Inflammatory Macrophage Interleukin-1β Mediates High-Fat Diet-Induced Heart Failure With Preserved Ejection Fraction

Diabetes mellitus (DM) is a main risk factor for diastolic dysfunction (DD) and heart failure with preserved ejection fraction. High-fat diet (HFD) mice presented with diabetes mellitus, DD, higher cardiac interleukin (IL)-1β levels, and proinflammatory cardiac macrophage accumulation. DD was significantly ameliorated by suppressing IL-1β signaling or depleting macrophages. Mice with macrophages unable to adopt a proinflammatory phenotype were low in cardiac IL-1β levels and were resistant to HFD-induced DD. IL-1β enhanced mitochondrial reactive oxygen species (mitoROS) in cardiomyocytes, and scavenging mitoROS improved HFD-induced DD. In conclusion, macrophage-mediated inflammation contributed to HFD-associated DD through IL-1β and mitoROS production.

STNM01, the RNA oligonucleotide targeting carbohydrate sulfotransferase 15, as second-line therapy for chemotherapy-refractory patients with unresectable pancreatic cancer: An open label, phase I/IIa trial

BACKGROUND

The impact of stroma-targeting therapy on tumor immune suppression is largely unexplored. An RNA oligonucleotide, STNM01, has been shown to repress carbohydrate sulfotransferase 15 (CHST15) responsible for tumor proteoglycan synthesis and matrix remodeling. This phase I/IIa study aimed to evaluate the safety and efficacy of STNM01 in patients with unresectable pancreatic ductal adenocarcinoma (PDAC).

METHODS

This was an open-label, dose-escalation study of STNM01 as second-line therapy in gemcitabine plus nab-paclitaxel-refractory PDAC. A cycle comprised three 2-weekly endoscopic ultrasound-guided locoregional injections of STNM01 at doses of 250, 1,000, 2,500, or 10,000 nM in combination with S-1 (80-120 mg twice a day for 14 days every 3 weeks). The primary outcome was the incidence of dose-liming toxicity (DLT). The secondary outcomes included overall survival (OS), tumor response, changes in tumor microenvironment on immunohistopathology, and safety (jRCT2031190055).

FINDINGS

A total of 22 patients were enrolled, and 3 cycles were repeated at maximum; no DLT was observed. The median OS was 7.8 months. The disease control rate was 77.3%; 1 patient showed complete disappearance of visible lesions in the pancreas and tumor-draining lymph nodes. Higher tumoral CHST15 expression was associated with poor CD3⁺ and CD8⁺ T cell infiltration at baseline. STNM01 led to a significant reduction in CHST15, and increased tumor-infiltrating CD3⁺ and CD8⁺ T cells in combination with S-1 at the end of cycle 1. Higher fold increase in CD3⁺ T cells correlated with longer OS. There were 8 grade 3 adverse events.

INTERPRETATION

Locoregional injection of STNM01 was well tolerated in patients with unresectable PDAC as combined second-line therapy. It prolonged survival by enhancing T cell infiltration in tumor microenvironment.

FUNDING

The present study was supported by the Japan Agency for Medical Research and Development (AMED).

Reduced Proteolytic Cleavage of von Willebrand Factor Leads to Aortic Valve Stenosis and Load-Dependent Ventricular Remodeling

We hypothesized that excess endothelial-associated von Willebrand factor (vWF) and secondary platelet adhesion contribute to aortic valve stenosis (AS). We studied hyperlipidemic mice lacking ADAMTS13 (LDLR ^-/- AD13 ^-/- ), which cleaves endothelial-associated vWF multimers. On echocardiography and molecular imaging, LDLR ^-/- AD13 ^-/- compared with control strains had increased aortic endothelial vWF and platelet adhesion and developed hemodynamically significant AS, arterial stiffening, high valvulo-aortic impedance, and secondary load-dependent reduction in LV systolic function. Histology revealed leaflet thickening and calcification with valve interstitial cell myofibroblastic and osteogenic transformation, and evidence for TGFβ1 pathway activation. We conclude that valve leaflet endothelial vWF-platelet interactions promote AS through juxtacrine platelet signaling.

Cardiovascular Disease in Myeloproliferative Neoplasms: JACC: CardioOncology State-of-the-Art Review

Myeloproliferative neoplasms are associated with increased risk for thrombotic complications. These conditions most commonly involve somatic mutations in genes that lead to constitutive activation of the Janus-associated kinase signaling pathway (eg, Janus kinase 2, calreticulin, myeloproliferative leukemia protein). Acquired gain-of-function mutations in these genes, particularly Janus kinase 2, can cause a spectrum of disorders, ranging from clonal hematopoiesis of indeterminate potential, a recently recognized age-related promoter of cardiovascular disease, to frank hematologic malignancy. Beyond thrombosis, patients with myeloproliferative neoplasms can develop other cardiovascular conditions, including heart failure and pulmonary hypertension. The authors review the pathophysiologic mechanisms of cardiovascular complications of myeloproliferative neoplasms, which involve inflammation, prothrombotic and profibrotic factors (including transforming growth factor-beta and lysyl oxidase), and abnormal function of circulating clones of mutated leukocytes and platelets from affected individuals. Anti-inflammatory therapies may provide cardiovascular benefit in patients with myeloproliferative neoplasms, a hypothesis that requires rigorous evaluation in clinical trials.

Platelets: Implications in Aortic Valve Stenosis and Bioprosthetic Valve Dysfunction From Pathophysiology to Clinical Care

Aortic stenosis (AS) is the most common heart valve disease requiring surgery in developed countries, with a rising global burden associated with aging populations. The predominant cause of AS is believed to be driven by calcific degeneration of the aortic valve and a growing body of evidence suggests that platelets play a major role in this disease pathophysiology. Furthermore, platelets are a player in bioprosthetic valve dysfunction caused by their role in leaflet thrombosis and thickening. This review presents the molecular function of platelets in the context of recent and rapidly evolving understanding the role of platelets in AS, both of the native aortic valve and bioprosthetic valves, where there remain concerns about the effects of subclinical leaflet thrombosis on long-term prosthesis durability. This review also presents the role of antiplatelet and anticoagulation therapies on modulating the impact of platelets on native and bioprosthetic aortic valves, highlighting the need for further studies to determine whether these therapies are protective and may increase the life span of surgical and transcatheter aortic valve implants. By linking molecular mechanisms through which platelets drive disease of native and bioprosthetic aortic valves with studies evaluating the clinical impact of antiplatelet and antithrombotic therapies, we aim to bridge the gaps between our basic science understanding of platelet biology and their role in patients with AS and ensuing preventive and therapeutic implications.

Ascending Aneurysms in Heart Transplant Patients: A Rare Opportunity to Assess Heredity Versus Biological Environment

Three patients developed severe ascending aortic aneurysm requiring surgical resection after heart transplantation. In all 3 cases, the donor aorta of the transplant remained normal in caliber, despite the development of a large aneurysm in the native upper ascending aorta. The aneurysmal disease did not cross the suture line. (Level of Difficulty: Advanced.)

Animal Models of Neointimal Hyperplasia and Restenosis: Species-Specific Differences and Implications for Translational Research

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Neointimal hyperplasia is the major factor contributing to restenosis after angioplasty procedures.

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Multiple animal models exist to study basic and translational aspects of restenosis formation.

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Animal models differ substantially, and species-specific differences have major impact on the pathophysiology of the model.

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Genetic, dietary, and mechanical interventions determine the translational potential of the animal model used and have to be considered when choosing the model.

The process of restenosis is based on the interplay of various mechanical and biological processes triggered by angioplasty-induced vascular trauma. Early arterial recoil, negative vascular remodeling, and neointimal formation therefore limit the long-term patency of interventional recanalization procedures. The most serious of these processes is neointimal hyperplasia, which can be traced back to 4 main mechanisms: endothelial damage and activation; monocyte accumulation in the subintimal space; fibroblast migration; and the transformation of vascular smooth muscle cells. A wide variety of animal models exists to investigate the underlying pathophysiology. Although mouse models, with their ease of genetic manipulation, enable cell- and molecular-focused fundamental research, and rats provide the opportunity to use stent and balloon models with high throughput, both rodents lack a lipid metabolism comparable to humans. Rabbits instead build a bridge to close the gap between basic and clinical research due to their human-like lipid metabolism, as well as their size being accessible for clinical angioplasty procedures. Every different combination of animal, dietary, and injury model has various advantages and disadvantages, and the decision for a proper model requires awareness of species-specific biological properties reaching from vessel morphology to distinct cellular and molecular features.

Macrophage Polarization as a Novel Therapeutic Target for Endovascular Intervention in Peripheral Artery Disease

Peripheral artery disease (PAD) has a significant impact on human health, affecting 200 million people globally. Advanced PAD severely diminishes quality of life, affecting mobility, and in its most severe form leads to limb amputation and death. Treatment of PAD is among the least effective of all endovascular procedures in terms of long-term efficacy. Chronic inflammation is a key driver of PAD; however, stents and coated balloons eluting antiproliferative drugs are most commonly used. As a result, neither stents nor coated balloons produce durable clinical outcomes in the superficial femoral artery, and both have recently been associated with significantly increased mortality. This review summarizes the most common clinical approaches and limitations to treating PAD and highlights the necessity to address the underlying causes of inflammation, identifying macrophages as a novel therapeutic target in the next generation of endovascular PAD intervention.

TGF-β1 facilitates MT1-MMP-mediated proMMP-9 activation and invasion in oral squamous cell carcinoma cells

Matrix metalloproteinase (MMP)-2 and MMP-9, also known as gelatinases or type IV collagenases, are recognized as major contributors to the proteolytic degradation of extracellular matrix during tumor invasion. Latent MMP-2 (proMMP-2) is activated by membrane type 1 MMP (MT1-MMP) on the cell surface of tumor cells. We previously reported that cell-bound proMMP-9 is activated by the MT1-MMP/MMP-2 axis in HT1080 cells treated with concanavalin A in the presence of exogenous proMMP-2. However, the regulatory mechanism of proMMP-9 activation remains largely unknown. Transforming growth factor (TGF)-β1 is frequently overexpressed in tumor tissues and is associated with tumor aggressiveness and poor prognosis. In this study, we examined the role of TGF-β1 on MT1-MMP-mediated proMMP-9 activation using human oral squamous cell carcinoma cells. TGF-β1 significantly increased the expression of MMP-9. By adding exogenous proMMP-2, TGF-β1-induced proMMP-9 was activated during collagen gel culture, which was suppressed by the inhibition of TGF-β1 signaling or MT1-MMP activity. This MT1-MMP-mediated proMMP-9 activation was needed to facilitate TGF-β1-induced cell invasion into collagen gel. Thus, TGF-β1 may facilitate MT1-MMP-mediated MMP-9 activation and thereby stimulate invasion of tumor cells in collaboration with MT1-MMP and MMP-2.

Superior Mesenteric Artery Dissection: Classical Presentation, Novel Genetic Determinants

Superior mesenteric artery dissection is a rare cause of acute abdomen. Potential etiologies include atherosclerosis, medial degeneration of the arterial wall, mycotic aneurysm, hypertension, and a variety of arteriopathies. Here, we present a case of superior mesenteric artery dissection prompting clinical genetic testing to investigate the underlying mechanisms of the vasculopathy. (Level of Difficulty: Intermediate.)

New insights on the role of vascular endothelial growth factor in biliary pathophysiology

The family of vascular endothelial growth factors (VEGFs) includes 5 members (VEGF-A to -D, and placenta growth factor), which regulate several critical biological processes. VEGF-A exerts a variety of biological effects through high-affinity binding to tyrosine kinase receptors (VEGFR-1, -2 and -3), co-receptors and accessory proteins. In addition to its fundamental function in angiogenesis and endothelial cell biology, VEGF/VEGFR signalling also plays a role in other cell types including epithelial cells. This review provides an overview of VEGF signalling in biliary epithelial cell biology in both normal and pathologic conditions. VEGF/VEGFR-2 signalling stimulates bile duct proliferation in an autocrine and paracrine fashion. VEGF/VEGFR-1/VEGFR-2 and angiopoietins are involved at different stages of biliary development. In certain conditions, cholangiocytes maintain the ability to secrete VEGF-A, and to express a functional VEGFR-2 receptor. For example, in polycystic liver disease, VEGF secreted by cystic cells stimulates cyst growth and vascular remodelling through a PKA/RAS/ERK/HIF1α-dependent mechanism, unveiling a new level of complexity in VEFG/VEGFR-2 regulation in epithelial cells. VEGF/VEGFR-2 signalling is also reactivated during the liver repair process. In this context, pro-angiogenic factors mediate the interactions between epithelial, mesenchymal and inflammatory cells. This process takes place during the wound healing response, however, in chronic biliary diseases, it may lead to pathological neo-angiogenesis, a condition strictly linked with fibrosis progression, the development of cirrhosis and related complications, and cholangiocarcinoma. Novel observations indicate that in cholangiocarcinoma, VEGF is a determinant of lymphangiogenesis and of the immune response to the tumour. Better insights into the role of VEGF signalling in biliary pathophysiology might help in the search for effective therapeutic strategies.

Bile acid-receptor TGR5 deficiency worsens liver injury in alcohol-fed mice by inducing intestinal microbiota dysbiosis

Background & Aims

Bile-acid metabolism and the intestinal microbiota are impaired in alcohol-related liver disease. Activation of the bile-acid receptor TGR5 (or GPBAR1) controls both biliary homeostasis and inflammatory processes. We examined the role of TGR5 in alcohol-induced liver injury in mice.

Methods

We used TGR5-deficient (TGR5-KO) and wild-type (WT) female mice, fed alcohol or not, to study the involvement of liver macrophages, the intestinal microbiota (16S sequencing), and bile-acid profiles (high-performance liquid chromatography coupled to tandem mass spectrometry). Hepatic triglyceride accumulation and inflammatory processes were assessed in parallel.

Results

TGR5 deficiency worsened liver injury, as shown by greater steatosis and inflammation than in WT mice. Isolation of liver macrophages from WT and TGR5-KO alcohol-fed mice showed that TGR5 deficiency did not increase the pro-inflammatory phenotype of liver macrophages but increased their recruitment to the liver. TGR5 deficiency induced dysbiosis, independently of alcohol intake, and transplantation of the TGR5-KO intestinal microbiota to WT mice was sufficient to worsen alcohol-induced liver inflammation. Secondary bile-acid levels were markedly lower in alcohol-fed TGR5-KO than normally fed WT and TGR5-KO mice. Consistent with these results, predictive analysis showed the abundance of bacterial genes involved in bile-acid transformation to be lower in alcohol-fed TGR5-KO than WT mice. This altered bile-acid profile may explain, in particular, why bile-acid synthesis was not repressed and inflammatory processes were exacerbated.

Conclusions

A lack of TGR5 was associated with worsening of alcohol-induced liver injury, a phenotype mainly related to intestinal microbiota dysbiosis and an altered bile-acid profile, following the consumption of alcohol.

Lay summary

Excessive chronic alcohol intake can induce liver disease. Bile acids are molecules produced by the liver and can modulate disease severity. We addressed the specific role of TGR5, a bile-acid receptor. We found that TGR5 deficiency worsened alcohol-induced liver injury and induced both intestinal microbiota dysbiosis and bile-acid pool remodelling. Our data suggest that both the intestinal microbiota and TGR5 may be targeted in the context of human alcohol-induced liver injury.

Profiling circulating microRNAs in patients with cirrhosis and acute-on-chronic liver failure

Background & Aims

MicroRNAs (miRNAs) circulate in several body fluids and can be useful biomarkers. The aim of this study was to identify blood-circulating miRNAs associated with cirrhosis progression and acute-on-chronic liver failure (ACLF).

Methods

Using high-throughput screening of 754 miRNAs, serum samples from 45 patients with compensated cirrhosis, decompensated cirrhosis, or ACLF were compared with those from healthy individuals (n = 15). miRNA levels were correlated with clinical parameters, organ failure, and disease progression and outcome. Dysregulated miRNAs were evaluated in portal and hepatic vein samples (n = 33), liver tissues (n = 17), and peripheral blood mononuclear cells (PBMCs) (n = 16).

Results

miRNA screening analysis revealed that circulating miRNAs are dysregulated in cirrhosis progression, with 51 miRNAs being differentially expressed among all groups of patients. Unsupervised clustering and principal component analysis indicated that the main differences in miRNA expression occurred at decompensation, showing similar levels in patients with decompensated cirrhosis and those with ACLF. Of 43 selected miRNAs examined for differences among groups, 10 were differentially expressed according to disease progression. Moreover, 20 circulating miRNAs were correlated with model for end-stage liver disease and Child-Pugh scores. Notably, 11 dysregulated miRNAs were associated with kidney or liver failure, encephalopathy, bacterial infection, and poor outcomes. The most severely dysregulated miRNAs (i.e. miR-146a-5p, miR-26a-5p, and miR-191-5p) were further evaluated in portal and hepatic vein blood and liver tissue, but showed no differences. However, PBMCs from patients with cirrhosis showed significant downregulation of miR-26 and miR-146a, suggesting a extrahepatic origin of some circulating miRNAs.

Conclusions

This study is a repository of circulating miRNA data following cirrhosis progression and ACLF. Circulating miRNAs were profoundly dysregulated during the progression of chronic liver disease, were associated with failure of several organs and could have prognostic utility.

Lay summary

Circulating miRNAs are small molecules in the blood that can be used to identify or predict a clinical condition. Our study aimed to identify miRNAs for use as biomarkers in patients with cirrhosis or acute-on-chronic liver failure. Several miRNAs were found to be dysregulated during the progression of disease, and some were also related to organ failure and disease-related outcomes.

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Circulating miRNAs are dysregulated with cirrhosis progression and in patients with ACLF.

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Patient decompensation is associated with important changes in the levels of circulating miRNAs.

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A total of 11 circulating miRNAs were identified as associated with organ failure and 7 with poor outcome.

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The miRNAs most dysregulated during cirrhosis progression were miR-146a, miR-26a, and miR-191.

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miR-146a was dysregulated in PBMCs of patients with decompensated cirrhosis vs. compensated cirrhosis.

Subcutaneous transplantation of engineered islet/adipose-derived mesenchymal stem cell sheets in diabetic pigs with total pancreatectomy

Introduction

Intraportal islet transplantation is a promising therapeutic approach for patients with type 1 diabetes mellitus (T1DM). However, despite being minimally invasive, the method has some limitations, such as short-term graft loss, portal venous thrombosis, and difficulty in collecting adequate amounts of islets. Subcutaneous islet transplantation on adipose-derived mesenchymal stem cell (ADSC) sheets has been suggested to overcome these limitations, and in this study, we have examined its feasibility in T1DM pigs.

Methods

Inguinal subcutaneous fat was harvested from young pigs and then isolated and cultured adequate ADSCs to prepare sheets. Islets were isolated from the pancreases of mature pigs and seeded on the ADSC sheets. T1DM pigs were generated by total pancreatectomy, and ADSC sheets with transplanted islets were administered subcutaneously to the waist (n = 2). The effects of the islets on the ADSC sheets and on blood glucose levels were evaluated. Insulin secretion was measured by insulin stimulation index.

Results

Islet viability was higher on ADSCs compared to islets alone (91.8 ± 4.3 vs. 81.7 ± 4.1%). The insulin stimulation index revealed higher glucose sensitivity of islets on ADSC sheets compared to islets alone (2.8 ± 2.0 vs. 0.8 ± 0.3). After transplantation, the blood glucose levels of two pigs were within the normal range, and sensitive insulin secretion was confirmed by intravenous glucose tolerance tests. After graftectomy, decreased insulin secretion and hyperglycemia were observed.

Conclusions

Subcutaneous islet transplantation using ADSC sheets can regulate the blood glucose levels of T1DM pigs.

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The adipose-derived mesenchymal stem cell sheet is useful to protect the islets.

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Subcutaneous islet transplantation on sheet normalized blood glucose in diabetic pig.

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Subcutaneous islet transplantation on sheet can be a useful tool.

Using CRISPR to enhance T cell effector function for therapeutic applications

T cells are critical to fight pathogenic microbes and combat malignantly transformed cells in the fight against cancer. To exert their effector function, T cells produce effector molecules, such as the pro-inflammatory cytokines IFN-γ, TNF-α and IL-2. Tumors possess many inhibitory mechanisms that dampen T cell effector function, limiting the secretion of cytotoxic molecules. As a result, the control and elimination of tumors is impaired. Through recent advances in genomic editing, T cells can now be successfully modified via CRISPR/Cas9 technology. For instance, engaging (post-)transcriptional mechanisms to enhance T cell cytokine production, the retargeting of T cell antigen specificity or rendering T cells refractive to inhibitory receptor signaling can augment T cell effector function. Therefore, CRISPR/Cas9-mediated genome editing might provide novel strategies for cancer immunotherapy. Recently, the first-in-patient clinical trial was successfully performed with CRISPR/Cas9-modified human T cell therapy. In this review, a brief overview of currently available techniques is provided, and recent advances in T cell genomic engineering for the enhancement of T cell effector function for therapeutic purposes are discussed.

Phospholipase C epsilon mediates cytokine cascade induced by acute disruption of epidermal permeability barrier in mice

Disruption of epidermal barrier is an important trigger in abnormal cutaneous inflammation. Phospholipase C epsilon (PLCε), a Ras/Rap1 effector, is essential for regulating cytokines production in different types of skin inflammation. Our previous studies have demonstrated that elevated expression of PLCε participates in the psoriasis-like inflammation in PLCε overexpressing transgenic mice model, while the reduction in PLCε expression attenuates inflammatory responses in either TPA- or DNFB-induced cutaneous inflammation. Here, we determined the role of PLCε in cutaneous inflammation induced by acute abrogation of epidermal permeability barrier. In comparison to wild type controls, PLCε KO mice exhibited reduced ear swelling and infiltration of granulocytes after tape-stripping. Moreover, expression levels of pro-inflammatory cytokines (IL-1α, IL-1β), chemokines (CXCL-1, CXCL-2, CCL20), and antimicrobial peptides (S100 proteins, MBD3) were lower in PLCε-deficient versus wild type mice. Likewise, expression levels of cytokines and chemokines were also lower in PLCε deficient keratinocytes and fibroblasts following IL-22 stimulation in vitro. Furthermore, knockdown of PLCε with its siRNA decreased expression of IL-1α, CCL20, and S100 proteins, and MBD3 in HEK cultures. Collectively, these results suggested that PLCε mediated cytokine cascade induced by acute barrier disruption. IL-22 is likely the upstream of PLCε-mediated cytokine cascade following acute barrier disruption.

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PLCε deficiency reduces inflammation cascade after barrier disruption.

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IL-22 serves as a possible upstream activator of PLCε in keratinocytes.

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IL-22/PLCε signaling potentially involves in barrier related diseases like psoriasis.

Macrophage-derived thrombospondin 1 promotes obesity-associated non-alcoholic fatty liver disease

Background & Aims

Thrombospondin 1 (TSP1) is a multifunctional matricellular protein. We previously showed that TSP1 has an important role in obesity-associated metabolic complications, including inflammation, insulin resistance, cardiovascular, and renal disease. However, its contribution to obesity-associated non-alcoholic fatty liver disease/non-alcoholic steatohepatitis (NAFLD or NASH) remains largely unknown; thus, we aimed to determine its role.

Methods

High-fat diet or AMLN (amylin liver NASH) diet-induced obese and insulin-resistant NAFLD/NASH mouse models were utilised, in addition to tissue-specific Tsp1-knockout mice, to determine the contribution of different cellular sources of obesity-induced TSP1 to NAFLD/NASH development.

Results

Liver TSP1 levels were increased in experimental obese and insulin-resistant NAFLD/NASH mouse models as well as in obese patients with NASH. Moreover, TSP1 deletion in adipocytes did not protect mice from diet-induced NAFLD/NASH. However, myeloid/macrophage-specific TSP1 deletion protected mice against obesity-associated liver injury, accompanied by reduced liver inflammation and fibrosis. Importantly, this protection was independent of the levels of obesity and hepatic steatosis. Mechanistically, through an autocrine effect, macrophage-derived TSP1 suppressed Smpdl3b expression in liver, which amplified liver proinflammatory signalling (Toll-like receptor 4 signal pathway) and promoted NAFLD progression.

Conclusions

Macrophage-derived TSP1 is a significant contributor to obesity-associated NAFLD/NASH development and progression and could serve as a therapeutic target for this disease.

Lay summary

Obesity-associated non-alcoholic fatty liver disease is a most common chronic liver disease in the Western world and can progress to liver cirrhosis and cancer. No treatment is currently available for this disease. The present study reveals an important factor (macrophage-derived TSP1) that drives macrophage activation and non-alcoholic fatty liver disease development and progression and that could serve as a therapeutic target for non-alcoholic fatty liver disease/steatohepatitis.

Blockade of Fibroblast YAP Attenuates Cardiac Fibrosis and Dysfunction Through MRTF-A Inhibition

Fibrotic remodeling of the heart in response to injury contributes to heart failure, yet therapies to treat fibrosis remain elusive. Yes-associated protein (YAP) is activated in cardiac fibroblasts by myocardial infarction, and genetic inhibition of fibroblast YAP attenuates myocardial infarction-induced cardiac dysfunction and fibrosis. YAP promotes myofibroblast differentiation and associated extracellular matrix gene expression through engagement of TEA domain transcription factor 1 and subsequent de novo expression of myocardin-related transcription factor A. Thus, fibroblast YAP is a promising therapeutic target to prevent fibrotic remodeling and heart failure.

Cardiac Endocrinology: Heart-Derived Hormones in Physiology and Disease

The heart plays a central role in the circulatory system and provides essential oxygen, nutrients, and growth factors to the whole organism. The heart can synthesize and secrete endocrine signals to communicate with distant target organs. Studies of long-known and recently discovered heart-derived hormones highlight a shared theme and reveal a unified mechanism of heart-derived hormones in coordinating cardiac function and target organ biology. This paper reviews the biochemistry, signaling, function, regulation, and clinical significance of representative heart-derived hormones, with a focus on the cardiovascular system. This review also discusses important and exciting questions that will advance the field of cardiac endocrinology.

Inflammatory Mediators in Glioma Microenvironment Play a Dual Role in Gliomagenesis and Mesenchymal Stem Cell Homing: Implication for Cellular Therapy

Glioblastoma is the most aggressive malignant primary brain tumor, with a dismal prognosis and a devastating overall survival. Despite aggressive surgical resection and adjuvant treatment, average survival remains approximately 14.6 months. The brain tumor microenvironment is heterogeneous, comprising multiple populations of tumor, stromal, and immune cells. Tumor cells evade the immune system by suppressing several immune functions to enable survival. Gliomas release immunosuppressive and tumor-supportive soluble factors into the microenvironment, leading to accelerated cancer proliferation, invasion, and immune escape. Mesenchymal stem cells (MSCs) isolated from bone marrow, adipose tissue, or umbilical cord are a promising tool for cell-based therapies. One crucial mechanism mediating the therapeutic outcomes often seen in MSC application is their tropism to sites of injury. Furthermore, MSCs interact with host immune cells to regulate the inflammatory response, and data points to the possibility of using MSCs to achieve immunomodulation in solid tumors. Interleukin 1β, interleukin 6, tumor necrosis factor α, transforming growth factor β, and stromal cell-derived factor 1 are notably up-regulated in glioblastoma and dually promote immune and MSC trafficking. Mesenchymal stem cells have widely been regarded as hypoimmunogenic, enabling this cell-based administration across major histocompatibility barriers. In this review, we will highlight (1) the bidirectional communication of glioma cells and tumor-associated immune cells, (2) the inflammatory mediators enabling leukocytes and transplantable MSC migration, and (3) review preclinical and human clinical trials using MSCs as delivery vehicles. Mesenchymal stem cells possess innate abilities to migrate great distances, cross the blood-brain barrier, and communicate with surrounding cells, all of which make them desirable "Trojan horses" for brain cancer therapy.

Hormonal Contribution to Liver Regeneration

An understanding of the molecular basis of liver regeneration will open new horizons for the development of novel therapies for chronic liver failure. Such therapies would solve the drawbacks associated with liver transplant, including the shortage of donor organs, long waitlist time, high medical costs, and lifelong use of immunosuppressive agents. Regeneration after partial hepatectomy has been studied in animal models, particularly fumarylacetoacetate hydrolase-deficient (FAH ^-/-) mice and pigs. The process of regeneration is distinctive, complex, and well coordinated, and it depends on the interplay among several signaling pathways (eg, nuclear factor κβ, Notch, Hippo), cytokines (eg, tumor necrosis factor α, interleukin 6), and growth factors (eg, hepatocyte growth factor, epidermal growth factor, vascular endothelial growth factor), and other components. Furthermore, endocrinal hormones (eg, norepinephrine, growth hormone, insulin, thyroid hormones) also can influence the aforementioned pathways and factors. We believe that these endocrinal hormones are important hepatic mitogens that strongly induce and accelerate hepatocyte proliferation (regeneration) by directly and indirectly triggering the activity of the involved signaling pathways, cytokines, growth factors, and transcription factors. The subsequent induction of cyclins and associated cyclin-dependent kinase complexes allow hepatocytes to enter the cell cycle. In this review article, we comprehensively summarize the current knowledge regarding the roles and mechanisms of these hormones in liver regeneration. Articles used for this review were identified by searching MEDLINE and EMBASE databases from inception through June 1, 2019.

Cardiac Fibrosis Is Associated With Decreased Circulating Levels of Full-Length CILP in Heart Failure

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After in vitro stimulation or in vivo pressure overload injury, activated cardiac fibroblasts express Ltbp2, Comp, and Cilp.

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In ischemic heart disease, LTBP2, COMP, and CILP localize to the fibrotic regions of the injured heart.

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Circulating levels of full-length CILP are decreased in patients with heart failure, suggestive of the potential to use this protein as a biomarker for the presence of cardiac fibrosis.

Cardiac fibrosis is a pathological process associated with various forms of heart failure. This study identified latent transforming growth factor-β binding protein 2, cartilage oligomeric matrix protein, and cartilage intermediate layer protein 1 as potential biomarkers for cardiac fibrosis. All 3 encoded proteins showed increased expression in fibroblasts after transforming growth factor-β stimulation in vitro and localized specifically to fibrotic regions in vivo. Of the 3, only the full-length cartilage intermediate layer protein 1 showed a significant decrease in circulating levels in patients with heart failure compared with healthy volunteers. Further studies on these 3 proteins will lead to a better understanding of their biomarker potential for cardiac fibrosis.

Reduced Left Atrial Emptying Fraction and Chymase Activation in Pathophysiology of Primary Mitral Regurgitation

Increasing left atrial (LA) size predicts outcomes in patients with isolated mitral regurgitation (MR). Chymase is plentiful in the human heart and affects extracellular matrix remodeling. Chymase activation correlates to LA fibrosis, LA enlargement, and a decreased total LA emptying fraction in addition to having a potential intracellular role in mediating myofibrillar breakdown in LA myocytes. Because of the unreliability of the left ventricular ejection fraction in predicting outcomes in MR, LA size and the total LA emptying fraction may be more suitable indicators for timing of surgical intervention.

Differential Leaflet Remodeling of Bone Marrow Cell Pre-Seeded Versus Nonseeded Bioresorbable Transcatheter Pulmonary Valve Replacements

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Bone marrow mononuclear cell pre-seeding of polycarbonate bisurea–based tissue-engineered heart valves has detrimental effects on long-term performance and in situ remodeling and, therefore, should be avoided.

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Leaflet-specific analysis revealed pronounced remodeling differences with regard to cell infiltration, scaffold resorption, and extracellular matrix deposition within the same valve explant.

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The heterogeneity in remodeling of polycarbonate bisurea–based tissue-engineered heart valves may have important safety implications in terms of clinical translation.

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An in-depth understanding of the mechanobiological mechanisms involved in the in situ remodeling is required to limit the risk of unpredictable (maladaptive) remodeling.

This study showed that bone marrow mononuclear cell pre-seeding had detrimental effects on functionality and in situ remodeling of bioresorbable bisurea-modified polycarbonate (PC-BU)-based tissue-engineered heart valves (TEHVs) used as transcatheter pulmonary valve replacement in sheep. We also showed heterogeneous valve and leaflet remodeling, which affects PC-BU TEHV safety, challenging their potential for clinical translation. We suggest that bone marrow mononuclear cell pre-seeding should not be used in combination with PC-BU TEHVs. A better understanding of cell–scaffold interaction and in situ remodeling processes is needed to improve transcatheter valve design and polymer absorption rates for a safe and clinically relevant translation of this approach.

Acute Kidney Injury Induces Remote Cardiac Damage and Dysfunction Through the Galectin-3 Pathway

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In 2 different mouse models, AKI increased Gal-3 expression and induced cardiac dysfunction, cardiac and systemic inflammation, cardiac macrophage infiltration, and fibrosis.

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Cardiac consequences of AKI were dependent on the Gal-3 pathway and were prevented using Gal-3 knockout mice or modified citrus pectin as a pharmaceutical inhibitor.

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Cardiac Gal-3 expression resulted from bone marrow-derived immune cells recruitment after AKI.

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In critically ill patients, development of AKI is associated with increased plasma Gal-3 levels and increased biomarkers of cardiac injury and damage.

Acute kidney injury is associated with increased risk of heart failure and mortality. This study demonstrates that acute kidney injury induces remote cardiac dysfunction, damage, injury, and fibrosis via a galectin-3 (Gal-3) dependent pathway. Gal-3 originates from bone marrow-derived immune cells. Cardiac damage could be prevented by blocking this pathway.

Atrial Myopathy

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The authors discuss the concept of atrial myopathy; its relationship to aging, electrophysiological remodeling, and autonomic remodeling; the interplay between atrial myopathy, AF, and stroke; and suggest how to identify patients with atrial myopathy and how to incorporate atrial myopathy into decisions about anticoagulation.

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Atrial myopathy seen in animal models of AF and in patients with AF is the result of a combination of factors that lead to electrical and structural remodeling in the atrium. Although AF may lead to the initiation and/or progression of this myopathy, the presence of AF is by no means essential to the development or the maintenance of the atrial myopathic state.

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Methods to identify atrial myopathy include atrial electrograms, tissue biopsy, cardiac imaging, and certain serum biomarkers. A promising modality is 4-dimensional flow cardiac magnetic resonance. The concept of atrial myopathy may help guide oral anticoagulant therapy in selected groups of patients with AF, particularly those with low to intermediate risk of strokes and those who have undergone successful AF ablation. This review highlights the need for prospective randomized trials to test these hypotheses.

This paper discusses the evolving concept of atrial myopathy by presenting how it develops and how it affects the properties of the atria. It also reviews the complex relationships among atrial myopathy, atrial fibrillation (AF), and stroke. Finally, it discusses how to apply the concept of atrial myopathy in the clinical setting—to identify patients with atrial myopathy and to be more selective in anticoagulation in a subset of patients with AF. An apparent lack of a temporal relationship between episodes of paroxysmal AF and stroke in patients with cardiac implantable electronic devices has led investigators to search for additional factors that are responsible for AF-related strokes. Multiple animal models and human studies have revealed a close interplay of atrial myopathy, AF, and stroke via various mechanisms (e.g., aging, inflammation, oxidative stress, and stretch), which, in turn, lead to fibrosis, electrical and autonomic remodeling, and a pro-thrombotic state. The complex interplay among these mechanisms creates a vicious cycle of ever-worsening atrial myopathy and a higher risk of more sustained AF and strokes. By highlighting the importance of atrial myopathy and the risk of strokes independent of AF, this paper reviews the methods to identify patients with atrial myopathy and proposes a way to incorporate the concept of atrial myopathy to guide anticoagulation in patients with AF.

Malondialdehyde Conjugated With Albumin Induces Pro-Inflammatory Activation of T Cells Isolated From Human Atherosclerotic Plaques Both Directly and Via Dendritic Cell-Mediated Mechanism

Human dendritic cells were differentiated from blood monocytes and treated with malondialdehyde (MDA) conjugated with human serum albumin (HSA). Autologous T cells from human plaques or blood were co-cultured with the pre-treated dendritic cells or treated directly. MDA modifications were studied by mass spectrometry. MDA-HSA induced a pro-inflammatory DC-mediated T-cell activation and also a strong direct effect on T cells, inhibited by an inhibitor of oxidative stress and antibodies against MDA. Atherogenic heat shock protein-60 was strongly induced in T cells activated by MDA-HSA. Two peptide modifications in atherosclerotic patients' HSA were similar to those present in in vitro MDA-modified HSA.

Fibroblasts in the Infarcted, Remodeling, and Failing Heart

Expansion and activation of fibroblasts following cardiac injury is important for repair but may also contribute to fibrosis, remodeling, and dysfunction. The authors discuss the dynamic alterations of fibroblasts in failing and remodeling myocardium. Emerging concepts suggest that fibroblasts are not unidimensional cells that act exclusively by secreting extracellular matrix proteins, thus promoting fibrosis and diastolic dysfunction. In addition to their involvement in extracellular matrix expansion, activated fibroblasts may also exert protective actions, preserving the cardiac extracellular matrix, transducing survival signals to cardiomyocytes, and regulating inflammation and angiogenesis. The functional diversity of cardiac fibroblasts may reflect their phenotypic heterogeneity.

Histological evaluation of tendon formation using a scaffold-free three-dimensional-bioprinted construct of human dermal fibroblasts under in vitro static tensile culture

Introduction

Tendon tissue engineering requires scaffold-free techniques for safe and long-term clinical applications and to explore alternative cell sources to tenocytes. Therefore, we histologically assessed tendon formation in a scaffold-free Bio-three-dimensional (3D) construct developed from normal human dermal fibroblasts (NHDFs) using our Bio-3D printer system under tensile culture in vitro.

Methods

Scaffold-free ring-like tissues were constructed from 120 multicellular spheroids comprising NHDFs using a bio-3D printer. Ring-like tissues were cultured in vitro under static tensile-loading with or without in-house tensile devices (tension-loaded and tension-free groups), with increases in tensile strength applied weekly to the tensile-loaded group. After a 4 or 8-week culture on the device, we evaluated histological findings according to tendon-maturing score and immunohistological findings of the middle portion of the tissues for both groups (n = 4, respectively).

Results

Histology of the tension-loaded group revealed longitudinally aligned collagen fibers with increased collagen deposition and spindle-shaped cells with prolonged culture. By contrast, the tension-free group showed no organized cell arrangement or collagen fiber structure. Additionally, the tension-loaded group showed a significantly improved tendon-maturing score as compared with that for the tension-free group at week 8. Moreover, immunohistochemistry revealed tenascin C distribution with a parallel arrangement in the tensile-loading direction at week 8 in the tension-loaded group, which exhibited stronger scleraxis-staining intensity than that observed in the tension-free group at weeks 4 and 8.

Conclusions

The NHDF-generated scaffold-free Bio-3D construct underwent remodeling and formed tendon-like structures under tensile culture in vitro.

Combined obeticholic acid and apoptosis inhibitor treatment alleviates liver fibrosis

Obeticholic acid (OCA), the first FXR-targeting drug, has been claimed effective in the therapy of liver fibrosis. However, recent clinical trials indicated that OCA might not be effective against liver fibrosis, possibly due to the lower dosage to reduce the incidence of the side-effect of pruritus. Here we propose a combinatory therapeutic strategy of OCA and apoptosis inhibitor for combating against liver fibrosis. CCl₄-injured mice, d-galactosamine/LPS (GalN/LPS)-treated mice and cycloheximide/TNFα (CHX/TNFα)-treated HepG2 cells were employed to assess the effects of OCA, or together with IDN-6556, an apoptosis inhibitor. OCA treatment significantly inhibited hepatic stellate cell (HSC) activation/proliferation and prevented fibrosis. Elevated bile acid (BA) levels and hepatocyte apoptosis triggered the activation and proliferation of HSCs. OCA treatment reduced BA levels but could not inhibit hepatocellular apoptosis. An enhanced anti-fibrotic effect was observed when OCA was co-administrated with IDN-6556. Our study demonstrated that OCA inhibits HSCs activation/proliferation partially by regulating BA homeostasis and thereby inhibiting activation of HSCs. The findings in this study suggest that combined use of apoptosis inhibitor and OCA at lower dosage represents a novel therapeutic strategy for liver fibrosis.

Phosphorylation of Hsp20 Promotes Fibrotic Remodeling and Heart Failure

Cardiomyocyte-specific increases in phosphorylated Hsp20 (S16D-Hsp20) to levels similar to those observed in human failing hearts are associated with early fibrotic remodeling and depressed left ventricular function, symptoms which progress to heart failure and early death. The underlying mechanisms appear to involve translocation of phosphorylated Hsp20 to the nucleus and upregulation of interleukin (IL)-6, which subsequently activates cardiac fibroblasts in a paracrine fashion through transcription factor STAT3 signaling. Accordingly, treatment of S16D-Hsp20 mice with a rat anti-mouse IL-6 receptor monoclonal antibody (MR16-1) attenuated interstitial fibrosis and preserved cardiac function. These findings suggest that phosphorylated Hsp20 may be a potential therapeutic target in heart failure.

Connective Tissue Growth Factor Inhibition Enhances Cardiac Repair and Limits Fibrosis After Myocardial Infarction

Myocardial infarction (MI)-induced cardiac fibrosis attenuates cardiac contractile function, and predisposes to arrhythmias and sudden cardiac death. Expression of connective tissue growth factor (CTGF) is elevated in affected organs in virtually every fibrotic disorder and in the diseased human myocardium. Mice were subjected to treatment with a CTGF monoclonal antibody (mAb) during infarct repair, post-MI left ventricular (LV) remodeling, or acute ischemia-reperfusion injury. CTGF mAb therapy during infarct repair improved survival and reduced LV dysfunction, and reduced post-MI LV hypertrophy and fibrosis. Mechanistically, CTGF mAb therapy induced expression of cardiac developmental and/or repair genes and attenuated expression of inflammatory and/or fibrotic genes.

Celecoxib Is Associated With Dystrophic Calcification and Aortic Valve Stenosis

Calcific aortic valve disease is a progressive fibrocalcific process that can only be treated with valve replacement. Cadherin-11 has recently been identified as a potential therapeutic target for calcific aortic valve disease. The already approved drug celecoxib, a cyclooxygenase-2 inhibitor, binds cadherin-11, and was investigated as a therapeutic against calcific aortic valve disease. Unexpectedly, celecoxib treatment led to hallmarks of myofibroblast activation and calcific nodule formation in vitro. Retrospective electronic medical record analysis of celecoxib, ibuprofen, and naproxen revealed a unique association of celecoxib use and aortic stenosis.

Bioactive Materials Facilitating Targeted Local Modulation of Inflammation

Cardiovascular disease is an inflammatory disorder that may benefit from appropriate modulation of inflammation. Systemic treatments lower cardiac events but have serious adverse effects. Localized modulation of inflammation in current standard treatments such as bypass grafting may more effectively treat CAD. The present study investigated a bioactive vascular graft coated with the macrophage polarizing cytokine interleukin-4. These grafts repolarize macrophages to anti-inflammatory phenotypes, leading to modulation of the pro-inflammatory microenvironment and ultimately to a reduction of foreign body encapsulation and inhibition of neointimal hyperplasia development. These resulting functional improvements have significant implications for the next generation of synthetic vascular grafts.

Cardiomyocyte SMAD4-Dependent TGF-β Signaling is Essential to Maintain Adult Heart Homeostasis

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SMAD4 is the central intracellular mediator of TGF-β pathway.

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CM-specific loss of SMAD4 causes cardiac dysfunction independent of fibrotic remodeling.

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Deletion CM-SMAD4 affects CM survival.

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CM-SMAD4 loss leads to down-regulation of several ion channels’ genes, resulting in cardiac conduction abnormalities.

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CM-SMAD4 deletion alters sarcomere shortening kinetics, in parallel with reduction in cardiac myosin-binding protein C levels.

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These results demonstrate a fundamental role for CM-SMAD4–dependent TGF-β signaling in adult heart homeostasis.

The role of the transforming growth factor (TGF)-β pathway in myocardial fibrosis is well recognized. However, the precise role of this signaling axis in cardiomyocyte (CM) biology is not defined. In TGF-β signaling, SMAD4 acts as the central intracellular mediator. To investigate the role of TGF-β signaling in CM biology, the authors deleted SMAD4 in adult mouse CMs. We demonstrate that CM-SMAD4–dependent TGF-β signaling is critical for maintaining cardiac function, sarcomere kinetics, ion-channel gene expression, and cardiomyocyte survival. Thus, our findings raise a significant concern regarding the therapeutic approaches that rely on systemic inhibition of the TGF-β pathway for the management of myocardial fibrosis.

The Tumor Suppressor SASH1 Interacts With the Signal Adaptor CRKL to Inhibit Epithelial-Mesenchymal Transition and Metastasis in Colorectal Cancer

BACKGROUND & AIMS

The tumor-suppressor sterile α motif- and Src-homology 3-domain containing 1 (SASH1) has clinical relevance in colorectal carcinoma and is associated specifically with metachronous metastasis. We sought to identify the molecular mechanisms linking decreased SASH1 expression with distant metastasis formation.

METHODS

SASH1-deficient, SASH1-depleted, or SASH1-overexpressing HCT116 colon cancer cells were generated by the Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR-associated 9-method, RNA interference, and transient plasmid transfection, respectively. Epithelial-mesenchymal transition (EMT) was analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblotting, immunofluorescence microscopy, migration/invasion assays, and 3-dimensional cell culture. Yeast 2-hybrid assays and co-immunoprecipitation/mass-spectrometry showed V-Crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) as a novel interaction partner of SASH1, further confirmed by domain mapping, site-directed mutagenesis, co-immunoprecipitation, and dynamic mass redistribution assays. CRKL-deficient cells were generated in parental or SASH1-deficient cells. Metastatic capacity was analyzed with an orthotopic mouse model. Expression and significance of SASH1 and CRKL for survival and response to chemotherapy was assessed in patient samples from our department and The Cancer Genome Atlas data set.

RESULTS

SASH1 expression is down-regulated during cytokine-induced EMT in cell lines from colorectal, pancreatic, or hepatocellular cancer, mediated by the putative SASH1 promoter. Deficiency or knock-down of SASH1 induces EMT, leading to an aggressive, invasive phenotype with increased chemoresistance. SASH1 counteracts EMT through interaction with the oncoprotein CRKL, inhibiting CRKL-mediated activation of SRC kinase, which is crucially required for EMT. SASH1-deficient cells form significantly more metastases in vivo, depending entirely on CRKL. Patient tumor samples show significantly decreased SASH1 and increased CRKL expression, associated with significantly decreased overall survival. Patients with increased CRKL expression show significantly worse response to adjuvant chemotherapy.

CONCLUSIONS

We propose SASH1 as an inhibitor of CRKL-mediated SRC signaling, introducing a potentially druggable mechanism counteracting chemoresistance and metastasis formation.

Micronutrients in Nonalcoholic Fatty Liver Disease Pathogenesis

Micronutrients include electrolytes, minerals, vitamins, and carotenoids, and are required in microgram or milligram quantities for cellular metabolism. The liver plays an important role in micronutrient metabolism and this metabolism often is altered in chronic liver diseases. Here, we review how the liver contributes to micronutrient metabolism; how impaired micronutrient metabolism may be involved in the pathogenesis of nonalcoholic fatty liver disease (NAFLD), a systemic disorder of energy, glucose, and lipid homeostasis; and how insights gained from micronutrient biology have informed NAFLD therapeutics. Finally, we highlight some of the challenges and opportunities that remain with investigating the contribution of micronutrients to NAFLD pathology and suggest strategies to incorporate our understanding into the care of NAFLD patients.

Differential time-dependent transcriptional changes in the osteoblast lineage in cortical bone associated with sclerostin antibody treatment in ovariectomized rats

Inhibition of sclerostin with sclerostin antibody (Scl-Ab) results in stimulation of bone formation on cancellous (Cn), endocortical (Ec), and periosteal (Ps) surfaces in rodents and non-human primates. With long-term dosing of Scl-Ab, the increase in bone formation is not sustained, attenuating first on Cn surfaces and later on Ec and Ps surfaces. In Cn bone, the attenuation in bone formation (self-regulation) is associated with transcriptional changes in the osteocyte (OCy) that would limit mitogenesis and are sustained with continued dosing. The expression changes in Cn OCy occur coincident with a decrease in osteoprogenitor (OP) numbers that may directly or indirectly be a consequence of the transcriptional changes in the OCy to limit OP proliferation. To characterize the Scl-Ab–mediated changes in cortical (Ct) bone and compare these changes to Cn bone, densitometric, histomorphometric, and transcriptional analyses were performed on femur diaphyses from aged ovariectomized rats. Animals were administered 50 mg/kg/wk of Scl-Ab or vehicle for up to 6 months (183 days), followed by a treatment-free period (up to 126 days). Scl-Ab increased Ct mass and area through day 183, which declined slightly when treatment was discontinued. Ps and Ec bone formation was sustained through the dosing on both Ct surfaces, with evidence of a decline in bone formation only at day 183 on the Ec surface. This is in contrast to Cn bone, where reduced bone formation was observed after day 29. TaqMan analysis of 60 genes with functional roles in the bone using mRNA isolated from laser capture micro-dissection samples enriched for Ec osteoblasts and Ct OCy suggest a pattern of gene expression in Ct bone that differed from Cn, especially in the OCy, and that corresponded to observed differences in the timing of phenotypic changes. Notable with Scl-Ab treatment was a “transcriptional switch” in Ct OCy at day 183, coincident with the initial decline in bone formation on the endocortex. A consistent sustained increase of expression for most genes in response to Scl-Ab was observed from day 8 through day 85 at the times of maximal bone formation on both Ct surfaces; however, at day 183, this increase was reversed, with expression of these genes generally returning to control values or decreasing compared to vehicle. Genes exhibiting this pattern included Wnt inhibitors Sost and Dkk1, though both had been up-regulated until the end of dosing in Cn OCy. Changes in cell cycle genes such as Cdkn1a and Ndrg1 in Ct OCy suggested up-regulation of p53 signaling, as observed in Cn OCy; however, unlike in Cn bone, p53 signaling was not associated with decreased bone formation and was absent at day 183, when bone formation began to decline on the Ec surface. These data demonstrate involvement of similar molecular pathways in Ct and Cn bone in response to Scl-Ab but with a different temporal relationship to bone formation and suggest that the specific mechanism underlying self-regulation of Scl-Ab–induced bone formation may be different between Cn and Ct bone.

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Sclerostin antibody stimulates bone formation that attenuates over time.

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Attenuation (self-regulation) is delayed in cortical versus cancellous bone.

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Self-regulation coincides with transcriptional changes in cortical osteocytes.

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Response of Wnt inhibitors differs between cortical and cancellous bone.

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Results suggest a distinct mechanism for self-regulation in cortical bone.

CCR2+ Monocyte-Derived Infiltrating Macrophages Are Required for Adverse Cardiac Remodeling During Pressure Overload

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Hypothesis: CCR2⁺ monocyte-derived cardiac macrophages are required for adverse LV remodeling, cardiac T-cell expansion, and the transition to HF following pressure overload.

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The imposition of pressure overload via TAC resulted in the early up-regulation of CCL2, CCL7, and CCL12 chemokines in the LV, increased Ly6C^hiCCR2⁺ monocytes in the blood, and augmented CCR2⁺ infiltrating macrophages in the heart.

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Specific and circumscribed inhibition of CCR2⁺ monocytes and macrophages early during pressure overload reduced pathological hypertrophy, fibrosis, and systolic dysfunction during the late phase of pressure overload.

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The early expansion of CCR2⁺ macrophages after pressure overload was required for long-term cardiac T-cell expansion.

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CCR2⁺ monocytes/macrophages may represent key targets for immunomodulation to delay or prevent HF in pressure-overload states.

Although chronic inflammation is a central feature of heart failure (HF), the immune cell profiles differ with different underlying causes. This suggests that for immunomodulatory therapy in HF to be successful, it needs to be tailored to the specific etiology. Here, the authors demonstrate that monocyte-derived C-C chemokine receptor 2 (CCR2)⁺ macrophages infiltrate the heart early during pressure overload in mice, and that blocking this response either pharmacologically or with antibody-mediated CCR2⁺ monocyte depletion alleviates late pathological left ventricular remodeling and dysfunction, T-cell expansion, and cardiac fibrosis. Hence, suppression of CCR2⁺ monocytes/macrophages may be an important immunomodulatory therapeutic target to ameliorate pressure-overload HF.

Endothelial- and Immune Cell-Derived Extracellular Vesicles in the Regulation of Cardiovascular Health and Disease

Intercellular signaling by extracellular vesicles (EVs) is a route of cell-cell crosstalk that allows cells to deliver biological messages to specific recipient cells. EVs convey these messages through their distinct cargoes consisting of cytokines, proteins, nucleic acids, and lipids, which they transport from the donor cell to the recipient cell. In cardiovascular disease (CVD), endothelial- and immune cell-derived EVs are emerging as key players in different stages of disease development. EVs can contribute to atherosclerosis development and progression by promoting endothelial dysfunction, intravascular calcification, unstable plaque progression, and thrombus formation after rupture. In contrast, an increasing body of evidence highlights the beneficial effects of certain EVs on vascular function and endothelial regeneration. However, the effects of EVs in CVD are extremely complex and depend on the cellular origin, the functional state of the releasing cells, the biological content, and the diverse recipient cells. This paper summarizes recent progress in our understanding of EV signaling in cardiovascular health and disease and its emerging potential as a therapeutic agent.

Activation of Myofibroblast TRPA1 by Steroids and Pirfenidone Ameliorates Fibrosis in Experimental Crohn's Disease

BACKGROUND & AIMS

The transient receptor potential ankyrin 1 (TRPA1) channel is highly expressed in the intestinal lamina propria, but its contribution to gut physiology/pathophysiology is unclear. Here, we evaluated the function of myofibroblast TRPA1 channels in intestinal remodeling.

METHODS

An intestinal myofibroblast cell line (InMyoFibs) was stimulated by transforming growth factor-β1 to induce in vitro fibrosis. Trpa1 knockout mice were generated using the Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) system. A murine chronic colitis model was established by weekly intrarectal trinitrobenzene sulfonic acid (TNBS) administration. Samples from the intestines of Crohn's disease (CD) patients were used for pathologic staining and quantitative analyses.

RESULTS

In InMyoFibs, TRPA1 showed the highest expression among TRP family members. In TNBS chronic colitis model mice, the extents of inflammation and fibrotic changes were more prominent in TRPA1^-/- knockout than in wild-type mice. One-week enema administration of prednisolone suppressed fibrotic lesions in wild-type mice, but not in TRPA1 knockout mice. Steroids and pirfenidone induced Ca²⁺ influx in InMyoFibs, which was antagonized by the selective TRPA1 channel blocker HC-030031. Steroids and pirfenidone counteracted transforming growth factor-β1-induced expression of heat shock protein 47, type 1 collagen, and α-smooth muscle actin, and reduced Smad-2 phosphorylation and myocardin expression in InMyoFibs. In stenotic intestinal regions of CD patients, TRPA1 expression was increased significantly. TRPA1/heat shock protein 47 double-positive cells accumulated in the stenotic intestinal regions of both CD patients and TNBS-treated mice.

CONCLUSIONS

TRPA1, in addition to its anti-inflammatory actions, may protect against intestinal fibrosis, thus being a novel therapeutic target for highly incurable inflammatory/fibrotic disorders.

The role of Tsukushi (TSK), a small leucine-rich repeat proteoglycan, in bone growth

INTRODUCTION

Endochondral ossification is one of a key process for bone maturation. Tsukushi (TSK) is a novel member of the secreted small leucine-rich repeat proteoglycan (SLRP) family. SLRPs localize to skeletal regions and play significant roles during whole phases of bone development. Although prior evidence suggests that TSK may be involved in the regulation of bone formation, its role in skeletal development has not yet been elucidated.

METHODS

In the present study, we examined TSK's function during bone growth by comparing skeletal growth of TSK deficient (TSK-/-) mice and wild type (WT) mice. And an in vitro experiment using siRNA transfection of a chondrogenic cell line was performed.

RESULTS

TSK-/- mice exhibited decreased weight and short stature at 3 weeks of age due to decreased longitudinal bone growth coupled with low bone mass. Furthermore, an in vitro experiment using siRNA transfection into a chondrogenic cell line revealed that decreased TSK expression induced down-regulation of key chondrogenic marker gene expression and up-regulation of mid-to-late chondrogenic markers gene expression.

CONCLUSIONS

Our results reveal that TSK regulates bone elongation and bone mass by modulating growth plate chondrocyte function and consequently, overall body size.

Angelica polysaccharides inhibit the growth and promote the apoptosis of U251 glioma cells in vitro and in vivo

BACKGROUND

Angelica sinensis (Oliv) Diels (Apiaceae) is a traditional medicine that has been used for more than 2000 years in China. It exhibits various therapeutic effects including neuroprotective, anti-oxidant, anti-inflammatory, and immunomodulatory activities. Angelica polysaccharides (APs), bioactive constituents of Angelica have been shown to be responsible for these effects; however, the utility of APs for the treatment of glioma and their mechanism of action remain to be elucidated.

PURPOSE

In this study, we investigated the inhibitory effects of APs on a glioma cell line and their molecular mechanism of action.

STUDY DESIGN

U251 cells were utilized to confirm the effects of APs on glioma.

METHODS

The human glioblastoma cell line U251 was utilized for both in vitro and in vivo models, in which we tested the effects of APs. Flow cytometry, gene expression analysis, western blotting, and MTT assays were used to elucidate the effects of APs on cell proliferation, cell cycle, and apoptosis.

RESULTS

The results demonstrated that APs significantly inhibited the growth and proliferation of U251 cells and induced their apoptosis. Furthermore, APs effectively reduced the expression of several cell cycle regulators: cyclins D1, B, and E. The apoptosis suppressor protein Bcl-2 was also downregulated, and the expression of pro-apoptotic proteins Bax and cleaved-caspase-3 increased. Additionally, APs inhibited the transforming growth factor (TGF)-β signaling pathway and stimulated the expression of E-cadherin, thus prohibiting cell growth.

CONCLUSION

In conclusion, the results indicate that APs attenuate the tumorigenicity of glioma cells and promote their apoptosis by suppressing the TGF-β signaling pathway. The present study therefore provides evidence of the inhibitory effects of APs against glioma progression, and proposes their potential application as alternative therapeutic agents for glioma.

Serotonin Activated Hepatic Stellate Cells Contribute to Sex Disparity in Hepatocellular Carcinoma

BACKGROUND & AIMS

Hepatocellular carcinoma (HCC) occurs more frequently and aggressively in men than in women. Although sex hormones are believed to play a critical role in this disparity, the possible contribution of other factors largely is unknown. We aimed to investigate the role of serotonin on its contribution of sex discrepancy during HCC.

METHODS

By using an inducible zebrafish HCC model through hepatocyte-specific transgenic krasV12 expression, differential rates of HCC in male and female fish were characterized by both pharmaceutical and genetic interventions. The findings were validated further in human liver disease samples.

RESULTS

Accelerated HCC progression was observed in krasV12-expressing male zebrafish and male fish liver tumors were found to have higher hepatic stellate cell (HSC) density and activation. Serotonin, which is essential for HSC survival and activation, similarly were found to be synthesized and accumulated more robustly in males than in females. Serotonin-activated HSCs could promote HCC carcinogenesis and concurrently increase serotonin synthesis via transforming growth factor (Tgf)b1 expression, hence contributing to sex disparity in HCC. Analysis of liver disease patient samples showed similar male predominant serotonin accumulation and Tgfb1 expression.

CONCLUSIONS

In both zebrafish HCC models and human liver disease samples, a predominant serotonin synthesis and accumulation in males resulted in higher HSC density and activation as well as Tgfb1 expression, thus accelerating HCC carcinogenesis in males.

Induction of Colonic Regulatory T Cells by Mesalamine by Activating the Aryl Hydrocarbon Receptor

BACKGROUND & AIMS

Mesalamine is a first-line drug for treatment of inflammatory bowel diseases (IBD). However, its mechanisms are not fully understood. CD4⁺ Foxp3⁺ regulatory T cells (Tregs) play a potential role in suppressing IBD. This study determined whether the anti-inflammatory activity of mesalamine is related to Treg induction in the colon.

METHODS

We examined the frequencies of Tregs in the colons of wild-type mice, mice deficient for aryl hydrocarbon receptor (AhR^-/- mice), and bone marrow-chimeric mice lacking AhR in hematopoietic cells (BM-AhR^-/- mice), following oral treatment with mesalamine. We also examined the effects of mesalamine on transforming growth factor (TGF)-β expression in the colon.

RESULTS

Treatment of wild-type mice with mesalamine increased the accumulation of Tregs in the colon and up-regulated the AhR target gene Cyp1A1, but this effect was not observed in AhR^-/- or BM-AhR^-/- mice. In addition, mesalamine promoted in vitro differentiation of naive T cells to Tregs, concomitant with AhR activation. Mice treated with mesalamine exhibited increased levels of the active form of TGF-β in the colon in an AhR-dependent manner and blockade of TGF-β signaling suppressed induction of Tregs by mesalamine in the colon. Furthermore, mice pretreated with mesalamine acquired resistance to dextran sodium sulfate-induced colitis.

CONCLUSIONS

We propose a novel anti-inflammatory mechanism of mesalamine for colitis: induction of Tregs in the colon via the AhR pathway, followed by TGF-β activation.

Regulation of Gastric Metaplasia, Dysplasia, and Neoplasia by Bone Morphogenetic Protein Signaling

The bone morphogenetic proteins, (BMP)s are regulatory peptides that have significant effects on the growth and differentiation of gastrointestinal tissues. In addition, the BMPs have been shown to exert anti-inflammatory actions in the gut and to negatively regulate the growth of gastric neoplasms. The role of BMP signaling in the regulation of gastric metaplasia, dysplasia and neoplasia has been poorly characterized. Transgenic expression in the mouse stomach of the BMP inhibitor noggin leads to decreased parietal cell number, increased epithelial cell proliferation, and to the emergence of SPEM. Moreover, expression of noggin increases Helicobacter-induced inflammation and epithelial cell proliferation, accelerates the development of dysplasia, and it increases the expression of signal transducer and activator of transcription 3 (STAT3) and of activation-induced cytidine deaminase (AID). These findings provide new clues for a better understanding of the pathophysiological mechanisms that regulate gastric inflammation and the development of both dysplastic and neoplastic lesions of the stomach.

Gastric Cancer in the Era of Precision Medicine

Gastric cancer (GC) remains the third most common cause of cancer death worldwide, with limited therapeutic strategies available. With the advent of next-generation sequencing and new preclinical model technologies, our understanding of its pathogenesis and molecular alterations continues to be revolutionized. Recently, the genomic landscape of GC has been delineated. Molecular characterization and novel therapeutic targets of each molecular subtype have been identified. At the same time, patient-derived tumor xenografts and organoids now comprise effective tools for genetic evolution studies, biomarker identification, drug screening, and preclinical evaluation of personalized medicine strategies for GC patients. These advances are making it feasible to integrate clinical, genome-based and phenotype-based diagnostic and therapeutic methods and apply them to individual GC patients in the era of precision medicine.