FNDC5/irisin ameliorates bone loss of type 1 diabetes by suppressing endoplasmic reticulum stress­mediated ferroptosis.

BACKGROUND: Ferroptosis is known to play a crucial role in diabetic osteopathy. However, key genes and molecular mechanisms remain largely unclear. This study aimed to identify a crucial ferroptosis-related differentially expressed gene (FR-DEG) in diabetic osteopathy and investigate its potential mechanism. METHODS: We identified fibronectin type III domain-containing protein 5 (FNDC5)/irisin as an essential FR-DEG in diabetic osteopathy using the Ferroptosis Database (FerrDb) and GSE189112 dataset. Initially, a diabetic mouse model was induced by intraperitoneal injection of streptozotocin (STZ), followed by intraperitoneal injection of irisin. MC3T3-E1 cells treated with high glucose (HG) were used as an in vitro model. FNDC5 overexpression plasmid was used to explore underlying mechanisms in vitro experiments. Femurs were collected for micro-CT scan, histomorphometry, and immunohistochemical analysis. Peripheral serum was collected for ELISA analysis. Cell viability was assessed using a CCK-8 kit. The levels of glutathione (GSH), malondialdehyde (MDA), iron, reactive oxygen species (ROS), and lipid ROS were detected by the corresponding kits. Mitochondria ultrastructure was observed through transmission electron microscopy (TEM). Finally, mRNA and protein expressions were examined by quantitative real-time PCR (qRT-PCR) and western blot analysis. RESULTS: The expression of FNDC5 was found to be significantly decreased in both in vivo and in vitro models. Treatment with irisin significantly suppressed ferroptosis and improved bone loss. This was demonstrated by reduced lipid peroxidation and iron overload, increased antioxidant capability, as well as the inhibition of the ferroptosis pathway in bone tissues. Furthermore, in vitro studies demonstrated that FNDC5 overexpression significantly improved HG-induced ferroptosis and promoted osteogenesis. Mechanistic investigations revealed that FNDC5 overexpression mitigated ferroptosis in osteoblasts by inhibiting the eukaryotic initiation factor 2 alpha (eIF2α)/activated transcription factor 4 (ATF4)/C/EBP-homologous protein (CHOP) pathway. CONCLUSIONS: Collectively, our study uncovered the important role of FNDC5/irisin in regulating ferroptosis of diabetic osteopathy, which might be a potential therapeutic target.

HMA-Net: A deep U-shaped network combined with HarDNet and multi-attention mechanism for medical image segmentation.

BACKGROUND: Automatic segmentation of lesion, organ, and tissue from the medical image is an important part of medical image analysis, which are useful for improving the accuracy of disease diagnosis and clinical analysis. For skin melanomas lesions, the contrast ratio between lesions and surrounding skin is low and there are many irregular shapes, uneven distribution, and local and boundary features. Moreover, some hair covering the lesions destroys the local context. Polyp characteristics such as shape, size, and appearance vary at different development stages. Early polyps with small sizes have no distinctive features and could be easily mistaken for other intestinal structures, such as wrinkles and folds. Imaging positions and illumination conditions would alter polyps' appearance and lead to no visible transitions between polyps and surrounding tissue. It remains a challenging task to accurately segment the skin lesions and polyps due to the high variability in the location, shape, size, color, and texture of the target object. Developing a robust and accurate segmentation method for medical images is necessary. PURPOSE: To achieve better segmentation performance while dealing with the difficulties above, a U-shape network based on the encoder and decoder structure is proposed to enhance the segmentation performance in target regions. METHODS: In this paper, a novel deep network of the encoder-decoder model that combines HarDNet, dual attention (DA), and reverse attention (RA) is proposed. First, HarDNet68 is employed to extract the backbone features while improving the inference speed and computational efficiency. Second, the DA block is adopted to capture the global feature dependency in spatial and channel dimensions, and enrich the contextual information on local features. At last, three RA blocks are exploited to fuse and refine the boundary features to obtain the final segmentation results. RESULTS: Extensive experiments are conducted on a skin lesion dataset which consists of ISIC2016, ISIC2017, and ISIC 2018, and a polyp dataset which consists of several public datasets, that is, Kvasir, CVC-ClinicDB, CVC-ColonDB, ETIS, Endosece. The proposed method outperforms some state-of-art segmentation models on the ISIC2018, ISIC2017, and ISIC2016 datasets, with Jaccard's indexes of 0.846, 0.881, and 0.894, mean Dice coefficients of 0.907, 0.929, and 03939, precisions of 0.908, 0.977, and 0.968, and accuracies of 0.953, 0.975, and 0.972. Additionally, the proposed method also performs better than some state-of-art segmentation models on the Kvasir, CVC-ClinicDB, CVC-ColonDB, ETIS, and Endosece datasets, with mean Dice coefficients of 0.907, 0.935, 0.716, 0.667, and 0.887, mean intersection over union coefficients of 0.850, 0.885, 0.644, 0.595, and 0.821, structural similarity measures of 0.918, 0.953, 0.823, 0.807, and 0.933, enhanced alignment measures of 0.952, 0.983, 0.850, 0.817, and 0.957, mean absolute errors of 0.026, 0.007, 0.037, 0.030, and 0.009. CONCLUSIONS: The proposed deep network could improve lesion segmentation performance in polyp and skin lesion images. The quantitative and qualitative results show that the proposed method can effectively handle the challenging task of segmentation while revealing the great potential for clinical application.

[Correlation between Cyclic GMP-AMP Synthase-Stimulator of Interferon Genes Signaling Pathway and Non-infectious Diseases].

As a DNA receptor in the cytoplasm,cyclic GMP-AMP synthase (cGAS) can recognize abnormal DNA in the cytoplasm and activate stimulator of interferon genes (STING) to regulate the immune response. The recent studies have demonstrated that this pathway plays a role in non-infectious inflammatory diseases by promoting the expression of type Ⅰ interferon and interferon-stimulated gene.This article reviews the activation and regulation of cGAS-STING pathway in multiple systems and the effect of this pathway on the occurrence and progression of non-infectious inflammatory diseases,providing theoretical reference for future application of cGAS-STING pathway-related drugs in non-infectious inflammatory diseases.

Identification of Serum Exosome-Derived circRNA-miRNA-TF-mRNA Regulatory Network in Postmenopausal Osteoporosis Using Bioinformatics Analysis and Validation in Peripheral Blood-Derived Mononuclear Cells.

Background: Osteoporosis is one of the most common systemic metabolic bone diseases, especially in postmenopausal women. Circular RNA (circRNA) has been implicated in various human diseases. However, the potential role of circRNAs in postmenopausal osteoporosis (PMOP) remains largely unknown. The study aims to identify potential biomarkers and further understand the mechanism of PMOP by constructing a circRNA-associated ceRNA network. Methods: The PMOP-related datasets GSE161361, GSE64433, and GSE56116 were downloaded from the Gene Expression Omnibus (GEO) database and were used to obtain differentially expressed genes (DEGs). Gene ontology (GO) enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were applied to determine possible relevant functions of differentially expressed messenger RNAs (mRNAs). The TRRUST database was used to predict differential transcription factor (TF)-mRNA regulatory pairs. Afterwards, combined CircBank and miRTarBase, circRNA-miRNA as well as miRNA-TF pairs were constructed. Then, a circRNA-miRNA-TF-mRNA network was established. Next, the correlation of mRNAs, TFs, and PMOP was verified by the Comparative Toxicogenomics Database. And expression levels of key genes, including circRNAs, miRNAs, TFs, and mRNAs in the ceRNA network were further validated by quantitative real-time PCR (qRT-PCR). Furthermore, to screen out signaling pathways related to key mRNAs of the ceRNA network, Gene Set Enrichment Analysis (GSEA) was performed. Results: A total of 1201 DE mRNAs, 44 DE miRNAs, and 1613 DE circRNAs associated with PMOP were obtained. GO function annotation showed DE mRNAs were mainly related to inflammatory responses. KEGG analysis revealed DE mRNAs were mainly enriched in osteoclast differentiation, rheumatoid arthritis, hematopoietic cell lineage, and cytokine-cytokine receptor interaction pathways. We first identified 26 TFs and their target mRNAs. Combining DE miRNAs, miRNA-TF/mRNA pairs were obtained. Combining DE circRNAs, we constructed the ceRNA network contained 6 circRNAs, 4 miRNAs, 4 TFs, and 12 mRNAs. The expression levels of most genes detected by qRT-PCR were generally consistent with the microarray results. Combined with the qRT-PCR validation results, we eventually identified the ceRNA network that contained 4 circRNAs, 3 miRNAs, 3 TFs, and 9 mRNAs. The GSEA revealed that 9 mRNAs participate in many important signaling pathways, such as "olfactory transduction", "T cell receptor signaling pathway", and "neuroactive ligand-receptor interaction". These pathways have been reported to the occurrence and development of PMOP. To sum up, key mRNAs in the ceRNA network may participate in the development of osteoporosis by regulating related signal pathways. Conclusions: A circRNA-associated ceRNA network containing TFs was established for PMOP. The study may help further explore the molecular mechanisms and may serve as potential biomarkers or therapeutic targets for PMOP.

The efficacy and mechanism of thoracic photodynamic therapy mediated by hematoporphyrin injection on disseminated pleural malignancies of Lewis lung carcinoma in mice.

In order to avoid the problems of long exposure time and high incidence of photosensitivity by intravenous injection of photosensitizer, our study explore the safety, efficacy, and possible mechanisms of photodynamic therapy (PDT) by intrathoracic administration of hematoporphyrin injection in the treatment of disseminated pleural malignancies of Lewis lung carcinoma in mice to provide a theoretical basis for thoracic PDT in the clinic. Hematoporphyrin was administered into the thoracic cavity of tumor-bearing mice, and the concentrations of hematoporphyrin in normal and tumor pleural tissues were detected by high-performance liquid chromatography. The tumor-bearing mice were randomly divided into four groups: model control, pure laser irradiation, PDT low-dose, and PDT high-dose groups. Hematoxylin and eosin (H&E) staining was used to observe the histological changes in normal pleural tissue. H&E and DNA in situ nick end-labeling staining were used to detect necrosis and apoptosis in the tumor tissues. The tumor volume in each group from high to low was as follows: model control group > pure laser irradiation group > PDT low-dose group > PDT high-dose group. Inflammatory cells infiltrated the normal pleural tissue of the PDT group. Necrosis was observed to different extents in the tumor tissues of the PDT group. The apoptosis index of each group from high to low was as follows: PDT high-dose group > PDT low-dose group > pure laser irradiation group > model control group. The differences were statistically significant (P<0.05). Hematoporphyrin selectively accumulated in tumor pleural tissues. PDT with intrathoracic administration of hematoporphyrin injection could inhibit the thoracic implant tumors in mice by inducing necrosis and apoptosis.

Association Between Stent Implantation and Progression of Nontarget Lesions in a Rabbit Model of Atherosclerosis.

BACKGROUND: Progression of nontarget lesions (NTLs) after percutaneous coronary intervention (PCI) has been reported. However, it remains unknown whether progression of NTLs was causally related to stenting. This study was undertaken to test the hypothesis that stent implantation triggers acute phase response and systemic inflammation which may be associated with progression of NTLs. METHODS: Thirty New Zealand rabbits receiving endothelial denudation and atherogenic diet were randomly divided into stenting, sham, and control groups. Angiography and intravascular ultrasonography were performed in the stenting and sham groups, and stent implantation performed only in the stenting group. Histopathologic study was conducted and serum levels of APPs (acute phase proteins) measured in all rabbits. Proteomics analysis was performed to screen the potential proteins related to NTLs progression after stent implantation. The serum levels of APPs and inflammatory cytokines were measured in 147 patients undergoing coronary angiography or PCI. RESULTS: Plaque burden in the NTLs was significantly increased 12 weeks after stent implantation in the stenting group versus sham group. Serum levels of APPs and their protein expression in NTLs were significantly increased and responsible for stenting-triggered inflammation. In patients receiving PCI, serum levels of SAA-1 (serum amyloid A protein 1), CRP (C-reactive protein), TNF (tumor necrosis factor)-α, and IL (interleukin)-6 were substantially elevated up to 1 month post-PCI. CONCLUSIONS: In a rabbit model of atherosclerosis, stent implantation triggered acute phase response and systemic inflammation, which was associated with increased plaque burden and pathological features of unstable plaque in NTLs. The potential mechanism involved vessel injury-triggered acute phase response manifested as increased serum levels of SAA-1, CRP, and LBP (lipopolysaccharide-binding protein) and their protein expression in NTLs. These findings provided a new insight into the relation between stent implantation and progression of NTLs, and further studies are warranted to clarify the detailed mechanism and clinical significance of these preliminary results. Registration: URL: http://www.chictr.org.cn; Unique identifier: ChiCTR1900026393. Graphic Abstract: A graphic abstract is available for this article.

A small-molecule activator of mitochondrial aldehyde dehydrogenase 2 reduces the severity of cerulein-induced acute pancreatitis.

Acute pancreatitis (AP) is one of the leading causes of hospital admission for gastrointestinal disorders. Although lipid peroxides are produced in AP, it is unknown if targeting lipid peroxides prevents AP. This study aimed to investigate the role of mitochondrial aldehyde dehydrogenase 2 (ALDH2), a critical enzyme for lipid peroxide degradation, in AP and the possible underlying mechanisms. Cerulein was used to induce AP in C57BL/6 J male mice and pancreatic acinar cells were used to elucidate underlying mechanisms in vitro. Pancreatic enzymes in the serum, lipid peroxidation products malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and Bcl-2, Bax and cleaved caspase-3 were measured. ALDH2 activation with a small-molecule activator, Alda-1, reduced the levels of the pancreatic enzymes in the serum and the lipid peroxidation products MDA and 4-HNE. In addition, Alda-1 decreased Bax and cleaved caspase-3 expression and increased Bcl-2 expression in vivo and in vitro. In conclusion, ALDH2 activation by Alda-1 has a protective effect in cerulein-induced AP by mitigating apoptosis in pancreatic acinar cells by alleviating lipid peroxidation.

Postinfarction Hearts Are Protected by Premature Senescent Cardiomyocytes Via GATA 4-Dependent CCN 1 Secretion.

Background Stress-induced cell premature senescence participates in a variety of tissue and organ remodeling by secreting such proteins as proinflammatory cytokines, chemokines, and growth factors. However, the role of cardiomyocyte senescence in heart remodeling after acute myocardial infarction has not been thoroughly elucidated to date. Therefore, we sought to clarify the impact of premature myocardial senescence on postinfarction heart function. Methods and Results Senescence markers, including p16 INK4a, p21 CIP1/WAF1, and SA -ß-gal staining, were analyzed in several heart disease models by immunostaining. Both postinfarction mouse hearts and ischemic human myocardium demonstrated increased senescence markers. Additionally, senescence-related secretory phenotype was activated after acute myocardial infarction, which upregulated senescence-related secretory phenotype factors, including CCN family member 1 ( CCN 1), interleukin-1α, tumor necrosis factor α, and monocyte chemoattractant protein-1. In vivo, a tail vein injection of AAV 9- Gata4-sh RNA significantly attenuated senescence-related secretory phenotype secretion and aggravated postinfarction heart dysfunction. Furthermore, among activated senescence-related secretory phenotype factors, CCN 1 administration reduced myofibroblast viability in vitro and rescued the deleterious effect of AAV 9- Gata4-sh RNA in vivo. Conclusions Myocardial premature senescence was observed in the ischemic hearts and improved postinfarction heart function, partly through the GATA-binding factor 4- CCN 1 pathway.

ALDH2 mediates the dose-response protection of chronic ethanol against endothelial senescence through SIRT1/p53 pathway.

Aldehyde dehydrogenase 2 (ALDH2) plays essential roles in drinking-associated diseases or effects. As we have previously reported, ALDH2 mediates acute ethanol-induced eNOS activation in vitro. However, whether chronic ethanol treatment has a dose-response endothelial protection, as well as the possible mediating role of ALDH2 involved, is unclear. Here, we show that appropriate dose of ethanol preserved the expression and activity of ALDH2 and eNOS, and alleviated senescence-associated phenotypes in human aortic endothelial cells. Furthermore, ALDH2 deficiency impairs the dose-response protection of ethanol against endothelial senescence by promoting the accumulation of 4-HNE, the formation of 4-HNE-SIRT1 protein adducts and the subsequent decrease in SIRT1-dependent p53 deacetylation. Collectively, our data indicate that ALDH2 mediates the protection of appropriate ethanol by modulating SIRT1/p53-dependent endothelial senescence.

Vaspin alleviates myocardial ischaemia/reperfusion injury via activating autophagic flux and restoring lysosomal function.

Visceral adipose tissue-derived serine protease inhibitor (vaspin), as a secretory adipokine, was reported to exert a protective role on insulin resistance. Recent studies showed that serum vaspin level was downregulated in patients with coronary artery disease. However, whether vaspin exerted specific effects on myocardial injury remains unknown. In this study, we determined to explore the role of vaspin overexpression in myocardial ischaemia/reperfusion (I/R) injury and the underlying mechanisms. Our results showed that the systemic delivery of adeno-associated virus-vaspin to mice reduced myocardial infarct size and apoptosis, and improved cardiac function after reperfusion, accompanied with upregulated autophagic flux and restored lysosomal function in the ischaemic heart. Blockage of the autophagic flux with choroquine mitigated the protection of vaspin on myocardial I/R injury. Moreover, we testified that administration of exogenous recombinant human vaspin on cultured cardiomyocytes suppressed hypoxia/reoxygenation-induced apoptosis, through the AMPK-mTOR-upregulated autophagic flux. Overall, we verified that vaspin functions as an adipokine which can alleviate I/R injury in the heart by suppressing myocardial apoptosis through AMPK-mTOR-dependent activation of autophagic flux, and then provided a potential breakthrough in the treatment of myocardial I/R injury and other ischaemic diseases.