Thymidine Phosphorylase Promotes the Formation of Abdominal Aortic Aneurysm in Mice Fed a Western Diet.

Aims: The precise molecular drivers of abdominal aortic aneurysm (AAA) remain unclear. Thymidine phosphorylase (TYMP) contributes to increased platelet activation, thrombosis, and inflammation, all of which are key factors in AAA development. Additionally, TYMP suppresses the proliferation of vascular smooth muscle cells (VSMCs), which are central to the development and progression of AAA. We hypothesize that TYMP plays a key role in AAA development. Methods and Results: We conducted a histological study using human AAA samples and normal abdominal aortas, revealing heightened levels of TYMP in human AAA vessel walls. To validate this observation, we utilized an Ang II perfusion-induced AAA model in wild-type C57BL/6J (WT) and Tymp-/- mice, feeding them a Western diet (TD.88137) starting from 4 weeks of age. We found that Tymp-/- mice were protected from Ang II perfusion-induced AAA formation. Furthermore, by using TYMP-expressing VSMCs as well as primarily cultured VSMCs from WT and Tymp-/- mice, we elucidated the essential role of TYMP in regulating MMP2 expression and activation. TYMP deficiency or inhibition by tipiracil, a selective TYMP inhibitor, led to reduced MMP2 production, release, and activation in VSMCs. Additionally, TYMP was found to promote pro-inflammatory cytokine expression systemically, and its absence attenuates TNF-α-stimulated activation of MMP2 and AKT. By co-culturing VSMCs and platelets, we observed that TYMP-deficient platelets had a reduced inhibitory effect on VSMC proliferation compared to WT platelets. Moreover, TYMP appeared to enhance the expression of activated TGFß1 in cultured VSMCs in vitro and in human AAA vessel walls in vivo. TYMP also boosted the activation of thrombospondin-1 type 1 repeat domain-enhanced TGFß1 signaling, resulting in increased connective tissue growth factor production. Conclusion: Our findings collectively demonstrated that TYMP serves as a novel regulatory force in vascular biology, exerting influence over VSMC functionality and inflammatory responses that promote the development of AAA.

Digital light 4D printing of bioresorbable shape memory elastomers for personalized biomedical implantation.

Four-dimensional (4D) printing unlocks new potentials for personalized biomedical implantation, but still with hurdles of lacking suitable materials. Herein, we demonstrate a bioresorbable shape memory elastomer (SME) with high elasticity at both below and above its phase transition temperature (Ttrans). This SME can be digital light 3D printed by co-polymerizing glycerol dodecanoate acrylate prepolymer (pre-PGDA) with acrylic acid monomer to form crosslinked Poly(glycerol dodecanoate acrylate) (PGDA)-Polyacrylic acid (PAA), or PGDA-PAA network. The printed complex, free-standing 3D structures with high-resolution features exhibit shape programming properties at a physiological temperature. By tuning the pre-PGDA weight ratios between 55 wt% and 70 wt%, Ttrans varies between 39.2 and 47.2 ℃ while Young's moduli (E) range 40-170 MPa below Ttrans with fractural strain (εf) of 170 %-200 %. Above Ttrans, E drops to 1-1.82 MPa which is close to those of soft tissue. Strikingly, εf of 130-180 % is still maintained. In vitro biocompatibility test on the material shows > 90 % cell proliferation and great cell attachment. In vivo vascular grafting trials underline the geometrical and mechanical adaptability of these 4D printed constructs in regenerating the aorta tissue. Biodegradation of the implants shows the possibility of their full replacement by natural tissue over time. To highlight its potential for personalized medicine, a patient-specific left atrial appendage (LAA) occluder was printed and implanted endovascularly into an in vitro heart model. STATEMENT OF SIGNIFICANCE: 4D printed shape-memory elastomer (SME) implants particularly designed and manufactured for a patient are greatly sought-after in minimally invasive surgery (MIS). Traditional shape-memory polymers used in these implants often suffer from issues like unsuitable transition temperatures, poor biocompatibility, limited 3D design complexity, and low toughness, making them unsuitable for MIS. Our new SME, with an adjustable transition temperature and enhanced toughness, is both biocompatible and naturally degradable, particularly in cardiovascular contexts. This allows implants, like biomedical scaffolds, to be programmed at room temperature and then adapt to the body's physiological conditions post-implantation. Our studies, including in vivo vascular grafts and in vitro device implantation, highlight the SME's effectiveness in aortic tissue regeneration and its promising applications in MIS.

DOCK2 Promotes Atherosclerosis by Mediating the Endothelial Cell Inflammatory Response.

The pathology of atherosclerosis, a leading cause of mortality in patients with cardiovascular disease, involves inflammatory phenotypic changes in vascular endothelial cells. This study explored the role of the dedicator of cytokinesis (DOCK)-2 protein in atherosclerosis. Mice with deficiencies in low-density lipoprotein receptor and Dock2 (Ldlr-/-Dock2-/-) and controls (Ldlr-/-) were fed a high-fat diet (HFD) to induce atherosclerosis. In controls, Dock2 was increased in atherosclerotic lesions, with increased intercellular adhesion molecule (Icam)-1 and vascular cell adhesion molecule (Vcam)-1, after HFD for 4 weeks. Ldlr-/-Dock2-/- mice exhibited significantly decreased oil red O staining in both aortic roots and aortas compared to that in controls after HFD for 12 weeks. In control mice and in humans, Dock2 was highly expressed in the ECs of atherosclerotic lesions. Dock2 deficiency was associated with attenuation of Icam-1, Vcam-1, and monocyte chemoattractant protein (Mcp)-1 in the aortic roots of mice fed HFD. Findings in human vascular ECs in vitro suggested that DOCK2 was required in TNF-α-mediated expression of ICAM-1/VCAM-1/MCP-1. DOCK2 knockdown was associated with attenuated NF-κB phosphorylation with TNF-α, partially accounting for DOCK2-mediated vascular inflammation. With DOCK2 knockdown in human vascular ECs, TNF-α-mediated VCAM-1 promoter activity was inhibited. The findings from this study suggest the novel concept that DOCK2 promotes the pathogenesis of atherosclerosis by modulating inflammation in vascular ECs.

ADAR1 exacerbates ischemic brain injury via astrocyte-mediated neuron apoptosis.

Astrocytes affect stroke outcomes by acquiring functionally dominant phenotypes. Understanding molecular mechanisms dictating astrocyte functional status after brain ischemia/reperfusion may reveal new therapeutic strategies. Adenosine deaminase acting on RNA (ADAR1), an RNA editing enzyme, is not normally expressed in astrocytes, but highly induced in astrocytes in ischemic stroke lesions. The expression of ADAR1 steeply increased from day 1 to day 7 after middle cerebral artery occlusion (MCAO) for 1 h followed by reperfusion. ADAR1 deficiency markedly ameliorated the volume of the cerebral infarction and neurological deficits as shown by the rotarod and cylinder tests, which was due to the reduction of the numbers of activated astrocytes and microglia. Surprisingly, ADAR1 was mainly expressed in astrocytes while only marginally in microglia. In primary cultured astrocytes, ADAR1 promoted astrocyte proliferation via phosphatidylinositol 3-kinase (PI3K)/Akt pathway. Furthermore, ADAR1 deficiency inhibited brain cell apoptosis in mice with MCAO as well as in activated astrocyte-conditioned medium-induced neurons in vitro. It appeared that ADAR1 induces neuron apoptosis by secretion of IL-1ß, IL-6 and TNF-α from astrocytes through the production of reactive oxygen species. These results indicated that ADAR1 is a novel regulator promoting the proliferation of the activated astrocytes following ischemic stroke, which produce various inflammatory cytokines, leading to neuron apoptosis and worsened ischemic stroke outcome.

DOCK2 Deficiency Attenuates Abdominal Aortic Aneurysm Formation-Brief Report.

BACKGROUND: Abdominal aortic aneurysm (AAA) is a potentially lethal disease that lacks pharmacological treatment. Degradation of extracellular matrix proteins, especially elastin laminae, is the hallmark for AAA development. DOCK2 (dedicator of cytokinesis 2) has shown proinflammatory effects in several inflammatory diseases and acts as a novel mediator for vascular remodeling. However, the role of DOCK2 in AAA formation remains unknown. METHODS: Ang II (angiotensin II) infusion of ApoE-/- (apolipoprotein E deficient) mouse and topical elastase-induced AAA combined with DOCK2-/- (DOCK2 knockout) mouse models were used to study DOCK2 function in AAA formation/dissection. The relevance of DOCK2 to human AAA was examined using human aneurysm specimens. Elastin fragmentation in AAA lesion was observed by elastin staining. Elastin-degrading enzyme MMP (matrix metalloproteinase) activity was measured by in situ zymography. RESULTS: DOCK2 was robustly upregulated in AAA lesion of Ang II-infused ApoE-/- mice, elastase-treated mice, as well as human AAA lesions. DOCK2-/- significantly attenuated the Ang II-induced AAA formation/dissection or rupture in mice along with reduction of MCP-1 (monocyte chemoattractant protein-1) and MMP expression and activity. Accordingly, the elastin fragmentation observed in ApoE-/- mouse aorta infused with Ang II and elastase-treated aorta was significantly attenuated by DOCK2 deficiency. Moreover, DOCK2-/- decreased the prevalence and severity of aneurysm formation, as well as the elastin degradation observed in the topical elastase model. CONCLUSIONS: Our results indicate that DOCK2 is a novel regulator for AAA formation. DOCK2 regulates AAA development by promoting MCP-1 and MMP2 expression to incite vascular inflammation and elastin degradation.

Surfactant protein A promotes atherosclerosis through mediating macrophage foam cell formation.

BACKGROUND: Atherosclerosis is a progressive inflammatory disease where macrophage foam cells play a central role in the pathogenesis. Surfactant protein A (SPA) is a lipid-associating protein involved with regulating macrophage function in various inflammatory diseases. However, the role of SPA in atherosclerosis and macrophage foam cell formation has not been investigated. METHODS: Primary resident peritoneal macrophages were extracted from wildtype (WT) and SPA deficient (SPA -/- ) mice to determine the functional effects of SPA in macrophage foam cell formation. SPA expression was assessed in healthy vessels and atherosclerotic aortic tissue from the human coronary artery and WT or apolipoprotein e-deficient (ApoE -/- ) mice brachiocephalic arteries fed high fat diets (HFD) for 4 weeks. Hypercholesteremic WT and SPA -/- mice fed a HFD for 6 weeks were investigated for atherosclerotic lesions in vivo . RESULTS: In vitro experiments revealed that global SPA deficiency reduced intracellular cholesterol accumulation and macrophage foam cell formation. Mechanistically, SPA -/- dramatically decreased CD36 cellular and mRNA expression. SPA expression was increased in atherosclerotic lesions in humans and ApoE -/- mice. In vivo SPA deficiency attenuated atherosclerosis and reduced the number of lesion-associated macrophage foam cells. CONCLUSIONS: Our results elucidate that SPA is a novel factor for atherosclerosis development. SPA enhances macrophage foam cell formation and atherosclerosis through increasing scavenger receptor cluster of differentiation antigen 36 (CD36) expression.

ADAR1 Non-Editing Function in Macrophage Activation and Abdominal Aortic Aneurysm.

BACKGROUND: Macrophage activation plays a critical role in abdominal aortic aneurysm (AAA) development. However, molecular mechanisms controlling macrophage activation and vascular inflammation in AAA remain largely unknown. The objective of the study was to identify novel mechanisms underlying adenosine deaminase acting on RNA (ADAR1) function in macrophage activation and AAA formation. METHODS: Aortic transplantation was conducted to determine the importance of nonvascular ADAR1 in AAA development/dissection. Ang II (Angiotensin II) infusion of ApoE-/- mouse model combined with macrophage-specific knockout of ADAR1 was used to study ADAR1 macrophage-specific role in AAA formation/dissection. The relevance of macrophage ADAR1 to human AAA was examined using human aneurysm specimens. Moreover, a novel humanized AAA model was established to test the role of human macrophages in aneurysm formation in human arteries. RESULTS: Allograft transplantation of wild-type abdominal aortas to ADAR1+/- recipient mice significantly attenuated AAA formation, suggesting that nonvascular ADAR1 is essential for AAA development. ADAR1 deficiency in hematopoietic cells decreased the prevalence and severity of AAA while inhibited macrophage infiltration and aorta wall inflammation. ADAR1 deletion blocked the classic macrophage activation, diminished NF-κB (nuclear factor kappa B) signaling, and enhanced the expression of a number of anti-inflammatory microRNAs. Mechanistically, ADAR1 interacted with Drosha to promote its degradation, which attenuated Drosha-DGCR8 (DiGeorge syndrome critical region 8) interaction, and consequently inhibited pri- to pre-microRNA processing of microRNAs targeting IKKß, resulting in an increased IKKß (inhibitor of nuclear factor kappa-B) expression and enhanced NF-κB signaling. Significantly, ADAR1 was induced in macrophages and interacted with Drosha in human AAA lesions. Reconstitution of ADAR1-deficient, but not the wild type, human monocytes to immunodeficient mice blocked the aneurysm formation in transplanted human arteries. CONCLUSIONS: Macrophage ADAR1 promotes aneurysm formation in both mouse and human arteries through a novel mechanism, that is, Drosha protein degradation, which inhibits the processing of microRNAs targeting NF-kB signaling and thus elicits macrophage-mediated vascular inflammation in AAA.

Blood serum analysis: A modified sandwich enzyme-linked immunosorbent assay protocol.

Blood serum analysis is a versatile tool used in diagnostics, in vivo research, and clinical studies. Enzyme-linked immunosorbent assay (ELISA) is a common method used to analyze blood serum cytokine levels; however, commercial kits are costly and not always available for novel or uncommon targets. Here we present a modified ELISA protocol that, once standardized, can be used to measure blood serum levels of any target and minimize the expense of commercial kits. Additionally, this method can be used for novel or unique targets for which commercial options are unavailable. Ultimately, the modified ELISA method is an efficient, cost-effective method of supplementing clinical and in vivo studies with consistently reliable serum cytokine measurements.

ADAR1 promotes systemic sclerosis via modulating classic macrophage activation.

Introduction: As a multisystem autoimmune disorder disease, systemic sclerosis (SSc) is characterized by inflammation and fibrosis in the skin and other internal organs. However, mechanisms underlying the inflammatory response that drives the development of SSc remain largely unknown. Methods: ADAR1 heterozygous knockout (AD1+/-) mice and myeloid-specific ADAR1 knockout mice were used to determine the function of ADAR1 in SSc. Histopathological analyses and western blot confirmed the role of ADAR1 in bleomycin-induced increased skin and lung fibrosis. Results: In this study, we discover that adenosine deaminase acting on RNA (ADAR1), a deaminase converting adenosine to inosine (i.e., RNA editing) in RNA, is abundantly expressed in macrophages in the early stage of bleomycin-induced SSc. Importantly, ADAR1 is essential for SSc formation and indispensable for classical macrophage activation because ADAR1 deficiency in macrophages significantly ameliorates skin and lung sclerosis and inhibits the expression of inflammation mediator inducible NO synthase (iNOS) and IL-1ß in macrophages. Mechanistically, deletion of ADAR1 blocks macrophage activation through diminishing NF-κB signaling. Discussion: Our studies reveal that ADAR1 promotes macrophage activation in the onset of SSc. Thus, targeting ADAR1 could be a potential novel therapeutic strategy for treating sclerosis formation.

Nanoparticle endothelial delivery of PGC-1α attenuates hypoxia-induced pulmonary hypertension by attenuating EndoMT-caused vascular wall remodeling.

Pulmonary hypertension (PH) induced by chronic hypoxia is characterized by thickening of pulmonary artery walls, elevated pulmonary vascular resistance, and right-heart failure. Dysfunction of endothelial cells is the hallmark event in the progression of PH. Among various mechanisms, endothelial to mesenchymal transition (EndoMT) has emerged as an important source of endothelial cell dysfunction in PH. However, the mechanisms underlying the EndoMT in PH remain largely unknown. Our results showed that peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) expression was decreased in pulmonary arterial endothelial cells (PAECs) in PH patients and hypoxia-induced PH mouse model compared to the normal controls. Endothelial-specific overexpression of PGC-1α using nanoparticle delivery significantly attenuated the progression of PH, as shown by the significantly decreased right ventricular systolic pressure and diminished artery thickness as well as reduced vascular muscularization. Moreover, Endothelial-specific overexpression of PGC-1α blocked the EndoMT of PAECs during PH, indicating that loss of PGC-1α promotes PH development by mediating EndoMT, which damages the integrity of endothelium. Intriguingly, we found that PGC-1α overexpression rescued the expression of endothelial nitric oxide synthase in mouse lung tissues that was deceased by hypoxia treatment in vivo and in endothelial cells treated with TGF-ß in vitro. Consistently, PAECs and vascular smooth muscle co-culture showed that overexpression of PGC-1α in PAECs increases nitric oxide release, which would likely diffuse to smooth muscle cells, where it activates specific protein kinases, and initiates SMC relaxation by diminishing the calcium flux. Endothelial-specific overexpression of PGC-1α also attenuated hypoxia-induced pulmonary artery stiffness which appeared to be caused by both the decreased endothelial nitric oxide production and increased vascular remodeling. Taken together, these results demonstrated that endothelial-specific delivery of PGC-1α prevents PH development by inhibiting EndoMT of PAECs and thus restoring endothelial function and reducing vascular remodeling.

Methamphetamine induces thoracic aortic aneurysm/dissection through C/EBPß.

AIMS: Thoracic aortic aneurysm/dissection (TAAD) is a life-threatening disease with diverse clinical manifestations. Although the association between methamphetamine (METH) and TAAD is frequently observed, the causal relationship between METH abuse and aortic aneurysm/dissection has not been established. This study was designed to determine if METH causes aortic aneurysm/dissection and delineate the underlying mechanism. METHODS AND RESULTS: A new TAAD model was developed by exposing METH to SD rats pre-treated with lysyl oxidase inhibitor ß-aminopropionitrile (BAPN). Combination of METH and BAPN caused thoracic aortic aneurysm/dissection in 60% of rats. BAPN+METH significantly increased the expression and activities of both matrix metalloproteinase MMP2 and MMP9, consistent with the severe elastin breakage and dissection. Mechanistically, METH increased CCAAT-enhancer binding protein ß (C/EBPß) expression by enhancing mothers against decapentaplegic homolog 3 (Smad3) and extracellular regulated protein kinase (ERK1/2) signaling. METH also promoted C/EBPß binding to MMP2 and MMP9 promoters. Blocking C/EBPß significantly attenuated METH+BAPN-induced TAAD and MMP2/MMP9 expression. Moreover, BAPN+METH promoted aortic medial smooth muscle cell (SMC) apoptosis through C/EBPß-mediated IGFBP5/p53/PUMA signaling pathways. More importantly, the expression of C/EBPß, MMP2/MMP9, and apoptosis-promoting proteins was increased in the aorta of human patients with thoracic aortic dissection, suggesting that the mechanisms identified in animal study could be relevant to human disease. CONCLUSIONS: Our study demonstrated that METH exposure has a casual effect on TAAD. C/EBPß mediates METH-introduced TAAD formation by causing elastin breakage, medial cell loss and degeneration. Therefore, C/EBPß may be a potential factor for TAAD clinical diagnosis or treatment.

A systems approach using Diversity Outbred mice distinguishes the cardiovascular effects and genetics of circulating GDF11 from those of its homolog, myostatin.

Growth differentiation factor 11 (GDF11) is a member of the TGF-ß protein family that has been implicated in the development of cardiac hypertrophy. While some studies have suggested that systemic GDF11 protects against cardiomyocyte enlargement and left ventricular wall thickening, there remains uncertainty about the true impact of GDF11 and whether its purported effects are actually attributable to its homolog myostatin. This study was conducted to resolve the statistical and genetic relationships among GDF11, myostatin, and cardiac hypertrophy in a mouse model of human genetics, the Diversity Outbred (DO) stock. In the DO population, serum GDF11 concentrations positively correlated with cardiomyocyte cross-sectional area, while circulating myostatin levels were negatively correlated with body weight, heart weight, and left ventricular wall thickness and mass. Genetic analyses revealed that serum GDF11 concentrations are modestly heritable (0.23) and identified a suggestive peak on murine chromosome 3 in close proximity to the gene Hey1, a transcriptional repressor. Bioinformatic analyses located putative binding sites for the HEY1 protein upstream of the Gdf11 gene in the mouse and human genomes. In contrast, serum myostatin concentrations were more heritable (0.57) than GDF11 concentrations, and mapping identified a significant locus near the gene FoxO1, which has binding motifs within the promoter regions of human and mouse myostatin genes. Together, these findings more precisely define the independent cardiovascular effects of GDF11 and myostatin, as well as their distinct regulatory pathways. Hey1 is a compelling candidate for the regulation of GDF11 and will be further evaluated in future studies.

A Novel Mechanism Underlying Inflammatory Smooth Muscle Phenotype in Abdominal Aortic Aneurysm.

[Figure: see text].

Methamphetamine mediates apoptosis of vascular smooth muscle cells via the chop-related endoplasmic reticulum stress pathway.

Methamphetamine (METH) is a highly addictive amphetamine-type drug that has caused persistent harm to society and human health in recent years. Most studies have shown that METH severely damages the central nervous system, and this drug has been found to be toxic to the cardiovascular system in recent years. Therefore, we hypothesized that METH may also damage vascular smooth muscle. We examined the expression of the apoptosis-related proteins Caspase 3 and PARP after METH treatment in vivo and in vitro and detected the expression of endoplasmic reticulum stress-related proteins. After treatment with the endoplasmic reticulum stress inhibitor 4-PBA, changes in the above indicators were examined. C/EBP homologous protein (Chop) expression was also detected, and the relationship between endoplasmic reticulum stress and apoptosis was further determined by siRNA silencing of Chop. The results indicated that METH can induce apoptosis of vascular smooth muscle cells (VSMCs) and upregulate the expression of Chop and endoplasmic reticulum stress-related proteins. Chop inhibits protein kinase B phosphorylation and further inhibits forkhead box class O3a (Foxo3a) dephosphorylation, resulting in increased p53 upregulated molecular of apoptosis (PUMA) transcription. Increased PUMA induces apoptosis through the mitochondrial pathway. These results indicate that Chop is involved in the METH-induced endoplasmic reticulum stress and apoptosis in VSMCs and may be a potential therapeutic target for METH-induced VSMC injury.

Janus Kinase 3 Deficiency Promotes Vascular Reendothelialization-Brief Report.

[Figure: see text].

Nupr1 mediates renal fibrosis via activating fibroblast and promoting epithelial-mesenchymal transition.

Renal interstitial fibrosis (RIF) is a pathological process that fibrotic components are excessively deposited in the renal interstitial space due to kidney injury, resulting in impaired renal function and chronic kidney disease. The molecular mechanisms controlling renal fibrosis are not fully understood. In this present study, we identified Nuclear protein 1 (Nupr1), a transcription factor also called p8, as a novel regulator promoting renal fibrosis. Unilateral ureteral obstruction (UUO) time-dependently induced Nupr1 mRNA and protein expression in mouse kidneys while causing renal damage and fibrosis. Nupr1 deficiency (Nupr1-/- ) attenuated the renal tubule dilatation, tubular epithelial cell atrophy, and interstitial collagen accumulation caused by UUO. Consistently, Nupr1-/- significantly decreased the expression of type I collagen, myofibroblast markers smooth muscle α-actin (α-SMA), fibroblast-specific protein 1 (FSP-1), and vimentin in mouse kidney that were upregulated by UUO. These results suggest that Nupr1 protein was essential for fibroblast activation and/or epithelial-mesenchymal transition (EMT) during renal fibrogenesis. Indeed, Nupr1 was indispensable for TGF-ß-induced myofibroblast activation of kidney interstitial NRK-49F fibroblasts, multipotent mesenchymal C3H10T1/2 cells, and the EMT of kidney epithelial NRK-52E cells. It appears that Nupr1 mediated TGF-ß-induced α-SMA expression and collagen synthesis by initiating Smad3 signaling pathway. Importantly, trifluoperazine (TFP), a Nupr1 inhibitor, alleviated UUO-induced renal fibrosis. Taken together, our results demonstrate that Nupr1 promotes renal fibrosis by activating myofibroblast transformation from both fibroblasts and tubular epithelial cells.

4D Printing of shape-memory polymeric scaffolds for adaptive biomedical implantation.

4D printing has shown great potential in a variety of biomedical applications due to the adaptability and minimal invasiveness of fabricated devices. However, commonly employed shape memory polymers (SMPs) possess undesirable transition temperatures (Ttranss), leading to complications in implantation operations. Herein, we demonstrate 4D printing of a new SMP named poly(glycerol dodecanoate) acrylate (PGDA) with a Ttrans in a range of 20 °C - 37 °C making it appropriate for shape programming at room temperature and then shape deployment within the human body. In addition, the material possesses suitable rheological properties to allow for the fabrication of a variety of delicate 3D structures such as "triangular star", "six-petal flower", "honeycomb", "tube", tilted "truncated hollow cones", as well as overhanging "bridge", "cage", and "mesh". The printed 3D structures show shape memory properties including a large fixity ratio of 100% at 20 °C, a large recovery ratio of 98% at 37 °C, a stable cyclability of > 100 times, and a fast recovery speed of 0.4 s at 37 °C. Moreover, the Young's moduli of the printed structures can be decreased by 5 times due to the phase transition of PGDA, which is compatible with biological tissues. Finally, in vitro stenting and in vivo vascular grafting demonstrated the geometrical and mechanical adaptivity of the printed constructs for biomedical implantation. This newly developed PGDA SMP based 4D printing technology has the potential to pave a new route to the fabrication of shape memory scaffolds for personalized biomedical applications.

Surfactant Protein A, a Novel Regulator for Smooth Muscle Phenotypic Modulation and Vascular Remodeling-Brief Report.

OBJECTIVE: The objective of this study is to determine the role of SPA (surfactant protein A) in vascular smooth muscle cell (SMC) phenotypic modulation and vascular remodeling. Approach and Results: PDGF-BB (Platelet-derived growth factor-BB) and serum induced SPA expression while downregulating SMC marker gene expression in SMCs. SPA deficiency increased the contractile protein expression. Mechanistically, SPA deficiency enhanced the expression of myocardin and TGF (transforming growth factor)-ß, the key regulators for contractile SMC phenotype. In vivo, SPA was induced in medial and neointimal SMCs following mechanical injury in both rat and mouse carotid arteries. SPA knockout in mice dramatically attenuated the wire injury-induced intimal hyperplasia while restoring SMC contractile protein expression in medial SMCs. These data indicate that SPA plays an important role in SMC phenotype modulation and vascular remodeling in vivo. CONCLUSIONS: SPA is a novel protein factor modulating SMC phenotype. Blocking the abnormal elevation of SPA may be a potential strategy to inhibit the development of proliferative vascular diseases.

Exacerbation of Type 1 Diabetes in Perinatally Genistein Exposed Female Non-Obese Diabetic (NOD) Mouse Is Associated With Alterations of Gut Microbiota and Immune Homeostasis.

Despite various hypothesized benefits of dietary isoflavone genistein (GEN) from soy-based products, many questions surrounding GEN's immunotoxic effects, especially during perinatal exposure, have yet to be answered. The objective of the study was to determine if there existed a sex-specific effect of GEN on type 1 diabetes (T1D) following perinatal exposure. We exposed offspring of non-obese diabetic (NOD) mice to GEN per oral at a physiological dose (20 mg/kg body weight) from embryonic day 7 to postnatal day (PND) 21. In female offspring, perinatal GEN dosing significantly increased the incidence of T1D at early time points, and the exacerbation was associated with decreased serum levels of interleukin (IL)-10, IgG2a, and IgM. In male offspring dosed with GEN, a decrease in serum IgG1 was also observed. Flow cytometric analysis in females suggested an increased pro-inflammatory splenic CD5+CD24- and CD4-CD8+ cell counts, while both %T cells and %CD4+ T cells were significantly decreased in males, suggesting an anti-inflammatory effect. Gut microbiota (GMB) analysis indicated that fecal microbiota from PND 90 female offspring exhibited an increased level of Enterobacteriales (suggesting a pro-inflammatory response), while the similar changes were not found in PND 30 females. Moreover, RNA sequencing showed that intestinal α-defensin expression was down-regulated in GEN-treated females, supporting a pro-inflammatory response. However, perinatal GEN administration perturbed GMB toward an anti-inflammatory response in PND 90 males. Taken together, a strong sex-specific effect was found in the perinatal GEN exposure window, and the T1D exacerbation in NOD females was associated with GMB-related immunomodulatory mechanisms.

Methamphetamine exposure triggers apoptosis and autophagy in neuronal cells by activating the C/EBPß-related signaling pathway.

Methamphetamine (Meth) is a widely abused psychoactive drug that primarily damages the nervous system, notably causing dopaminergic neuronal apoptosis. CCAAT-enhancer binding protein (C/EBPß) is a transcription factor and an important regulator of cell apoptosis and autophagy. Insulin-like growth factor binding protein (IGFBP5) is a proapoptotic factor that mediates Meth-induced neuronal apoptosis, and Trib3 (tribbles pseudokinase 3) is an endoplasmic reticulum (ER) stress-inducible gene involved in autophagic cell death through the mammalian target of rapamycin (mTOR) signaling pathway. To test the hypothesis that C/EBPß is involved in Meth-induced IGFBP5-mediated neuronal apoptosis and Trib3-mediated neuronal autophagy, we measured the protein expression of C/EBPß after Meth exposure and evaluated the effects of silencing C/EBPß, IGFBP5, or Trib3 on Meth-induced apoptosis and autophagy in neuronal cells and in the rat striatum after intrastriatal Meth injection. We found that, at relatively high doses, Meth exposure increased C/EBPß protein expression, which was accompanied by increased neuronal apoptosis and autophagy; triggered the IGFBP5-mediated, p53-up-regulated modulator of apoptosis (PUMA)-related mitochondrial apoptotic signaling pathway; and stimulated the Trib3-mediated ER stress signaling pathway through the Akt-mTOR signaling axis. We also found that autophagy is an early response to Meth-induced stress upstream of apoptosis and plays a detrimental role in Meth-induced neuronal cell death. These results suggest that Meth exposure induces C/EBPß expression, which plays an essential role in the neuronal apoptosis and autophagy induced by relatively high doses of Meth; however, relatively low concentrations of Meth did not change the expression of C/EBPß in vitro. Further studies are needed to elucidate the role of C/EBPß in low-dose Meth-induced neurotoxicity.-Xu, X., Huang, E., Luo, B., Cai, D., Zhao, X., Luo, Q., Jin, Y., Chen, L., Wang, Q., Liu, C., Lin, Z., Xie, W.-B., Wang, H. Methamphetamine exposure triggers apoptosis and autophagy in neuronal cells by activating the C/EBPß-related signaling pathway.