Mitochondria-associated endoplasmic reticulum membranes tethering protein VAPB-PTPIP51 protects against ischemic stroke through inhibiting the activation of autophagy.

AIMS: Mitochondria-associated endoplasmic reticulum membranes (MAMs) serve as a crucial bridge connecting the endoplasmic reticulum (ER) and mitochondria within cells. Vesicle-associated membrane protein-associated protein B (VAPB) and protein tyrosine phosphatase interacting protein 51 (PTPIP51) are responsible for the formation and stability of MAMs, which have been implicated in the pathogenesis of various diseases. However, the role of MAMs in ischemic stroke (IS) remains unclear. We aimed to investigate the role of MAMs tethering protein VAPB-PTPIP51 in experimental cerebral ischemia. METHODS: We simulated cerebral ischemia-reperfusion injury (CIRI) by using a mouse middle cerebral artery occlusion (MCAO) model. RESULTS: We observed a decrease in VAPB-PTPIP51 expression in the brain tissue. Our findings suggested compromised MAMs after MCAO, as a decreased mitochondria-ER contact (MERC) coverage and an increased distance were observed through the transmission electron microscope (TEM). Upon VAPB or PTPIP51 knockdown, the damage to MAMs was exacerbated, accompanied by excessive autophagy activation and increased reactive oxygen species (ROS) production, resulting in an enlarged infarct area and exacerbated neurological deficits. Notably, we observed that this damage was concomitant with the inhibition of the PI3K/AKT/mTOR pathway and was successfully mitigated by the treatment with the PI3K activator. CONCLUSIONS: Our findings suggest that the downregulation of VAPB-PTPIP51 expression after IS mediates structural damage to MAMs. This may exacerbate CIRI by inhibiting the PI3K pathway and activating autophagy, thus providing new therapeutic targets for IS.

Reproductive-dependent effects of B vitamin deficiency on lifespan and physiology.

B vitamins constitute essential micronutrients in animal organisms, executing crucial roles in numerous biological processes. B vitamin deficiency can result in severe health consequences, including the impairment of reproductive functions and increased susceptibility to age-related diseases. However, the understanding of how reproduction alters the requirements of each individual B vitamins for healthy aging and lifespan remains limited. Here, utilizing Drosophila as a model organism, we revealed the substantial impacts of deficiencies in specific B vitamins on lifespan and diverse physiological functions, with the effects being significantly shaped by reproductive status. Notably, the dietary absence of VB1, VB3, VB5, VB6, or VB7 significantly decreased the lifespan of wild-type females, yet demonstrated relatively little effect on ovoD1 infertile mutant females' lifespan. B vitamin deficiencies also resulted in distinct impacts on the reproduction, starvation tolerance and fat metabolism of wild-type females, though no apparent effects were observed in the infertile mutant females. Moreover, a deficiency in VB1 reshaped the impacts of macronutrient intervention on the physiology and lifespan of fertile females in a reproductive-dependent manner. Overall, our study unravels that the reproductive status of females serves as a critical modulator of the lifespan and physiological alterations elicited by B-vitamin deficiencies.

Importance of timing and training to implement awake prone positioning in patients with COVID-19: a single-center prospective observational study.

Background: Awake prone positioning (APP) is broadly implemented in patients with severe acute respiratory syndrome coronavirus 2 related disease [coronavirus disease 2019 (COVID-19)] admitted to hospital with severe respiratory distress syndrome. This prospective observational study aimed to explore the factors influencing the implementation of APP in patients with acute respiratory failure due to COVID-19. Methods: Patients with COVID-19, all hospitalized with positive X-ray findings and oxygen supplementation requirement, in the Respiratory Step-Down Unit of the Peking University Third Hospital between January 6th, 2023, and January 20th, 2023, were included in this study. Data regarding basic information, activities of daily living (ADLs) scores, oxygen therapy, vital signs, and duration of APP were collected to investigate the factors influencing prone positioning. Results: Among the 134 patients included, 55.2% showed an improvement in oxygen saturation 1 hour after APP. Logistic regression revealed that the pre-APP heart rate (HR) [odds ratio (OR) =1.032; P=0.046] and peripheral oxygen saturation (SpO2) (OR =0.720; P<0.001) were the associated factors of the improvement in SpO2 after treatment. Multiple linear regression revealed that the ADL scores and pre-APP respiratory rate (RR) were the associated factors of the duration of prone positioning (P<0.01). The APP technical steering group effectively improved duration of APP. Conclusions: Patients with low SpO2 and increased HR before treatment showed greater improvement in oxygen saturation. Patients with lower tolerance to ADL but lower RRs were those to demonstrate a longer duration of prone positioning. This is pointing towards establishing the most favorable time window for APP during the course of COVID-19: after the ADLs have already decreased, but before significant tachypnea has appeared.

VhaAC39-1 regulates gut homeostasis and affects the health span in Drosophila.

Gut homeostasis is a dynamically balanced state to maintain intestinal health. Vacuolar ATPases (V-ATPases) are multi-subunit proton pumps that were driven by ATP hydrolysis. Several subunits of V-ATPases may be involved in the maintenance of intestinal pH and gut homeostasis in Drosophila. However, the specific role of each subunit in this process remains to be elucidated. Here, we knocked down the Drosophila gene VhaAC39-1 encoding the V0d1 subunit of V-ATPases to assess its function in gut homeostasis. Knockdown of VhaAC39-1 resulted in the loss of midgut acidity, the increase of the number of gut microbiota and the impairment of intestinal epithelial integrity in flies. The knockdown of VhaAC39-1 led to the hyperproliferation of intestinal stem cells, increasing the number of enteroendocrine cells, and activated IMD signaling pathway and JAK-STAT signaling pathway, inducing intestinal immune response of Drosophila. In addition, knockdown of VhaAC39-1 caused the disturbance of many physiological indicators such as food intake, triglyceride level and fecundity of flies, which ultimately led to the shortening of the life span of Drosophila. These results shed light on the gut homeostasis mechanisms which would help to identify interventions to promote healthy aging.

Inhibitor GSK690693 extends Drosophila lifespan via reduce AKT signaling pathway.

Aging is a process involving physiological changes that lead to the decline of biological functions of various tissues and organs of the body. Therefore, it is crucial to find anti-aging drugs that can intervene with the changes induced because of aging and slow down the degeneration of the biological functions. Among many signaling pathways linked with aging and aging-related diseases, PI3K-AKT signaling pathway has attracted major attention in aging biology. In this research paper, we have demonstrated that AKT inhibitor GSK690693 can extend lifespan in Drosophila irrespective of start of the treatment from the beginning of life or the mid-life. Effect of GSK690693 for lifespan extension has been primarily related to the improvements in oxidative resistance, intestinal integrity and increased autophagy, but not in physical activity or starvation resistance. Furthermore, GSK690693 treatment reduced the activation of AKT and ERK, consequently activating FOXO, GSK-3ß and apoptosis to modulate longevity of flies. Remarkably, GSK690693 did not induce hyperglycemia after treatment. The results indicate that GSK690693 may become an effective compound for anti-aging intervention.

Sexual dimorphism in the nutritional requirement for adult lifespan in Drosophila melanogaster.

The nutritional requirements of Drosophila have mostly been studied for development and reproduction, but the minimal requirements for adult male and female flies for lifespan have not been established. Following development on a complete diet, we find substantial sex difference in the basic nutritional requirement of adult flies for full length of life. Relative to females, males require less of each nutrient, and for some nutrients that are essential for development, adult males have no requirement at all for lifespan. The most extreme (and surprising) sex differences were that chronic cholesterol and vitamin deficiencies had no effect on the lifespan of adult males, but they greatly decreased lifespan in females. Female oogenesis rather than chromosomal karyotype and mating status is the key cause of this gender difference in life-sustaining nutritional requirements. These data are important to the way we understand the mechanisms by which diet modifies lifespan.

Excreta Quantification (EX-Q) for Longitudinal Measurements of Food Intake in Drosophila.

Longitudinal measurements of food intake remain a challenge in Drosophila studies of nutrition and behavior. Here, we report an improved method for measuring fly food intake using dye-labeled food and excreta quantification (EX-Q). Reducing the surface area of the medium maximized excreta recovery and the accuracy in estimating total consumption. The EX-Q method is compatible with agar-based medium and makes it possible to measure consumption over an extended period and at multiple time points without sacrificing flies. Using EX-Q, we revealed nutrient- and age-specific features of Drosophila feeding behavior. Daily consumption of a chemically defined diet was relatively consistent over the first 25 days of adulthood. Omitting amino acids or vitamins from the diet reduced consumption in both sexes, whereas omitting sugars or cholesterol primarily affected female food intake. Our results demonstrate EX-Q as a simple, reliable, and nondestructive method for longitudinal studies of solid food intake in Drosophila.

The Epigenetics of Aging in Invertebrates.

Aging is an unstoppable process coupled to the loss of physiological function and increased susceptibility to diseases. Epigenetic alteration is one of the hallmarks of aging, which involves changes in DNA methylation patterns, post-translational modification of histones, chromatin remodeling and non-coding RNA interference. Invertebrate model organisms, such as Drosophila melanogaster and Caenorhabditis elegans, have been used to investigate the biological mechanisms of aging because they show, evolutionarily, the conservation of many aspects of aging. In this review, we focus on recent advances in the epigenetic changes of aging with invertebrate models, providing insight into the relationship between epigenetic dynamics and aging.

Drosophila Gut-A Nexus Between Dietary Restriction and Lifespan.

Aging is often defined as the accumulation of damage at the molecular and cellular levels which, over time, results in marked physiological impairments throughout the organism. Dietary restriction (DR) has been recognized as one of the strongest lifespan extending therapies observed in a wide array of organisms. Recent studies aimed at elucidating how DR promotes healthy aging have demonstrated a vital role of the digestive tract in mediating the beneficial effects of DR. Here, we review how dietary restriction influences gut metabolic homeostasis and immune function. Our discussion is focused on studies of the Drosophila digestive tract, where we describe in detail the potential mechanisms in which DR enhances maintenance of the intestinal epithelial barrier, up-regulates lipid metabolic processes, and improves the ability of the gut to deal with damage or stress. We also examine evidence of a tissue-tissue crosstalk between gut and neighboring organs including brain and fat body. Taken together, we argue that the Drosophila gut plays a critical role in DR-mediated lifespan extension.

[Comparative study of endoscopic mucous resection with transparent cap and endoscopic multi-band mucosectomy for early esophageal cancer and precancerous lesion].

OBJECTIVE: To evaluate the efficacy and safety of endoscopic mucous resection with transparent cap (EMR-Cap) and endoscopic multi-band mucosectomy (MBM) in the treatment of early esophageal cancer and precancerous lesion. METHODS: A retrospective study was performed to review 30 EMR-Cap cases from December 2008 to December 2009 and 32 MBM cases from January 2010 to January 2011 of early esophageal cancer and precancerous lesions. The differences between these two techniques in efficacy, safety, and cost were compared. RESULTS: In EMR-Cap group, the median resection time was 26(10-56) min and median procedure time was 43(22-81) min, significantly longer than those in MBM group [10(7-18) min and 32(28-45) min, P=0.036 and 0.038, respectively]. There were no significant differences between the two groups in total thickness and depth of resected lesions (P>0.05). In EMR-Cap group, the median cost was significantly higher than that of MBM group [(5466±354) vs. (4014±368) RMB, P=0.008)]. CONCLUSIONS: EMR-Cap and MBM are minimally invasive, safe and effective methods in the treatment of early esophageal cancer and precancerous lesions. Compared to the EMR-Cap, MBM is simple with shorter treatment time and lower cost.

[Value of endobronchial ultrasound-guided transbronchial needle aspiration in hilar and mediastinal lesions].

OBJECTIVE: To evaluate the diagnostic yield of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in cases of undiagnosed intrapulmonary lesions. METHODS: A total of 89 patients with intrathoracic lesions underwent EBUS-TBNA, including 56 pulmonary lesions, 7 lymph node staging in lung cancer patients, 21 unknown hilar and/or mediastinal lymphadenopathies and 5 mediastinal tumors. All samples were evaluated for cytological and pathological examinations. RESULTS: No complication of EBUS-TBNA was observed. Among 89 cases, 76 had positive results, 5 negative and 5 cases excluded as unsatisfied samples. In 56 patients with pulmonary lesions, EBUS-TBNA demonstrated 45 malignant tumors, 5 benign diseases, 3 suspicious cancers, 1 negative and 2 unsatisfied samples. In 7 lung cancer patients staged by EBUS-TBNA, 5 showed metastasis and 2 showed no metastasis. In 21 cases with mediastinal and/or hilar lymphadenopathy, EBUS-TBNA demonstrated 3 malignant tumors, 13 benign diseases, 2 negative and 3 unsatisfied samples. All 5 mediastinal lesions were malignant. Three suspicious cancers were confirmed, 1 by CT-guided percutaneous transthoracic needle biopsy and 2 by clinical follow-ups. In 2 lung cancer patients EBUS-TBNA showed negative, 1 surgical sample showed metastasis and another no metastasis by PET-CT. Three negative cases were diagnosed as benign by clinical follow-ups. The diagnostic sensitivity, specificity, positive predictive value and negative predictive value of EBUS-TBNA were 95%, 100%, 100% and 20% respectively. CONCLUSION: EBUS-TBNA is both effective and safe in making a diagnosis of intrathoracic lesions.

[Diagnostic value of transbronchial needle aspiration combined with transesophageal endoscopic ultrasound-guided fine needle aspiration in mediastinal and pulmonary hilar lesions].

OBJECTIVE: To evaluate the value of transbronchial needle aspiration (TBNA) combined with transesophageal endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the diagnosis of mediastinal and pulmonary hilar lesions as well as in the lymph node staging (N staging) of lung cancer. METHODS: 129 patients with mediastinal and pulmonary hilar lesions underwent either TBNA or EUS-FNA with cytological needle aspiration. The samples obtained from TBNA or EUS-FNA were examined by both cytologiy and histopathology. RESULTS: Of the 129 patients, 59 underwent TBNA and 70 EUS-FNA. The diagnostic rate were 84.7% (50/59) by TBNA and 94.3% (66/70) by EUS-FNA, resepectively. The diagnosis of 116 (89.9%) patients were confirmed by either TBNA or EUS-FNA. The pathological and cytological diagnostic rates were 92.2% (107/116) and 88.0% (102/116), resepectively. The diagnostic rate was elevated by 8.4% (9/107) through pathological examination. The histological classification rates by cytological and pathological examination were 73.8% (76/116) and 89.3% (92/103), respectively. The diagnostic rate of histological classification was elevated by 35.5% (27/76) through pathological examination. CONCLUSION: The combination of TBNA and EUS-FNA can improve the diagnostic rate for wider mediastinal and pulmlonary hilar lesions. Pathological examination of the samples obtained from the TBNA and EUS-FNA can elevate not only the rate of diagnosis but also the rate of histological classification.

[Minimal invasive treatment of early esophageal cancer and its precancerous lesion: endoscopic mucosal resection using transparent cap-fitted endoscope].

OBJECTIVE: To explore the effect of endoscopic esophageal mucosal resection using transparent cap-fitted endoscope to treat early esophageal cancer and severe hyperplasia, precancerous lesion of esophageal cancer. METHODS: Endoscopic esophageal mucosal resection were performed with transparent-cap technique on 29 cases of early esophageal cancer and 42 cases of severe hyperplasia, and the residual lesions were treated by Argon plasma coagulation (APC). All patients were followed up by endoscopic examination one month, 4 months, and 12 months after the therapy. RESULTS: (1) Local esophageal mucosa with the size of 21.8 mm +/- 1.02 mm x 18.2 mm +/- 1.02 mm on average was resected from 71 cases, with 88 lesions, using transparent cap-fitted endoscope. 1:1,000 saline-epinephrine at an average dose of 18 ml was injected submucosally for each lesion. (2) After the mucosectomy 5 cases had bleeding which was controlled successfully by compression, local injection of saline-epinephrine, and APC. None case suffered from perforation. Stenosis was found in 4 cases after mucosal resection, in three of which the extent of resected mucosa exceeded 3/4 of the esophageal circumference. Water-balloon dilator was used once a month for 3 - 4 times since one month after mucosal resection. All cases were cured. (3) The lesions of 58 cases (81.2%) were completely resected, and the remaining cases had residual lesions that were treated by APC. Three cases of early cancer and 2 cases of severe atypical hyperplasia were discovered endoscopically 4 months after resection and were cured by APC. (4) All cases survived without any discomfort after a follow-up of 4.6 months on average. CONCLUSION: Safe, simple, minimally invasive and effective on early esophageal cancer and precancerous lesion, endoscopic esophageal mucosal resection (EEMR) is promising clinically.