Dystrophin 71 deficiency causes impaired aquaporin-4 polarization contributing to glymphatic dysfunction and brain edema in cerebral ischemia.

OBJECTIVE: The glymphatic system serves as a perivascular pathway that aids in clearing liquid and solute waste from the brain, thereby enhancing neurological function. Disorders in glymphatic drainage contribute to the development of vasogenic edema following cerebral ischemia, although the molecular mechanisms involved remain poorly understood. This study aims to determine whether a deficiency in dystrophin 71 (DP71) leads to aquaporin-4 (AQP4) depolarization, contributing to glymphatic dysfunction in cerebral ischemia and resulting in brain edema. METHODS: A mice model of middle cerebral artery occlusion and reperfusion was used. A fluorescence tracer was injected into the cortex and evaluated glymphatic clearance. To investigate the role of DP71 in maintaining AQP4 polarization, an adeno-associated virus with the astrocyte promoter was used to overexpress Dp71. The expression and distribution of DP71 and AQP4 were analyzed using immunoblotting, immunofluorescence, and co-immunoprecipitation techniques. The behavior ability of mice was evaluated by open field test. Open-access transcriptome sequencing data were used to analyze the functional changes of astrocytes after cerebral ischemia. MG132 was used to inhibit the ubiquitin-proteasome system. The ubiquitination of DP71 was detected by immunoblotting and co-immunoprecipitation. RESULTS: During the vasogenic edema stage following cerebral ischemia, a decline in the efflux of interstitial fluid tracer was observed. DP71 and AQP4 were co-localized and interacted with each other in the perivascular astrocyte endfeet. After cerebral ischemia, there was a notable reduction in DP71 protein expression, accompanied by AQP4 depolarization and proliferation of reactive astrocytes. Increased DP71 expression restored glymphatic drainage and reduced brain edema. AQP4 depolarization, reactive astrocyte proliferation, and the behavior of mice were improved. After cerebral ischemia, DP71 was degraded by ubiquitination, and MG132 inhibited the decrease of DP71 protein level. CONCLUSION: AQP4 depolarization after cerebral ischemia leads to glymphatic clearance disorder and aggravates cerebral edema. DP71 plays a pivotal role in regulating AQP4 polarization and consequently influences glymphatic function. Changes in DP71 expression are associated with the ubiquitin-proteasome system. This study offers a novel perspective on the pathogenesis of brain edema following cerebral ischemia.

Oncogenic fatty acid oxidation senses circadian disruption in sleep-deficiency-enhanced tumorigenesis.

Circadian disruption predicts poor cancer prognosis, yet how circadian disruption is sensed in sleep-deficiency (SD)-enhanced tumorigenesis remains obscure. Here, we show fatty acid oxidation (FAO) as a circadian sensor relaying from clock disruption to oncogenic metabolic signal in SD-enhanced lung tumorigenesis. Both unbiased transcriptomic and metabolomic analyses reveal that FAO senses SD-induced circadian disruption, as illustrated by continuously increased palmitoyl-coenzyme A (PA-CoA) catalyzed by long-chain fatty acyl-CoA synthetase 1 (ACSL1). Mechanistically, SD-dysregulated CLOCK hypertransactivates ACSL1 to produce PA-CoA, which facilitates CLOCK-Cys194 S-palmitoylation in a ZDHHC5-dependent manner. This positive transcription-palmitoylation feedback loop prevents ubiquitin-proteasomal degradation of CLOCK, causing FAO-sensed circadian disruption to maintain SD-enhanced cancer stemness. Intriguingly, timed ß-endorphin resets rhythmic Clock and Acsl1 expression to alleviate SD-enhanced tumorigenesis. Sleep quality and serum ß-endorphin are negatively associated with both cancer development and CLOCK/ACSL1 expression in patients with cancer, suggesting dawn-supplemented ß-endorphin as a potential chronotherapeutic strategy for SD-related cancer.

Cathepsin B as a key regulator of ferroptosis in microglia following intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is a subtype of stroke marked by elevated mortality and disability rates. Recently, mounting evidence suggests a significant role of ferroptosis in the pathogenesis of ICH. Through a combination of bioinformatics analysis and basic experiments, our goal is to identify the primary cell types and key molecules implicated in ferroptosis post-ICH. This aims to propel the advancement of ferroptosis research, offering potential therapeutic targets for ICH treatment. Our study reveals pronounced ferroptosis in microglia and identifies the target gene, cathepsin B (Ctsb), by analyzing differentially expressed genes following ICH. Ctsb, a cysteine protease primarily located in lysosomes, becomes a focal point in our investigation. Utilizing in vitro and in vivo models, we explore the correlation between Ctsb and ferroptosis in microglia post-ICH. Results demonstrate that ICH and hemin-induced ferroptosis in microglia coincide with elevated levels and activity of Ctsb protein. Effective alleviation of ferroptosis in microglia after ICH is achieved through the inhibition of Ctsb protease activity and protein levels using inhibitors and shRNA. Additionally, a notable increase in m6A methylation levels of Ctsb mRNA post-ICH is observed, suggesting a pivotal role of m6A methylation in regulating Ctsb translation. These research insights deepen our comprehension of the molecular pathways involved in ferroptosis after ICH, underscoring the potential of Ctsb as a promising target for mitigating brain damage resulting from ICH.

Pyrroline-5-carboxylate reductase 1 reprograms proline metabolism to drive breast cancer stemness under psychological stress.

Cancer stem-like cells (CSCs) contribute to cancer metastasis, drug resistance and tumor relapse, yet how amino acid metabolism promotes CSC maintenance remains exclusive. Here, we identify that proline synthetase PYCR1 is critical for breast cancer stemness and tumor growth. Mechanistically, PYCR1-synthesized proline activates cGMP-PKG signaling to enhance cancer stem-like traits. Importantly, cGMP-PKG signaling mediates psychological stress-induced cancer stem-like phenotypes and tumorigenesis. Ablation of PYCR1 markedly reverses psychological stress-induced proline synthesis, cGMP-PKG signaling activation and cancer progression. Clinically, PYCR1 and cGMP-PKG signaling components are highly expressed in breast tumor specimens, conferring poor survival in breast cancer patients. Targeting proline metabolism or cGMP-PKG signaling pathway provides a potential therapeutic strategy for breast patients undergoing psychological stress. Collectively, our findings unveil that PYCR1-enhanced proline synthesis displays a critical role in maintaining breast cancer stemness.

Oestrogen ameliorates blood-brain barrier damage after experimental subarachnoid haemorrhage via the SHH pathway in male rats.

BACKGROUND: Sex differences affect the occurrence, progression and regression of subarachnoid haemorrhage (SAH). Oestrogen plays a protective role in alleviating the vasospasm and neuronal apoptosis induced by SAH. However, whether oestrogen affects blood‒brain barrier (BBB) integrity has not been fully studied. Oestrogen has been found to regulate the sonic hedgehog (SHH) signalling pathway through the oestrogen receptor in gastric cancer and adrenal glands, and the SHH signalling pathway has an important role in maintaining the BBB by upregulating the expression of tight junction proteins. In this study, we investigated the relationship between oestrogen and the SHH signalling pathway using clinical data and established an experimental SAH model to explore whether oestrogen could ameliorate BBB damage after SAH through the SHH pathway. METHODS: Correlations between oestrogen and the SHH pathway were analysed by patients' cerebrospinal fluid (CSF) samples and the Genotype-Tissue Expression database (GTEx). Then, an experimental rat SAH model was established using the endovascular perforation method and treated with oestrogen, oestrogen inhibitors and SHH signalling pathway inhibitors. Then, the effects of oestrogen on BBB damage were analysed by western blot, immunofluorescence and neurobehavioural experiments. RESULTS: ESLIA detection and correlation analysis showed that oestrogen levels in patients' CSF were positively correlated with the SHH pathway, which was further verified by GTEx gene-correlation analysis. SHH was found to be mainly expressed in neurons and astrocytes in rats under physiological conditions and was upregulated by oestrogen pretreatment. In the SAH model, oestrogen pretreatment was found to reverse SAH-induced decreases in the SHH pathway, which were counteracted by oestrogen receptor inhibitors. Furthermore, oestrogen pretreatment reduced SAH-induced BBB damage, brain oedema and neurological dysfunction, which were eliminated by SHH pathway inhibitors. CONCLUSION: In conclusion, we demonstrate here that oestrogen pretreatment ameliorates brain injury after SAH, at least in part through SHH pathway-mediated BBB protection.

A broken circadian clock: The emerging neuro-immune link connecting depression to cancer.

Circadian clocks orchestrate daily rhythms in many organisms and are essential for optimal health. Circadian rhythm disrupting events, such as jet-lag, shift-work, night-light exposure and clock gene alterations, give rise to pathologic conditions that include cancer and clinical depression. This review systemically describes the fundamental mechanisms of circadian clocks and the interacting relationships among a broken circadian clock, cancer and depression. We propose that this broken clock is an emerging link that connects depression and cancer development. Importantly, broken circadian clocks, cancer and depression form a vicious feedback loop that threatens systemic fitness. Arresting this harmful loop by restoring normal circadian rhythms is a potential therapeutic strategy for treating both cancer and depression.

Impact of B-lines-guided intensive heart failure management on outcome of discharged heart failure patients with residual B-lines.

AIMS: Pulmonary congestion (PC) expressed by residual lung ultrasound B-lines (LUS-BL) could exist in some discharged heart failure (HF) patients, which is a known determinant of poor outcomes. Detection efficacy for PC is suboptimal with widely used imaging modalities, like X-ray or echocardiography, while lung ultrasound (LUS) can sufficiently detect PC by visualizing LUS-BL. In this trial, we sought to evaluate the impact LUS-BL-guided intensive HF management post-discharge on outcome of HF patients discharged with residual LUS-BL up to 1 year after discharge. IMP-OUTCOME is a prospective, single-centre, single-blinded, randomized cohort study, which is designed to investigate if LUS-BL-guided intensive HF management post-discharge in patients with residual LUS-BL could improve the clinical outcome up to 1 year after discharge or not. METHODS AND RESULTS: After receiving the standardized treatment of HF according to current guidelines, 318 patients with ≥3 LUS-BL assessed by LUS within 48 h before discharge will be randomly divided into the conventional HF management group and the LUS-BL-guided intensive HF management group at 1:1 ratio. Patient-related basic clinical data including sex, age, blood chemistry, imaging examination, and drug utilization will be obtained and analysed. LUS-BL will be assessed at 2 month interval post-discharge in both groups, but LUS-BL results will be enveloped in the conventional HF management group, and diuretics will be adjusted based on symptom and physical examination results with or without knowing the LUS-BL results. Echocardiography examination will be performed for all patients at 12 month post-discharge. The primary endpoint is consisted of the composite of readmission for worsening HF and all-cause death during follow up as indicated. The secondary endpoints consisted of the change in the New York Heart Association classification, Duke Activity Status Index, N terminal pro brain natriuretic peptide value, malignant arrhythmia event and 6 min walk distance at each designed follow up, echocardiography-derived left ventricular ejection fraction, and number of LUS-BL at 12 month post-discharge. Safety profile will be recorded and managed accordingly for all patients. CONCLUSIONS: This trial will explore the impact of LUS-BL-guided intensive HF management on the outcome of discharged HF patients with residual LUS-BL up to 1 year after discharge in the era of sodium-glucose cotransporter-2 inhibitors and angiotensin receptor blocker-neprilysin inhibitor. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05035459.

Oncogenic AURKA-enhanced N6-methyladenosine modification increases DROSHA mRNA stability to transactivate STC1 in breast cancer stem-like cells.

RNase III DROSHA is upregulated in multiple cancers and contributes to tumor progression by hitherto unclear mechanisms. Here, we demonstrate that DROSHA interacts with ß-Catenin to transactivate STC1 in an RNA cleavage-independent manner, contributing to breast cancer stem-like cell (BCSC) properties. DROSHA mRNA stability is enhanced by N6-methyladenosine (m6A) modification which is activated by AURKA in BCSCs. AURKA stabilizes METTL14 by inhibiting its ubiquitylation and degradation to promote DROSHA mRNA methylation. Moreover, binding of AURKA to DROSHA transcript further strengthens the binding of the m6A reader IGF2BP2 to stabilize m6A-modified DROSHA. In addition, wild-type DROSHA, but not an m6A methylation-deficient mutant, enhances BCSC stemness maintenance, while inhibition of DROSHA m6A modification attenuates BCSC traits. Our study unveils the AURKA-induced oncogenic m6A modification as a key regulator of DROSHA in breast cancer and identifies a novel DROSHA transcriptional function in promoting the BCSC phenotype.

Cancer and stress: NextGen strategies.

Chronic stress is well-known to cause physiological distress that leads to body balance perturbations by altering signaling pathways in the neuroendocrine and sympathetic nervous systems. This increases allostatic load, which is the cost of physiological fluctuations that are required to cope with psychological challenges as well as changes in the physical environment. Recent studies have enriched our knowledge about the role of chronic stress in disease development, especially carcinogenesis. Stress stimulates the hypothalamic-pituitaryadrenal (HPA) axis and the sympathetic nervous system (SNS), resulting in an abnormal release of hormones. These activate signaling pathways that elevate expression of downstream oncogenes. This occurs by activation of specific receptors that promote numerous cancer biological processes, including proliferation, genomic instability, angiogenesis, metastasis, immune evasion and metabolic disorders. Moreover, accumulating evidence has revealed that ß-adrenergic receptor (ADRB) antagonists and downstream target inhibitors exhibit remarkable anti-tumor effects. Psychosomatic behavioral interventions (PBI) and traditional Chinese medicine (TCM) also effectively relieve the impact of stress in cancer patients. In this review, we discuss recent advances in the underlying mechanisms that are responsible for stress in promoting malignancies. Collectively, these data provide approaches for NextGen pharmacological therapies, PBI and TCM to reduce the burden of tumorigenesis.

Zfp217 mediates m6A mRNA methylation to orchestrate transcriptional and post-transcriptional regulation to promote adipogenic differentiation.

A complex and highly orchestrated gene expression program chiefly establishes the properties that define the adipocyte phenotype, in which the vast majority of factors are involved in transcriptional regulation. However, the mechanisms by post-transcriptional modulation are poorly understood. Here, we showed that zinc finger protein (Zfp217) couples gene transcription to m6A mRNA modification to facilitate adipogenesis. Zfp217 modulates m6A mRNA methylation by activating the transcription of m6A demethylase FTO. Consistently, depletion of Zfp217 compromises adipogenic differentiation of 3T3L1 cells and results in a global increase of m6A modification. Moreover, the interaction of Zfp217 with YTHDF2 is critical for allowing FTO to maintain its interaction with m6A sites on various mRNAs, as loss of Zfp217 leads to FTO decrease and augmented m6A levels. These findings highlight a role for Zfp217-dependent m6A modification to coordinate transcriptional and post-transcriptional regulation and thus promote adipogenic differentiation.

Stress-induced epinephrine enhances lactate dehydrogenase A and promotes breast cancer stem-like cells.

Chronic stress triggers activation of the sympathetic nervous system and drives malignancy. Using an immunodeficient murine system, we showed that chronic stress-induced epinephrine promoted breast cancer stem-like properties via lactate dehydrogenase A-dependent (LDHA-dependent) metabolic rewiring. Chronic stress-induced epinephrine activated LDHA to generate lactate, and the adjusted pH directed USP28-mediated deubiquitination and stabilization of MYC. The SLUG promoter was then activated by MYC, which promoted development of breast cancer stem-like traits. Using a drug screen that targeted LDHA, we found that a chronic stress-induced cancer stem-like phenotype could be reversed by vitamin C. These findings demonstrated the critical importance of psychological factors in promoting stem-like properties in breast cancer cells. Thus, the LDHA-lowering agent vitamin C can be a potential approach for combating stress-associated breast cancer.

Maternal obesity aggravates the abnormality of porcine placenta by increasing N6-methyladenosine.

BACKGROUND: The growing prevalence of overweight or obese pregnancies shows an increasing risk for aberrant fetal growth and postnatal complications. Maternal obesity is associated with low birth weight (LBW) of piglets. However, the development of LBW from maternal obesity is not well understood. OBJECTIVE: This study attempts to investigate the novel RNA modification N6-methyladenosine (m6A) in the placenta tissues by using sows with high backfat thickness as a model for obese pregnancy. SUBJECTS/METHODS: Forty four placentas from eight sows (backfat thickness ≥21 mm) were divided into four groups by piglet weight, with group1 being LBW group (<1.0 kg), group2 (1.0-1.4 kg), group3 (1.4-1.6 kg), and group4 (>1.6 kg) as the comparative groups of normal birth weight. QPCR was used to measure the mRNA levels of the genes and western blot was used to test the content of proteins. At the same time, LC-MS/MS method was built to test the content of m6A modification in the placental RNA, and finally MeRIP-QPCR technology was employed to check the specific m6A modification in the key genes. RESULTS: Compared with the comparative groups, the expression levels of PPARγ, VEGFA, ABHD5, and GPR120 in both mRNA and protein decreased noticeably in the LBW group. It was also observed that the density of the H&E stained vessels became attenuated in LBW group. Importantly, for the first time, the increased m6A levels were found in LBW placentas. Lower protein level of FTO (the key demethylase of m6A) was observed in LBW placentas, whereas no difference was found among the four groups in the expression levels of METTL3, the main methyltransferase of m6A. By using MeRIP-QPCR technology, the m6A modification in PPARγ, VEGFA, ABHD5, and GPR120, as well as FTO, was considerably enhanced in the placentas from LBW group. CONCLUSION: We infer that in maternity obesity, the higher m6A modification displayed in the genes related to placental development, lipid metabolism and angiogenesis may result in the down regulation of these genes, which could be associated with m6A demethylase FTO.

Blend of organic acids and medium chain fatty acids prevents the inflammatory response and intestinal barrier dysfunction in mice challenged with enterohemorrhagic Escherichia coli O157:H7.

Impaired epithelial barrier function disrupts immune homeostasis and increases inflammation in intestines, leading to many intestinal diseases. The blend of organic acids (OAs) and medium chain fatty acids (MCFAs) has been shown to have synergistic bactericidal effect. In this study, we demonstrated that two blends of OAs and MCFAs (OM1 and OM2) could prevent the inflammatory response and intestinal barrier dysfunction in enterohemorrhagic Escherichia coli (EHEC)-infected mice. Treatments of OM1 and OM2 significantly reduced the body weight loss and production of IL-6 and TNF-α induced by EHEC. Mice treated with OM1 and OM2 showed decrease in serum D-lactic concentration, DAO activity and bacterial transfer to liver and spleen. Furthermore, OM1 and OM2 increased the expression of tight junction proteins occludin and ZO-1, mucus protein MUC-2, and host defense peptides mBD1, mBD2 and mBD3. Finally, OM1 and OM2 increased the population of Lactobacillus spp. and Bifidobacterium spp., but decreased that of E. coli in the cecum. These findings indicate that OM1 and OM2 may be used to develop a prophylactic agent for intestinal inflammation and injury in enteric pathogen infection.

The proportion and trend of human immunodeficiency virus infections associated with men who have sex with men from Chinese voluntary blood donors: a systematic review and meta-analysis.

BACKGROUND: Human immunodeficiency virus (HIV)-positive cases associated with men who have sex with men (MSM) have rapidly increased over the past years. The objective of this study is to comprehensively evaluate the proportions, changing trends, and geographical distribution of MSM-associated HIV cases from Chinese voluntary blood donors by systematically reviewing the available literature. STUDY DESIGN AND METHODS: Major English and Chinese research databases were searched for studies reporting study locations, study years, the number of HIV infections among blood donors, and the number of HIV-positive donations associated with MSM in China. The proportion estimates were calculated; subgroup analyses and test for time trend were performed using software of comprehensive meta-analysis. RESULTS: Thirty-four studies met eligibility criteria. The pooled proportion of HIV-positive donations associated with MSM from 2001 to 2012 was 36.5% (95% confidence interval, 29.6%-44.1%). The epidemic was found to be more severe in northeast and north China compared to south China (59.6%; 55.0% vs. 3.8%, respectively). The proportion showed a significantly increasing trend over the study period (10.3% in 2001-2005; 38.6% in 2006-2009; and 47.6% in 2010-2012; trend test chi-square = 16.42, p < 0.001). CONCLUSION: The relatively high proportion of MSM- associated HIV-positive donors is of concern. Efficient and effective measures focused on public education and improving knowledge of blood safety are needed to prevent this at-risk population from seeking HIV testing through blood donation. It is also imperative to expand the scope of postdonation nucleic acid testing to shorten the window period to improve blood supply safety in China.

Prevalence and predictors of HIV among Chinese tuberculosis patients by provider-initiated HIV testing and counselling (PITC): a multisite study in South Central of China.

BACKGROUND: Tuberculosis (TB) and HIV are two worldwide public health concerns. Co-infection of these two diseases has been considered to be a major obstacle for the global efforts in reaching the goals for the prevention of HIV and TB. METHOD: A comprehensive cross-sectional study was conducted to recruit TB patients in three provinces (Guangxi, Henan and Sichuan) of China between April 1 and September 30, 2010. RESULTS: A total of 1,032 consenting TB patients attended this survey during the study period. Among the participants, 3.30% were HIV positive; about one quarter had opportunistic infections. Nearly half of the participants were 50 years or older, the majority were male and about one third were from minority ethnic groups. After adjusting for site, gender and areas of residence (using the partial/selective Model 1), former commercial plasma donors (adjusted OR [aOR] = 33.71) and injecting drug users(aOR = 15.86) were found to have significantly higher risk of being HIV-positivity. In addition, having extramarital sexual relationship (aOR = 307.16), being engaged in commercial sex (aOR = 252.37), suffering from opportunistic infections in the past six months (aOR = 2.79), losing 10% or more of the body weight in the past six months (aOR = 5.90) and having abnormal chest X-ray findings (aOR = 20.40) were all significantly associated with HIV seropositivity (each p<0.05). CONCLUSIONS: HIV prevalence among TB patients was high in the study areas of China. To control the dual epidemic, intervention strategies targeting socio-demographic and behavioral factors associated with higher risk of TB-HIV co-infection are urgently called for.

Determination of non-protein cysteine in human serum by a designed BODIPY-based fluorescent probe.

A novel fluorescent probe is designed and synthesized for the determination of cysteine in biological samples by incorporating 2,4-dinitrobenzenesulfonyl (DBS) group as a quencher into the BODIPY skeleton. The BODIPY-based probe itself shows weak fluorescence due to the strong intramolecular charge transfer process. Upon reaction with cysteine, however, the probe produces a rapid and large fluorescence enhancement through the removal of the DBS unit by nucleophilic aromatic substitution. This valuable property leads to the development of a new and simple method for cysteine assay. Under the optimized conditions, the fluorescence enhancement value is directly proportional to the concentration of cysteine in the range 2-12 µM, with a detection limit of 30 nM (S/N=3). The applicability of the developed method has been successfully demonstrated on the determination of non-protein cysteine in human serum. Compared to most of the existing fluorescent probes proposed for cysteine, the BODIPY-based one exhibits an excellent overall performance in terms of selectivity, sensitivity and simplicity.