mHealth-Based Gamification Interventions Among Men Who Have Sex With Men in the HIV Prevention and Care Continuum: Systematic Review and Meta-Analysis.

Background: In the past few years, a burgeoning interest has emerged in applying gamification to promote desired health behaviors. However, little is known about the effectiveness of such applications in the HIV prevention and care continuum among men who have sex with men (MSM). Objective: This study aims to summarize and evaluate research on the effectiveness of gamification on the HIV prevention and care continuum, including HIV-testing promotion; condomless anal sex (CAS) reduction; and uptake of and adherence to pre-exposure prophylaxis (PrEP), postexposure prophylaxis (PEP), and antiretroviral therapy (ART). Methods: We comprehensively searched PubMed, Embase, the Cochrane Library, Web of Science, Scopus, and the Journal of Medical Internet Research and its sister journals for studies published in English and Chinese from inception to January 2024. Eligible studies were included when they used gamified interventions with an active or inactive control group and assessed at least one of the following outcomes: HIV testing; CAS; and uptake of and adherence to PrEP, PEP, and ART. During the meta-analysis, a random-effects model was applied. Two reviewers independently assessed the quality and risk of bias of each included study. Results: The systematic review identified 26 studies, including 10 randomized controlled trials (RCTs). The results indicated that gamified digital interventions had been applied to various HIV outcomes, such as HIV testing, CAS, PrEP uptake and adherence, PEP uptake, and ART adherence. Most of the studies were conducted in the United States (n=19, 73%). The most frequently used game component was gaining points, followed by challenges. The meta-analysis showed gamification interventions could reduce the number of CAS acts at the 3-month follow-up (n=2 RCTs; incidence rate ratio 0.62, 95% CI 0.44-0.88). The meta-analysis also suggested an effective but nonstatistically significant effect of PrEP adherence at the 3-month follow-up (n=3 RCTs; risk ratio 1.16, 95% CI 0.96-1.38) and 6-month follow-up (n=4 RCTs; risk ratio 1.28, 95% CI 0.89-1.84). Only 1 pilot RCT was designed to evaluate the effectiveness of a gamified app in promoting HIV testing and PrEP uptake. No RCT was conducted to evaluate the effect of the gamified digital intervention on PEP uptake and adherence, and ART initiation among MSM. Conclusions: Our findings suggest the short-term effect of gamified digital interventions on lowering the number of CAS acts in MSM. Further well-powered studies are still needed to evaluate the effect of the gamified digital intervention on HIV testing, PrEP uptake, PEP initiation and adherence, and ART initiation in MSM.

Digital remote monitoring for screening and early detection of urinary tract infections.

Urinary Tract Infections (UTIs) are one of the most prevalent bacterial infections in older adults and a significant contributor to unplanned hospital admissions in People Living with Dementia (PLWD), with early detection being crucial due to the predicament of reporting symptoms and limited help-seeking behaviour. The most common diagnostic tool is urine sample analysis, which can be time-consuming and is only employed where UTI clinical suspicion exists. In this method development and proof-of-concept study, participants living with dementia were monitored via low-cost devices in the home that passively measure activity, sleep, and nocturnal physiology. Using 27828 person-days of remote monitoring data (from 117 participants), we engineered features representing symptoms used for diagnosing a UTI. We then evaluate explainable machine learning techniques in passively calculating UTI risk and perform stratification on scores to support clinical translation and allow control over the balance between alert rate and sensitivity and specificity. The proposed UTI algorithm achieves a sensitivity of 65.3% (95% Confidence Interval (CI) = 64.3-66.2) and specificity of 70.9% (68.6-73.1) when predicting UTIs on unseen participants and after risk stratification, a sensitivity of 74.7% (67.9-81.5) and specificity of 87.9% (85.0-90.9). In addition, feature importance methods reveal that the largest contributions to the predictions were bathroom visit statistics, night-time respiratory rate, and the number of previous UTI events, aligning with the literature. Our machine learning method alerts clinicians of UTI risk in subjects, enabling earlier detection and enhanced screening when considering treatment.

Telomerase reverse transcriptase restores pancreatic microcirculation profiles and attenuates endothelial dysfunction by inhibiting mitochondrial superoxide production: A potential target for acute pancreatitis therapy.

BACKGROUND: Acute pancreatitis (AP) is a potentially lethal disease related to prominent microcirculation dysfunction. Pancreatic microvascular endothelial dysfunction enhances oxidative stress with tissue damage. Increased superoxide production disrupts endothelial junction integrity and increases endothelial permeability. Endothelial mitochondrial ROS (mtROS) represent a major intracellular source of superoxide anions. The non-canonical function of telomerase reverse transcriptase (TERT) involves the maintenance of cellular redox homeostasis in somatic tissues. METHODS: We investigated whether TERT restores microcirculation dysfunction and attenuates the endothelium injury by inhibiting superoxide production during AP progression. We established TERT transgenic and TERT knock-down mice and used cerulein (CER) and lipopolysaccharide (LPS) injections to induce AP models. In addition, we exposed HUVECs to LPS following TERT overexpression or silencing to explore the role of TERT in endothelial dysfunction. We also performed flow cytometry and confocal microscopy assays by using HUVECs. And a mtROS inhibitor, MitoTempo, was used to scavenge mitochondria superoxide and alkyl. RESULTS: TERT transgenic mice were found to have restored pancreatic microcirculation profiles and microvascular endothelial morphology compared with wild-type mice under cerulein injection. In contrast, TERT silencing displayed the opposite effect in response to cerulein. Subsequently, we showed that TERT overexpression attenuates mtROS production and mitochondrial dysfunction during LPS-stimulated endothelial dysfunction. Furthermore, we found that TERT overexpression maintains the balance between mitochondrial contents and ATP level during endothelial dysfunction. In addition, the protective trend of MitoTempo is impeded after TERT silencing. CONCLUSION: TERT restores pancreatic microcirculation dysfunction and attenuates microvascular endothelium lesions by inhibiting the increase of superoxide production and mitochondrial dysfunction.

Extracellular Electron Transfer in Microbiologically Influenced Corrosion of 201 Stainless Steel by Shewanella algae.

The microbiologically influenced corrosion of 201 stainless steel by Shewanella algae was investigated via modulating the concentration of fumarate (electron acceptor) in the medium and constructing mutant strains induced by ΔOmcA. The ICP-MS and electrochemical tests showed that the presence of S. algae enhanced the degradation of the passive film; the lack of an electron acceptor further aggravated the effect and mainly affected the early stage of MIC. The electrochemical tests and atomic force microscopy characterization revealed that the ability of ΔOmcA to transfer electrons to the passive film was significantly reduced in the absence of the c-type cytochrome OmcA related to EET progress, leading to the lower corrosion rate of the steel.

DELFMUT: duplex sequencing-oriented depth estimation model for stable detection of low-frequency mutations.

Duplex sequencing technology has been widely used in the detection of low-frequency mutations in circulating tumor deoxyribonucleic acid (DNA), but how to determine the sequencing depth and other experimental parameters to ensure the stable detection of low-frequency mutations is still an urgent problem to be solved. The mutation detection rules of duplex sequencing constrain not only the number of mutated templates but also the number of mutation-supportive reads corresponding to each forward and reverse strand of the mutated templates. To tackle this problem, we proposed a Depth Estimation model for stable detection of Low-Frequency MUTations in duplex sequencing (DELFMUT), which models the identity correspondence and quantitative relationships between templates and reads using the zero-truncated negative binomial distribution without considering the sequences composed of bases. The results of DELFMUT were verified by real duplex sequencing data. In the case of known mutation frequency and mutation detection rule, DELFMUT can recommend the combinations of DNA input and sequencing depth to guarantee the stable detection of mutations, and it has a great application value in guiding the experimental parameter setting of duplex sequencing technology.

Angiotensin-(1-7) ameliorates intestinal barrier dysfunction by activating the Keap1/Nrf2/HO-1 signaling pathway in acute pancreatitis.

BACKGROUND: Intestinal barrier dysfunction is a serious complication associated with acute pancreatitis (AP). Angiotensin (Ang)-(1-7) plays a protective role in the intestinal barrier, but the underlying mechanism remains clear. This study investigated the impact of Ang-(1-7) on AP-induced intestinal dysfunction and its involvement in the Keap1/Nrf2/HO-1 pathway. METHODS AND RESULTS: We studied caerulein- and lipopolysaccharide (LPS)-induced AP in mice and an epithelial cell line (IEC-6) from the small intestinal crypt of rats. Ang-(1-7) was administered orally or via the tail vein. IEC-6 cells were divided into five groups: control; LPS; LPS + Ang-(1-7); LPS + Ang-(1-7) + ML385 (an Nrf2 inhibitor); and LPS + ML385. Pancreatic and intestinal histopathology scores were analyzed using the Schmidt and Chiu scores. The expression of intestinal barrier-associated proteins and Keap1/Nrf2/HO-1 pathway constituents was assessed by RT-PCR and western blotting. The peroxide and antioxidant activities in the IEC-6 cells were measured. Compared to those in AP mice, Ang-(1-7) diminished the intestinal levels of proinflammatory factors (interleukin-1ß and tumor necrosis factor α) and serum levels of intestine permeability (D-lactate). Ang-(1-7) increased the expression of barrier-associated proteins (aquaporin-1, claudin-1, and occludin) compared to those in the AP and LPS group. Moreover, Ang-(1-7) promoted the Keap/Nrf2/HO-1 pathway, which resulted in significantly reduced malondialdehyde and increased superoxide dismutase levels.. However, ML385 abolished the effects of Ang-(1-7) on barrier-associated proteins and reversed the Keap1/Nrf2/HO-1 pathway. CONCLUSIONS: Ang-(1-7) reduces AP-induced intestinal inflammation and oxidative injuries by activating the Keap1/Nrf2/HO-1 pathway.

SKIL/SnoN attenuates TGF-ß1/SMAD signaling-dependent collagen synthesis in hepatic fibrosis.

The ski-related novel gene (SnoN), encoded by the SKIL gene, has been shown to negatively regulated transforming growth factor-ß1 (TGF-ß1) signaling pathway. However, the roles of SnoN in hepatic stellate cell (HSC) activation and hepatic fibrosis (HF) are still unclear. To evaluate the role of SnoN in HF, we combined bulk RNA sequencing analysis and single-cell RNA sequencing analysis to analyse patients with HF. The role of SKIL/SnoN was verified using liver samples from rat model transfected HSC-T6 and LX-2 cell lines. Immunohistochemistry, immunofluorescence, PCR, and western blotting techniques were used to demonstrate the expression of SnoN and its regulatory effects on TGF-ß1 signaling in fibrotic liver tissues and cells. Furthermore, we constructed competitive endogenous RNA regulatory network and potential drug network associated with the SnoN gene. We identified SKIL gene as a differentially expressed gene in hepatic fibrosis. SnoN protein was found to be widely expressed in the cytoplasm of normal hepatic tissues, whereas it was almost absent in HF tissues. In the rat group subjected to bile duct ligation (BDL), SnoN protein expression decreased, while TGF-ß1, collagen III, tissue inhibitor of metalloproteinase 1 (TIMP-1), and fibronectin levels increased. We observed the interaction of SnoN with p-SMAD2 and p-SMAD3 in the cytoplasm. Following SnoN overexpression, apoptosis of HSCs was promoted, and the expression of HF-associated proteins, including collagen I, collagen III, and TIMP-1, was reduced. Conversely, downregulation of SnoN inhibited HSC apoptosis, increased collagen III and TIMP-1 levels, and decreased matrix metalloproteinase 13 (MMP-13) expression. In conclusion, SnoN expression is downregulated in fibrotic livers, and could attenuate TGF-ß1/SMADs signaling-dependent de-repression of collagen synthesis.

Effect of Cu addition to AISI 8630 steel on the resistance to microbial corrosion.

Low-alloy, high-strength structural steel AISI 8630 is exposed to severe microbiologically influenced corrosion (MIC) in its application environment. To address this issue, we independently designed and developed an AISI 8630 steel containing 0.4 wt% Cu (Cu-AISI 8630) to exploit the Cu antimicrobial effect. The corrosion behavior of two steels in the presence of marine Pseudomonas aeruginosa biofilm was explored by analyzing weight loss, electrochemical tests, SEM images, corrosion pit dimensions, and corrosion products. The electrochemical test results showed an increase in Rp and a significant positive shift in Ecorr for Cu-AISI 8630 steel compared to AISI 8630 steel during the immersion cycles. A comparison of the pit morphology of AISI 8630 steel and Cu-AISI 8630 steel after 14 days showed that the maximum MIC pit depth was significantly reduced in the latter compared to the former (3.65 µm vs 9.47 µm). The XPS results showed that protective Cu2O and CuO layers were formed on the surface of Cu-AISI 8630 steel. The experimental results show that Cu improves the MIC resistance of Pseudomonas aeruginosa biofilms significantly.

Performance of HIV Infection Prediction Models in Men Who Have Sex with Men: A Systematic Review and Meta-Analysis.

Effective ways to identify and predict men who have sex with men (MSM) at substantial risk for HIV is a global priority. HIV risk assessment tools can improve individual risk awareness and subsequent health-seeking actions. We sought to identify and characterize the performance of HIV infection risk prediction models in MSM through systematic review and meta-analysis. PubMed, Embase, and The Cochrane Library were searched. Eighteen HIV infection risk assessment models with a total of 151,422 participants and 3643 HIV cases were identified, eight of which have been externally validated by at least one study (HIRI-MSM, Menza Score, SDET Score, Li Model, DHRS, Amsterdam Score, SexPro model, and UMRSS). The number of predictor variables in each model ranged from three to 12, age, the number of male sexual partners, unprotected receptive anal intercourse, recreational drug usage (amphetamines, poppers), and sexually transmitted infections were critical scoring variables. All eight externally validated models performed well in terms of discrimination, with the pooled area under the receiver operating characteristic curve (AUC) ranging from 0.62 (95%CI: 0.51 to 0.73, SDET Score) to 0.83 (95%CI: 0.48 to 0.99, Amsterdam Score). Calibration performance was only reported in 10 studies (35.7%, 10/28). The HIV infection risk prediction models showed moderate-to-good discrimination performance. Validation of prediction models across different geographic and ethnic environments is needed to ensure their real-world application.

Creatine ameliorates high-fat diet-induced obesity by regulation of lipolysis and lipophagy in brown adipose tissue and liver.

Diet-induced obesity in mice and humans is commonly associated with an imbalance between energy intake and expenditure. Reportedly, creatine can enhance energy expenditure in brown adipose tissue and reduce hepatic triglycerides accumulation; however, the molecular mechanism underlying the role of exogenous creatine supplementation in regulating lipid droplet mobilization remains elusive. Herein, we employed a high-fat diet (HFD)- induced mouse model to investigate the role of creatine in regulating lipolysis and lipophagy in brown adipose tissue and the liver. Exogenous creatine supplementation ameliorated HFD-induced obesity, increased insulin sensitivity and improved glucose homeostasis. Creatine supplementation enhanced the expression of uncoupling protein 1 (UCP1), cell death-inducing DNA fragmentation factor alpha-like effector A (CIDEA), and other brown adipose tissue-specific thermogenic genes Cpt1a, Gyk, and Pgc1ß in brown adipose tissue. Furthermore, creatine inhibited the expression of CIDEA, which promotes hepatic lipid accumulation. Creatine stimulated the expression of triglyceride lipase adipose triglyceride lipase, and phospho-hormone-sensitive lipase (HSL) induced increased lipolysis in brown adipose tissue and the liver. Meanwhile, reduced LC3B expression was accompanied by an increased level of p62 in HFD-fed mice, indicating diminished basal autophagy in brown adipose tissue and the liver; however, creatine enhanced P62/LC3B induced lipophagy in brown adipose tissue and the liver. Collectively, our results suggest that creatine may function as a brown adipose tissue activator to increase whole-body energy metabolism via coordinated lipolysis and lipophagy in brown adipose tissue and the liver.

LncReader: identification of dual functional long noncoding RNAs using a multi-head self-attention mechanism.

Long noncoding ribonucleic acids (RNAs; LncRNAs) endowed with both protein-coding and noncoding functions are referred to as 'dual functional lncRNAs'. Recently, dual functional lncRNAs have been intensively studied and identified as involved in various fundamental cellular processes. However, apart from time-consuming and cell-type-specific experiments, there is virtually no in silico method for predicting the identity of dual functional lncRNAs. Here, we developed a deep-learning model with a multi-head self-attention mechanism, LncReader, to identify dual functional lncRNAs. Our data demonstrated that LncReader showed multiple advantages compared to various classical machine learning methods using benchmark datasets from our previously reported cncRNAdb project. Moreover, to obtain independent in-house datasets for robust testing, mass spectrometry proteomics combined with RNA-seq and Ribo-seq were applied in four leukaemia cell lines, which further confirmed that LncReader achieved the best performance compared to other tools. Therefore, LncReader provides an accurate and practical tool that enables fast dual functional lncRNA identification.

An integrated online-to-offline model for HIV post-exposure prophylaxis (O2O-PEP) scale-up among men who have sex with men (MSM): Protocol for developing a pilot randomized controlled trial.

Background: HIV post-exposure prophylaxis (PEP) is an evidence-based biomedical HIV prevention strategy consisting of a 28-day course of highly active antiretroviral therapy after recent potential exposure to HIV. However, awareness and uptake of PEP among men who have sex with men (MSM) are very low. Innovative and effective methods are needed to support PEP implementation among MSM. This work reports a protocol to design and evaluate an online-to-offline-based delivery model for HIV PEP uptake (O2O-PEP) in Chinese MSM. Methods and analysis: This will be a two-phase study. In phase 1, we will develop an O2O-PEP model delivered through the WeChat mini-app (an app built into the WeChat platform). The O2O-PEP model initially includes four core components: a gamification-based education package for PEP, an online HIV risk assessment tool, a free online booking system for PEP initiation, and offline PEP prescription in the study hospitals. In phase 2, a two-arm pilot stratified randomized controlled trial comparing the O2O-PEP group with the standard care group will be designed to assess the feasibility, usability, and preliminary evidence of the efficacy of the O2O-PEP model in increasing PEP uptake among Chinese MSM. Model feasibility and usability will be further explored for broader model implementation. Discussion: The O2O-PEP model is one of the first interventions in China aiming to promote PEP initiation in Chinese MSM. Components in the O2O-PEP model could assist MSM in better understanding their HIV infection risk and increasing accessibility of PEP. Moreover, coupled with online and offline recruitment, the O2O-PEP model has great potential to reach and engage MSM who are not involved in care by traditional methods. Clinical trial registration: No. ChiCTR2200062538.

Gene-gene interaction detection with deep learning.

The extent to which genetic interactions affect observed phenotypes is generally unknown because current interaction detection approaches only consider simple interactions between top SNPs of genes. We introduce an open-source framework for increasing the power of interaction detection by considering all SNPs within a selected set of genes and complex interactions between them, beyond only the currently considered multiplicative relationships. In brief, the relation between SNPs and a phenotype is captured by a neural network, and the interactions are quantified by Shapley scores between hidden nodes, which are gene representations that optimally combine information from the corresponding SNPs. Additionally, we design a permutation procedure tailored for neural networks to assess the significance of interactions, which outperformed existing alternatives on simulated datasets with complex interactions, and in a cholesterol study on the UK Biobank it detected nine interactions which replicated on an independent FINRISK dataset.

Revealing spatiotemporal interaction patterns behind complex cities.

Cities are typical dynamic complex systems that connect people and facilitate interactions. Revealing general collective patterns behind spatiotemporal interactions between residents is crucial for various urban studies, of which we are still lacking a comprehensive understanding. Massive cellphone data enable us to construct interaction networks based on spatiotemporal co-occurrence of individuals. The rank-size distributions of dynamic population of locations in all unit time windows are stable, although people are almost constantly moving in cities and hot-spots that attract people are changing over time in a day. A larger city is of a stronger heterogeneity as indicated by a larger scaling exponent. After aggregating spatiotemporal interaction networks over consecutive time windows, we reveal a switching behavior of cities between two states. During the "active" state, the whole city is concentrated in fewer larger communities, while in the "inactive" state, people are scattered in smaller communities. Above discoveries are universal over three cities across continents. In addition, a city stays in an active state for a longer time when its population grows larger. Spatiotemporal interaction segregation can be well approximated by residential patterns only in smaller cities. In addition, we propose a temporal-population-weighted-opportunity model by integrating a time-dependent departure probability to make dynamic predictions on human mobility, which can reasonably well explain the observed patterns of spatiotemporal interactions in cities.

Effect Evaluation and Action Mechanism Analysis of "Profile Control + Plugging Removal" after Chemical Flooding.

The existing plugging removal operation in JZ9-3 oilfield has the disadvantages of small amount of plugging remover, fast injection speed, and short construction time. Under the condition of injection well suction profile reversal, plugging remover is difficult to enter the low permeability part and play the role of deep plugging removal. In order to improve the plugging removal effect, this paper used the physical simulation method to carry out the experimental study and mechanism analysis on the effect of water flooding, chemical flooding, and plugging removal measures of the multi-layer system combination model. The results showed that the recovery of general plugging removal after chemical flooding increases by only 0.70%, while the recovery of 'profile control + plugging removal' increases by '9.34% + 2.59%', and the amount of produced liquid decreases by more than 40%. It can be seen that the combined operation of profile control and plugging removal has dual effects of plugging and dredging and synergistic effect, which not only expands the swept volume, but also reduces the inefficient and ineffective cycles. On this basis, the optimization design and effect prediction of the target well W4-2 plugging removal scheme were carried out by using the numerical simulation method. Recommended scheme: inorganic gel profile control agent volume 13,243.6 m3, produced by the main agent (Na2O·nSiO2), isolation fluid (Water), and auxiliary agent (CaCl2) through multiple rounds of alternating injection into the reservoir. The plug removal agent (K2S2O8) injection volume is 100 m3, the concentration is 0.8%. The post-implementation 'Output/Input' ratio is expected to be 3.7.

The effect of riboflavin on the microbiologically influenced corrosion of pure iron by Shewanella oneidensis MR-1.

The microbiologically influenced corrosion of pure iron was investigated in the presence of Shewanella oneidensis MR-1 with various levels of exogenous riboflavin (RF) serving as electron shuttles for extracellular electron transfer (EET). With more RF available, a larger and denser phosphate layer was formed on the surface of pure iron by the bacteria. The results of electrochemical impedance spectroscopy, linear polarization resistance and potentiodynamic polarization tests showed that the product layer provided good corrosion protection to the pure iron. Using electrochemical noise, we observed that the addition of RF accelerated the corrosion at the initial stage of immersion, thereby accelerating the deposition of products to form a protective layer subsequently.

LDL receptor-related protein 1 (LRP1), a novel target for opening the blood-labyrinth barrier (BLB).

Inner ear disorders are a cluster of diseases that cause hearing loss in more than 1.5 billion people worldwide. However, the presence of the blood-labyrinth barrier (BLB) on the surface of the inner ear capillaries greatly hinders the effectiveness of systemic drugs for prevention and intervention due to the low permeability, which restricts the entry of most drug compounds from the bloodstream into the inner ear tissue. Here, we report the finding of a novel receptor, low-density lipoprotein receptor-related protein 1 (LRP1), that is expressed on the BLB, as a potential target for shuttling therapeutics across this barrier. As a proof-of-concept, we developed an LRP1-binding peptide, IETP2, and covalently conjugated a series of model small-molecule compounds to it, including potential drugs and imaging agents. All compounds were successfully delivered into the inner ear and inner ear lymph, indicating that targeting the receptor LRP1 is a promising strategy to enhance the permeability of the BLB. The discovery of the receptor LRP1 will illuminate developing strategies for crossing the BLB and for improving systemic drug delivery for inner ear disorders.

Dual Responsive Molecular-Arm Modified Single Enzyme Molecules for Efficient Cellulose Hydrolysis.

Immobilizing cellulase for improving its hydrolysis activity and recyclability is critical for a cost-effective and environment-friendly conversion of cellulosic biomass. However, developing a strategy for achieving a high mass-transfer rate and good separation efficiency between an insoluble cellulose substrate and cellulase remains difficult. Instead of the traditional method, a single-enzyme molecular modification method is used in this study. To modify cellulase and provide it with a temperature-pH dual responsive property, systemized poly(acrylic-acrylonitrile) (PAA-PAN) molecular arms are used. The modified cellulase can reversibly transform between liquid and solid phases. In the liquid phase, the modified cellulase can adjust its active center, increasing its hydrolysis efficiency and separation efficiency. Cellulase and glucose products can be easily separated in the solid phase, allowing the reuse of cellulase. The results show that the modified cellulase's hydrolysis efficiency is comparable to that of free cellulase and that the modified enzyme preserves more than 60% of its initial activity after 15 batches of efficient hydrolysis. Thus, the proposed modification route considerably lowers the cost of cellulose enzymatic hydrolysis.

Angiotensin-(1-7) promotes mitochondrial translocation of human telomerase reverse transcriptase in HUVECs through the TOM20 complex.

BACKGROUND: Angiotensin (Ang) (1-7) is a vasodilator peptide that ameliorates microcirculation dysfunction, increases telomerase activity in cells, and exerts vasodilatory, anti-inflammatory, antioxidative stress, and antiapoptotic effects. Mitochondrial human telomerase reverse transcriptase (hTERT) plays an important role in the processes of antiapoptosis, antioxidative stress, and immortalization. This study aimed to investigate the effect of Ang(1-7) on the mitochondrial translocation of hTERT. METHODS: An in vitro model of lipopolysaccharide (LPS)-induced inflammation was established in human umbilical vein endothelial cells (HUVECs). Ang(1-7) was added to cells 30 min before LPS stimulation. The Ang(1-7)/Mas receptor antagonist A779 plus Ang(1-7) were added to the cells 30 min before LPS stimulation. The translocase outer membrane (TOM)20-overexpression HUVECs (HUVEC-TOM20OE), TOM20-knockdown HUVECs (HUVEC-TOM20KD), and the corresponding negative control cell lines were constructed by lentiviral transfection of HUVECs. Cells subjected to LPS stimulation alone, LPS plus Ang(1-7), LPS plus Ang(1-7) and A779, vehicle and no treatment were termed the LPS group, LPS + A group, LPS + A + A779 group, Con group and Neg group, respectively. Immunofluorescence staining was used to detect the distribution of hTERT in the nuclei and mitochondria of HUVECs and to locate TOM20, TOM40, and translocase inner membrane (TIM)23 in the mitochondria. The protein expression levels of total hTERT, mitochondrial hTERT, TOM20, TOM40, and TIM23 were measured by Western blot. The mRNA expression levels of hTERT, TOM20, TOM40, and TIM23 were assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: hTERT colocalized with TOM40, TOM20 and TIM23 in the mitochondria. The mitochondrial hTERT protein level of the LPS + A group was significantly greater than that of the LPS group (P = 0.001), and the LPS group showed significantly increased expression of mitochondrial hTERT compared with that of the control group (P = 0.001). No significant difference in the level of total hTERT was observed between the LPS + A and LPS groups. The mitochondrial hTERT protein level of the LPS + A + A779 group was significantly lower than that of the LPS + A group (P = 0.021). The protein level of mitochondrial hTERT in HUVEC-TOM20KD treated with or without LPS alone or LPS + A was significantly decreased compared with the corresponding groups of control HUVECs (HUVEC-TOM20KD-Con vs. HUVEC-Con, P = 0.035; HUVEC-TOM20KD-LPS vs. HUVEC-LPS, P = 0.003; HUVEC-TOM20KD-LPS + A vs. HUVEC-LPS + A, P = 0.001), and treatment with Ang(1-7) did not restore the downregulation of mitochondrial hTERT in HUVEC-TOM20KD. HUVEC-TOM20OE showed a significantly increased level of mitochondrial hTERT (HUVEC-TOM20OE-Con vs. HUVEC-Con, P = 0.010), which was further elevated by Ang(1-7) stimulation (HUVEC-TOM20OE-LPS + A vs. HUVEC-TOM20OE-Con, P = 0.011). Lastly, the protein expression levels of TOM40 (HUVEC-TOM20KD-Con vs. HUVEC-Con, P = 0.007) and TIM23 (HUVEC-TOM20KD-Con vs. HUVEC-Con, P = 0.001) were significantly increased in HUVEC-TOM20KD in comparison to HUVECs. CONCLUSIONS: Ang(1-7) effectively promoted mitochondrial translocation of hTERT in HUVECs via TOM20, indicating that hTERT may be transported to the mitochondria through the TOM20 complex. In addition, A779 could block the effects of Ang(1-7) in HUVECs.

Single-cell architecture and functional requirement of alternative splicing during hematopoietic stem cell formation.

Single-cell transcriptional profiling has rapidly advanced our understanding of the embryonic hematopoiesis; however, whether and what role RNA alternative splicing (AS) plays remains an enigma. This is important for understanding the mechanisms underlying splicing-associated hematopoietic diseases and for the derivation of therapeutic stem cells. Here, we used single-cell full-length transcriptome data to construct an isoform-based transcriptional atlas of the murine endothelial-to-hematopoietic stem cell (HSC) transition, which enables the identification of hemogenic signature isoforms and stage-specific AS events. We showed that the inclusion of these hemogenic-specific AS events was essential for hemogenic function in vitro. Expression data and knockout mouse studies highlighted the critical role of Srsf2: Early Srsf2 deficiency from endothelial cells affected the splicing pattern of several master hematopoietic regulators and significantly impaired HSC generation. These results redefine our understanding of the dynamic HSC developmental transcriptome and demonstrate that elaborately controlled RNA splicing governs cell fate in HSC formation.