The HEAT repeat protein HPO-27 is a lysosome fission factor.

Lysosomes are degradation and signalling centres crucial for homeostasis, development and ageing1. To meet diverse cellular demands, lysosomes remodel their morphology and function through constant fusion and fission2,3. Little is known about the molecular basis of fission. Here we identify HPO-27, a conserved HEAT repeat protein, as a lysosome scission factor in Caenorhabditis elegans. Loss of HPO-27 impairs lysosome fission and leads to an excessive tubular network that ultimately collapses. HPO-27 and its human homologue MROH1 are recruited to lysosomes by RAB-7 and enriched at scission sites. Super-resolution imaging, negative-staining electron microscopy and in vitro reconstitution assays reveal that HPO-27 and MROH1 self-assemble to mediate the constriction and scission of lysosomal tubules in worms and mammalian cells, respectively, and assemble to sever supported membrane tubes in vitro. Loss of HPO-27 affects lysosomal morphology, integrity and degradation activity, which impairs animal development and longevity. Thus, HPO-27 and MROH1 act as self-assembling scission factors to maintain lysosomal homeostasis and function.

Nebulization versus metered-dose inhaler and spacer in bronchodilator responsiveness testing: a retrospective study.

BACKGROUND: The recommended delivery mode for bronchodilators in bronchodilator responsiveness (BDR) testing remains controversial. OBJECTIVE: To compare the efficacy of salbutamol administration using a nebulizer versus a metered-dose inhaler (MDI) with spacer in BDR testing. DESIGN: A retrospective study. METHODS: This study examined the data of patients with chronic obstructive pulmonary disease who completed BDR testing between 1 December 2021 and 30 June 2022, at Xiangya Hospital, Central South University. After administering 400 µg of salbutamol through an MDI with spacer or 2.5 mg using a nebulizer, the changes in forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) were analyzed in patients with moderate-to-very severe spirometric abnormalities [pre-bronchodilator FEV1 percentage predicted values (FEV1%pred) ⩽59%]. Significant responsiveness was assessed as >12% and >200 mL improvement in FEV1 and/or FVC or >10% increase in FEV1%pred or FVC percentage predicted values (FVC%pred) from pre- to post-bronchodilator administration. RESULTS: Of the enrolled 894 patients, 83.2% were male (median age, 63 years). After propensity score matching, 240 pairs of patients were selected. The increment in FEV1 and increased FEV1 relative to the predicted value (ΔFEV1%pred) were significantly higher in patients <65 years and those with severe spirometric abnormalities in the nebulization group than patients in the MDI group (all p < 0.05). Compared with MDI with spacer, patients who used nebulization had a 30 mL greater increase in ΔFEV1 (95% CI: 0.01-0.05, p = 0.004) and a 1.09% greater increase in ΔFEV1%pred (95% CI: 0.303-1.896, p = 0.007) from baseline. According to the > 12% and >200 mL increase criterion, the significant BDR rate with nebulization was 1.67 times higher than that with an MDI with spacer (OR = 1.67, 95% CI: 1.13-2.47, p = 0.009). CONCLUSION: Salbutamol delivered using a nebulizer may be preferable to an MDI with spacer in certain circumstances. Nebulization has the potential to increase responsiveness to salbutamol in BDR testing.

Nebulization versus metered-dose inhaler and spacer in bronchodilator responsiveness testingBronchodilator responsiveness testing is commonly undertaken as an important part of spirometry testing to determine the degree of volume and airflow improvement after bronchodilator administration. BDR testing results may affect patients' diagnosis and treatment. This study compared the effects of two delivery models (a metered dose inhaler (MDI) with spacer and nebulization) on responsiveness to bronchodilators and the results of bronchodilator responsiveness testing among patients with chronic obstructive pulmonary disease. We found that the increment in forced expiratory volume in one second were significantly higher in patients aged <65 years and in those with severe spirometric abnormalities in the nebulization group than in those in the MDI group. The study provides evidence that salbutamol delivered by a nebulizer is preferable to an MDI with spacer in patients <65 years and in those with severe spirometric abnormalities and could increase positive responsiveness to bronchodilators. The study will assist in clinical decision-making by selecting the appropriate dosing regimen for different patients.

A plasma-derived extracellular vesicle mRNA classifier for the detection of breast cancer.

BACKGROUND: According to the global cancer burden data released in 2020, breast cancer (BC) has become the most common cancer in the world. Similar to those of other cancers, the present methods used in clinic for diagnosing early BC are invasive, inaccurate, and insensitive. Hence, new non-invasive methods capable of early diagnosis are needed. METHODS: We applied next-generation sequencing and analyzed the messenger RNA (mRNA) profiles of plasma extracellular vesicles (EVs) derived from 14 BC patients and 6 patients with benign breast lesions. We used 3 regression models, namely support vector machine (SVM), linear discriminate analysis (LDA), and logistic regression (LR), to develop classifiers for use in making predictive BC diagnoses; and used 259 plasma samples, including those obtained from 144 patients with BC, 72 patients with benign breast lesions, and 43 healthy women, which were divided into training groups and validation groups to verify their performances as classifiers by quantitative reverse transcription polymerase chain reaction (RT-qPCR). The area under the curve (AUC) and accuracy, sensitivity, and specificity of the classifiers were cross-validated with the leave-1-out cross-validation (LOOCV) method. RESULTS: Among all combinations assessed with the 3 different regression models, an 8-mRNA combination, named EXOBmRNA, exhibited high performance [accuracy =71.9% and AUC =0.718, 95% confidence interval (CI): 0.652 to 0.784] in the training cohort after LOOCV was performed, showing the largest AUC in the SVM model. The mRNAs in EXOBmRNA were HLA-DRB1, HAVCR1, ENPEP, TIMP1, CD36, MARCKS, DAB2, and CXCL14. In the validation cohort, the AUC of EXOBmRNA was 0.737 (95% CI: 0.636 to 0.837). In addition, gene function and pathway analyses revealed that different levels of gene expression were associated with cancer. CONCLUSIONS: We developed a high-performing predictive classifiers including 8 mRNAs from plasma extracellular vesicles for diagnosing breast cancer.

Preparation of Zoledronate liposome and its impact on apoptosis of Kupffer cells in rat liver

Abstract Purpose: To establish a method for the preparation of zoledronate liposome and to observe its effect on inducing the apoptosis of rat liver Kupffer cells. Methods: Zoledronate was encapsulated in liposomes, and then the entrapment rate was detected on a spectrophotometer. The prepared Zoledronate liposome (0.01 mg/mL) was injected into the tail vein of SD rats. Three days later, the number of Kupffer cells (CD68 positive) in rat liver tissue was detected by immunohistochemistry. Flow cytometry was used to detect the apoptosis rate of the isolated liver Kupffer cell cultured in vitro. Results: The entrapment rate of Zoledronate was 43.4±7.8%. Immunohistochemistry revealed that the number of Kupffer cells was 19.3±2.1 in PBS group and 5.5±1.7 in Zoledronate liposome group, with a significant difference (P<0.05). The apoptosis rate of Kupffer cells was 4.1±0.8% in PBS group, while it was 9±2.2% and 23.3±5.9% in Zoledronate liposomes groups with different concentrations of Zoledronate liposome (P<0.05). Conclusions: Zoledronate liposomes can effectively induce the apoptosis of Kupffer cells in vivo and in vitro, and the apoptosis rate is related to the concentration of Zoledronate liposome. To establish a rat liver Kupffer cell apoptosis model can provide a new means for further study on Kupffer cell function.

Protective Effects of Apoptosis of Kupffer Cells Induced by Zoledronate Liposomes Following Hepatic Ischemia-Reperfusion Injury.

BACKGROUND The goal of this study was to observe the effect of the apoptosis of Kupffer cells (KCs) selectively induced by zoledronate liposomes following the hepatic ischemia-reperfusion injury (IRI) in the rat liver transplantation model and to explore its mechanisms. MATERIAL AND METHODS The rat liver transplantation model was established using the improved Kamada method. Male Sprague Dawley rats were randomly divided into 3 groups: no liver transplantation or drug treatment (Group A); donor rats were injected with 1 mL normal saline through the tail vein for 3 continuous days before transplantation, and the donor liver was preserved in cold for 2 hours (Group B); donor rats were injected with 1 mL zoledronate liposomes (0.001 mg/mL) through the tail vein for 3 continuous days before transplantation, and the donor liver was preserved in cold for 2 hours (Group C). At 24 hours after transplantation, the receiving rats were sacrificed for sampling. RESULTS Compared with Group C and Group A, the bile secretion flow was dramatically decreased in Group B, whereas the serum liver function index [alanine aminotransferase (ALT), glutamate aminotransferase (AST), and γ-glutamyl transpeptidase (γ-GT)] was significantly increased (P<0.01), and the pathological injury area was obviously increased. Compared with Group B, the levels of serum interleukin1 (IL-1), tumor necrosis factor-α (TNF-α), and the apoptotic index in Group C were significantly decreased (P<0.05), and Suzuki scores of congestion, vacuolar degeneration, and necrosis were all reduced (P<0.05). CONCLUSIONS The apoptosis of KCs selectively induced by zoledronate liposomes inhibited the inflammatory cascade reaction induced by KC activation and reduced the release of cytokines and decreased the extent of IRI in the liver transplantation in animal model.

Preparation of Zoledronate liposome and its impact on apoptosis of Kupffer cells in rat liver.

PURPOSE: To establish a method for the preparation of zoledronate liposome and to observe its effect on inducing the apoptosis of rat liver Kupffer cells. METHODS: Zoledronate was encapsulated in liposomes, and then the entrapment rate was detected on a spectrophotometer. The prepared Zoledronate liposome (0.01 mg/mL) was injected into the tail vein of SD rats. Three days later, the number of Kupffer cells (CD68 positive) in rat liver tissue was detected by immunohistochemistry. Flow cytometry was used to detect the apoptosis rate of the isolated liver Kupffer cell cultured in vitro. RESULTS: The entrapment rate of Zoledronate was 43.4±7.8%. Immunohistochemistry revealed that the number of Kupffer cells was 19.3±2.1 in PBS group and 5.5±1.7 in Zoledronate liposome group, with a significant difference (P<0.05). The apoptosis rate of Kupffer cells was 4.1±0.8% in PBS group, while it was 9±2.2% and 23.3±5.9% in Zoledronate liposomes groups with different concentrations of Zoledronate liposome (P<0.05). CONCLUSIONS: Zoledronate liposomes can effectively induce the apoptosis of Kupffer cells in vivo and in vitro, and the apoptosis rate is related to the concentration of Zoledronate liposome. To establish a rat liver Kupffer cell apoptosis model can provide a new means for further study on Kupffer cell function.