectory distance, trajectory speed, displacement distance, and displacement speed ( Td/ t)] and more efficient migration (directionality and Td/ t along the x axis, among others). Meanwhile, EFs induced a time-dependent increase in autophagic activity in keratinocytes, with constant autophagic flux, accompanied by increased transcription of numerous autophagy-related genes. Deficiency in Atg5, a key protein necessary for autophagosome formation, led to significant reduction of autophagy, which was accompanied by a substantial reduction in EF-stimulated directed motility. These results demonstrated a causal relationship between autophagy and EF-directed migratory speed. In addition, both cell migration under normal conditions and EF-biased directionality were autophagy independent. Thus, our findings define autophagy as an important functional regulator of electrically enhanced directed motility, adding to a growing understanding of EFs.-Yan, T., Jiang, X., Lin, G., Tang, D., Zhang, J., Guo, X., Zhang, D., Zhang, Q., Jia, J., Huang, Y. Autophagy is required for the directed motility of keratinocytes driven by electric fields.

Long non-coding RNA TGLC15 advances hepatocellular carcinoma by stabilizing Sox4.

BACKGROUND: The hepatocellular carcinoma (HCC) belongs to a common malignancy especially in China. Recent data have clarified important roles of long non-coding RNAs (lncRNAs) in HCC. However, the role of a novel intergenic lncRNA termed TGLC15 is still elusive. METHODS: We screened for novel lncRNAs using lncRNA profiling. TGLC15 expression was quantified by qRT-PCR. In vitro experiments such as migration and viability assays were performed. In vivo implantation experiments were conducted to investigate tumorigenic functions of TGLC15. Combined RNA immunoprecipitation (RIP) and mass spectrometry (MS) were utilized to uncover Sox4 as TGLC15 binding protein. RESULTS: TGLC15 is significantly overexpressed in tumor tissues and HCC cell lines. Higher TGLC15 levels correlated with advanced malignant characteristics such as TNM stages, tumor size, and metastasis. TGLC15 advanced HCC migration and viability. The in vivo experiments supported that xenograft tumor growth and proliferation were facilitated by TGLC15 overexpression. Mechanistic studies showed that TGLC15 interacted with Sox4 and interaction between TGLC15 and Sox4 could stabilize Sox4 via reduction in proteasome-mediated degradation. CONCLUSIONS: Collectively, our data have identified a novel lncRNA TGLC15 during HCC development. The TGLC15-Sox4 signaling might be a potential target for pharmaceutical intervention.

A hybrid gene selection method based on gene scoring strategy and improved particle swarm optimization.

BACKGROUND: Gene selection is one of the critical steps in the course of the classification of microarray data. Since particle swarm optimization has no complicated evolutionary operators and fewer parameters need to be adjusted, it has been used increasingly as an effective technique for gene selection. Since particle swarm optimization is apt to converge to local minima which lead to premature convergence, some particle swarm optimization based gene selection methods may select non-optimal genes with high probability. To select predictive genes with low redundancy as well as not filtering out key genes is still a challenge. RESULTS: To obtain predictive genes with lower redundancy as well as overcome the deficiencies of traditional particle swarm optimization based gene selection methods, a hybrid gene selection method based on gene scoring strategy and improved particle swarm optimization is proposed in this paper. To select the genes highly related to out samples' classes, a gene scoring strategy based on randomization and extreme learning machine is proposed to filter much irrelevant genes. With the third-level gene pool established by multiple filter strategy, an improved particle swarm optimization is proposed to perform gene selection. In the improved particle swarm optimization, to decrease the likelihood of the premature of the swarm the Metropolis criterion of simulated annealing algorithm is introduced to update the particles, and the half of the swarm are reinitialized when the swarm is trapped into local minima. CONCLUSIONS: Combining the gene scoring strategy with the improved particle swarm optimization, the new method could select functional gene subsets which are significantly sensitive to the samples' classes. With the few discriminative genes selected by the proposed method, extreme learning machine and support vector machine classifiers achieve much high prediction accuracy on several public microarray data, which in turn verifies the efficiency and effectiveness of the proposed gene selection method.

MicroRNA-1271 functions as a potential tumor suppressor in hepatitis B virus-associated hepatocellular carcinoma through the AMPK signaling pathway by binding to CCNA1.

Hepatocellular carcinoma (HCC) is mainly associated with hepatitis B virus (HBV) infection and characterized by metastasizing and infiltrating adjacent and distant tissues. Notably, microRNA-1271 (miR-1271) is a tumor suppressor in various cancers. Therefore, we evaluate the ability of miR-1271 to influence cell proliferation, migration, invasion, and apoptosis in HBV-associated HCC through the Adenosine monophosphate-activated protein kinase (AMPK) signaling pathway via targeting CCNA1. HBV-associated HCC and adjacent normal tissues were collected to identify the expression of miR-1271 and CCNA1. To verify the relationship between miR-1271 and CCNA1, we used bioinformatics prediction and the dual-luciferase reporter gene assay. The effects of miR-1271 on HBV-associated HCC cell behaviors were investigated by treatment of the miR-1271 mimic, the miR-1271 inhibitor, or small interfering RNA against CCNA1. The HBV-DNA quantitative assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromid assay, scratch test, transwell assay, and flow cytometry were used to detect HBV-DNA replication, cell proliferation, invasion, migration, and apoptosis. MiR-1271 showed a low expression, whereas CCNA1 showed a high expression in HBV-associated HCC tissues. We identified that miR-1271 targeted and negatively regulated CCNA1. Upregulated miR-1271 and downregulated CCNA1 inhibited the HBV-associated HCC cell HBV-DNA replication, proliferation, migration, and invasion, while accelerating apoptosis by activating the AMPK signaling pathway. MiR-1271 promotes the activation of the AMPK signaling pathway by binding to CCNA1, whereby miR-1271 suppresses HBV-associated HCC progression. This study points to a potential therapeutic approach of downregulation of miR-1271 in HBV-associated HCC treatment.

In Situ Construction of a Two-Dimensional Heterojunction by Stacking Bismuth Trioxide Nanoplates with Reduced Graphene Oxide for Enhanced Water Oxidation Performance.

In this study, a two-dimensional heterojunction consisting of bismuth trioxide nanoplates and layered reduced graphene oxide was synthesized using a facile In Situ growth route. A series of characterization tests indicated that the reduction of graphene oxide played a key role as an electron collector for enhancing photoinduced charge carrier separation efficiency. Thus, the as-prepared reduced graphene oxide/bismuth trioxide composite exhibited enhanced photocatalytic water oxidation, which was higher than that of pristine bismuth trioxide under simulated solar light irradiation. Furthermore, the photoelectrochemical properties of the prepared hybrid system were investigated to understand the transfer of photoinduced electrons and holes between layered reduced graphene oxide and bismuth trioxide nanoplates. Thus, this strategy provided an efficient approach for the fabrication of graphene composites containing hierarchical ternary oxides for photocatalysis.

The effects of compulsory health insurance on birth outcomes: evidence from China's UEBMI scheme.

BACKGROUND: Despite extensive research concerning the impact of health insurance on the advancement of infant health in developed countries, few studies have adjusted their results for potential confounding due to adverse selection in insurance coverage, wherein those who anticipate a need for health services tend to be the ones that acquire insurance. The presence of compulsory health insurance in China, such as the Urban Employee Basic Medical Insurance (UEBMI) scheme may provide an opportunity to estimate the effect of health insurance on infant health, by reducing the endogeneity problem into insurance due to the adverse selection. The objective is to assess the relationship between UEBMI and infant health outcomes in one sizeable municipal-level obstetrics hospital in Shanghai, East China. METHODS: Medical records data from the Shanghai First Maternity and Infant Hospital from January 1, 2013 to April 30, 2019 were used to form an analysis dataset of 160,429 live births which was comprised of Shanghai residents with UEBMI coverage (n = 101,153) and women without any insurance coverage (n = 59,276). A propensity score matching approach using conjoint quantile regression and probit regression models was used to eliminate latent endogeneity of UEBMI coverage in order to garner robust results. Further analysis stratified by maternal migrant status was conducted to further assess the sensitivity of the findings to distinct patient subgroups. RESULTS: The UEBMI scheme was shown to be associated with improvements in infant birth outcomes. The scheme was associated with: an increase in birth weight of about 30 g (p <  0.001, 95% CI 23.908-35.295). This finding was evident in other five different birth outcomes (premature birth, low birth weight, very low birth weight, low Apgar score, and an abnormal health condition at birth). After stratifying by migrant status, the UEBMI was shown to have a greater effect on migrants compared to local residents of Shanghai. CONCLUSIONS: Our findings suggest that health insurance coverage for pregnant women, especially for migrants, has the potential to significantly and directly improve infant health outcomes. Further research is required to determine whether these findings can be replicated for other Chinese jurisdictions.

FG-4592 Accelerates Cutaneous Wound Healing by Epidermal Stem Cell Activation via HIF-1α Stabilization.

BACKGROUND/AIMS: Regional hypoxia promptly develops after trauma because of microvascular injury and increased oxygen consumption. This acute hypoxia plays a positive role in early skin wound healing. One of the mechanisms underlying the beneficial effects of acute hypoxia on wound healing may be increased hypoxia-inducible factor-1 (HIF-1α) expression. HIF-1α may affect the wound-healing process through many aspects, including angiogenesis, metabolism, and extra-cellular matrix synthesis and remodelling. Epidermal stem cells (EpSCs) are important participants in wound repair; however, whether these cells are regulated by hypoxia is unclear. This study aimed to elucidate the regulatory mechanism by which hypoxia acts on EpSCs. METHODS: CCK8 assays, western blots and live cell station observation were employed to compare the viability, proliferation and motility of EpSCs cultured under normoxic conditions (21% O2) with those cultured under hypoxic conditions (2% O2). Moreover, we used FG-4592 (a prolyl hydroxylase inhibitor that stabilizes HIF-1α in normoxia), KC7F2 (a selective inhibitor of HIF-1α transcription) and siRNA against HIF-1α to regulate HIF-1α expression. RESULTS: Acute hypoxia caused EpSCs to switch from a quiescent state to an activated state with higher viability and motility, as well as an earlier proliferation peak. We demonstrated that the HIF-1 signalling pathway mediated hypoxia-induced activation of EpSCs. Finally, the in vivo experiments showed that exogenous FG-4592 effectively accelerates wound healing, shortens healing times and even induces epidermal hyperplasia. CONCLUSION: This study demonstrated that both hypoxia and exogenous FG-4592 improve EpSC proliferation and motility by stabilizing HIF-1α, and its results suggest that HIF-1α is an important target through which wound healing can be accelerated and that FG-4592 is a promising new drug for wound repair.

Neutrophil infiltration mediated by CXCL5 accumulation in the laryngeal squamous cell carcinoma microenvironment: A mechanism by which tumour cells escape immune surveillance.

The CXCL5 chemokine is important for neutrophil accumulation in tumour tissues. In this report, we attempted to clarify whether and how infiltrating tumour-associated neutrophils (TANs) in laryngeal squamous cell carcinoma (LSCC) affect the proliferation and activation of T cells. We examined chemokine expression by real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA) and performed an immunohistochemical analysis of LSCC microarrays. The relationship between CXCL5 and CD66b (a neutrophil marker) was investigated by immunofluorescence staining. We found that CXCL5 was upregulated in LSCC tissues, whereas CXCL5 levels were decreased in LSCC patient serum. Furthermore, high levels of CXCL5 were significantly correlated with intratumoural neutrophil infiltration. Compared with peripheral blood neutrophils (PBNs), TANs significantly inhibited T cell proliferation and decreased IFN-γ and TNF-α secretion. These data suggest that excessive neutrophil infiltration is associated with advanced clinical stages of LSCC (T3 or T4, III or IV, and N1 or N2).

BNIP3 promotes the motility and migration of keratinocyte under hypoxia.

The migration of keratinocytes from wound margins plays a critical role in the re-epithelialization of skin wounds. Hypoxia occurs immediately after injury and acts as an early stimulus to initiate the healing processes. Although our previous studies have revealed that hypoxia promotes keratinocyte migration, the precise mechanisms involved remain unclear. Here, we found that BNIP3 expression was upregulated in hypoxic keratinocytes, and BNIP3 silencing suppressed hypoxia-induced cell migration. Additionally, hypoxia activated the focal adhesion kinase (FAK) pathway through upregulation of BNIP3, while FAK inhibition attenuated hypoxic keratinocyte migration. Here, we conclusively demonstrate a novel role for BNIP3 in hypoxia-induced keratinocyte migration. Furthermore, we provide a new perspective on the molecular mechanisms of wound healing and identify BNIP3 as a potential new molecular target for clinical treatments to enhance wound healing.