Overexpressing Mice Research Articles

TXNIP regulates pulmonary inflammation induced by Asian sand dust

Asian sand dust (ASD), a seasonal dust storm originating from the deserts of China and Mongolia, affects Korea and Japan during the spring, carrying soil particles and a variety of biochemical components. Exposure to ASD has been associated with the onset and exacerbation of respiratory disorders, although the underlying mechanisms remain unclear. This study investigates ASD-induced pulmonary toxicity and its mechanistic pathways, focusing on the role of thioredoxin-interacting protein (TXNIP). Using TXNIP knock-out (KO) mice and adeno-associated virus (AAV)-mediated TXNIP overexpression transgenic mice, we explored how TXNIP modulates ASD-induced pulmonary inflammation. Mice were exposed to ASD via intranasal administration on days 1, 3, and 5 to induce inflammation. ASD exposure led to significant pulmonary inflammation, evidenced by increased inflammatory cell counts and elevated cytokine levels in bronchoalveolar lavage fluid, as well as heightened protein expression of the TXNIP/NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome. TXNIP KO mice exhibited attenuated airway inflammation and downregulation of the NLRP3 inflammasome compared to wild-type controls, while AAV-mediated TXNIP overexpression mice showed exacerbated inflammatory responses, including elevated NLRP3 inflammasome expression, compared to AAV-GFP controls. These findings suggest that TXNIP is a key regulator of ASD-induced pulmonary inflammation.

Gain of bipolar disorder-related lncRNA AP1AR-DT in mice induces depressive and anxiety-like behaviors by reducing Negr1-mediated excitatory synaptic transmission

Abstract Background Bipolar disorder is a complex polygenic disorder that is characterized by recurrent episodes of depression and mania, the heterogeneity of which is likely complicated by epigenetic modifications that remain to be elucidated. Methods We performed transcriptomic analysis of peripheral blood RNA from monozygotic (MZ) twins discordant for bipolar disorder to identify disease-associated differentially expressed long noncoding RNAs (DE-lncRNAs), which were further validated in the PsychENCODE brain RNA-seq dataset. We then performed behavioral tests, electrophysiological assays, chromatin immunoprecipitation, and PCR to investigate the function of DE-lncRNAs in the mouse and cell models. Statistical analyses were performed using GraphPad Prism 9.0 or SPSS. Results We identified a bipolar disorder-associated upregulated long non-coding RNA (lncRNA), AP1AR-DT. We observed that overexpression of AP1AR-DT in the mouse medial prefrontal cortex (mPFC) resulted in a reduction of both the total spine density and the spontaneous excitatory postsynaptic current (sEPSC) frequency of mPFC neurons as well as depressive and anxiety-like behaviors. A combination of the results of brain transcriptome analysis of AP1AR-DT overexpressing mice brains with the known genes associated with bipolar disorder revealed that NEGR1, which encodes neuronal growth regulator 1, is one of the AP1AR-DT targets and is reduced in vivo upon gain of AP1AR-DT in mice. We further demonstrated that overexpression of recombinant Negr1 in the mPFC neurons of AP1AR-DTOE mice ameliorates depressive and anxiety-like behaviors and normalizes the reduced excitatory synaptic transmission induced by the gain of AP1AR-DT. We finally identified that AP1AR-DT reduces NEGR1 expression by competing for the transcriptional activator NRF1 in the overlapping binding site of the NEGR1 promoter region. Conclusions The epigenetic and pathophysiological mechanism linking AP1AR-DT to the modulation of depressive and anxiety-like behaviors and excitatory synaptic function provides etiological implications for bipolar disorder.

REGγ is essential to maintain bone homeostasis by degrading TRAF6, preventing osteoporosis

Primary osteoporosis, manifesting as decreased bone mass and increased bone fragility, is a "silent disease" that is often ignored until a bone breaks. Accordingly, it is urgent to develop reliable biomarkers and novel therapeutic strategies for osteoporosis treatment. Here, we identified REGγ as a potential biomarker of osteoporotic populations through proteomics analysis. Next, we demonstrated that REGγ deficiency increased osteoclast activity and triggered bone mass loss in REGγ knockout (KO) and bone marrow-derive macrophage (BMM)-conditional REGγ KO mice. However, the osteoclast activity decreased in BMM-conditional REGγ overexpression mice. Mechanistically, we defined that REGγ-20S proteasome directly degraded TRAF6 to inhibit bone absorption in a ubiquitin-independent pathway. More importantly, BMM-conditional Traf6 KO with REGγ KO mice could "rescue" the osteoporosis phenotypes. Based on NIP30 (a REGγ "inhibitor") dephosphorylation by CKII inhibition activated the ubiquitin-independent degradation of TRAF6, we selected TTP22, an inhibitor of CKII, and defined that TTP22 could alleviate osteoporosis in vitro and in vivo. Overall, our study reveals a unique function of NIP30/REGγ/TRAF6 axis in osteoporosis and provides a potential therapeutic drug TTP22 for osteoporosis.

Abstract 4139176: SUMOylation of TP53INP1 Is Involved in miR-30a-5p-Regulated Heart Senescence

Introduction: During natural aging, physiological remodeling of the heart is a critical for the cardiovascular disease and heart failure. miR-30a-5p is related to kidney injury, cancer, and autoimmune diseases. However, whether miR-30a-5p has an effect in cardiac aging has yet to be explored. Hypothesis: This study aimed to characterize the role and mechanism of action of miR-30a-5p in cardiac senescence. Methods: We established miR-30a-5p knockout/overexpressing mouse model. Natural heart aging (18-months-old) and D-galactose-induced aging mouse model were established. The mechanism was explored in D-galactose- or 10-days-cultured cardiomyocytes. Results: miR-30a-5p was downregulated in aged mouse hearts and neonatal rat cardiomyocytes (NRCMs). In vivo, using a combination of echocardiography and different molecular biological approaches, we investigated the role of miR-30a-5p knockout or overexpressed mice on natural- or D-galactose-induced heart aging. In vitro, using RNA-sequence and a series of molecular biology, the mechanism of miR-30a-5p-regulated cardiac senescence was explored in cardiomyocytes. miR-30a-5p knockout mice showed aggravated natural- or D-galactose-induced heart aging compared to wild-type littermate mice, with significantly decreased heart function, increased number of γH2AX-positive cells, reduced telomere length, and upregulated p21 and p53 expression. Cardiac-specific knockdown of miR-30a-5p using adeno-associated virus 9 in D-galactose-induced senescent wild-type mice showed effects similar to those observed in knockout mice. Notably, overexpression of miR-30a-5p in wild-type murine hearts alleviated D-galactose-induced heart senescence by improving heart function, increasing telomere length, decreasing the number of γH2AX-positive cells, and downregulating p53 and p21 expression. This was confirmed in D-galactose-treated or naturally aged NRCMs. Mechanistically, TP53INP1 was identified as a target of miR-30a-5p by mediating the SUMOylation of TP53INP1 and its translocation from the cytoplasm to the nucleus to interact with p53. Further evidence demonstrated that cardiac-specific TP53INP1 deficiency ameliorates miR-30a-5p knockout-aggravated cardiac dysfunction and heart senescence. Conclusions: This study identified miR-30a-5p as a crucial modulator of heart senescence and revealed that the miR-30a-5p–TP53INP1–p53 axis is essential for heart and cardiomyocyte aging.

Psmb8 inhibits mitochondrial fission and alleviates myocardial ischaemia/reperfusion injury by targeting Drp1 degradation

The mitochondrial dynamic imbalance is an important cause of myocardial ischaemia/reperfusion (I/R) injury and dysfunction. Psmb8, as one of the immunoproteasome catalytic subunits, is a key regulator of protein homoeostasis, inflammation and some cardiac diseases. Here, we found that the expression level and activity of Psmb8 were significantly reduced in the heart of I/R mice and in subjects with myocardial infarction (MI). Cardiomyocyte-specific Psmb8 overexpression in mice markedly ameliorated I/R-mediated cardiac injury and dysfunction, which was accompanied by reduced mitochondrial division via the downregulation of dynamin-related protein-1 (Drp1). However, Psmb8 knockout (KO) mice exhibited the opposite changes. The effects of Psmb8 on mitochondrial fission and apoptosis was confirmed in primary cardiomyocytes with overexpression or knockdown of Psmb8 in vitro. Mechanistically, Psmb8 was directly associated with Drp1 and enhanced its degradation, which subsequently suppressed I/R-mediated mitochondrial fission and cardiac injury. Conversely, knockdown of Drp1 in Psmb8-KO mice restored I/R-induced cardiac dysfunction and mitochondrial dynamic imbalance. Our study identified a new cardioprotective role of Psmb8 in cardiac I/R damage through targeting Drp1, and highlight that increasing Psmb8 activity may constitute a promising therapy for ischaemic heart disease.

OTUD7B inhibited hepatic injury from NAFLD by inhibiting K48-linked ubiquitination and degradation of β-catenin

Non-alcoholic fatty liver disease (NAFLD) is the prevalent liver disease. Ovarian tumor domain-containing 7B (OTUD7B) is a deubiquitinating enzyme and its role in NAFLD remains unclear. In high-fat diet (HFD)-induced NAFLD mouse model and palmitic acid (PA)-treated HepG2 cells, OTUD7B expression was decreased. Adenoviral overexpression of OTUD7B in mice resulted in reduced body weight and liver injury, with decreased serum aminotransferase (ALT) and aspartate aminotransferase (AST) levels. OTUD7B overexpression attenuated hepatic lipid deposition (serum TG, TC, LDL-C, HDLC, and FFA levels), which might be through the suppression of lipogenesis and β-oxidation-related genes. The contents of hepatic inflammatory factors (TNF-α, IL-6, and IL-1β) were decreased following OTUD7B overexpression in NAFLD mice. A mechanism study indicated that the protective effect of OTUD7B overexpression might be associated with β-catenin signal activation. OTUD7B overexpression promoted PA-induced β-catenin activity in TopFlash assay, and increased total β-catenin and c-myc levels in cells. The increase in β-catenin levels was contributed to the stabilization via inhibiting K48-linked ubiquitination and proteasomal degradation by OTUD7B. NR4A2 role in NASH has been proved. NR4A2 ChIP-seq and RNA-seq data excluded transcriptional regulation of NR4A2 to OTUD7B, and it was experimentally evidenced that NR4A2 bound to OTUD7B promoter region and positively transcriptionally regulate OTUD7B expression. In summary, OTUD7B overexpression ameliorated hepatic inflammation and steatosis in NAFLD. The possible mechanism of OTUD7B might be through the inhibition of β-catenin degradation by removing K48-linked ubiquitination, which might be regulated by NR4A2.

Dendritic cell mineralocorticoid receptor controls blood pressure by regulating T helper 17 differentiation: role of the Plcβ1/4-Stat5-NF-κB pathway.

Dendritic cells (DCs) are closely related to blood pressure (BP) regulation. Mineralocorticoid receptor (MR) is an important drug target for antihypertensive treatment. However, the role of DC MR in the pathogenesis of hypertension has not been fully elucidated. This study aimed to determine the role of DC MR in BP regulation and to explore the mechanism. Renal biopsy and peripheral blood samples were collected from hypertensive patients (HTN) for immunostaining and flow cytometry. Dendritic cell MR knockout (DCMRKO) mice, DC MR overexpressing (DCMROV) mice, DCMROV/IL-17A knockout (DCMROV/IL-17AKO) mice and finerenone-treated C57BL/6 mice were infused with angiotensin II (Ang II) to establish hypertensive models. Western blotting, chromatin immunoprecipitation, co-immunoprecipitation, and in vivo DC depletion or adoptive transfer were used to delineate the functional importance of DC MR in hypertension development. Mineralocorticoid receptor antagonists (spironolactone and finerenone) suppressed DC aggregation and activation, as well as hypertension in HTN and mice. Compared with littermate control (LC) mice, dendritic cell MR knockout mice had strikingly decreased BPs and attenuated target organ damage after Ang II infusion. Flow cytometry showed that DC MR deficiency mitigated Ang II-induced DC activation and T helper 17 (Th17) cell differentiation. RNA sequencing revealed that MR-deficient DCs had elevated expression of Plcβ1 and Plcβ4, knockdown of which reversed the inhibitory effect of MR deficiency on DC activation and Th17 differentiation. Adoptive transfer of MR-deficient DCs protected Ang II-induced hypertension, whereas knockdown of Plcβ1/4 eliminated the protective effects. At the molecular level, MR negatively regulated Plcβ1/4, which recruited SHP-1 to inactivate of Stat5 activity, resulting in enhanced NF-κB activation and Th17 polarization. Furthermore, DCMROV mice manifested more elevated BPs and target organ damage than control mice after Ang II infusion, and these differences were abolished in DCMROV/IL-17AKO mice. Finally, MR antagonists decreased the aggregation of Th17 in HTN and mice. Dendritic cell MR plays important roles in the pathogenesis of hypertension by regulating Th17 through Plcβ1/4-Stat5-NF-κB signalling, and blockade of DC MR is beneficial for treating hypertension.

The activation of inflammatory responses in the brain is potentiated by over-expressing acetylcholinesterase in myeloid lineage of transgenic mice.

Acetylcholinesterase (AChE) has functions in neuroinflammation, beyond its classical role in neurotransmission. Understanding the role of AChE in neuroinflammation is of great significance, as it highlights the potential therapeutic targets for the treatment of neurodegenerative diseases. In an invitro study, the expression of AChE was up-regulated in lipopolysaccharide (LPS)-induced microglia/macrophage and contrarily potentiated the inflammatory responses via disturbing the cholinergic anti-inflammatory pathway (CAP). However, the regulation of AChE in neuroinflammation has not been revealed invivo yet. Here, we aim to uncover the inflammatory roles of microglial AChE in LPS-induced neuroinflammation by using the conditional AChE over-expression mouse model. AChE was specifically over-expressed in the myeloid cell linkage of mouse by applying CRISPR/cas9 combined with Cre-LoxP system. LPS was intraperitoneally injected into the mice to induce inflammation. The results showed that the inflammation, induced by LPS, was aggravated in the brain of transgenic mice having over-expression of AChE in microglia. The expressions of pro-inflammatory cytokines were robustly up-regulated in the brains of LPS-treated transgenic mice, as compared to the LPS-treated wildtypes. In parallel, the activations of microglia and astrocytes in hippocampus were enhanced significantly in AChE transgenic mice. Transcriptomics analysis further confirmed the severer inflammation in the transgenic mice than the wildtype after LPS administration. These findings shed light on the regulation of microglial AChE in neuroinflammation invivo for the first time, presenting another angle to understand the role of AChE in neurodegenerative diseases.

Navigating Alzheimer’s Disease Mouse Models: Age-Related Pathology and Cognitive Deficits

Since the mid-1990s, scientists have been generating mouse models of Alzheimer’s disease to elucidate key mechanisms underlying the onset and progression of the disease and aid in developing potential therapeutic approaches. The first successful mouse model of Alzheimer’s disease was reported in 1995 with the generation of the PDAPP mice, which were obtained by the overexpression of gene coding for the amyloid precursor protein (APP). Since then, scientists have used different approaches to develop other APP overexpression mice, mice overexpressing tau, or a combination of them. More recently, Saito and colleagues generated a mouse model by knocking in mutations associated with familial Alzheimer’s disease into the APP gene. In this review, we will describe the most used animal models and provide a practical guide for the disease’s age of onset and progression. We believe that this guide will be valuable for the planning and experimental design of studies utilizing these mouse models.

Ly6E on tumor cells impairs anti-tumor T-cell responses: a novel mechanism of tumor-induced immune exclusion

BackgroundLymphocyte antigen 6 complex, locus E (Ly6E) has been initially demonstrated to involve in T cell activity and impair viral infectivity. Recently, high expression levels of Ly6E have been reported in tumor microenvironment (TME) of various types of cancers. However, the immunoregulatory mechanism of Ly6E manipulating TME remains unknown.MethodsTCGA database and Kaplan–Meier plotter database were used to evaluate the correlation between Ly6E expression levels and cancer patient survival. After analyzing Ly6E expression levels in human breast cancer tissues and tumor cell lines, we generated Ly6E knockout (KO) and overexpression (OE) mouse cell lines. Cell proliferation ability in vitro and the ability of growth and metastasis in mouse tumor models were compared between KO/OE and wild-type tumor cells. On day 7 after tumor implantation, tumor tissues were separated for flow cytometric assay, bulk RNA sequencing and single-cell RNA sequencing (ScRNA-seq). The role of Ly6E-expressing tumor cell on macrophage was analyzed in vitro.ResultsOur result surprisingly found that high Ly6E expression levels were associated with CD8+ T cell exclusion in tumor tissues and resistance to immunotherapy. Our data showed that knockout of Ly6E in tumor cells prompts tumor regression and inhibits tumor metastases, and Ly6E-OE tumor cells vice versa. The enhanced anti-tumor effect of Ly6E knockout in tumor cells was dependent on T cell response and formed long-lasting memory. The increase in the CD8+ T-cell infiltration into the tumor islet of Ly6E-KO tumors confirmed the role of Ly6E on T cell exclusion. ScRNA-seq analysis showed that M2 macrophages are particularly abundant in the Ly6E-expressing tumor tissues, especially M2-4 macrophage cluster identified by high levels of Arg-1, indicates that Ly6E-expressing tumor cells might restrict T cell infiltration via M2 macrophages. Moreover, in vitro assay showed that cell culture media derived from Ly6E-positive tumor cells promoted macrophage migration and M2 polarization.ConclusionOur study illuminated that Ly6E-expressing tumor cells facilitated the accumulation of M2 macrophages in TME, which contributes to CD8+ T cell exclusion and provides new insights for improving efficacy of cancer immunotherapy.

AVE0991 ameliorates dopaminergic neuronal damage in Parkinson’s disease through HOTAIRM1/miR-223-3p/α-synuclein axis

Parkinson’s disease (PD) is a prevalent type of neurodegenerative disorder. AVE0991, a non-peptide analogue of Ang-(1–7), by which the progression of PD has been discovered to be ameliorated, but the specific mechanism whereby AVE0991 modulates the progression of PD re-mains unclear. The mice overexpressing human α-syn (A53T) were established to simulate PD pathology, and we also constructed an in vitro model of mouse dopaminergic neurons overexpressing hα-syn (A53T). The [18F] FDG-PET/CT method was employed to assess FDG uptake in human α-syn (A53T) overexpressing mice. Levels of lnc HOTAIRM1 and miR-223-3p were detected via qRT-PCR. Flow cytometry was deployed to assay cell apoptosis. Here, we found that AVE0991 improved behaviour disorders and decreased α-syn expression in the substantia nigra of mice with Parkinson’s disease. AVE0991 inhibited the apoptosis of dopaminergic neurons overexpressing hα-syn (A53T) via lncRNA HOTAIRM1. MiR-223-3p binds to HOTAIRM1 as a ceRNA and directly targets α-syn. Moreover, miR-223-3p level in peripheral blood was found negatively correlated with the α-syn. Our present study shows that the angiotensin-(1–7) analogue AVE0991 targeted at the HOTAIRM1/miR-223-3p axis to degrade α-synuclein in PD mice, and showed neuroprotection in vitro.

RBM20 promotes doxorubicin-induced cardiotoxicity by Atp6v0a1 alternative splicing

Abstract Background & Objective: Doxorubicin (dox), an effective chemotherapy drug, is extremely limited in clinical practice by its lethal cardiotoxicity. Whereas dysregulation of splice-regulatory networks has been reported in cardiomyopathies, the role of RNA binding motif protein 20 (RBM20), an adaptive splice regulator, in doxorubicin-induced cardiotoxicity (DIC) remained to be elucidated. Purpose Here we aimed to show the role of RBM20 in DIC and elucidate the relationship between alternative splicing and lysosome acidification impairment. Method Mice were treated with intraperitoneal injection of cumulative 20mg/kg doxorubicin with four equal injections over a period of 2 weeks to induce DIC. The contribution of RBM20 in cardiotoxicity was evaluated in conditional cardiomyocyte-specific RBM20 overexpression (RBM20tg/+/Myh6-CreERT) mice. The regulatory factor of RBM20 was determined through luciferase assay and chromatin immunoprecipitation in vitro. Autophagic flux was evaluated by transmission electron microscope in RBM20tg/+/Myh6-CreERT mice and by lysotracker and a tandem fluorescence RFP-GFP-LC3 reporter system in RBM20 overexpressed or knockdown cardiomyocyte. RBM20-dependent splicing events were identified by rMATS 3.2.5 on the RNA-sequencing data. Results In the DIC human myocardium and murine model, we observed significant elevation of RBM20 in cardiomyocytes. Cardiomyocyte-specific RBM20 overexpression resulted in severe cardiac dysfunction reflected by dilated ventricles, declined left ventricular ejection fraction, increased chamber stiffness and lower survival rate. After screening for potential upstream transcription factors, c-Jun was identified to bind and upregulate RBM20 directly. The inhibition of c-Jun by SR 11302 could partially mitigate DIC in vitro. Mechanistically, RBM20 was positively related with autophagic flux blockade and impaired lysosome acidification by shifting Atp6v0a1, the a1-subunit of the V0 domain of vacuolar H+-ATPases, toward an exon 6-7 exclusion isoform without altering total transcript levels. By restoring exon 6-7-containing ATP6V0a1 level, we were able to reduce DIC by restoring normal autophagic flux. Conclusion Overall, our study reveals that elevation of RBM20 disturbed lysosome acidification in doxorubicin induced cardiotoxicity via the alternative splicing of Atp6v0a1, leading to heart failure.JUN-Rbm20 upregulattion promoted DICRBM20 alternative spliced atp6v0a1

Lipin1 prevents ischemic heart disease by regulating lipid homeostasis

Abstract Background Lipid metabolism plays a crucial role in the pathophysiology of cardiovascular diseases. Lipin1 plays a pivotal role in lipid metabolism regulation. In the nucleus, Lipin1 acts as a transcriptional co-stimulatory molecule, interacting with peroxisome proliferator–activated receptor–gamma coactivator 1 alpha (PGC1α) and peroxisome proliferator–activated receptor alpha (PPARα). In the cytoplasm, Lipin1 functions as a phosphatidate phosphatase, converting phosphatidic acid to diacylglycerol to regulate lipid metabolism. Low expression of Lipin1 has been implicated in the severity of cardiac dysfunction in mice. Purpose This study aimed to investigate the role of Lipin1 in the cardiac remodeling after myocardial infarction (MI), revealing its impact on lipid metabolism and molecular pathway associated with cardiac dysfunction. Methods Two types of transgenic mice, cardiomyocyte-specific Lipin1 knockout (cKO) and overexpression (cOE) mice were used in this study. Eight to ten-week-old male mice were subjected to MI by coronary artery ligation. Cardiac lipid droplets were quantified, and triacylglycerol and free fatty acid levels were measured one week after MI surgery. Four weeks after MI, cardiac morphology and function were evaluated using echocardiography, alongside measurements of body weight (BW) and heart weight (HW). Additionally, gene expression analysis and histological evaluation were conducted to assess fatty acid metabolism, cardiac fibrosis, inflammation, and oxidative damage. Results Before MI surgery, there were no differences in HW/BW ratio, left ventricular end-diastolic diameter (LVDd) or LV fractional area change (LVFAC) among cKO/ cOE mice and their littermate controls. After MI, cKO mice exhibited significant cardiac dysfunction with larger LVDd, lower LVFAC and increased HW/BW ratio compared to littermate controls. This was accompanied by exacerbated cardiac fibrosis, increased inflammation, and augmented reactive oxygen species accumulation compared with their controls. Conversely, cOE mice displayed improved LVFAC, reduced cardiac fibrosis, inflammation, and reactive oxygen species accumulation compared to their littermate controls. Notably, the transgene of Lipin1 induced changes in the number of cardiac lipid droplets (LDs). cKO mice hearts showed a reduction in cardiac LDs with decreased levels of triacylglycerol and free fatty acids compared to the littermate controls. In contrast, cOE mice displayed increased cardiac LDs and upregulated expression of fatty acid metabolism–related genes after MI. Conclusion These results suggested that Lipin1 has a protective role against ischemic injury through controlling lipid metabolism in ischemic cardiomyocytes. Thus, Lipin1 emerges as a potential therapeutic target for myocardial infarction.

Itga9 protects against thoracic aortic aneurysm or dissection

Abstract Background The thoracic aortic aneurysm or dissection (TAAD) is a fatal cardiovascular disease with unclear pathogenic mechanisms. Integrins are important in coordinating the transmembrane connections between the extracellular matrix (ECM) and cytoskeleton, contributing to pathological processes of various diseases. Integrin α9 (Itga9), one of the integrin family subunits, has emerged as critical for vascular homeostasis. However, the contribution of Itga9 to TAAD remains elusive. Purpose The present study aimed to determine the role of Itga9 in the development of TAAD and its underlying mechanisms. Methods Western blotting and immunofluorescence staining were used to evaluate ITGA9 expression in the human Standford-A AAD tissues and rodent model of TAAD. Beta-aminopropionitrile monofumarate (BAPN) was used to induce TAAD mouse model. Vascular smooth muscle cell (VSMC)-specific Itga9 knockout mice or adeno-associated virus (AAV)-treated Itga9 overexpressed mice were generated to detect the role of Itga9 in the progression of TAAD. RNA-sequencing analysis was performed to discern possible transcriptome changes in the aorta tissues of VSMC-specific Itga9 knockout mice after BAPN treatment. Primary mouse aortic VSMC culture, flow cytometry analysis, EdU incorporation assay, transmission electron microscopy, and autophagy flux experiments were performed to evaluate the function of Itga9 on VSMCs and uncover its downstream target. Results ITGA9 expression levels were reduced in the aorta tissues of Standford-A AAD patients and BAPN-induced TAAD mice. VSMC-specific deletion of Itga9 exacerbated the incidence of BAPN-induced TAAD in mice. Itga9 deficiency downregulated Valosin-containing protein (Vcp) expression in mice aorta and caused reduced autophagy biomarkers of LC3 after BAPN treatment. In the primary aortic VSMCs, Itga9 deficiency resulted in repressed autophagy, accelerated apoptosis, and reduced proliferation ability. Mechanistically, Itga9 recruited the transcription factor Pre-B-cell leukemia transcription factor 1 (Pbx1) to activate the Vcp and promote VSMC autophagy. Consistently, overexpression of Itga9 in vitro and in vivo rescued the autophagic change and protected against the TAAD progression by upregulating the expression of Pbx1 and Vcp. Conclusions Our findings indicate a critical role of Itga9 in the regulation of VSMC autophagy by controlling Pbx1-Vcp. The Itga9-Pbx1-Vcp axis may represent a novel therapeutic target against TAAD.

Human RAMP1 overexpressing mice are resistant to migraine therapies for motion sensitivity.

Both enhanced motion-induced nausea and increased static imbalance are observed symptoms in migraine and especially vestibular migraine (VM). Motion-induced nausea and static imbalance were investigated in a mouse model, nestin/hRAMP1, expressing elevated levels of human RAMP1 which enhances CGRP signaling in the nervous system, and compared to non-affected littermate controls. Behavioral surrogates such as the motion- induced thermoregulation and postural sway center of pressure (CoP) assays were used to assess motion sensitivity. Nausea readouts revealed that the nestin/hRAMP1 mouse exhibit an increased sensitivity to CGRP's effects at lower doses compared to unaffected controls. In addition, the nestin/hRAMP1 mice exhibit a higher dynamic range in postural sway than their wildtype counterparts, along with increased sway observed in nestin/hRAMP1 male mice that was not present in male unaffected controls. Results from migraine blocker experiments were challenging to interpret, but the data suggests that olcegepant is incapable of reversing CGRP-induced or endogenous alterations in the nestin/hRAMP1 mice, while rizatriptan was ineffective in both the nestin/hRAMP1 and control mice. The results indicate that overexpression of hRAMP1 leads to heightened endogenous CGRP signaling. Results also suggest that both olcegepant and rizatriptan are ineffective in reducing nausea and sway in this hypersensitive CGRP mouse model. This study suggests that the hypersensitive nestin/hRAMP1 mouse may serve as a model for difficult to treat cases of migraine that exhibit increased motion sensitivity.

Cardiomyocyte proliferation is promoted by intracellular Gas6-mediated Yap activity during neonatal heart regeneration

Abstract Purpose The adult mammalian heart has limited regenerative capacity after injury, mostly attributable to postnatal cardiomyocyte (CM) cell cycle arrest. The key to unlocking the regenerative potential of the adult hearts may lie within the developmental transitions occurring during neonatal life. Gas6, a secretory protein, stimulates the proliferation of various type cells through binding to TAM receptor family, such as endothelial progenitor cells, tumor cells, and hair follicle stem-cell. However, no study to date has studied the role of Gas6 during the proliferation of CMs. Herein, our study uncovers that Gas6 is transiently expressed during early postnatal heart and regenerative heart, and functions through intracellular pathway by regulating Yap activity to promote CM proliferation. Methods CM isolation was conducted to assess the change of Gas6 expression in both postnatal development and regenerated stages using the CM-specific Tdtomato mice. Cardiac deletion of Gas6 gene mice was used to evaluate the impaired heart regeneration. CM-specific Gas6 overexpression mice were generated using adeno-associated virus system to evaluate Gas6 pro-proliferate and protect effect after ischemic injury. Secreted signal peptide truncation (ΔSP-Gas6) and predicted functional region truncation (ΔCC-Gas6) were generated to identify the intracellular mechanism of Gas6 via Sav1/p-mst1/p-lats1/ p-yap axis. Results We found that Gas6 expression is enriched in CM4 and the expression profile correlates with the expression of the CM4 marker Acta2, as well as cell-cycle genes Mki67 and Aurora B, in individual CM. Gas6 was highly expressed in the neonatal heart and continued to increase during the neonatal heart regenerative process, but was nearly absent in the adult heart under physiological and ischemia conditions. CM-specific Gas6 deletion resulted in significantly reduced CM proliferation rate and increased CM size in P0 hearts, and congestive heart failure in P28 hearts. Conversely, sustained CM-specific overexpression of Gas6 in postnatal hearts increased CM division, elevated CM numbers, and reduced CM size; and reduced infarct scar area and enhanced cardiac function after ischemia injury. Pre-overexpression of Gas6 in adult CMs protected adult cardiac function against ischemia injury, indicated by the activation of mitosis, angiogenesis and reduced oxidative phosphorylation. In primary neonatal CMs, both Gas6 and ΔSP-Gas6promoted CM proliferation with sarcomere disassembly. Mechanistically, Gas6 interacted with Sav1to inhibit Mst1recruitment and Mst1/Lats1/Yap phosphorylation cascade, therefore, promoted Yap translocation into nucleus. Conclusions We demonstrate that Gas6 is an important intrinsic regulator of neonatal heart regeneration, which acts as a promoter of Yap transcriptional activity to enhance CM proliferation. Supplementing Gas6 in the adult heart represents a potential therapeutic approach for cardiac repair.

NEK4 modulates circadian fluctuations of emotional behaviors and synaptogenesis in male mice

GWASs have linked the 3p21.1 locus, which is associated with the expression levels of NEK4, to bipolar disorder. Here, we use integrative analyses of GWAS statistics and eQTL annotations to establish that elevated NEK4 expression in the hippocampus is associated with an increased risk of bipolar disorder. To further study this association, we generate transgenic male mice that conditionally overexpress NEK4 in the pyramidal neurons of the adult forebrain, or use AAV to overexpress NEK4 in the dorsal hippocampus. Compared to the control mice, male mice of both strains exhibit a shift from a diurnal anxiety state to a nocturnal normal or anxiolytic-like state. Overexpression of NEK4 also affects the circadian fluctuations in dendritic spine morphology and synaptic structure. Furthermore, we show that treatment with lithium ameliorates the effects of NEK4 overexpression in male mice. We then perform phosphoproteomic analyses to demonstrate that the diurnal and nocturnal phosphoproteomic profiles of male control and NEK4 overexpressing mice are different. These results suggest that male mice with different NEK4 expression levels may recapitulate some of the core features observed in patients with bipolar disorder, indicating that interruption of the homeostatic dynamics of synapses may underlie the emotional swings in bipolar disorder.

MiR-210 is essential to retinal homeostasis in fruit flies and mice

BackgroundmiR-210 is one of the most evolutionarily conserved microRNAs. It is known to be involved in several physiological and pathological processes, including response to hypoxia, angiogenesis, cardiovascular diseases and cancer. Recently, new roles of this microRNA are emerging in the context of eye and visual system homeostasis. Recent studies in Drosophila melanogaster unveiled that the absence of miR-210 leads to a progressive retinal degeneration characterized by the accumulation of lipid droplets and disruptions in lipid metabolism. However, the possible conservation of miR-210 knock-out effect in the mammalian retina has yet to be explored.ResultsWe further investigated lipid anabolism and catabolism in miR-210 knock-out (KO) flies, uncovering significant alterations in gene expression within these pathways. Additionally, we characterized the retinal morphology of flies overexpressing (OE) miR-210, which was not affected by the increased levels of the microRNA. For the first time, we also characterized the retinal morphology of miR-210 KO and OE mice. Similar to flies, miR-210 OE did not affect retinal homeostasis, whereas miR-210 KO mice exhibited photoreceptor degeneration. To explore other potential parallels between miR-210 KO models in flies and mice, we examined lipid metabolism, circadian behaviour, and retinal transcriptome in mice, but found no similarities. Specifically, RNA-seq confirmed the lack of involvement of lipid metabolism in the mice’s pathological phenotype, revealing that the differentially expressed genes were predominantly associated with chloride channel activity and extracellular matrix homeostasis. Simultaneously, transcriptome analysis of miR-210 KO fly brains indicated that the observed alterations extend beyond the eye and may be linked to neuronal deficiencies in signal detection and transduction.ConclusionsWe provide the first morphological characterization of the retina of miR-210 KO and OE mice, investigating the role of this microRNA in mammalian retinal physiology and exploring potential parallels with phenotypes observed in fly models. Although the lack of similarities in lipid metabolism, circadian behaviour, and retinal transcriptome in mice suggests divergent mechanisms of retinal degeneration between the two species, transcriptome analysis of miR-210 KO fly brains indicates the potential existence of a shared upstream mechanism contributing to retinal degeneration in both flies and mammals.

Cardiac-derived CTRP9 mediates the protection of empagliflozin against diabetes-induced male subfertility in mice.

Previous studies have shown beneficial effects of empagliflozin (Empa), a selective inhibitor of the sodium-glucose cotransporter 2 (SGLT2), on diabetes and cardiovascular outcomes in patients with diabetes. However, whether Empa could ameliorate diabetes mellitus (DM)-induced male spermatogenesis dysfunction remains unclear. Our study aimed to investigate the effect of Empa in the development of DM-induced male spermatogenesis dysfunction and to reveal the molecular mechanisms. DM mice were orally treated with Empa to investigate the effects of Empa on DM-induced male mice spermatogenesis dysfunction. We employed a cardiac-specific C1q/tumor necrosis factor-related protein 9 (CTRP9)-deficient mouse model and a cardiac-specific CTRP9 overexpression mouse model to investigate its role in the protection of Empa against diabetes-induced male subfertility. We found that Empa treatment could improve DM-induced male mice subfertility. Interestingly, we discovered that cardiac-derived CTRP9 was decreased in DM mice and this decrease was prevented by Empa treatment. A CTRP9 blocking antibody or cardiac-specific depletion of CTRP9 abolished the protection of Empa on DM-induced male subfertility. Cardiac-specific CTRP9 overexpression ameliorated DM-induced male subfertility. Mechanistically, we identified that cardiac-derived CTRP9 increased steroidogenesis in mice with diabetes in a PKA-dependent manner. We also provided direct evidence that activation of AMP activated protein kinase α (AMPKα)/nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathway by CTRP9 was responsible for the attenuation of ferroptosis in Leydig cells. In conclusions, we supposed that Empa was a potential therapeutic agent against DM-induced male mice spermatogenesis dysfunction.

SLAMF8 regulates osteogenesis and adipogenesis of bone marrow mesenchymal stem cells via S100A6/Wnt/β-catenin signaling pathway

BackgroundThe inflammatory microenvironment plays an essential role in bone healing after fracture. The signaling lymphocytic activation molecule family (SLAMF) members deeply participate in inflammatory response and make a vast difference.MethodsWe identified SLAMF8 in GEO datasets (GSE129165 and GSE176086) and co-expression analyses were performed to define the relationships between SLAMF8 and osteogenesis relative genes (RUNX2 and COL1A1). In vitro, we established SLAMF8 knockdown and overexpression mouse bone marrow mesenchymal stem cells (mBMSCs) lines. qPCR, Western blot, ALP staining, ARS staining, Oil Red O staining and Immunofluorescence analyses were performed to investigate the effect of SLAMF8 in mBMSCs osteogenesis and adipogenesis. In vivo, mice femoral fracture model was performed to explore the function of SLAMF8.ResultsSLAMF8 knockdown significantly suppressed the expression of osteogenesis relative genes (RUNX2, SP7 and COL1A1), ALP activity and mineral deposition, but increased the expression of adipogenesis relative genes (PPARγ and C/EBPα). Additionally, SLAMF8 overexpression had the opposite effects. The role SLAMF8 played in mBMSCs osteogenic and adipogenic differentiation were through S100A6 and Wnt/β-Catenin signaling pathway. Moreover, SLAMF8 overexpression mBMSCs promoted the healing of femoral fracture.ConclusionsSLAMF8 promotes osteogenesis and inhibits adipogenesis of mBMSCs via S100A6 and Wnt/β-Catenin signaling pathway. SLAMF8 overexpression mBMSCs effectively accelerate the healing of femoral fracture in mice.