Hyperplasia In Response Research Articles

Fractal analysis of left ventricular trabeculae in heart failure with preserved ejection fraction patients with multivessel coronary artery disease

ObjectivesEndocardial trabeculae undergo varicose changes and hyperplasia in response to hemodynamic influences and are a variable phenotype reflecting changes in disease. Fractal analysis has been used to analyze the complexity of endocardial trabeculae in a variety of cardiomyopathies. The aim of this paper was to quantify the myocardial trabecular complexity through fractal analysis and to investigate its predictive value for the diagnosis of heart failure with preserved ejection fraction (HFpEF) in patients with multivessel coronary artery disease (CAD).MethodsThe retrospective study population consisted of 97 patients with multivessel CAD, 39 of them were diagnosed with HFpEF, while 46 healthy volunteers were recruited as controls. Fractal dimension (FD) was obtained through fractal analysis of endocardial trabeculae on LV short-axis cine images. Logistic regression analyses were used to confirm the predictors and compare different prediction models.ResultsMean basal FD was significantly higher in patients with HFpEF than in patients without HFpEF or in the healthy group (median: 1.289; IQR: 0.078; p < 0.05). Mean basal FD was also a significant independent predictor in univariate and multivariate logistic regression (OR: 1.107 and 1.043, p < 0.05). Furthermore, adding FD to the prediction model improved the calibration and accuracy of the model (c-index: 0.806).ConclusionThe left ventricular FD obtained with fractal analysis can reflect the complexity of myocardial trabeculae and has an independent predictive value for the diagnosis of HFpEF in patients with multivessel CAD. Including FD into the diagnostic model can help improve the diagnosis.Critical relevance statementDifferences show in the complexity of endocardial trabeculae in multivessel coronary artery disease patients, and obtaining fractal dimensions (FD) by fractal analysis can help identify heart failure with preserved ejection fraction (HFpEF) patients.Key PointsThe complexity of myocardial trabeculae differs among patients with multivessel coronary artery disease.Left ventricular fractal dimensions can reflect the complexity of the myocardial trabecular.Fractal dimensions have predictive value for the diagnosis of heart failure with preserved ejection fraction.Graphical

Establishing a causal link between the human papilloma virus and oral fibromas

Fibroma, a benign tumour of fibrous connective tissue, can be seen as a reactive connective tissue hyperplasia in response to trauma and irritation. They typically have a firm consistency, are nodular and asymptomatic, have a colour that is similar to the mucosa, a sessile base, a smooth surface, and are situated in the buccal mucosa along the line of occlusion, tongue, and lip mucosa. We retrospectively investigated total 79 cases and intriguingly, 41 cases were not associated with any history or clinical evidence of chronic trauma of dental origin suggesting different pathogenesis mechanism. Out of 79 cases of oral fibroma, 18 showed evidence of koilocytes in the overlying epithelium with 14 cases not associated with history of any trauma. This might suggest the cause and effect relationship between HPV and oral fibromas, however, the possibility of secondary infection in already existing fibroma can be considered. This intriguing finding prompt us to propose a novel hypothesis explaining the role of human papilloma virus in the pathogenesis of fibroma.

The Outcome of Prolactinoma in the Postpartum Period: a Study from a Tertiary Care Hospital in Pakistan

Objective: Prolactin is an essential hormone secreted by the pituitary gland of pregnant women. The pituitary gland undergoes growth, due to lactotroph hyperplasia in response to placental estrogen during pregnancy. Research on the postpartum outcomes of prolactinomas is less. This study evaluates the prevalence of Prolactinoma and the occurrence of spontaneous resolution of Prolactinomas after pregnancy. Materials and Methods: A cross-section study was conducted at the Punjab Institute of Neurosciences, Lahore. 200 pregnant women were recruited; their blood samples were collected to evaluate serum prolactin levels. Women diagnosed with prolactinomas exhibiting positive symptoms were given dopamine agonists. The administration of dopamine agonist was discontinued at the 24th week of gestation. All participants were monitored till birth, at 40 days after delivery, and throughout breastfeeding. Their prolactin levels were evaluated, and magnetic resonance imaging (MRI) was conducted to verify the resolution of prolactinoma. Results: The mean age of females in the study was 29.03 ± 7.20 years. Out of 200, 40 (20%) females had prolactinoma. Out of 40, 13 (32.5%) were given Bromocriptine while 27 (67.5%) were given Cabergoline. At presentation, the mean serum prolactin level was 138.91 ± 149.02 ng/ml, which reduced to 21.38 ± 9.80 ng/ml. The mean tumor size at presentation was 7.23 ± 2.07 mm, which reduced to 0.79 ± 0.66 mm after delivery. Out of 40, 30 (75.0%) had spontaneous resolution. Conclusion: The occurrence of prolactinoma is low in symptomatic patients and can resolve spontaneously after delivery in the majority of cases.

Preclinical exploration of combined glucagon inhibition and liver-preferential insulin for treatment of diabetes using in vitro assays and rat and mouse models

Aims/hypothesisNormalisation of blood glucose in individuals with diabetes is recommended to reduce development of diabetic complications. However, risk of severe hypoglycaemia with intensive insulin therapy is a major obstacle that prevents many individuals with diabetes from obtaining the recommended reduction in HbA1c. Inhibition of glucagon receptor signalling and liver-preferential insulin action have been shown individually to have beneficial effects in preclinical models and individuals with diabetes (i.e. improved glycaemic control), but also have effects that are potential safety risks (i.e. alpha cell hyperplasia in response to glucagon receptor antagonists and increased levels of liver triacylglycerols and plasma alanine aminotransferase activity in response to glucagon receptor antagonists and liver-preferential insulin). We hypothesised that a combination of glucagon inhibition and liver-preferential insulin action in a dual-acting molecule would widen the therapeutic window. By correcting two pathogenic mechanisms (dysregulated glucagon signalling and non-physiological distribution of conventional insulin administered s.c.), we hypothesised that lower doses of each component would be required to obtain sufficient reduction of hyperglycaemia, and that the undesirable effects that have previously been observed for monotreatment with glucagon antagonists and liver-preferential insulin could be avoided.MethodsA dual-acting glucagon receptor inhibitor and liver-preferential insulin molecule was designed and tested in rodent models (normal rats, rats with streptozotocin-induced hyperglycaemia, db/db mice and mice with diet-induced obesity and streptozotocin-induced hyperglycaemia), allowing detailed characterisation of the pharmacokinetic and pharmacodynamic properties of the dual-acting molecule and relevant control compounds, as well as exploration of how the dual-acting molecule influenced glucagon-induced recovery and spontaneous recovery from acute hypoglycaemia.ResultsThis molecule normalised blood glucose in diabetic models, and was markedly less prone to induce hypoglycaemia than conventional insulin treatment (approximately 4.6-fold less potent under hypoglycaemic conditions than under normoglycaemic conditions). However, compared to treatment with conventional long-acting insulin, this dual-acting molecule also increased triacylglycerol levels in the liver (approximately 60%), plasma alanine aminotransferase levels (approximately twofold) and alpha cell mass (approximately twofold).Conclusions/interpretationWhile the dual-acting glucagon receptor inhibitor and liver-preferential insulin molecule showed markedly improved regulation of blood glucose, effects that are potential safety concerns persisted in the pharmacologically relevant dose range.Graphical abstract

E2F1 transcription factor mediates a link between fat and islets to promote β cell proliferation in response to acute insulin resistance.

SUMMARYPrevention or amelioration of declining β cell mass is a potential strategy to cure diabetes. Here, we report the pathways utilized by β cells to robustly replicate in response to acute insulin resistance induced by S961, a pharmacological insulin receptor antagonist. Interestingly, pathways that include CENP-A and the transcription factor E2F1 that are independent of insulin signaling and its substrates appeared to mediate S961-induced β cell multiplication. Consistently, pharmacological inhibition of E2F1 blocks β-cell proliferation in S961-injected mice. Serum from S961-treated mice recapitulates replication of β cells in mouse and human islets in an E2F1-dependent manner. Co-culture of islets with adipocytes isolated from S961-treated mice enables β cells to duplicate, while E2F1 inhibition limits their growth even in the presence of adipocytes. These data suggest insulin resistance-induced proliferative signals from adipocytes activate E2F1, a potential therapeutic target, to promote β cell compensation.

P2RY6 Has a Critical Role in Mouse Skin Carcinogenesis by Regulating the YAP and β-Catenin Signaling Pathways

P2RY6 is highly expressed in skin keratinocytes, but its function in skin diseases is unclear. We use a two-step chemical induction method to induce mouse skin tumor formation. Multiple invitro and invivo assays were used to explore the role of P2RY6 in skin tumors. We report that P2ry6-deficient mice exhibit marked resistance to 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced skin papilloma formation compared with wild-type mice. Consistent with these findings, epidermal hyperplasia in response to TPA was suppressed in the P2ry6-knockout or MRS2578 (P2RY6 antagonist)-treated mice. The dramatic decrease in hyperplasia and tumorigenesis due to P2ry6 disruption was associated with the suppression of TPA-induced keratinocyte proliferation and inflammatory reactions. Notably, P2ry6 deletion prevented the TPA-induced increase in YAP nuclear accumulation and its downstream gene expression in an MST/LATS1-dependent manner. On TPA stimulation, enhanced activation of MAPK/extracellular signal‒regulated kinase kinase 1 and β-catenin were also impaired in P2ry6-knockout primary keratinocytes, tumor tissues, or MRS2578-treated HaCaT cells. Moreover, mutual promotion of the YAP and β-catenin signaling pathways was observed in normal skin cells treated with TPA, whereas P2ry6 deletion could inhibit their crosstalk by regulating MAPK/extracellular signal‒regulated kinase kinase 1. Thus, P2RY6 is a critical positive regulator of skin tumorigenesis through the modulation of the Hippo/YAP and Wnt/β-catenin signaling pathways.

Fate of adipocyte progenitors during adipogenesis in mice fed a high-fat diet

ObjectiveExpansion of adipose tissue during obesity through the recruitment of newly generated adipocytes (hyperplasia) is metabolically healthy, whereas that through the enlargement of pre-existing adipocytes (hypertrophy) leads to metabolic complications. Accumulating evidence from genetic fate mapping studies suggests that in animal models receiving a high-fat diet (HFD), only adipocyte progenitors (APs) in gonadal white adipose tissue (gWAT) have proliferative potential. However, the proliferative potential and differentiating capacity of APs in the inguinal WAT (iWAT) of male mice remains controversial. The objective of this study was to investigate the proliferative and adipogenic potential of APs in the iWAT of HFD-fed male mice. MethodsWe generated PDGFRα-GFP-Cre-ERT2/tdTomato (KI/td) mice and traced PDGFRα-positive APs in male mice fed HFD for 8 weeks. We performed a comprehensive phenotypic analysis, including the histology, immunohistochemistry, flow cytometry, and gene expression analysis, of KI/td mice fed HFD. ResultsContrary to the findings of others, we found an increased number of newly generated tdTomato+ adipocytes in the iWAT of male mice, which was smaller than that observed in the gWAT. We found that in male mice, the iWAT has more proliferating tdTomato+ APs than the gWAT. We also found that tdTomato+ APs showed a higher expression of Dpp4 and Pi16 than tdTomato− APs, and the expression of these genes was significantly higher in the iWAT than in the gWAT of mice fed HFD for 8 weeks. Collectively, our results reveal that HFD feeding induces the proliferation of tdTomato+ APs in the iWAT of male mice. ConclusionIn male mice, compared with gWAT, iWAT undergoes hyperplasia in response to 8 weeks of HFD feeding through the recruitment of newly generated adipocytes due to an abundance of APs with a high potential for proliferation and differentiation.

Chief cell plasticity is the origin of metaplasia following acute injury in the stomach mucosa

ObjectiveMetaplasia arises from differentiated cell types in response to injury and is considered a precursor in many cancers. Heterogeneous cell lineages are present in the reparative metaplastic mucosa with response...

Management of oral mucosal irritational fibroma with laser therapy: A case report

Traumatic or irritational fibroma is a general benign exophytic tumor or neoplasm of fibrous connective tissue origin that can be considered a reactionary connective tissue hyperplasia in response to trauma and irritation. They are clinically marked by solid well-demarcated rounded, sessile, or pedunculated growths covered by normal mucosa and are a relatively uncommon lesion. Local trauma can generate ulceration of these lesions. They are usually seen on the buccal mucosa but can also occur at any intra-oral site. These lesions are more common in adults and can befall at any age. Simple, complete excision and removal of the cause of irritation are the preferred treatment. The use of lasers in different dental procedures has become very common. Lasers have obvious benefits for all the patients without administering anesthetic shots and that means less time spent in the dental chair. Procedures were performed more conservatively, with less trauma for patients. The excision of the fibroma with the diode laser is a safe, quick procedure, with minimum postoperative discomfort and complications. This paper reports the management of a fibroma in a 25-year-old male with a mass in the inner surface of left check with a 940 nm diode laser. Keywords: Irritational fibroma, Fibroepithelial hyperplasia, Diode LASER, Minimal bleeding, Improved healing.

Abstract 15691: The Novel High Mobility Group Protein Hmgxb4 Promotes Neointimal Formation in Response to Arterial Injury

Introduction: Restenosis after percutaneous intervention is predominantly attributed to proliferation and migration of vascular smooth muscle cells (VSMCs). However, the key regulators responsible for VSMC proliferation and migration remain to be identified. Hypothesis: We previously reported that the novel high mobility group (HMG) nuclear protein HMGXB4 (HMG-Box containing 4) plays a critical role in the de-differentiation of vascular smooth muscle cells in vitro and in acute inflammatory response to septic shock. We hypothesize that HMGXB4 is critical for neointimal hyperplasia in response to inflammatory stimuli. Methods and Results: We found that the expression of HMGXB4 is dramatically induced in ligation or wire injury-induced neointimal hyperplasia and correlated with the activation of inflammatory signaling in mice. Using an inducible smooth muscle-specific Hmgxb4 KO (knockout) mice model, we found specific KO of Hmgxb4 in VSMCs ameliorates ligation- or wire- injury induced neointimal formation. Among an array of growth factors and inflammation cytokines, we found that TNFα and INFγ effectively induces the expression of HMGXB4 in VSMCs and correlates with the VSMC proliferation in vitro. Furthermore, we found deletion of HMGXB4 attenuates while over-expression of HMGXB4 promotes inflammation cytokines-induced VSMC proliferation in vitro. These results suggest injury-induced inflammatory signal triggers HMGXB4 induction, which, in turn, promotes the VSMC proliferation and neointimal formation. Conclusions: Our study not only demonstrates a critical role of HMGXB4 in promoting neointimal hyperplasia in response the arterial injury, but also suggests HMGXB4 is a potential novel target for the management of restenosis in human.

Adipose Tissue Immunomodulation: A Novel Therapeutic Approach in Cardiovascular and Metabolic Diseases.

Adipose tissue is a critical regulator of systemic metabolism and bodily homeostasis as it secretes a myriad of adipokines, including inflammatory and anti-inflammatory cytokines. As the main storage pool of lipids, subcutaneous and visceral adipose tissues undergo marked hypertrophy and hyperplasia in response to nutritional excess leading to hypoxia, adipokine dysregulation, and subsequent low-grade inflammation that is characterized by increased infiltration and activation of innate and adaptive immune cells. The specific localization, physiology, susceptibility to inflammation and the heterogeneity of the inflammatory cell population of each adipose depot are unique and thus dictate the possible complications of adipose tissue chronic inflammation. Several lines of evidence link visceral and particularly perivascular, pericardial, and perirenal adipose tissue inflammation to the development of metabolic syndrome, insulin resistance, type 2 diabetes and cardiovascular diseases. In addition to the implication of the immune system in the regulation of adipose tissue function, adipose tissue immune components are pivotal in detrimental or otherwise favorable adipose tissue remodeling and thermogenesis. Adipose tissue resident and infiltrating immune cells undergo metabolic and morphological adaptation based on the systemic energy status and thus a better comprehension of the metabolic regulation of immune cells in adipose tissues is pivotal to address complications of chronic adipose tissue inflammation. In this review, we discuss the role of adipose innate and adaptive immune cells across various physiological and pathophysiological states that pertain to the development or progression of cardiovascular diseases associated with metabolic disorders. Understanding such mechanisms allows for the exploitation of the adipose tissue-immune system crosstalk, exploring how the adipose immune system might be targeted as a strategy to treat cardiovascular derangements associated with metabolic dysfunctions.

Fibrous Epulis: The Reactive Gingival Enlargement to Excise or Not to Excise

The volume thickening of soft tissue covering the alveolar ridges, designed gingival enlargement, is one of the frequent findings in clinical practice. However, they fail under varied presentations and their distinction allows a clinical diagnosis and defines an appropriate treatment to reduce recurrence. Among the diverse types of enlargement, fibrous epulis is the most common one. It is a localized uniform gingival overgrowth caused by tissue oedema and inflammatory hyperplasia in response to local irritations. This report outlines a case of fibrous epulis concerning a 56 years old male patient, in our periodontology department. A careful medical history, examination of the gingival, periodontal health status, and its reevaluation were assessed. Conventional periodontal treatment has been sufficient to minimize the gingival size. After an excisional biopsy, the histopathological examination was the determinants tool to accurate the diagnosis of fibrous epulis. Patient motivation and compliance during and after therapy has been a critical factor in the success of periodontal treatment and a key to prevent the recurrence of such lesions.

Factors Regulating Murine Tuft cell Hyperplasia in the Small Intestine during Infection with Hymenolepis Diminuta

IntroductionAt homeostasis, tuft cells form a rare epithelial cell population in the intestine. During parasitic infections with nematodes, the tuft cell has been shown to mobilize innate lymphoid type 2 cells (ILC2) by releasing the alarmin cytokine IL‐25. Enteric tuft cells possess key elements of the taste receptor pathway and may be luminal sensors of parasitic infections. Hymenolepis diminuta is a rat tapeworm that is rapidly expelled when introduced in immunocompetent murine hosts. During infection with this non‐abrasive, lumen dwelling parasite, immunocompetent mice display dramatic tuft cell hyperplasia across the small intestine. The factors regulating tuft cell response in this cestode model of infection are poorly understood. As observed in the nematode model of infection, we previously showed that tuft cell hyperplasia in response to H. diminuta is dependent on IL‐4 receptor mediated signalling. The influence of the adaptive immune system, which partakes in immunity against H. diminuta, was yet to be understood. Helminth infections are accompanied by alterations in the composition of the microbiota and may contribute to important luminal influences. Finally, it is poorly understood if tuft cell hyperplasia is regulated by changes in the sensory‐motor functions of the gut during helminth infection.AimsTo test if mice lacking (1) a functional adaptive immune system, (2) a microbiome, and (3) TRPV1+ gut‐innervating sensory nerves display enteric tuft cell hyperplasia following infection with H. diminuta.MethodsRAG‐1−/− (male and female) and germ‐free mice (n=3–6) were orally gavaged with 5 cysticercoids of H. diminuta. Age matched non‐infected mice served as control groups. Male C57BL/6j mice (n=3–4) were treated with resiniferatoxin (RTX) to ablate TRPV1+ sensory neurons before infection. Mid‐jejunum cryosections (10mm) or paraffin embedded sections (5mm) were immuno‐stained against doublecortin‐like kinase ‐1 (DCLK‐1), a tuft cell marker, at 5, 8, 11 and 14 days post‐infection.ResultsWild‐type C57BL/6j mice expel H. diminuta by 11 days post infection and display ~ 10–15 fold increase in tuft cells at this time. In RAG‐1−/− mice, tuft cell hyperplasia at 11 days post‐infection was observed at a lesser magnitude than wild type mice. Germ‐free mice displayed tuft cell hyperplasia and kinetics of worm expulsion that were not different from wild‐type mice. RTX‐treated mice with confirmed loss of TRPV1+ nerve fibers in the gut and their cell soma in the dorsal root and nodose ganglia, had a greater increase (~2‐fold) in tuft cell numbers compared to the untreated infected wild‐type mice at day 11 post infection.ConclusionIn the H. diminuta‐ mouse model system, we find that tuft cell hyperplasia is largely, but not entirely dependent on adaptive immunity and occurs independent of the gut microbiota. The observation that TRPV1+ sensory nerves appear to contribute to regulation of tuft cell hyperplasia warrants further study on tuft cell‐sensory nerve interactions.Support or Funding InformationNSERC, CIHR, Henry Koopman Memorial Entrance Scholarship in Gastrointestinal Nutrition, Metabolism and Inflammation

Deficiency of cysteinyl cathepsin K suppresses the development of experimental intimal hyperplasia in response to chronic stress.

Chronic psychological stress (CPS) is linked to cardiovascular disease initiation and progression. Given that cysteinyl cathepsin K (CatK) participates in vascular remodeling and atherosclerotic plaque growth in several animal models, we investigated the role of CatK in the development of experimental neointimal hyperplasia in response to chronic stress. At first, male wild-type (CatK) mice that underwent carotid ligation injury were subjected to chronic immobilization stress. On postoperative and stressed day 14, the results demonstrated that stress accelerated injury-induced neointima hyperplasia. On day 4, stressed mice showed following: increased levels of monocyte chemoattractant protein-1, gp91phox, toll-like receptor-2 (TLR2), TLR4, and CatK mRNAs or/and proteins, oxidative stress production, aorta-derived smooth muscle cell (SMC) migration, and macrophage infiltration as well as targeted intracellular proliferating-related molecules. Stressed mice showed increased matrix metalloproteinase-2 (MMP-2) and MMP-9 mRNA expressions and activities and elastin disruption in the injured carotid arteries. Second, CatK and CatK deficiency (CatK) mice received ligation injury and stress to explore the role of CatK. The stress-induced harmful changes were prevented by CatK. Finally, CatK mice that had undergone ligation surgery were randomly assigned to one of two groups and administered vehicle or CatK inhibitor for 14 days. Pharmacological CatK intervention produced a vascular benefit. These data indicate that CatK deletion protects against the development of experimental neointimal hyperplasia via the attenuation of inflammatory overaction, oxidative stress production, and VSMC proliferation, suggesting that CatK is a novel therapeutic target for the management of CPS-related restenosis after intravascular intervention therapies.

Osteoprotegerin promotes intimal hyperplasia and contributes to in-stent restenosis: Role of an αVβ3/FAK dependent YAP pathway

ObjectiveAbnormal proliferation and migration of vascular smooth muscle cells (VSMCs) are related to in-stent-restenosis (ISR) following percutaneous coronary intervention (PCI). Osteoprotegerin (OPG) has been implicated in various vascular diseases. However, the effects of OPG on ISR and the underlying mechanism remained elusive. We here investigated the association between OPG and ISR, and to demonstrate the role and potential mechanisms of OPG in neointimal hyperplasia. Approach and resultsFrom 2962 patients who received coronary angiography and follow-up coronary angiography at approximately one year, 291 patients were diagnosed with ISR, and another 291 gender- and age- matched patients without ISR were selected as controls. Serum OPG levels were significantly increased in patients with ISR. Multivariable logistic regression analysis indicated that OPG level was independently associated with the increased risk of ISR. In a mouse femoral artery wire injury model, upregulated OPG was evidenced in vascular tissue after injury. OPG deletion attenuated the vascular injury-induced neointimal hyperplasia and related gene expression in mice. OPG promoted neointimal hyperplasia and human aortic smooth muscle cell (hASMC) proliferation and migration through activation of yes-associated protein (YAP), a major downstream effector of the Hippo signaling pathway, whereas knockdown or inhibition of YAP in hASMCs blunted OPG-induced above effects. Moreover, we found that OPG, as a ligand for integrin αVβ3, mediated phosphorylation of focal adhesion kinase (FAK) and actin cytoskeleton reorganization, resulting in YAP dephosphorylation in hASMCs. OPG-dependent YAP and VSMC activation was prevented by treatment with αVβ3-blocking antibodies and inhibitors of FAK and actin stress fibers. ConclusionsIncreased serum OPG levels are associated with increased risk of ISR following PCI and OPG could promote neointimal hyperplasia in response to injury through integrin αVβ3 mediated FAK and YAP activation, indicating OPG/YAP inhibition might serve as an attractive novel target for the prevention of ISR after PCI.

Resveratrol and the Interaction between Gut Microbiota and Arterial Remodelling.

Arterial remodelling refers to the alteration in the structure of blood vessel that contributes to the progression of hypertension and other cardiovascular complications. Arterial remodelling is orchestrated by the crosstalk between the endothelium and vascular smooth muscle cells (VSMC). Vascular inflammation participates in arterial remodelling. Resveratrol is a natural polyphenol that possesses anti-oxidant and anti-inflammatory properties and has beneficial effects in both the endothelium and VSMC. Resveratrol has been studied for the protective effects in arterial remodelling and gut microbiota, respectively. Gut microbiota plays a critical role in the immune system and inflammatory processes. Gut microbiota may also regulate vascular remodelling in cardiovascular complications via affecting endothelium function and VSMC proliferation. Currently, there is new evidence showing that gut microbiota regulate the proliferation of VSMC and the formation of neointimal hyperplasia in response to injury. The change in population of the gut microbiota, as well as their metabolites (e.g., short-chain fatty acids) could critically contribute to VSMC proliferation, cell cycle progression, and migration. Recent studies have provided strong evidence that correlate the effects of resveratrol in arterial remodelling and gut microbiota. This review aims to summarize recent findings on the resveratrol effects on cardiovascular complications focusing on arterial remodelling and discuss the possible interactions of resveratrol and the gut microbiota that modulate arterial remodelling.

Macrophage Hypercellularity Accompanies Erythroid Hyperplasia in Sickle Cell Mice and during Recovery from Blood Loss in Wild Type Mice

Red blood cell (RBC) homeostasis tightly balances production of new erythroid cells and clearance of damaged or senescent RBCs. Macrophages play a central role in this process in the specialized niches termed erythroblastic island. Macrophages expressing CD169 (Sialoadhesin or Siglec-1), F4/80, CD11b, VCAM-1, ER-HR3 and Ly-6G play important roles in physiological and pathological erythropoiesis. Sickle cell disease (SCD) is characterized by chronic stress erythropoiesis as a compensatory mechanism for anemia. Recent publications have detected macrophage hypercellularity correlated with erythroid hyperplasia in genetic models of erythrocytosis and monocyte-derived macrophage proliferation in the spleen. Because macrophages are integral part of the erythropoietic niche, our objective was to assess the macrophage compartment in transgenic sickle cell mice (SS) at steady state compared to AA controls. Furthermore, we used acute blood loss in C57BL/6J wild type (WT) to confirm if macrophage hypercellularity accompanies erythroid hyperplasia in a mouse model without erythrocytosis or sickling. Using flow cytometry, macrophages were identified with F4/80, CD45, CD11b and CD169, while erythroid progenitor cells were identified with Ter119 and CD71 in the BM and spleen of SS mice and age-matched control (AA) mice. Each subset of macrophages is 3.8 to 6.8-fold higher in SS mice bone marrow compared to AA at steady state (p≤0.05, Fig 1a). Findings were similar for other CD169 subsets in the spleens of SS mice. This macrophage hypercellularity was accompanied by expected erythroid hyperplasia, with 12-fold higher immature erythroid progenitor cells (CD71hiTer119hi) in SS mice than AA controls (p≤0.001). To confirm the increase in macrophage numbers that accompanied erythroid hyperplasia in SS mice as a response to erythroid stress, we induce stress with acute blood loss in WT mice by phlebotomy (once). Interestingly, we found macrophage hypercellularity accompanies erythroid hyperplasia in WT mice during recovery from acute blood loss. WT mice showed about 47-61% increases in CD169 macrophages subsets in the marrow and 47-83% increase in the spleen during recovery from acute blood loss (5-7 days) compared to untreated mice (Fig. 1b). This macrophage hypercellularity was accompanied with 88% increase in immature erythroid progenitor cell. Similarly, we investigated if there was age dependence in macrophage hypercellularity that accompanies erythroid hyperplasia in SS mice. In SS mice, there was no significant differences in macrophage numbers in the BM juvenile mice (5 weeks old) compared to young adults (14 weeks old), presumably because the higher demand for erythroid production to compensate for anemia had already started in the juvenile animals. However, there was a significantly higher macrophage hypercellularity in the spleen at 14 weeks compared to juvenile animals (p≤0.001). There was also a reduction in hematocrit (p≤0.05) and hemoglobin (p≤0.01) from 5 to 14 weeks in SS mice, although this does not correlate to either macrophage hypercellularity or erythroid hyperplasia. We also quantified mRNA expression of heme oxygenase 1 (Hmox1), a critical regulator of erythroid stress response, in the BM of untreated SS mice, and untreated and stressed WT mice. As expected, BM cells from SS mice at steady state expressed significantly higher Hmox1 expression than in WT mice (p≤0.001). Acute blood loss induced-stress raised the Hmox1 expression in WT mice to comparable levels to that of SS mice at steady state. Our investigation is the first to our knowledge to detect BM macrophage hypercellularity is associated with erythroid hyperplasia in response to acute blood loss and in congenital hemolytic anemia. Our data of macrophage hypercellularity in SCD opens up further research opportunity to elucidate the role of these cells in multiorgan complication in SCD. Figure 1: Macrophage hypercellularity accompanies erythroid hyperplasia in sickle cell disease and during recovery from acute blood loss. (a) BM macrophage quantification (per femur) in untreated sickle cell mice compared to AA controls (n = 5). Student's Ttest * SS mice compared to AA mice. (b) Acute blood loss induced macrophage hypercellularity in the BM of WT mice (n = 4 - 5). Student's Ttest * Untreated compared to stressed WT mice. Figure 1 Disclosures Ofori-Acquah: Shire Human Genetic Therapies Inc: Other: Financial Relationship. Kato:Novartis, Global Blood Therapeutics: Consultancy, Research Funding; Bayer: Research Funding.

Cathepsin S Deficiency Mitigated Chronic Stress-Related Neointimal Hyperplasia in Mice.

BackgroundExposure to chronic psychosocial stress is a risk factor for atherosclerosis‐based cardiovascular disease. We previously demonstrated the increased expressions of cathepsin S (CatS) in atherosclerotic lesions. Whether CatS participates directly in stress‐related neointimal hyperplasia has been unknown.Methods and ResultsMale wild‐type and CatS‐deficient mice that underwent carotid ligation injury were subjected to chronic immobilization stress for morphological and biochemical studies at specific times. On day 14 after stress/surgery, stress enhanced the neointima formation. At the early time points, the stressed mice had increased plaque elastin disruption, cell proliferation, macrophage accumulation, mRNA and/or protein levels of vascular cell adhesion molecule‐1, angiotensin II type 1 receptor, monocyte chemoattractant protein‐1, gp91phox, stromal cell–derived factor‐1, C‐X‐C chemokine receptor‐4, toll‐like receptor‐2, toll‐like receptor‐4, SC35, galectin‐3, and CatS as well as targeted intracellular proliferating‐related molecules (mammalian target of rapamycin, phosphorylated protein kinase B, and p‐glycogen synthase kinase‐3α/β). Stress also increased the plaque matrix metalloproteinase‐9 and matrix metalloproteinase‐2 mRNA expressions and activities and aorta‐derived smooth muscle cell migration and proliferation. The genetic or pharmacological inhibition of CatS by its specific inhibitor (Z‐FL‐COCHO) ameliorated the stressed arterial targeted molecular and morphological changes and stressed aorta‐derived smooth muscle cell migration. Both the genetic and pharmacological interventions had no effect on increased blood pressure in stressed mice.ConclusionsThese results demonstrate an essential role of CatS in chronic stress–related neointimal hyperplasia in response to injury, possibly via the reduction of toll‐like receptor‐2/toll‐like receptor‐4–mediated inflammation, immune action, and smooth muscle cell proliferation, suggesting that CatS will be a novel therapeutic target for stress‐related atherosclerosis‐based cardiovascular disease.

A vascular smooth muscle cell X-box binding protein 1 and transglutaminase 2 regulatory circuit limits neointimal hyperplasia.

Neointimal hyperplasia, stimulated by injury and certain vascular diseases, promotes artery obstruction and tissue ischemia. In vascular smooth muscle cell (VSMCs), multiple modulators of protein handling machinery regulate intimal hyperplasia. These include elements of the VSMC unfolded protein response to endoplasmic reticulum stress (UPRER), and transglutaminase 2 (TG2), which catalyzes post-translational protein modification. Previous results for deficiency of UPRER-specific mediator XBP1, and of TG2, have been significant, but in multiple instances contradictory, for effects on cultured VSMC function, and, using multiple models, for neointimal hyperplasia in vivo. Here, we engineered VSMC-specific deficiency of XBP1, and studied cultured VSMCs, and neointimal hyperplasia in response to carotid artery ligation in vivo. Intimal area almost doubled in Xbp1fl/fl SM22α-CRE+ mice 21 days post-ligation. Cultured murine Xbp1 deficient VSMCs migrated more in response to platelet derived growth factor (PDGF) than control VSMCs, and had an increased level of inositol-requiring enzyme 1α (Ire1α), a PDGF receptor-binding UPRER transmembrane endonuclease whose substrates include XBP1. Cultured XBP1-deficient VSMCs demonstrated decreased levels of TG2 protein, in association with increased TG2 polyubiquitination, but with increased TG transamidation catalytic activity. Moreover, IRE1α, and TG2-specific transamidation cross-links were increased in carotid artery neointima in Xbp1fl/fl SM22α-CRE+ mice. Cultured TG2-deficient VSMCs had decreased XBP1 associated with increased IRE1α, and increased migration in response to PDGF. Neointimal hyperplasia also was significantly increased in Tgm2fl/fl SM22α-CRE+ mice at 21 days after carotid ligation. In conclusion, a VSMC regulatory circuit between XBP1 and TG2 limits neointimal hyperplasia in response to carotid ligation.

Macrophage-derived MMP-8 determines smooth muscle cell differentiation from adventitia stem/progenitor cells and promotes neointima hyperplasia.

Emerging evidence has suggested that adventitia stem/progenitor cells (AdSPCs) migrate into the intima of arteries in response to injury, where they differentiate towards smooth muscle cells (SMCs) and participate in neointimal hyperplasia. We have previously identified matrix metalloproteinase-8 (MMP8) as a key player in atherogenesis. In this study, we aimed to investigate the functional roles of macrophage-derived MMP8 in AdSPC differentiation and injury-induced arterial remodelling. We first observed an important role for MMP8 in SMC differentiation from embryonic stem cells, but this effect was not seen in AdSPCs. Instead, through macrophages/AdSPCs co-culture and macrophage conditional culture medium studies, we have demonstrated that the MMP8 protein secreted from macrophages promotes SMC differentiation from AdSPCs. Mechanistically, we showed that macrophage-derived MMP8 promotes SMC differentiation from AdSPCs through modulating transforming growth factor-β activity and a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10)/Notch1 signalling. We further demonstrated that the binding site for CBF1, Suppressor of Hairless, and Lag-1 (CSL) within SMC gene promoters is responsible for Notch1 mediated SMC differentiation. Finally, we demonstrated that macrophage-derived MMP8 increased injury-induced neointimal SMC hyperplasia by activating ADAM10/Notch1 signalling. We have identified macrophage-derived MMP8 as a regulator in SMC differentiation from AdSPCs and neointimal SMC hyperplasia in response to injury. Our data provide new insights into the roles of MMP8 in AdSPC differentiation and the pathogenesis of neointima formation in the context of angiographic restenosis, and therefore may aid in the development of novel therapeutic agents for the prevention of this disease.