A novel senolytic drug for pulmonary fibrosis: BTSA1 targets apoptosis of senescent myofibroblasts by activating BAX.

Idiopathic pulmonary fibrosis is a progressive and age-related disease that results from impaired lung repair following injury. Targeting senescent myofibroblasts with senolytic drugs attenuates pulmonary fibrosis, revealing a detrimental role of these cells in pulmonary fibrosis. The mechanisms underlying the occurrence and persistence of senescent myofibroblasts in fibrotic lung tissue require further clarification. In this study, we demonstrated that senescent myofibroblasts are resistant to apoptosis by upregulating the proapoptotic protein BAX and antiapoptotic protein BCL-2 and BCL-XL, leading to BAX inactivation. We further showed that high levels of inactive BAX-mediated minority mitochondrial outer membrane permeabilization (minority MOMP) promoted DNA damage and myofibroblasts senescence after insult by a sublethal stimulus. Intervention of minority MOMP via the inhibition of caspase activity by quinolyl-valyl-O-methylaspartyl-[2,6-difluorophenoxy]-methyl ketone (QVD-OPH) or BAX knockdown significantly reduced DNA damage and ultimately delayed the progression of senescence. Moreover, the BAX activator BTSA1 selectively promoted the apoptosis of senescent myofibroblasts, as BTSA1-activated BAX converted minority MOMP to complete MOMP while not injuring other cells with low levels of BAX. Furthermore, therapeutic activation of BAX with BTSA1 effectively reduced the number of senescent myofibroblasts in the lung tissue and alleviated both reversible and irreversible pulmonary fibrosis. These findings advance the understanding of apoptosis resistance and cellular senescence mechanisms in senescent myofibroblasts in pulmonary fibrosis and demonstrate a novel senolytic drug for pulmonary fibrosis treatment.

Abnormal mitochondrial iron metabolism damages alveolar type II epithelial cells involved in bleomycin-induced pulmonary fibrosis.

Rationale: Pulmonary fibrosis is a chronic progressive lung disease with limited therapeutic options. We previously revealed that there is iron deposition in alveolar epithelial type II cell (AECII) in pulmonary fibrosis, which can be prevented by the iron chelator deferoxamine. However, iron in the cytoplasm and the mitochondria has two relatively independent roles and regulatory systems. In this study, we aimed to investigate the role of mitochondrial iron deposition in AECII injury and pulmonary fibrosis, and to find potential therapeutic strategies. Methods: BLM-treated mice, MLE-12 cells, and primary AECII were employed to establish the mouse pulmonary fibrosis model and epithelial cells injury model, respectively. Mitochondrial transplantation, siRNA and plasmid transfection, western blotting (WB), quantitative real-time polymerase chain reaction (RT-qPCR), polymerase chain reaction (PCR), immunofluorescence, immunoprecipitation (IP), MitoSOX staining, JC-1 staining, oxygen consumption rate (OCR) measurement, and Cell Counting Kit-8 (CCK8) assay were utilized to elucidate the role of mitochondrial iron deposition in cell and lung fibrosis and determine its mechanism. Results: This study showed that prominent mitochondrial iron deposition occurs within AECII in bleomycin (BLM)-induced pulmonary fibrosis mouse model and in BLM-treated MLE-12 epithelial cells. Further, the study revealed that healthy mitochondria rescue BLM-damaged AECII mitochondrial iron deposition and cell damage loss. Mitoferrin-2 (MFRN2) is the main transporter that regulates mitochondrial iron metabolism by transferring cytosolic iron into mitochondria, which is upregulated in BLM-treated MLE-12 epithelial cells. Direct overexpression of MFRN2 causes mitochondrial iron deposition and cell damage. In this study, decreased ubiquitination of the ubiquitin ligase F-box/LRR-repeat protein 5 (FBXL5) degraded iron-reactive element-binding protein 2 (IREB2) and promoted MFRN2 expression as well as mitochondrial iron deposition in damaged AECII. Activation of the prostaglandin E2 receptor EP4 subtype (EP4) receptor signaling pathway counteracted mitochondrial iron deposition by downregulating IREB2-MFRN2 signaling through upregulation of FBXL5. This intervention not only reduced mitochondrial iron content but also preserved mitochondrial function and protected against AECII damage after BLM treatment. Conclusion: Our findings highlight the unexplored roles, mechanisms, and regulatory approaches of abnormal mitochondrial iron metabolism of AECII in pulmonary fibrosis. Therefore, this study deepens the understanding of the mechanisms underlying pulmonary fibrosis and offers a promising strategy for developing effective therapeutic interventions using the EP4 receptor activator.

Omentin-1 induces mechanically activated fibroblasts lipogenic differentiation through pkm2/yap/pparγ pathway to promote lung fibrosis resolution.

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disease characterized by extensive extracellular matrix (ECM) deposition by activated myofibroblasts, which are specialized hyper-contractile cells that promote ECM remodeling and matrix stiffening. New insights on therapeutic strategies aimed at reversing fibrosis by targeting myofibroblast fate are showing promise in promoting fibrosis resolution. Previously, we showed that a novel adipocytokine, omentin-1, attenuated bleomycin (BLM)-induced lung fibrosis by reducing the number of myofibroblasts. Apoptosis, deactivation, and reprogramming of myofibroblasts are important processes in the resolution of fibrosis. Here we report that omentin-1 reverses established lung fibrosis by promoting mechanically activated myofibroblasts dedifferentiation into lipofibroblasts. Omentin-1 promotes myofibroblasts lipogenic differentiation by inhibiting dimerization and nuclear translocation of glycolytic enzymes pyruvate kinase isoform M2 (PKM2) and activation of the downstream Yes-associated protein (YAP) by increasing the cofactor fructose-1,6-bisphosphate (F1, 6BP, FBP). Moreover, omentin-1 activates proliferator-activated receptor gamma (PPARγ) signaling, the master regulator of lipogenesis, and promotes the upregulation of the lipogenic differentiation-related protein perilipin 2 (PLIN2) by suppressing the PKM2-YAP pathway. Ultimately, omentin-1 facilitates myofibroblasts transformation into the lipofibroblast phenotype, with reduced collagen synthesis and enhanced degradation properties, which are crucial mechanisms to clear the ECM deposition in fibrotic tissue, leading to fibrosis resolution. Our results indicate that omentin-1 targets mechanical signal accelerates fibrosis resolution and reverses established lung fibrosis by promoting myofibroblasts lipogenic differentiation, which is closely associated with ECM clearance in fibrotic tissue. These findings suggest that targeting mechanical force to promote myofibroblast lipogenic differentiation is a promising therapeutic strategy against persistent lung fibrosis.

NMDA receptor activation induces damage of alveolar type II cells and lung fibrogenesis through ferroptosis.

Ferroptosis, a newly discovered type of regulated cell death, has been implicated in numerous human diseases. Idiopathic pulmonary fibrosis (IPF) is a progressive and ultimately fatal interstitial lung disease with poor prognosis and limited treatment options. Emerging evidence has linked ferroptosis and glutamate-determined cell fate which is considered a new light on the etiology of pulmonary fibrosis. Here, we observed that N-methyl d-aspartate receptor (NMDAR) activation promoted cell damage and iron deposition in MLE-12 cells in a dose-, time-, and receptor-dependent manner. This mediated substantial Ca2+ influx, upregulated the expression levels of nNOS and IRP1, and affected intracellular iron homeostasis by regulating the expression of iron transport-related proteins (i.e., TFR1, DMT1, and FPN). Excessive iron load promoted the continuous accumulation of total intracellular and mitochondrial reactive oxygen species, which ultimately led to ferroptosis. NMDAR inhibition reduced lung injury and pulmonary fibrosis in bleomycin-induced mice. Bleomycin stimulation upregulated the expression of NMDAR1, nNOS, and IRP1 in mouse lung tissues, which ultimately led to iron deposition via regulation of the expression of various iron metabolism-related genes. NMDAR activation initiated the pulmonary fibrosis process by inducing iron deposition in lung tissues and ferroptosis of alveolar type II cells. Our data suggest that NMDAR activation regulates the expression of iron metabolism-related genes by promoting calcium influx, increasing nNOS and IRP1 expression, and increasing iron deposition by affecting cellular iron homeostasis, ultimately leading to mitochondrial damage, mitochondrial dysfunction, and ferroptosis. NMDAR activation-induced ferroptosis of alveolar type II cells might be a key event to the initiation of pulmonary fibrosis.

The Effects of Ventilation, Humidity, and Temperature on Bacterial Growth and Bacterial Genera Distribution.

BACKGROUND: Bacteria are readily nourished in airtight environments with high humidity, such as storage cabinets, clothing closets, and corners, where ventilation is normally low and humidity is high. OBJECTIVES: We characterized the role of humidity and ventilation in bacterial growth and genus distribution at different temperatures (26 °C and 34 °C). METHODS: Fresh pork, which was used as the substrate for bacterial culture, was placed in storage cabinets. Bacterial growth and genera distribution on the surface of pork placed in a storage cabinet under different temperatures (26 °C and 34 °C); relative humidity levels (RH: 50%, 70%, 90%); and ventilation conditions (no ventilation and low, medium, and high levels of ventilation) were assessed by rDNA sequencing. RESULTS: Increased ventilation and reduced humidity significantly decreased bacterial growth at 26 °C and 34 °C. The contribution of increased ventilation to the reduction in bacterial growth exceeded that of decreased humidity. Ventilation had the greatest effect on reducing bacterial growth compared to the unventilated conditions at 70% RH. At 34 °C, medium and high levels of ventilation were required to reduce bacterial growth. High temperatures greatly increased bacterial growth, but ventilation could reduce the degree of this increase.

Molecular and morphological evidence reveals a new fern species of Hymenasplenium (Aspleniaceae) from south and southwestern China.

Hymenaspleniumobtusidentatum, a new fern species of the H.excisum subclade of Hymenasplenium (Aspleniaceae) from south and southwestern China was described. Molecular phylogenetic analyses and morphological observations of H.obtusidentatum and related species clearly indicated that this is a distinct taxonomic entity. Phylogenetically, H.obtusidentatum was confirmed to represent a diverging lineage in the H.excisum subclade of Hymenasplenium and was closely related to one lineage that includes accessions identified as H.obscurum, H.pseudobscurum and H.tholiformis. Morphologically, H.obtusidentatum can be distinguished by the combination of its lamina base truncate, stipe not shiny and with color of reddish brown to dark brown, and pinna marginal teeth that are not sharp, but blunt or rounded. A complete species description and comparison with related species in the H.excisum subclade were provided. The holotype of H.obtusidentatum was designated.

Experimental Identification of Electric Dipoles Induced by Magnetic Monopoles in Tb_{2}Ti_{2}O_{7}.

The fundamental principles of electrodynamics allow an electron carrying both electric monopole (charge) and magnetic dipole (spin) but prohibit its magnetic counterpart. Recently, it was predicted that the magnetic "monopoles" carrying emergent magnetic charges in spin ice systems can induce electric dipoles. The inspiring prediction offers a novel way to study magnetic monopole excitations and magnetoelectric coupling. However, no clear example has been identified up to now. Here, we report the experimental evidence for electric dipoles induced by magnetic monopoles in spin frustrated Tb_{2}Ti_{2}O_{7}. The magnetic field applied to pyrochlore Tb_{2}Ti_{2}O_{7} along the [111] direction, brings out a "3-in-1-out" magnetic monopole configuration, and then induces a subtle structural phase transition at H_{c}∼2.3 T. The transition is made evident by the nonlinear phonon splitting under magnetic fields and the anomalous crystal-field excitations of Tb^{3+} ions. The observations consistently point to the displacement of the oxygen O^{''} anions along the [111] axis which gives rise to the formation of electric dipoles. The finding demonstrates that the scenario of magnetic monopole having both magnetic charge and electric dipole is realized in Tb_{2}Ti_{2}O_{7} and sheds light into the coupling between electricity and magnetism of magnetic monopoles in spin frustrated systems.

Protective effects of Scutellaria baicalensis Georgi extract on D-galactose induced aging rats.

Scutellaria baicalensis Georgi (SBG), a traditional Chinese herb, has attracted considerable attention for its wide range of pharmacological activities. This study aimed to investigate the intervention effects of SBG ethanol extract on aging rats induced by D-galactose (D-gal) and to explore potential mechanisms by serum and liver metabolic profiles. The aging rats were induced by the D-gal (100 mg/kg) for 10 weeks continuously with subcutaneous injection, while the control rats received physiological saline. Two other groups of rats were administered with 100 mg/kg/day and 200 mg/kg/day of SBG by oral route following D-gal injections. The abilities of spatial and learning memory were evaluated by open-field test and Morris water maze test. Then, some biochemical indexes related to cognitive ability and aging were measured. Histopathological feature in hippocampal region was observed by Hematoxylin and eosin (HE) staining. The changes of metabolic profiles were evaluated using proton nuclear magnetic resonance (1H NMR) spectroscopy coupled with multivariate data analysis. Results showed that SBG could significantly improve the learning and memory functions, reducing oxidative damage and histological abnormalities of hippocampus neurons. In addition, significant differences in the metabolic profiles were observed both in serum and liver between the model group and the control group. After the treatment using SBG, the levels of these metabolites are significantly changed back to their similar levels in the control group. These metabolic changes are related to the disturbance in amino acid metabolism, glycometabolism and choline metabolism. Hence, SBG may have the potential to improve neurodegeneration and provide brain protection. Graphical abstract A 1H NMR-based metabonomic study was conducted to provide a global view of metabolites related to D-gal induced aging rats and assess the holistic efficacy of Scutellaria baicalensis Georgi.

Integrated taxonomy of the Asplenium normale complex (Aspleniaceae) in China and adjacent areas.

The Asplenium normale D. Don complex comprises several taxa that are either diploid or tetraploid. The tetraploids are assumed to have originated from diploid ancestors by relatively recent autopolyploidization or allopolyploidization. Some of the diploids are readily recognized morphologically but most of the taxa have until now been placed into a single species. However, phylogenetic studies have challenged this treatment and emphasized the notion that the taxonomic treatment of this complex needs to be revised. An integrative taxonomic approach was employed to delimit species in the complex using cytological, morphological, and DNA sequence data. Initially, we employed a diploid first approach to establish a robust taxonomic framework. Special efforts were made to collect and identify the diploid progenitors of each polyploid lineage identified in the plastid DNA based phylogenetic hypothesis. A total of six distinct diploid species were identified. The distinctive nature of the six diploids is strongly supported by sequence differences in plastid DNA and nuclear loci, as well as by the results of morphometric analysis. Diagnostic morphological characters were identified to distinguish the six diploid species, resulting in their revised taxonomy, which includes two novel species, namely, Asplenium normaloides and A. guangdongense. Further studies to strengthen the taxonomic classification of all of the tetraploid taxa are warranted.

[Urinary metabolomics study of the effects of Scutellaria baicalensis Georgi ethanol extract on D-galactose-induced rats].

The purpose of this study is to evaluate the anti-aging effects and reveal the underlying mechanism of Scutellaria baicalensis Georgi ethanol extract (SBG) in D-galactose-induced rats. Fifty rats were randomly divided into five groups: vehicle control group, D-galactose group, and D-galactose combined with 50, 100, 200 mg x kg(-1) SBG. A rat aging model was induced by injecting subcutaneously D-galactose (100 mg x kg(-1)) for ten weeks. At the tenth week, the locomotor activity (in open-field test) and the learning and memory abilities (in Morris water maze test) were examined respectively. The urine was collected using metabolic cages and analyzed by high-resolution 1H NMR spectroscopy combined with multivariate statistical analyses. The SBG at doses of 50, 100 and 200 mg x kg(-1) treatments groups could significantly ameliorate aging process in rats' cognitive performance. The 50, 100, 200 mg x kg(-1) SBG regulated citrate, pyruvate, lactate, trimethylamine (TMA), pantothenate, ß-hydroxybutyrate in urine favorably toward the control group. These biochemical changes are related to the disturbance in energy metabolism, glycometabolism and microbiome metabolism, which is helpful to further understanding the D-galactose induced aging rats and the therapeutic mechanism of SBG.

Survival and Growth of Epiphytic Ferns Depend on Resource Sharing.

Locally available resources can be shared within clonal plant systems through physiological integration, thus enhancing their survival and growth. Most epiphytes exhibit clonal growth habit, but few studies have tested effects of physiological integration (resource sharing) on survival and growth of epiphytes and whether such effects vary with species. We conducted two experiments, one on individuals (single ramets) and another on groups (several ramets within a plot), with severed and intact rhizome treatments (without and with physiological integration) on two dominant epiphytic ferns (Polypodiodes subamoena and Lepisorus scolopendrium) in a subtropical montane moist forest in Southwest China. Rhizome severing (preventing integration) significantly reduced ramet survival in the individual experiment and number of surviving ramets in the group experiment, and it also decreased biomass of both species in both experiments. However, the magnitude of such integration effects did not vary significantly between the two species. We conclude that resource sharing may be a general strategy for clonal epiphytes to adapt to forest canopies where resources are limited and heterogeneously distributed in space and time.