P311 Promotes IL-4 Receptor‒Mediated M2 Polarization of Macrophages to Enhance Angiogenesis for Efficient Skin Wound Healing.

The transition from the proinflammatory phase to the prohealing phase in wound healing is essential for effective skin wound repair, which involves the balance of M1 and M2 polarization of wound-infiltrating macrophages. P311 plays an essential role in promoting wound closure by enhancing the biological function of epidermal stem cells, endothelial cells, and fibroblasts. Nevertheless, whether and how P311 regulates macrophage polarization remains unclear. In this study, we showed that P311 deficiency reduced the M2 polarization of macrophages, thereby attenuating the secretion of M2-like cytokines. The P311 deficiency prolonged the transition from the proinflammatory phase to the prohealing phase, accompanied by weakened angiogenesis and retarded granulation tissue formation, both of which coordinately hinder the healing of skin wounds. Mechanistically, P311 deficiency downregulated the expression of IL-4 receptor on macrophages, followed by less activation of the IL-4 receptor‒signal transducer and activator of transcription 6 signaling pathway, resulting in impaired M2 macrophage polarization. We further revealed that the mTOR signaling pathway was associated with the regulation of P311 on the expression of IL-4 receptor in macrophages. Thus, our study has highlighted the pivotal role of P311 in promoting the M2 polarization of macrophages for effective skin wound healing.

The promising significance of liraglutide combined with dapagliflozin or empagliflozin in the prevention of early diabetic nephropathy.

OBJECTIVE: To explore the significance of liraglutide combined with dapagliflozin or empagliflozin in the prevention of early diabetic nephropathy (DN) and its effects on renal function indices. METHODS: Three hundred patients with type 2 diabetes mellitus (T2DM) treated in our hospital from April 2019 to April 2020 were retrospectively included and divided into two groups according to different treatment regimens. Among them, 150 patients who received liraglutide alone were included in the single-drug group, and 150 patients treated with liraglutide combined with dapagliflozin or empagliflozin were included in the combination group. The baseline data and the improvement of inflammatory indices, blood glucose indices and renal function-related indices were compared between the two groups of patients. RESULTS: The baseline data such as age, body mass index, retinopathy, and course of disease had no significant difference between the two groups (P > 0.05). After treatment, the waist-to-hip ratio, total body fat percentage, total body fat mass, total body lean mass, and A/G ratio were significantly decreased in both groups (P < 0.05) compared with before treatment, and were significantly lower in the combination group than in the single-drug group (P < 0.05). The combination group had significantly lower urinary transferrin (Tf), neutrophil gelatinase-associated lipocalin (NGAL) and tumor necrosis factor (TNF)-α, insulin-like growth factor 1 (IGF-1), retinol-binding protein (RBP), homocysteine (Hcy), brain natriuretic peptide (BNP), 24 h urinary albumin excretion ratio (UAER), urine albumin to creatinine ratio (UACR) and urinary liver-type fatty acid binding protein (L-FABP) levels, and higher secretory frizzled-related protein 5 levels than the single-drug group after treatment (P < 0.05). CONCLUSION: Liraglutide combined with dapagliflozin or empagliflozin treatment can effectively reduce the levels of Tf, NGAL and TNF-α in patients with T2DM, and improve the renal function in terms of IGF-1, RBP, Hcy, BNP, UAER, UACR, L-FABP, showing high treatment safety.

Progranulin improves neural development via the PI3K/Akt/GSK-3ß pathway in the cerebellum of a VPA-induced rat model of ASD.

Autism spectrum disorder (ASD) is a neurodevelopmental disease featuring social interaction deficits and repetitive/stereotyped behaviours; the prevalence of this disorder has continuously increased. Progranulin (PGRN) is a neurotrophic factor that promotes neuronal survival and differentiation. However, there have not been sufficient studies investigating its effect in animal models of autism. This study investigated the effects of PGRN on autistic phenotypes in rats treated with valproic acid (VPA) and assessed the underlying molecular mechanisms. PGRN was significantly downregulated in the cerebellum at postnatal day 14 (PND14) and PND35 in VPA-exposed rats, which simultaneously showed defective social preference, increased repetitive behaviours, and uncoordinated movements. When human recombinant PGRN (r-PGRN) was injected into the cerebellum of newborn ASD model rats (PND10 and PND17), some of the behavioural defects were alleviated. r-PGRN supplementation also reduced cerebellar neuronal apoptosis and rescued synapse formation in ASD rats. Mechanistically, we confirmed that PGRN protects neurodevelopment via the PI3K/Akt/GSK-3ß pathway in the cerebellum of a rat ASD model. Moreover, we found that prosaposin (PSAP) promoted the internalisation and neurotrophic activity of PGRN. These results experimentally demonstrate the therapeutic effects of PGRN on a rat model of ASD for the first time and provide a novel therapeutic strategy for autism.

P311 Facilitates the Angiogenesis and Wound Healing Function of MSCs by Increasing VEGF Production.

As a potential clinical therapeutic cell for injured tissue repair, mesenchymal stem cells (MSCs) have attracted increasing attention. Enhancing the pro-healing function of MSCs has gradually become an essential topic in improving the clinical efficacy of MSCs. Recently, studies have shown that neuronal protein 3.1 (P311) plays a crucial role in promoting skin wound healing, suggesting P311 gene modification may improve the pro-healing function of MSCs. In this study, we demonstrated that increasing the in vivo expression of P311 could significantly enhance the ability of MSCs to lessen the number of inflammatory cells, increase the expression of IL10, reduce the levels of TNF-α and IFN-γ, increase collagen deposition, promote angiogenesis, and ultimately accelerate skin wound closure and improve the quality of wound healing. Importantly, we uncovered that P311 enhanced the pro-angiogenesis function of MSCs by increasing the production of vascular endothelial growth factor (VEGF) in vitro and in vivo. Mechanistically, we revealed that the mTOR signalling pathway was closely related to the regulation of P311 on VEGF production in MSCs. Together, our data displayed that P311 gene modification in MSCs augments their capabilities to promote skin wound closure, which might bring the dawn for its clinical application in the future.

Mass Spectrometry and Antibody-Based Characterization of Blood Vessels from Brachylophosaurus canadensis.

Structures similar to blood vessels in location, morphology, flexibility, and transparency have been recovered after demineralization of multiple dinosaur cortical bone fragments from multiple specimens, some of which are as old as 80 Ma. These structures were hypothesized to be either endogenous to the bone (i.e., of vascular origin) or the result of biofilm colonizing the empty osteonal network after degradation of original organic components. Here, we test the hypothesis that these structures are endogenous and thus retain proteins in common with extant archosaur blood vessels that can be detected with high-resolution mass spectrometry and confirmed by immunofluorescence. Two lines of evidence support this hypothesis. First, peptide sequencing of Brachylophosaurus canadensis blood vessel extracts is consistent with peptides comprising extant archosaurian blood vessels and is not consistent with a bacterial, cellular slime mold, or fungal origin. Second, proteins identified by mass spectrometry can be localized to the tissues using antibodies specific to these proteins, validating their identity. Data are available via ProteomeXchange with identifier PXD001738.

Baicalin inhibiting cerebral ischemia/hypoxia-induced neuronal apoptosis via MRTF-A-mediated transactivity.

Baicalin has been shown to provide the neuroprotective effect by alleviating cerebral ischemia injury. However, little's known about the underlying mechanism. Here, a cerebral artery occlusion (MACO)/reperfusion rat model and rat primary cortical neuron culture exposed to hydrogen peroxide (H2O2) were established to evaluate the effect of baicalin on ischemia-induced neuronal apoptosis. We found baicalin can significantly less neurological deficit and reduced infarct volume in vivo. And it efficiently inhibited neuronal apoptosis in vivo and vitro, which was especially characterized by the enhancing of transcription and expression of myeloid cell leukemia-1 (MCL-1) and B-cell lymphoma-2 (BCL-2) in a dose-dependent manner. Furthermore, Baicalin markedly increased myocardin-related transcription factor-A (MRTF-A) level either in ischemic hemisphere or in primary cortical neuron cultures, whiles the anti-apoptosis effect of baicalin was significantly inhibited by transfected with the small interfering RNA of MRTF-A (MRTF-A siRNA) in primary cortical neuron cultures. The luciferase assays also indicated baicalin enhanced the transactivity of MCL-1 and BCL-2 promoter by activating the key CArG box (CC [A/T] 6GG) element, which was reduced by MRTF-A siRNA, suggesting MRTF-A may participate the anti-apoptosis effect of baicalin, and MRTF-A was involved in the transcriptional activity of MCL-1 and BCL-2 that was induced by baicalin. LY294002 (phosphatidylinositol-3 kinase (PI3K) inhibitor) and PD98059 (extracellular signal regulates kinase-1/2 (ERK1/2) inhibitor) obviously reduced baicalin-induced MRTF-A expression and transactivity and expression of MCL-1 and BCL-2, which further abolished the anti-apoptotic effect of baicalin on neuronal apoptosis. Taken together, our data provided the evidence demonstrating the neuroprotective effect of baicalin partially due to MRTF-A-mediated transactivity and expression of MCL-1 and BCL-2 by triggering the CArG box, which might be controlled by the activation of PI3K and ERK1/2.

A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time.

The persistence of original soft tissues in Mesozoic fossil bone is not explained by current chemical degradation models. We identified iron particles (goethite-αFeO(OH)) associated with soft tissues recovered from two Mesozoic dinosaurs, using transmission electron microscopy, electron energy loss spectroscopy, micro-X-ray diffraction and Fe micro-X-ray absorption near-edge structure. Iron chelators increased fossil tissue immunoreactivity to multiple antibodies dramatically, suggesting a role for iron in both preserving and masking proteins in fossil tissues. Haemoglobin (HB) increased tissue stability more than 200-fold, from approximately 3 days to more than two years at room temperature (25°C) in an ostrich blood vessel model developed to test post-mortem 'tissue fixation' by cross-linking or peroxidation. HB-induced solution hypoxia coupled with iron chelation enhances preservation as follows: HB + O2 > HB - O2 > -O2 >> +O2. The well-known O2/haeme interactions in the chemistry of life, such as respiration and bioenergetics, are complemented by O2/haeme interactions in the preservation of fossil soft tissues.

Coexistence of hyperlipidemia and acute cerebral ischemia/reperfusion induces severe liver damage in a rat model.

AIM: To investigate the correlation of hyperlipemia (HL) and acute cerebral ischemia/reperfusion (I/R) injury on liver damage and its mechanism. METHODS: Rats were divided into 4 groups: control, HL, I/R and HL+I/R. After the induction of HL via a high-fat diet for 18 wk, middle cerebral artery occlusion was followed by 24 h of reperfusion to capture I/R. Serum alanine transaminase (ALT) and aspartate aminotransferase (AST) were analyzed as part of liver function tests and liver damage was further assessed by histological examination. Hepatocyte apoptosis was evaluated by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. The expression of genes related to apoptosis (caspase-3, bcl-2) was assayed by immunohistochemistry and Western blotting. Serum tumor necrosis factor-α (TNF-α), interleukin-1 (IL-1) and liver mitochondrial superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), malondialdehyde (MDA) and Ca(2+) levels were measured to determine inflammatory and oxidative/antioxidative status respectively. Microsomal hydroxylase activity of the cytochrome P450 2E1 (CYP2E1)-containing enzyme was measured with aniline as the substrate, and CYP2E1 expression in the liver tissue and microsome was determined by immunohistochemistry and Western blotting respectively. RESULTS: HL alone induced by high-fat diet for 18 wk resulted in liver damage, indicated by histopathological analysis, and a considerable increase in serum ALT (25.13 ± 16.90 vs 9.56 ± 1.99, P < 0.01) and AST levels (18.01 ± 10.00 vs 11.33 ± 4.17, P < 0.05) compared with control. Moreover, HL alone induced hepatocyte apoptosis, which was determined by increased TUNEL-positive cells (4.47 ± 0.45 vs 1.5 ± 0.22, P < 0.01), higher caspase-3 and lower bcl-2 expression. Interestingly, compared with those in control, HL or I/R groups, massive increases of serum ALT (93.62 ± 24.00 vs 9.56 ± 1.99, 25.13 ± 16.90 or 12.93 ± 6.14, P < 0.01) and AST (82.32 ± 26.92 vs 11.33 ± 4.17, 18.01 ± 10.00 or 14.00 ± 6.19, P < 0.01) levels in HL+I/R group were observed suggesting severe liver damage, which was confirmed by liver histology. In addition, HL combined with I/R also caused significantly increased hepatocyte apoptosis, as evidenced by increased TUNEL-positive cells (6.20 ± 0.29 vs 1.5 ± 0.22, 4.47 ± 0.45 or 1.97 ± 0.47, P < 0.01), elevated expression of caspase-3 and lower expression of bcl-2. Furthermore, when compared to HL or I/R alone, HL plus I/R enhanced serum TNF-α, IL-1, liver mitochondrial MDA and Ca(2+) levels, suppressed SOD and GSH-Px in liver mitochondria, and markedly up-regulated the activity (11.76 ± 2.36 vs 4.77 ± 2.31 or 3.11 ± 1.35, P < 0.01) and expression (3.24 ± 0.38 vs 1.98 ± 0.88 or 1.72 ± 0.58, P < 0.01) of CYP2E1 in liver. CONCLUSION: The coexistence of HL and acute cerebral I/R induces severe liver damage, suggesting that cerebral ischemic stroke would exaggerate the damage of liver caused by HL. This effect is possibly due to enhanced CYP2E1 induction which further promotes oxidative damage, inflammation and hepatocyte apoptosis.