Preliminary Report: Osteoarthritis and Rheumatoid Arthritis Synovial Fluid Increased Osteoclastogenesis In Vitro by Monocyte Differentiation Pathway Regulating Cytokines.

Background: Rheumatoid arthritis (RA) and osteoarthritis (OA) are common joint diseases associated with changes in local, as well as systemic bone structure and osteoclast function. We investigated how the different soluble inflammatory stimuli in these diseases can affect osteoclastogenesis and bone resorption in vitro. Methods. Human peripheral blood mononuclear cell-derived osteoclasts were cultured on bone slices with serum from treatment-naïve RA patients and healthy controls and with synovial fluid samples acquired from RA and OA patients. The concentrations of 29 different cytokines and related proteins, including RANKL and OPG, were analyzed in the fluids tested. Results: RA serum and synovial fluid increased both osteoclastogenesis and bone resorption. Osteoclastogenesis and activity increased more in the cultures containing OA than RA synovial fluid. The osteoclasts cultured in different culture media exhibited different phenotypes, especially the cells cultured with OA synovial fluid were generally larger and had more nuclei. A general increase in proinflammatory cytokines in RA synovial fluid and serum was found. Surprisingly, OA synovial fluid showed lower levels of osteoclastogenesis inhibiting cytokines, such as IL-4 and IL-10, than RA synovial fluid, which at least partly explains more pronounced osteoclastogenesis. No significant difference was found in RANKL or OPG levels. Conclusion: The proinflammatory stimulus in OA and RA drives the monocyte differentiation towards inflammatory osteoclastogenesis and altered osteoclast phenotype.

Clinical Diagnostics of Fecal Calprotectin: a Comparative Study of Actim® Calprotectin and LIAISON® Calprotectin.

BACKGROUND: Fecal calprotectin (fCal) is an important surrogate biomarker of chronic inflammatory bowel disease (IBD): Crohn's disease and ulcerative colitis. Non-invasive, immunochromatographic rapid tests are excellent tools for the real-time monitoring of disease activity and reduce the need for invasive and costly colonoscopy procedures. METHODS: In this study the accuracy of fCal detection by the semi-quantitative Actim® Calprotectin and the quantitative automated LIAISON® Calprotectin assay was assessed on a panel of clinical stool samples. RESULTS: Of the 119 fecal samples tested, Actim® Calprotectin agreed on 94 samples (79.0%) with the reference test. Furthermore, of the positive samples detected with LIAISON® Calprotectin, 94.0% were interpreted as positive by Actim® Calprotectin. CONCLUSIONS: Actim® Calprotectin is a rapid test that can be utilized for the initial differentiation between negative and positive samples in an outpatient setting, thus helping to limit more laborious quantitative methods to positive samples.

A single intra-articular dose of vitamin D analog calcipotriol alleviates synovitis without adverse effects in rats.

1,25-dihydroxyvitamin-D3 and its derivatives have shown anti-arthritic and chondroprotective effects in experimental animal models with prophylactic dosing. The purpose of this preliminary study was to test the efficacy and safety of calcipotriol, vitamin D analog, as a treatment for a fully-developed knee arthritis in Zymosan-induced arthritis (ZIA) model. Forty 5-month-old male Sprague-Dawley rats were randomized into three arthritis groups and a non-arthritic control group with no injections (10 rats/group). A day after Zymosan (0.1 mg) had been administrated into the right knee joints, the same knees were injected with calcipotriol (0.1 mg/kg), dexamethasone (0.1 mg/kg) or vehicle in a 100 µl volume. The left control knees were injected with saline (PBS) on two consecutive days. All injections, blood sampling and measurements were performed under general anesthesia on days 0, 1, 3 and 8. Internal organs and knees were harvested on day 8 and the histology of the whole knees was assessed blinded. Joints treated with calcipotriol showed a milder histological synovitis than those treated with vehicle (p = 0.041), but there was no statistically significant difference between the dexamethasone and vehicle groups. The clinical severity of arthritis did not differ between the arthritis groups measured by body temperature, swelling of the knee, thermal imaging, clinical scoring or cytokine levels on days 1, 3 and 8. Weight loss was bigger in rats treated with dexamethasone, propably due to loss of appetite,compared to other arthritis groups on days 2-3 (p<0.05). Study drugs did not influence serum calcium ion and glucose levels. Taken together, this preliminary study shows that a single intra-articular injection of calcipotriol reduces histological grade of synovitis a week after the local injection, but dexamethasone did not differ from the vehicle. Calcipotriol may have an early disease-modifying effect in the rat ZIA model without obvious side effects.

Fetal cardiovascular hemodynamics in type 1 diabetic pregnancies at near-term gestation.

INTRODUCTION: Poor glycemic control in maternal type 1 diabetes mellitus during pregnancy can affect fetal cardiac and placental function. However, studies concerning fetal central hemodynamics have revealed conflicting results. We hypothesized that in pregnancies complicated by maternal type 1 diabetes, fetal cardiovascular and placental hemodynamics are comparable to the control fetuses at near-term gestation. In addition, we investigated the relation between newborn serum biomarkers of cardiac function and fetal cardiovascular and placental hemodynamics. Furthermore, we studied whether maternal diabetes is associated with placental inflammation. MATERIAL AND METHODS: In this prospective case-control study, fetal central and peripheral hemodynamics were assessed by ultrasonography in 33 women with type 1 diabetes and in 67 controls with singleton pregnancies between 34+2 and 40+2 gestational weeks. Newborn umbilical cord serum was collected to analyze cardiac natriuretic peptides (atrial and B-type natriuretic peptides) and troponin T concentrations. Placental tissue samples were obtained for cytokine analyses. RESULTS: Fetal ventricular wall thicknesses were greater and weight-adjusted stroke volumes and cardiac outputs were lower in the type 1 diabetes group than in the control group. Pulsatility in the aortic isthmus and inferior vena cava blood flow velocity waveforms was greater in the type 1 diabetes group fetuses than in the controls. A positive correlation was found between branch pulmonary artery and aortic isthmus pulsatility index values. Umbilical artery pulsatility indices were comparable between the groups. Umbilical cord serum natriuretic peptide and troponin T concentrations were elevated in the type 1 diabetes fetuses. These cardiac biomarkers correlated significantly with cardiovascular hemodynamics. Placental cytokine levels were not different between the groups. CONCLUSIONS: In maternal type 1 diabetes pregnancies, fetal cardiovascular hemodynamics is impaired. Maternal type 1 diabetes does not seem to alter placental vascular impedance or induce placental inflammation.

Narrow-band ultraviolet B (NB UV-B) exposures improve mood in healthy individuals differently depending on chronotype.

The evening chronotype is associated with psychological symptoms such as depressed mood, while skin exposure to ultraviolet radiation (UVR) may affect mood and behavior through neural and humoral routes. This pilot study aimed to investigate the impact of whole-body narrow-band (NB) UV-B exposure on current mood state and circulating 25-hydroxyvitamin D3 (25(OH)D3), interleukin-6 (IL-6), cortisol and ß-endorphin (ß-END) levels in healthy participants. Here, eleven healthy women received full-body NB UV-B exposures on four afternoons, and the chronotype was assessed with a shortened version of Horne and Östberg's Morningness-Eveningness Questionnaire (MEQ). Perceived mood was evaluated using the Visual Analogue Scale (VAS), and serum 25(OH)D3, IL-6, cortisol and ß-END concentrations were monitored daily. Decreasing VAS values showed mood to improve significantly over the five days after the four suberythematous NB UV-B exposures (p = .038), and the more the circadian preference was inclined toward eveningness, the greater the improvement in the mood dimension of wellbeing (p = .021). Baseline mood state was correlated with baseline 25(OH)D3 (r = -0.54, 95% CI: -0.86 to -0.09) and with baseline cortisol (r = -0.57, 95% CI: -0.87 to -0.04). During the NB UV-B exposures, 25(OH)D3 increased significantly, as expected, and IL-6 declined significantly by -0.35 (95% CI: -0.69 to -0.07) pg/mL from the initial values of 1.12 ± 0.66 pg/mL (p = .025). In conclusion, in our pilot study, NB UV-B exposure improved mood, especially among those with evening preference for their daily activities, as well as circulating 25(OH)D3 levels, whereas circulating IL-6 levels decreased. Abbreviations: UVR: Ultraviolet radiation; NB UV-B: narrow-band UV-B; VAS: Visual Analogue Scales; ß-END: ß-endorphin; IL-6: Interleukin-6.

Ambulatory Pulse Pressure Predicts the Development of Left Ventricular Diastolic Dysfunction in Over 20 Years of Follow-up.

BACKGROUND: Ambulatory blood pressure (ABP) has been shown to have an association with left ventricular diastolic dysfunction (LVDD) in cross-sectional assessments. We evaluated the association between ABP measurement (ABPM) and the development of LVDD during over 20 years of follow up in 414 middle-aged subjects from OPERA cohort. METHODS: ABPM, clinical, and anthropometric measurements were performed in baseline. Echocardiographic measurements were performed at baseline and during follow-up and E/E' ≥15 was considered indicating significant LVDD. RESULTS: Several baseline clinical characteristics (age, female gender, short stature, body mass index, prevalence of diabetes, in-office systolic BP (SBP), in-office pulse pressure (PP), N-terminal pro-atrial natriuretic peptide, and the use of antihypertensive therapy) were associated with the development of LVDD. Baseline 24-hour mean, daytime mean or nighttime mean SBP or diastolic BP were not associated with the development of LVDD, neither were different circadian BP profiles. Instead 24-hour mean, daytime mean and nighttime mean PP showed significant association with the development of LVDD (P from <0.001 to 0.001) even after adjustment with significant baseline clinical characteristics (P from 0.001 to 0.016). CONCLUSION: These findings suggest that ambulatory PP has an independent predictive value in the development of LVDD during over 20 years of follow-up.

Systemic Hypoxia Increases Circulating Concentration of Apelin in Humans.

Heinonen, Ilkka, Olli Vuolteenaho, Juha Koskenvuo, Olli Arjamaa, and Mikko Nikinmaa. Systemic hypoxia increases circulating concentration of apelin in humans. High Alt Med Biol. 18:292-295, 2017. BACKGROUND: Apelin is a hormone that regulates cardiovascular function, and its concentration is increased by hypoxia based on cell culture and animal studies. As it remains unknown as to whether hypoxia could affect apelin levels in humans, we investigated whether breathing normobaric hypoxic gas mixture increases the circulating apelin concentration in healthy male subjects. METHODS: Ten healthy young men (age 29 ± 5 years, body mass index 24.7 ± 2.8 kg/m2) breathed normobaric hypoxic gas mixture (11% O2/89% N2) for 1 hour. Venous blood samples were obtained immediately before, and 2 and 24 hours after the start of the hypoxic exposure and analyzed for circulating apelin concentrations. RESULTS: Arterial oxygen saturation decreased steadily from a baseline value of 99% ± 1% after the initiation hypoxia challenge and reached a steady-state level of 73% ± 6% within 20-30 minutes. Baseline apelin concentration was 3.3 ± 1.3 pmol/L and remained comparable (3.3 ± 1.4 pmol/L) to the baseline concentration at a 2-hour time point. However, apelin concentration at the 24-hour time point (5.5 ± 2.8 pmol/L) was significantly (by ∼67%) higher as compared with at both baseline and 2-hour time points (p < 0.05). CONCLUSION: In conclusion, in line with cell culture and animal studies, acute systemic hypoxia increases circulating apelin concentration also in humans.

Cytokine data obtained from synovial stromal cells of patients with rheumatoid arthritis or osteoarthritis.

In this article, we share the raw cytokine data obtained from basal and stimulated synovial stromal cells cultured from patients with rheumatoid arthritis or osteoarthritis. This data article is related to the research article entitled "1,25D3 and calcipotriol, its hypocalcemic analog, exert a long-lasting anti-inflammatory and anti-proliferative effect in synoviocytes cultured from patients with rheumatoid arthritis and osteoarthritis (1). Cytokine levels were analyzed by a magnetic bead-based multiplex assay (a panel of 27 important cytokines) in two separate sets of experiments. The first was conducted with IL-1ß and 1,25(OH)2D3 and the other with TNFα, calcipotriol, i.e. the hypocalcemic analog 1,25(OH)2D3, and dexamethasone. The raw data of this article display the individual variation in basal secretion of cytokines and in their response to different stimuli.

Niche matters: The comparison between bone marrow stem cells and endometrial stem cells and stromal fibroblasts reveal distinct migration and cytokine profiles in response to inflammatory stimulus.

OBJECTIVE: Intrinsic inflammatory characteristics play a pivotal role in stem cell recruitment and homing through migration where the subsequent change in niche has been shown to alter these characteristics. The bone marrow mesenchymal stem cells (bmMSCs) have been demonstrated to migrate to the endometrium contributing to the stem cell reservoir and regeneration of endometrial tissue. Thus, the aim of the present study was to compare the inflammation-driven migration and cytokine secretion profile of human bmMSCs to endometrial mesenchymal stem cells (eMSCs) and endometrial fibroblasts (eSFs). MATERIALS AND METHODS: The bmMSCs were isolated from bone marrow aspirates through culturing, whereas eMSCs and eSFs were FACS-isolated. All cell types were tested for their surface marker, proliferation profiles and migration properties towards serum and inflammatory attractants. The cytokine/chemokine secretion profile of 35 targets was analysed in each cell type at basal level along with lipopolysaccharide (LPS)-induced state. RESULTS: Both stem cell types, bmMSCs and eMSCs, presented with similar stem cell surface marker profiles as well as possessed high proliferation and migration potential compared to eSFs. In multiplex assays, the secretion of 16 cytokine targets was detected and LPS stimulation expanded the cytokine secretion pattern by triggering the secretion of several targets. The bmMSCs exhibited higher cytokine secretion of vascular endothelial growth factor (VEGF)-A, stromal cell-derived factor-1 alpha (SDF)-1α, interleukin-1 receptor antagonist (IL-1RA), IL-6, interferon-gamma inducible protein (IP)-10, monocyte chemoattractant protein (MCP)-1, macrophage inflammatory protein (MIP)1α and RANTES compared to eMSCs and/or eSFs after stimulation with LPS. The basal IL-8 secretion was higher in both endometrial cell types compared to bmMSCs. CONCLUSION: Our results highlight that similar to bmMSCs, the eMSCs possess high migration activity while the differentiation process towards stromal fibroblasts seemed to result in loss of stem cell surface markers, minimal migration activity and a subtler cytokine profile likely contributing to normal endometrial function.

Gestational hyperglycemia reprograms cardiac gene expression in rat offspring.

BackgroundRat fetuses with maternal pregestational hyperglycemia develop cardiac dysfunction, and their cardiac gene expression differs from that of healthy control fetuses near term. We hypothesized that cardiac gene expression and morphologic abnormalities of rat fetuses with maternal pregestational hyperglycemia become normal after birth.MethodsNine rats were preconceptually injected with streptozotocin to induce maternal hyperglycemia and nine rats served as controls. The hyperglycemia group comprised 82 mice and the control group 74 offspring fed by euglycemic dams. Hearts of the offspring were collected on postnatal days 0, 7, and 14, and processed for histologic and gene expression analyses.ResultsOn day 0, heart weight was increased, and expression of cardiac genes involved in contractility, growth, and metabolism was decreased in the hyperglycemia group. On day 7, although cardiomyocyte apoptosis was enhanced, most of the changes in gene expression had normalized in the hyperglycemia group. By day 14, the expression of genes important for myocardial growth, function, and metabolism was again abnormal in the hyperglycemia group.ConclusionMost cardiac gene expression abnormalities become transiently normal during the first week of life of offspring to hyperglycemic rats. However, by day 14, cardiac expressions of genes involved in growth, function, and metabolism are again abnormal in relation to control offspring.

1,25(OH)2D3 and calcipotriol, its hypocalcemic analog, exert a long-lasting anti-inflammatory and anti-proliferative effect in synoviocytes cultured from patients with rheumatoid arthritis and osteoarthritis.

OBJECTIVES: We investigated the effects of 1,25-dihydroxy vitamin D3 (1,25(OH)2D3), i.e. biologically active vitamin D and calcipotriol, a vitamin D analog, on growth and secretion of inflammatory mediators in synovial stromal cells (SSC) of patients with rheumatoid arthritis (RA) or osteoarthritis (OA). METHODS: Synovial stromal cells (SSC) isolated during knee prosthesis surgery from four patients with RA and four with OA were exposed to 1,25(OH)2D3 or calcipotriol with or without stimulation of cells with IL-1ß or TNF-α. The proliferation of cells was studied by MTT assay. Levels of cytokines were analyzed by a magnetic bead-based multiplex assay (a panel of 27 important cytokines and IL-6 alone) and RT-PCR was used to validate the concentrations of the key cytokines secreted by SSC. The vitamin D receptor (VDR) was visualized by immunofluorescence in SSC and by immunohistochemistry in the synovial tissues of three RA and three OA patients. RESULTS: We detected intense staining for VDR in the synovial lining and vascular endothelium in tissue sections from all our RA and OA patients. Both 1,25(OH)2D3 and calcipotriol inhibited SSC proliferation for a prolonged time (up to 23 days with calcipotriol), but dexamethasone tended to increase SSC proliferation in a 4-day culture. 1,25(OH)2D3, calcipotriol and dexamethasone reduced the secretion of most inflammatory factors. Calcipotriol and dexamethasone additively reduced the secretions of IL-6, IFN-γ, basic FGF and VEGF in TNF-α stimulated SSC. The level of IL-6 was still diminished at 10 days after exposure, emphasizing the long-term impact of calcipotriol on SSC. CONCLUSIONS: Exposure for 24-48h to 1,25(OH)2D3 or calcipotriol causes a long-lasting inhibition of cell proliferation and cytokine production in SSC in vitro.

Effect of Hypoxemia with or without Increased Placental Vascular Resistance on Fetal Left and Right Ventricular Myocardial Performance Index in Chronically Instrumented Sheep.

Myocardial performance index (MPI) is increased in growth-restricted fetuses with placental insufficiency, but it is unknown if this is due to fetal hypoxemia or increased placental vascular resistance (Rplac). We used chronically instrumented sheep fetuses (n = 24). In 12 fetuses, placental embolization was performed 24 h before experiments. On the day of the experiment, left (LV) and right (RV) ventricular MPIs were obtained by pulsed Doppler at baseline and in the hypoxemia and recovery phases. At baseline, Rplac was greater and fetal pO2 lower in the placental embolization group, but RV and LV MPIs were comparable to those of the control group. During hypoxemia, mean LV MPI increased significantly only in fetuses with an intact placenta (0.34 vs. 0.46), returning to baseline during the recovery phase. Right ventricular MPI was unaffected. We conclude that fetal LV function is sensitive to acute hypoxemia. Exposure to chronic hypoxemia could pre-condition the fetal heart and protect its function with worsening hypoxemia.

Placental structural abnormalities have detrimental hemodynamic consequences in a rat model of maternal hyperglycemia.

INTRODUCTION: Human type 1 diabetic pregnancy is associated with placental structural and hemodynamic abnormalities. We hypothesized that in rat fetuses of hyperglycemic dams, placental and fetal blood flow velocity waveforms demonstrate compromised hemodynamics when compared to control fetuses, and these hemodynamic parameters correlate with placental structural abnormalities at near term gestation. METHODS: Streptozotocin-induced maternal hyperglycemia group comprised 10 dams with 107 fetuses and the control group 20 dams with 219 fetuses. Doppler-ultrasonographic examinations were performed at gestational days 13-14, 16-17, and 19-21. After the last examination, placentas were collected for morphologic, gene expression, and cytokine analysis. RESULTS: Umbilical artery (UA), descending aorta (DAO), and ductus venosus (DV) pulsatility indices (PI) were significantly higher at each study point in maternal hyperglycemia compared to controls. Placental size, glycogen storages, venous thrombosis formation, and fluid accumulation were increased in maternal hyperglycemia. Epidermal growth factor receptor (Edgfrb), platelet derived growth factor receptor beta polypeptide (Pdgfrb), and tumor necrosis factor receptor superfamily, member 12α (Tnfrsf12α) expressions were decreased. Interleukin (IL) -2 and -4 concentrations were decreased, and IL-1beta levels were increased in maternal hyperglycemia. UA PIs correlated positively with DV PIV, DAO PI, fluid accumulation, and glycogen storages. UA PIs correlated negatively with IL-4, Edgfrb, and Pdgfrb. DISCUSSION: In maternal hyperglycemia, placental and fetal hemodynamics were compromised during the last trimester of pregnancy compared to normoglycemic pregnancies. Placental structural, metabolic, and growth related gene expression, and inflammatory marker abnormalities were associated with hemodynamic compromise.

Neoplastic extracellular matrix environment promotes cancer invasion in vitro.

The invasion of carcinoma cells is a crucial feature in carcinogenesis. The penetration efficiency not only depends on the cancer cells, but also on the composition of the tumor microenvironment. Our group has developed a 3D invasion assay based on human uterine leiomyoma tissue. Here we tested whether human, porcine, mouse or rat hearts as well as porcine tongue tissues could be similarly used to study carcinoma cell invasion in vitro. Three invasive human oral tongue squamous cell carcinoma (HSC-3, SCC-25 and SCC-15), melanoma (G-361) and ductal breast adenocarcinoma (MDA-MB-231) cell lines, and co-cultures of HSC-3 and carcinoma-associated or normal oral fibroblasts were assayed. Myoma tissue, both native and lyophilized, promoted invasion and growth of the cancer cells. However, the healthy heart or tongue matrices were unable to induce the invasion of any type of cancer cells tested. Moreover, when studied in more detail, small molecular weight fragments derived from heart tissue rinsing media inhibited HSC-3 horizontal migration. Proteome analysis of myoma rinsing media, on the other hand, revealed migration enhancing factors. These results highlight the important role of matrix composition for cancer invasion studies in vitro and further demonstrate the unique properties of human myoma organotypic model.

Characterization of apela, a novel endogenous ligand of apelin receptor, in the adult heart.

The G protein-coupled apelin receptor regulates important processes of the cardiovascular homeostasis, including cardiac development, cardiac contractility, and vascular tone. Most recently, a novel endogenous peptide ligand for the apelin receptor was identified in zebrafish, and it was named apela/elabela/toddler. The peptide was originally considered as an exclusively embryonic regulator, and so far its function in the adult organism remains elusive. We show here that apela is predominantly expressed in the non-cardiomyocyte fraction in the adult rodent heart. We also provide evidence that apela binds to apelin receptors in the heart. Using isolated adult rat hearts, we demonstrate, that just like the fellow receptor agonist apelin, apela increases cardiac contractility and induces coronary vasodilation already in the nanomolar level. The inotropic effect, as revealed by Western blot analysis, is accompanied by a significant increase in extracellular signal-regulated kinase (ERK) 1/2 phosphorylation. Pharmacological inhibition of ERK1/2 activation markedly attenuates the apela-induced inotropy. Analysis of samples from infarcted mouse hearts showed that expression of both apela and apelin receptor is induced in failing mouse hearts and correlate with left ventricular ejection fraction. Hence, we conclude that apela is present in the adult heart, is upregulated in post-infarction cardiac remodeling, and increases cardiac contractility in an ERK1/2-dependent manner.

Bone Marrow Mononuclear Cell Transplantation Restores Inflammatory Balance of Cytokines after ST Segment Elevation Myocardial Infarction.

BACKGROUND: Acute myocardial infarction (AMI) launches an inflammatory response and a repair process to compensate cardiac function. During this process, the balance between proinflammatory and anti-inflammatory cytokines is important for optimal cardiac repair. Stem cell transplantation after AMI improves tissue repair and increases the ventricular ejection fraction. Here, we studied in detail the acute effect of bone marrow mononuclear cell (BMMNC) transplantation on proinflammatory and anti-inflammatory cytokines in patients with ST segment elevation myocardial infarction (STEMI). METHODS: Patients with STEMI treated with thrombolysis followed by percutaneous coronary intervention (PCI) were randomly assigned to receive either BMMNC or saline as an intracoronary injection. Cardiac function was evaluated by left ventricle angiogram during the PCI and again after 6 months. The concentrations of 27 cytokines were measured from plasma samples up to 4 days after the PCI and the intracoronary injection. RESULTS: Twenty-six patients (control group, n = 12; BMMNC group, n = 14) from the previously reported FINCELL study (n = 80) were included to this study. At day 2, the change in the proinflammatory cytokines correlated with the change in the anti-inflammatory cytokines in both groups (Kendall's tau, control 0.6; BMMNC 0.7). At day 4, the correlation had completely disappeared in the control group but was preserved in the BMMNC group (Kendall's tau, control 0.3; BMMNC 0.7). CONCLUSIONS: BMMNC transplantation is associated with preserved balance between pro- and anti-inflammatory cytokines after STEMI in PCI-treated patients. This may partly explain the favorable effect of stem cell transplantation after AMI.

Bone morphogenetic protein-2--a potential autocrine/paracrine factor in mediating the stretch activated B-type and atrial natriuretic peptide expression in cardiac myocytes.

Hemodynamic overload exposes the heart to variety of neural, humoral and mechanical stresses. Even without the neurohumoral control of the entire organism cardiac myocytes have the ability to sense mechanical stretch and convert it into adaptive intracellular signals. This process is controlled by several growth factors. Here we show that mechanical stretch in vitro and hemodynamic overload in vivo activated the expression of bone morphogenetic protein-2 (BMP-2), while expression of BMP-4 was temporarily attenuated by stretch. BMP-2 and BMP-4 alone stimulated B-type and atrial natriuretic peptide (BNP and ANP) expression and protein synthesis, and activated transcription factor GATA-4 resembling the effects of mechanical stretch of cultured cardiac myocytes. Further, BMP antagonist Noggin was able to inhibit stretch and hypertrophic agonist induced BNP and ANP expression. Together these data provide evidence for BMP-2 as a new autocrine/paracrine factor that regulates cardiomyocyte mechanotransduction and adaptation to increased mechanical stretch.

Circulating N-terminal brain natriuretic peptide and cardiac function in response to acute systemic hypoxia in healthy humans.

BACKGROUND: As it remains unclear whether hypoxia of cardiomyocytes could trigger the release of brain natriuretic peptide (BNP) in humans, we investigated whether breathing normobaric hypoxic gas mixture increases the circulating NT-proBNP in healthy male subjects. METHODS: Ten healthy young men (age 29 ± 5 yrs, BMI 24.7 ± 2.8 kg/m2) breathed normobaric hypoxic gas mixture (11% O2/89% N2) for one hour. Venous blood samples were obtained immediately before, during, and 2 and 24 hours after hypoxic exposure. Cardiac function and flow velocity profile in the middle left anterior descending coronary artery (LAD) were measured by Doppler echocardiography. RESULTS: Arterial oxygen saturation decreased steadily from baseline value of 99 ± 1% after the initiation hypoxia challenge and reached steady-state level of 73 ± 6% within 20-30 minutes. Cardiac output increased from 6.0 ± 1.2 to 8.1 ± 1.6 L/min and ejection fraction from 67 ± 4% to 75 ± 6% (both p < 0.001). Peak diastolic flow velocity in the LAD increased from 0.16 ± 0.04 to 0.28 ± 0.07 m/s, while its diameter remained unchanged. In the whole study group, NT-proBNP was similar to baseline (60 ± 32 pmol/ml) at all time points. However, at 24 h, concentration of NT-proBNP was higher (34 ± 18%) in five subjects and lower (17 ± 17%), p = 0.002 between the groups) in five subjects than at baseline. CONCLUSION: In conclusion, there is no consistent increase in circulating NT-proBNP in response to breathing severely hypoxic normobaric gas mixture in healthy humans, a possible reason being that the oxygen flux to cardiac myocytes does not decrease because of increased coronary blood flow. However, the divergent individual responses as well as responses in different cardiac diseases warrant further investigations.

Connective tissue growth factor inhibition attenuates left ventricular remodeling and dysfunction in pressure overload-induced heart failure.

Connective tissue growth factor (CTGF) is involved in the pathogenesis of various fibrotic disorders. However, its role in the heart is not clear. To investigate the role of CTGF in regulating the development of cardiac fibrosis and heart failure, we subjected mice to thoracic aortic constriction (TAC) or angiotensin II infusion, and antagonized the function of CTGF with CTGF monoclonal antibody (mAb). After 8 weeks of TAC, mice treated with CTGF mAb had significantly better preserved left ventricular (LV) systolic function and reduced LV dilatation compared with mice treated with control immunoglobulin G. CTGF mAb-treated mice exhibited significantly smaller cardiomyocyte cross-sectional area and reduced expression of hypertrophic marker genes. CTGF mAb treatment reduced the TAC-induced production of collagen 1 but did not significantly attenuate TAC-induced accumulation of interstitial fibrosis. Analysis of genes regulating extracellular matrix proteolysis showed decreased expression of plasminogen activator inhibitor-1 and matrix metalloproteinase-2 in mice treated with CTGF mAb. In contrast to TAC, antagonizing the function of CTGF had no effect on LV dysfunction or LV hypertrophy in mice subjected to 4-week angiotensin II infusion. Further analysis showed that angiotensin II-induced expression of hypertrophic marker genes or collagens was not affected by treatment with CTGF mAb. In conclusion, CTGF mAb protects from adverse LV remodeling and LV dysfunction in hearts subjected to pressure overload by TAC. Antagonizing the function of CTGF may offer protection from cardiac end-organ damage in patients with hypertension.

Depressive symptoms and cardiovascular burden-related mortality among the aged.

BACKGROUND: Depressive symptoms have been linked to increased cardiovascular mortality among the elderly. This study was aimed to test the independent and additive predictive value of depressive symptoms and B-type natriuretic peptide (BNP), a marker of direct cardiovascular stress and a strong predictor of mortality, together with traditional cardiovascular risk markers on total and cardiovascular mortalities in a general elderly population. METHODS: A total of 508 subjects aged 75 or older participated in the study. The prognostic capacity of depressive symptoms and BNP in regard to total and cardiovascular mortalities was assessed with Cox regression analyses. Depressive symptoms were handled as a dichotomous variable based on the Zung self-rated depression scale score with a cut-off point of 40. RESULTS: The median follow-up time was 84 months with an interquartile range of 36-99 months. Depressive symptoms reflected susceptibility to all-cause (HR 1·60; 95% CI 1·26-2·04) and cardiovascular mortalities (HR 1·81; 95% CI 1·30-2·52) only in univariable analyses. When cardiovascular illnesses and risk markers were taken into account, depressive symptoms lost their significance as an independent predictor of mortality. BNP as a continuous variable was a significant predictor of both all-cause (HR 1·44; 95% CI 1·22-1·69) and cardiovascular mortalities (HR 1·79; 95% CI 1·44-2·22) in fully adjusted models including depressive symptoms as a covariate. CONCLUSIONS: The prognostic capacity of depressive symptoms is closely linked to cardiovascular morbidity and has no independent power in an elderly general population. BNP remains a strong harbinger of death regardless of depressive symptoms status.