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To investigate the COVID-19 pandemic related alteration of health promoting behaviour during lockdown among medical students compared to other students.In this cross-sectional study, we enrolled 1940 Bavarian students. Participants were asked to complete an online questionnaire 3 weeks after lockdown implementation, evaluating their lifestyle behaviour focusing on self-reported and objectively assessed physical activity.1154 medical (59.5%) and 786 non-medical (40.5%) students were included (median age 22.0 [IQR, 20.0–25.0], 71.5% female). Physical activity decreased in both groups after lockdown implementation. During lockdown, medical students reported higher physical activity levels compared to non-medical students. This was corroborated by daily step count data assessed by wearables (median steps per day [IQR], 6979 [5218–9348] versus 6581 [4497–8491], p = 0.02). Smoking behaviour during lockdown did not differ between medical and non-medical students (increased in 11.8% vs 13.6%, decreased in 31.9% versus 36.9%).During the COVID-19 pandemic, alteration of lifestyle behaviour among medical students was significantly different compared to non-medical students. This result suggests that medical students are more concerned about health promoting behaviour even in crisis situations.

Background Since the onset of the COVID-19 pandemic in December 2019, many countries around the world have imposed lockdown measures in order to reduce virus spread. Social isolation is known to have a significant psychological impact, potentially triggering alcohol misuse in adults. In our study, we aimed to investigate the effect of COVID-19 lockdown measures on alcohol consumption in adults in Bavaria. Methods In this cross-sectional study, we enrolled 2067 participants, with 1961 young adults (mean age 23.3 ± 4.1) and 106 mature adults (mean age 66.7 ± 9.7). Participants were asked to complete a standardized questionnaire, semi-quantitatively evaluating the alcohol drinking behaviour before and during the pandemic lockdown. Results After implementation of lockdown, the alteration of alcohol consumption was significantly different between young and mature adults (p 0 to p Conclusion The COVID-19 pandemic lockdown significantly affected alcohol drinking behaviour. Further studies exploring long-term effects on potential alcohol misuse and the relevance on public health are warranted. Trial registration The study was retrospectively registered at ClinicalTrials.gov (NCT04361877) on April 24, 2020.

Hamm, Wolfgang, Sari Kassem, Lukas von Stülpnagel, Florian Maier, Mathias Klemm, Dominik Schüttler, Felix Grabher, Ludwig T. Weckbach, Bruno C. Huber, Axel Bauer, Konstantinos D. Rizas, and Stefan Brunner. Deceleration capacity and periodic repolarization dynamics as predictors of acute mountain sickness.

Purpose The COVID-19 pandemic and the implemented lockdown strongly impact on everyone’s daily life. Stressful situations are known to alter eating habits and increase the risk for obesity. In our study, we aimed to investigate the effect of the lockdown measures on nutrition behavior among young adults. Methods In this cross-sectional study, we enrolled 1964 voluntary participants from Bavarian universities. All participants were asked to complete an online questionnaire, semi-quantitatively evaluating the amount and type of food before and during pandemic lockdown. Study subjects were inquired to give information about acquisition and food procurement. The primary outcome was the change in food amount, secondary outcomes included alterations of food composition and procurement. Results Our study cohort (mean age 23.3 ± 4.0 years, 28.5% male) had a mean body mass index of 22.1 ± 4.5 kg/m2. The overall food amount increased in 31.2% of participants (n = 610) during lockdown and decreased in 16.8% (n = 328). A multinominal regression model revealed that an increased food intake was less likely in male participants (OR, 0.7 [CI 0.6–0.9]) and more likely with increasing BMI (OR, 1.4 [CI 1.3–2.0]), increased sports activity (OR, 1.3 [CI 1.2–1.8]), augmented mental stress (OR 1.4 [1.1–1.7]), and an alteration of alcohol consumption (reduced alcohol amount, OR, 1.4 [CI 1.1–1.7], increased alcohol, OR, 1.9 [CI 1.4–2.5]). Increase in food intake was mainly triggered by consumption of bread (increased in 46.8%, n = 284) and confectionary (increased in 64.4%, n = 389). Conclusion The COVID-19 pandemic lockdown significantly affected eating habits in young adults. Further investigation to evaluate long-term effects on weight change and comorbidities are warranted.

Treatment with extracorporeal life support (ECLS) in acute myocardial infarction (AMI) complicated by cardiogenic shock (CS) fell short of improving myocardial recovery measured by 30 day ejection fraction in the ECLS-SHOCK trial. However, to date, no data regarding impact of ECLS on long-term outcomes exist. In this randomized, controlled, prospective, open-label trial, 42 patients with CS complicating AMI were randomly assigned to ECLS (ECLS group, n = 21) or no ECLS (control group, n = 21). The primary endpoint was left ventricular ejection fraction (LVEF) after 30 days. Secondary endpoints included mortality and neurological outcome after 12 months. Evaluation of neurological outcome used the modified Rankin Scale. The 12-month all-cause mortality was 19% in the ECLS group versus 38% in the control group (p = 0.31). Only one patient (control group) died after the initial 30 days. Three patients underwent elective percutaneous coronary intervention (PCI) during follow-up (one in the control and two in the ECLS group). Favorable neurological outcome (modified Rankin Score ≤ 2) was seen in 61.9% of patients in the ECLS group versus 57.1% in the control group (p = 1). This pilot study showed that randomized studies with ECLS in CS patients are feasible and safe. Small numbers of included patients impede meaningful conclusions about mortality and neurological outcome. Our findings of numerical differences in mortality and survival with severe neurological impairment give an urgent call for larger multi-centric randomized trials assessing the endpoint of all-cause mortality but also considering the effects on neurological outcome measures.

Background The chemokine receptor CXCR4 and its ligand CXCL12 have been shown to be a possible imaging and therapeutic target after myocardial infarction (MI). The murine-based and mouse-specific 68Ga-mCXCL12 PET tracer could be suitable for serial in vivo quantification of cardiac CXCR4 expression in a murine model of MI. Methods and Results At days 1-6 after MI, mice were intravenously injected with 68Ga-mCXCL12. Autoradiography was performed and the infarct-to-remote ratio (I/R) was determined. In vivo PET imaging with 68Ga-mCXCL12 was conducted on days 1-6 after MI and the percentage of the injected dose (%ID/g) of the tracer uptake in the infarct area was calculated. 18F-FDG-PET was performed for anatomical landmarking. Ex vivo autoradiography identified CXCR4 upregulation in the infarct region with an increasing I/R after 12 hours (1.4 ± 0.3), showing a significant increase until day 2 (4.5 ± 0.6), followed by a plateau phase (day 4) and decrease after 10 days (1.3 ± 1.0). In vivo PET imaging identified similar CXCR4 upregulation in the infarct region which peaked around day 3 post MI (9.7 ± 5.0 %ID/g) and then subsequently decreased by day 6 (2.8 ± 1.0 %ID/g). Conclusion Noninvasive molecular imaging of cardiac CXCR4 expression using a novel, murine-based, and specific 68Ga-mCXCL12 tracer is feasible both ex vivo and in vivo.

Zusammenfassung Anamnese und klinischer Befund Ein 33-jähriger Koch stellte sich notfallmäßig mit Angina pectoris und Schüttelfrost sowie signifikant erhöhten Troponin-, CK- und CRP-Werten vor. Untersuchungen Eine koronare Herzerkrankung wurde koronarangiografisch ausgeschlossen. Der Verdacht auf eine akute Myokarditis erhärtete sich später MR-morphologisch. Diagnostik Aufgrund von Fieberschüben und Berufsanamnese vermuteten wir eine Q-Fieber-Erkrankung, die sich serologisch bestätigte. Therapie und Verlauf Unter antimikrobieller Therapie sistierte das Fieber und der Patient konnte wenige Tage später entlassen werden. Zur Vermeidung einer Chronifizierung empfahlen wir eine mehrwöchige Azithromycin-Therapie. Nach 1 Monat imponierte der Patient in einem guten klinischen Zustand ohne Zeichen einer Herzinsuffizienz oder Anhalt für eine persistierende Infektion. Folgerung Myokarditis ist eine sehr seltene Erscheinungsform von Q-Fieber, die nicht übersehen werden sollte. Die Diagnostik mittels Antikörpertiter ist leicht durchführbar. Die antibiotische Therapie ist gut verträglich, behandelt die Myokarditis kausal und dient der Vermeidung von Langzeitschäden.

Due to the rapid spread of the COVID-19 pandemic, a lockdown including limitation of activity and restrictions of non-essential travel was imposed on March 21, 2020 in the State of Bavaria, Germany. The implementation of activity restrictions not only strongly affects the economy but will possibly also impact the mental and physical health status of the general population. Therefore, the present study aimed to explore psychological effects of the COVID-19 crisis on a sample of Bavarian students. In this cross-sectional study, we enrolled 1943 voluntary subjects from Bavarian universities. All subjects completed an online questionnaire asking for mental health stress, as well as potential factors, influencing the state of mental stress during pandemic lockdown. In our study cohort, 17.3% (n=336) of the students indicated that they experienced less mental stress through COVID-19 pandemic, while 39.6% (n=770) stated that they had an increased psychological burden. The bivariate analysis identified sex and the level of physical activity as potential risk factors for the level of mental stress during the COVID-19 pandemic. Further research is necessary to investigate specific symptoms of mental stress and the overall long-term impact on mental health.

Coronary artery disease (CAD) is associated with increased mortality in patients with chronic lung disease. However, non-invasive diagnostic of CAD is difficult, especially in patients with more advanced disease. Therefore, we aimed to assess the feasibility and accuracy of SPECT-myocardial perfusion imaging (MPI) stress testing with regadenoson in patients with end-stage lung disease (ELD) undergoing assessment of stable CAD. Between January 2012 and May 2018, 102 patients with ELD, who were referred to our institution for lung transplant evaluation, were assessed retrospectively. All patients underwent both stress SPECT-MPI as well as coronary angiography. The mean age in our population was 57±6 years. All patients had severe pulmonary function impairment. During stress SPECT-MPI 14 patients (14%) reported regadenoson-related symptoms, but only 2 patients (2%) required medical treatment. Coronary angiography revealed obstructive CAD in 20 patients (20%). Among those, 5 patients had abnormal SPECT-MPI and PCI was performed in 3 patients accordingly. In 14 patients with obstructive CAD, revascularization was deferred based on normal SPECT-MPI findings. SPECT-MPI using regadenoson is well tolerated in patients with ELD and can help to make decisions about coronary revascularization before lung transplant.

A 33-year old Romanian chef presented with sudden onset of chest pain and chills as well as a significant elevation of myocardial markers and CRP.Coronary angiography showed no signs of relevant atherosclerosis. A myocarditis was assumed and later diagnosed on cardiac MRI.Due to fevers up to 40 °C and occupational history, Q fever was assumed. Serologic findings confirmed the diagnosis.After the start of antibiotic treatment, temperatures remained normal and the patient could be discharged a few days later. Azithromycin was recommended for several weeks to prevent a chronic infection. At the check-up visit one month later the patient appeared to have no signs of chronic heart failure or persistent infection.Myocarditis is a rare manifestation of Q fever, which should not be missed. The diagnostic evaluation with antibody titers is easy. The antibiotic therapy is well tolerated and is a causal treatment that helps to prevent long-term damage.Ein 33-jähriger Koch stellte sich notfallmäßig mit Angina pectoris und Schüttelfrost sowie signifikant erhöhten Troponin-, CK- und CRP-Werten vor.Eine koronare Herzerkrankung wurde koronarangiografisch ausgeschlossen. Der Verdacht auf eine akute Myokarditis erhärtete sich später MR-morphologisch.Aufgrund von Fieberschüben und Berufsanamnese vermuteten wir eine Q-Fieber-Erkrankung, die sich serologisch bestätigte.Unter antimikrobieller Therapie sistierte das Fieber und der Patient konnte wenige Tage später entlassen werden. Zur Vermeidung einer Chronifizierung empfahlen wir eine mehrwöchige Azithromycin-Therapie. Nach 1 Monat imponierte der Patient in einem guten klinischen Zustand ohne Zeichen einer Herzinsuffizienz oder Anhalt für eine persistierende Infektion.Myokarditis ist eine sehr seltene Erscheinungsform von Q-Fieber, die nicht übersehen werden sollte. Die Diagnostik mittels Antikörpertiter ist leicht durchführbar. Die antibiotische Therapie ist gut verträglich, behandelt die Myokarditis kausal und dient der Vermeidung von Langzeitschäden.

This study aims to analyze the left ventricular function parameters, scar load, and hypertrophy in a mouse model of pressure-overload left ventricular (LV) hypertrophy over the course of 8 weeks using 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) micro-positron emission tomography (microPET) imaging. LV hypertrophy was induced in C57BL/6 mice by transverse aortic constriction (TAC). Myocardial hypertrophy developed after 2–4 weeks. ECG-gated microPET scans with [18F]FDG were performed 4 and 8 weeks after surgery. The extent of fibrosis was measured by histopathologic analysis. LV function parameters and scar load were calculated using QGS®/QPS®. LV metabolic volume (LVMV) and percentage injected dose per gram were estimated by threshold-based analysis. The fibrotic tissue volume increased significantly from 4 to 8 weeks after TAC (​1.67 vs. 3.91 mm3; P = 0.044). There was a significant increase of the EDV (4 weeks: 54 ± 15 μl, 8 weeks: 79 ± 32 μl, P

Background The chemokine receptor CXCR4 and its ligand CXCL12 have been shown to be a possible imaging and therapeutic target after myocardial infarction (MI). The murine-based and mouse-specific 68Ga-mCXCL12 PET tracer could be suitable for serial in vivo quantification of cardiac CXCR4 expression in a murine model of MI. Methods and Results At days 1-6 after MI, mice were intravenously injected with 68Ga-mCXCL12. Autoradiography was performed and the infarct-to-remote ratio (I/R) was determined. In vivo PET imaging with 68Ga-mCXCL12 was conducted on days 1-6 after MI and the percentage of the injected dose (%ID/g) of the tracer uptake in the infarct area was calculated. 18F-FDG-PET was performed for anatomical landmarking. Ex vivo autoradiography identified CXCR4 upregulation in the infarct region with an increasing I/R after 12 hours (1.4 ± 0.3), showing a significant increase until day 2 (4.5 ± 0.6), followed by a plateau phase (day 4) and decrease after 10 days (1.3 ± 1.0). In vivo PET imaging identified similar CXCR4 upregulation in the infarct region which peaked around day 3 post MI (9.7 ± 5.0 %ID/g) and then subsequently decreased by day 6 (2.8 ± 1.0 %ID/g). Conclusion Noninvasive molecular imaging of cardiac CXCR4 expression using a novel, murine-based, and specific 68Ga-mCXCL12 tracer is feasible both ex vivo and in vivo. Electronic supplementary material The online version of this article (10.1007/s12350-020-02262-6) contains supplementary material, which is available to authorized users.

Background In cardiogenic shock (CS) the Impella CP® device provides a fast available left ventricular circulatory support of up to 4.0L/min. However, the use of the Impella CP® device was not systematically analysed yet. Methods We performed a retrospective analysis of 28 consecutive patients suffering from severe therapy refractory CS treated with Impella CP®. Mortality was estimated using the SAPS II-Score. Primary outcome was 30-day survival. We compared the different aetiologies of CS and the effect of additional extracorporeal life support (ECLS). Results Aetiology of CS was acute coronary syndrome (ACS) in 15 patients, 9 patients received additional therapy with ECLS. SAPS II was 73±14, representing an estimated mortality of 87.1%. 18 patients deceased representing a 30-day survival of 36%. Comparing the different aetiologies, ACS-CS patients show a trend towards better survival. Additional therapy with ECLS did not change 30-day survival. In 3 cases, vascular complication needing surgical treatment occurred. All other patients showed no relevant complications except for the commonly seen haemolysis with consecutive need of transfusion. Conclusion Our data could demonstrate that the Impella CP ® application in these severely diseased patients is feasible and safe. Compared to the estimated mortality, the 30-day survival seems to be improved.

The lymphocyte function-associated antigen 1 (LFA-1) is a member of the beta2-integrin family and plays a pivotal role for T cell activation and leukocyte trafficking under inflammatory conditions. Blocking LFA-1 has reduced or aggravated inflammation depending on the inflammation model. To investigate the effect of LFA-1 in myocarditis, mice with experimental autoimmune myocarditis (EAM) were treated with a function blocking anti-LFA-1 antibody from day 1 of disease until day 21, the peak of inflammation. Cardiac inflammation was evaluated by measuring infiltration of leukocytes into the inflamed cardiac tissue using histology and flow cytometry and was assessed by analysis of the heart weight/body weight ratio. LFA-1 antibody treatment severely enhanced leukocyte infiltration, in particular infiltration of CD11b+ monocytes, F4/80+ macrophages, CD4+ T cells, Ly6G+ neutrophils, and CD133+ progenitor cells at peak of inflammation which was accompanied by an increased heart weight/body weight ratio. Thus, blocking LFA-1 starting at the time of immunization severely aggravated acute cardiac inflammation in the EAM model.

Aims Dual therapy comprising G-CSF for mobilization of bone marrow-derived progenitor cells (BMPCs), with simultaneous pharmacological inhibition of dipeptidylpeptidase-IV for enhanced myocardial recruitment of circulating BMPC via the SDF-1α/CXCR4-axis, has been shown to improve survival after acute myocardial infarction (AMI). Using an innovative method to provide non-invasive serial in vivo measurements and information on metabolic processes, we aimed to substantiate the possible effects of this therapeutic concept on cardiac remodelling after AMI using 2-deoxy-2-[18F]fluoro-d-glucose positron emission tomography (FDG-PET). Methods and results AMI was induced in C57BL/6 mice by performing surgical ligation of the left anterior descending artery in these mice. Animals were then treated with granulocyte-colony stimulating factor + Sitagliptin (GS) or placebo for a duration of 5 days following AMI. From serial PET scans, we verified that the infarct size in GS-treated mice ( n = 13) was significantly reduced at Day 30 after AMI when compared with the mice receiving placebo ( n = 10). Analyses showed a normalized FDG uptake on Day 6 in GS-treated mice, indicating an attenuation of the cardiac inflammatory response to AMI in treated animals. Furthermore, flow cytometry showed a significant increase in the anti-inflammatory M2-macrophages subpopulation in GS-treated animals. In comparing GS treated with placebo animals, those receiving GS-therapy showed a reduction in myocardial hypertrophy and left ventricular dilatation, which indicates the beneficial effect of GS treatment on cardiac remodelling. Remarkably, flow cytometry and immunohistochemistry showed an increase of myocardial c-kit positive cells in treated mice ( n = 12 in both groups). Conclusion Using the innovative method of micro-PET for non-invasive serial in vivo measurements of metabolic myocardial processes in mice, we were able to provide mechanistic evidence that GS therapy improves cardiac regeneration and reduces adverse remodelling after AMI.

Parathyroid hormone (PTH) is the predominant regulator of calcium/phosphate homeostasis in the human body. Beside this classical function, preclinical and clinical studies indicated a relevant role for PTH in mobilisation of bone marrow-derived cells into peripheral blood. In addition, recombinant PTH (teriparatide) was recently approved for the treatment of severe osteoporosis. Therefore, it was the aim of the present study to investigate the dynamics of haemopoietic stem cells and corresponding in peripheral blood of 13 patients with osteoporosis during treatment with teriparatide. We were able to show that administration of teriparatide is sufficient to mobilise haemopoietic stem cells into the bloodstream accompanied by an alteration of mobilising cytokines. In conclusion, teriparatide might be a useful tool in the context of stem cell mobilisation.

BackgroundHuman-induced pluripotent stem cells (iPSCs) are a potentially unlimited source for generation of cardiomyocytes (iPSC-CMs). However, current protocols for iPSC-CM derivation face several challenges, including variability in somatic cell sources and inconsistencies in cardiac differentiation efficiency.ObjectivesThis study aimed to assess the effect of epigenetic memory on differentiation and function of iPSC-CMs generated from somatic cell sources of cardiac versus noncardiac origins.MethodsCardiac progenitor cells (CPCs) and skin fibroblasts from the same donors were reprogrammed into iPSCs and differentiated into iPSC-CMs via embryoid body and monolayer-based differentiation protocols.ResultsDifferentiation efficiency was found to be higher in CPC-derived iPSC-CMs (CPC-iPSC-CMs) than in fibroblast-derived iPSC-CMs (Fib-iPSC-CMs). Gene expression analysis during cardiac differentiation demonstrated up-regulation of cardiac transcription factors in CPC-iPSC-CMs, including NKX2-5, MESP1, ISL1, HAND2, MYOCD, MEF2C, and GATA4. Epigenetic assessment revealed higher methylation in the promoter region of NKX2-5 in Fib-iPSC-CMs compared with CPC-iPSC-CMs. Epigenetic differences were found to dissipate with increased cell passaging, and a battery of in vitro assays revealed no significant differences in their morphological and electrophysiological properties at early passage. Finally, cell delivery into a small animal myocardial infarction model indicated that CPC-iPSC-CMs and Fib-iPSC-CMs possess comparable therapeutic capabilities in improving functional recovery in vivo.ConclusionsThis is the first study to compare differentiation of iPSC-CMs from human CPCs versus human fibroblasts from the same donors. The authors demonstrate that although epigenetic memory improves differentiation efficiency of cardiac versus noncardiac somatic cell sources in vitro, it does not contribute to improved functional outcome in vivo.

Vascular cell adhesion molecule-1 (VCAM-1) is strongly upregulated in hearts of mice with coxsackie virus-induced as well as in patients with viral infection-triggered dilated cardiomyopathy. Nevertheless, the role of its soluble form as a biomarker in inflammatory heart diseases remains unclear. Therefore, we investigated whether plasma levels of soluble VCAM-1 (sVCAM-1) directly correlated with disease activity and progression of cardiac dysfunction in the mouse model of experimental autoimmune myocarditis (EAM). EAM was induced by immunization of BALB/c mice with heart-specific myosin-alpha heavy chain peptide together with complete Freund`s adjuvant. ELISA revealed strong expression of cardiac VCAM-1 (cVCAM-1) throughout the course of EAM in immunized mice compared to control animals. Furthermore, sVCAM-1 was elevated in the plasma of immunized compared to control mice at acute and chronic stages of the disease. sVCAM-1 did not correlate with the degree of acute cardiac inflammation analyzed by histology or cardiac cytokine expression investigated by ELISA. Nevertheless, heart to body weight ratio correlated significantly with sVCAM-1 at chronic stages of EAM. Cardiac systolic dysfunction studied with positron emission tomography indicated a weak relationship with sVCAM-1 at the chronic stage of the disease. Our data provide evidence that plasma levels of sVCAM-1 are elevated throughout all stages of the disease but showed no strong correlation with the severity of EAM.

Objective— Clinical trials of bone marrow–derived stem cell therapy for the heart have yielded variable results. The basic mechanism(s) that underlies their potential efficacy remains unknown. In the present study, we evaluated the survival kinetics, transcriptional response, and functional outcome of intramyocardial bone marrow mononuclear cell (BMMC) transplantation for cardiac repair in a murine myocardial infarction model. Methods and Results— We used bioluminescence imaging and high-throughput transcriptional profiling to evaluate the in vivo survival kinetics and gene expression changes of transplanted BMMCs after their engraftment into ischemic myocardium. Our results demonstrate short-lived survival of cells following transplant, with less than 1% of cells surviving by 6 weeks posttransplantation. Moreover, transcriptomic analysis of BMMCs revealed nonspecific upregulation of various cell regulatory genes, with a marked downregulation of cell differentiation and maturation pathways. BMMC therapy caused limited improvement of heart function as assessed by echocardiography, invasive hemodynamics, and positron emission tomography. Histological evaluation of cell fate further confirmed findings of the in vivo cell tracking and transcriptomic analysis. Conclusion— Collectively, these data suggest that BMMC therapy, in its present iteration, may be less efficacious than once thought. Additional refinement of existing cell delivery protocols should be considered to induce better therapeutic efficacy.

Erythropoietin (EPO) was shown to have protective effects after myocardial infarction (MI) by neovascularization and antiapoptotic mechanisms. Beside direct receptor-dependent mechanisms, mobilization and homing of bone marrow-derived cells (BMCs) may play a pivotal role in this regard. In this study, we intended to track different subpopulations of BMCs and to assess serially myocardial perfusion changes in EPO-treated mice after MI. To allow tracking of BMCs, we used a chimeric mouse model. Therefore, mice (C57BL/6J) were sublethally irradiated, and bone marrow (BM) from green fluorescent protein transgenic mice was transplanted. Ten weeks later coronary artery ligation was performed to induce MI. EPO was injected for 3 days with a total dose of 5000 IU/kg. Subpopulations (CD31, c-kit, CXCR-4 and Sca-1) of EGFP+ cells were studied in peripheral blood, bone marrow and hearts by flow cytometry. Myocardial perfusion was serially investigated in vivo by pinhole single-photon emission computed tomography (SPECT) at days 6 and 30 after MI. EPO-treated animals revealed an enhanced mobilization of BMCs into peripheral blood. The numbers of these cells in BM remained unchanged. Homing of all BMCs subpopulations to the ischaemic myocardium was significantly increased in EPO-treated mice. Among the investigated subpopulations, EPO predominantly affected migration of CXCR-4+ (4.3-fold increase). Repetitively SPECT analyses revealed a reduction of perfusion defects after EPO treatment over time. Our study shows that EPO treatment after MI enhances the migration capacity of BMCs into ischaemic tissue, which may attribute to an improved perfusion and reduced size of infarction, respectively.

Aims Parathyroid hormone (PTH) administration after myocardial infarction (MI) is known to attenuate ischaemic cardiomyopathy. This effect mainly resulted from an increase in mobilization and homing of CD34+/CD45+ cells into the ischaemic myocardium. PTH-related stem cell mobilization was shown to be related to endogenous granulocyte-colony stimulating factor (G-CSF) release. The aim of our study is to determine the role of G-CSF on the cardioprotective effects of PTH. Methods and results G-CSF +/+ (C57BL/6) and G-CSF −/− mice were treated with PTH for 6 days after inducing a MI. The myocardial homing factor stromal cell-derived factor-1 (SDF-1) was analysed on day 2 with enzyme-linked immunosorbent assay. Stem cell populations in peripheral blood and hearts were examined by FACS on days 6 and 2, respectively. Cardiac function and immunohistochemistry were investigated on day 6 and day 30. PTH treatment resulted in a significant increase in CD45+/CD34+ cells in peripheral blood in G-CSF +/+ but not in G-CSF −/− mice. However, a significant increase in SDF-1 and enhanced migration of CD45+/CD34+ cells into the ischaemic myocardium was revealed after PTH administration in both G-CSF +/+ and G-CSF −/− mice. Enhanced stem cell homing was associated with improved cardiac function and post-MI survival after PTH treatment. Furthermore, infarct size, wall thickness, and neovascularization showed a significant improvement in both groups 30 days after MI. Conclusion The cardioprotective effects of PTH were shown to be independent of endogenous G-CSF release and therefore from stem cell mobilization. This puts more emphasis on the role of stem cell homing into ischaemic myocardium.

Background G-CSF based stem cell mobilization and stabilization of cardiac SDF-1 by DPP-IV-inhibition (dual stem cell therapy) improve heart function and survival after myocardial infarction. However, it is barely understood whether this new approach acts specifically through the SDF-1/CXCR4 axis, stimulation of resident cardiac stem cells and improved myocardial perfusion. Therefore, we aimed to clarify the role of the SDF1/CXCR4 axis with respect to the benefits of a dual stem cell based therapy. Methodology/principal findings After surgically induced ligation of the LAD, SDF-1/CXCR4 interactions were specifically blocked by the CXCR4 receptor antagonist AMD3100 in G-CSF and Diprotin A treated C57BL/6 mice. G-CSF + DipA treated and non-treated animals served as controls. Because AMD3100 is known to mobilize bone marrow derived stem cells (BMCs) in high concentrations, the optimal dosage (1.25 mg per kg body weight) sufficient to block CXCR4 without stimulating mobilization was established. AMD3100 treatment of G-CSF and Diprotin A stimulated mice significantly decreased myocardial homing of circulating stem cells (FACS analysis) and inverted the beneficial effects of (i) cardiac remodeling (histological analyses), (ii) heart function (Millar tip catheterization) and (iii) survival (Kaplan–Meier curves). G-CSF treatment in combination with DPP-IV inhibition enhanced neovascularization at the infarct border zone which was related to an improved myocardial blood flow as measured by SPECT. Moreover, dual stem cell treatment effectively stimulated the pool of resident cardiac stem cells (FACS) which was reversed by AMD3100 treatment. Conclusions/significance Our data give final proof that homing through the SDF-1/CXCR-4 axis is essential for the success of dual stem cell therapy.

Aims Parathyroid hormone (PTH) has been shown to promote stem cell mobilization into peripheral blood. Moreover, PTH treatment after myocardial infarction (MI) improved survival and myocardial function associated with enhanced homing of bone marrow-derived stem cells (BMCs). To unravel the molecular mechanisms of PTH-mediated stem cell trafficking, we analysed wild-type (wt) and green fluorescent protein (GFP)-transgenic mice after MI with respect to the pivotal stromal cell-derived factor-1 (SDF-1)/chemokine receptor type 4 (CXCR4) axis. Methods and results WT and GFP-transgenic mice (C57BL/6J) were infarcted by coronary artery ligation and PTH (80 μg/kg/day) was injected for 6 days afterwards. Number of BMCs was analysed by flow cytometry. SDF-1 protein levels and activity of dipeptidyl peptidase-IV (DPP-IV) were investigated by ELISA and activity assay. Functional analyses were performed at day 30 after MI. PTH-treated animals revealed an enhanced homing of CXCR4+ BMCs associated with an increased protein level of the corresponding homing factor SDF-1 in the ischaemic heart. In vitro and in vivo , PTH inhibited the activity of DPP-IV, which cleaves and inactivates SDF-1. Functionally, PTH significantly improved myocardial function after MI. Both stem cell homing as well as functional recovery were reversed by the CXCR4 antagonist AMD3100. Conclusion In summary, PTH is a DPP-IV inhibitor leading to an increased cardiac SDF-1 level, which enhances recruitment of CXCR4+ BMCs into the ischaemic heart associated with attenuated ischaemic cardiomyopathy. Since PTH is already clinically used our findings may have direct impact on the initiation of studies in patients with ischaemic disorders.

Ischemic cardiomyopathy is one of the main causes of death, which may be prevented by stem cell-based therapies. SDF-1alpha is the major chemokine attracting stem cells to the heart. Since SDF-1alpha is cleaved and inactivated by CD26/dipeptidylpeptidase IV (DPP-IV), we established a therapeutic concept--applicable to ischemic disorders in general--by combining genetic and pharmacologic inhibition of DPP-IV with G-CSF-mediated stem cell mobilization after myocardial infarction in mice. This approach leads to (1) decreased myocardial DPP-IV activity, (2) increased myocardial homing of circulating CXCR-4+ stem cells, (3) reduced cardiac remodeling, and (4) improved heart function and survival. Indeed, CD26 depletion promoted posttranslational stabilization of active SDF-1alpha in heart lysates and preserved the cardiac SDF-1-CXCR4 homing axis. Therefore, we propose pharmacological DPP-IV inhibition and G-CSF-based stem cell mobilization as a therapeutic concept for future stem cell trials after myocardial infarction.

Aims An ongoing concept is that stem cells have the potential to regenerate the injured myocardium. In addition to direct vasorelaxing effects on the vasculature, which are mediated by an increased cAMP production leading to a decreased calcium influx in smooth muscle cells, parathyroid hormone (PTH) was recently shown to facilitate stem cell mobilization. Therefore, we analysed in a murine model of experimental myocardial infarction (MI) the influence of PTH treatment on survival, functional parameters, stem cell migration, and expression of vascular endothelial growth factor A (VEGF-A). Methods and results Mice (C57BL/6) were treated with PTH (80 µg/kg/d) for up to 14 days after coronary artery ligation. Functional and immunohistochemical analyses were performed at days 6 and 30 after MI. Stem cells and VEGF expression in the myocardium were analysed by FACS and qRT-PCR at day 2 after MI. PTH-treated animals revealed a significant improvement of post-MI survival and myocardial function that was related to a subsequent reduction of left ventricular wall thinning and scar extension. Infarcted hearts of PTH-treated mice revealed increased numbers of CD45+/CD34+ progenitor cells as well as an upregulation of VEGF-A mRNA associated with increased neovascularization and cell survival. Conclusions PTH application after MI increases migration of angiogenic CD45+/CD34+ progenitor cells to the ischaemic heart, which may attenuate ischaemic cardiomyopathy. As PTH is already used in patients with osteoporosis, our findings may have a direct impact on the initiation of clinical studies in patients with ischaemic heart disease.

BACKGROUND: Recent studies suggest that stem cells may represent a putative source for the generation of beta cells. However, the identity and characteristics of stem cells from adult pancreas and conditions for their large scale expansion are still poorly defined. METHODS: DPC were isolated from adult pancreatic ducts of C57BI/6 mice. Expression profile was investigated by PCR, FAGS and immunohistochemistry. RESULTS: DPC express a panel of stem cell associated markers such as Pdx-1, cytokeratin-19 (CK19), nestin, Sox9 together with the transcription factor MafA and hepatic nuclear factors HNF1 beta, HNF3 beta, HNF4 alpha and HNF6. This gene expression profile is suggesting that DPC might be a promising tool for endocrine diMrentiation. Atter stimulation with picolinic acid and hypoxia, DPC expressed the endocrine differentiation marker Ngn3. Nevertheless, insulin production was not observed. CONCLUSIONS: We here describe a protocol for the isolation end expansion of murine pancreatic ductal progenitor cells (DPC) displaying high self-renewal, spheroid-and colony-forming capacity. Further studies are required to elucidate the conditions for differentiation into mature pancreatic endocrine cell lineages.

Background— Human induced pluripotent stem cells (iPSCs) are attractive candidates for therapeutic use, with the potential to replace deficient cells and to improve functional recovery in injury or disease settings. Here, we test the hypothesis that human iPSC-derived cardiomyocytes (iPSC-CMs) can secrete cytokines as a molecular basis to attenuate adverse cardiac remodeling after myocardial infarction. Methods and Results— Human iPSCs were generated from skin fibroblasts and differentiated in vitro with a small molecule–based protocol. Troponin + iPSC-CMs were confirmed by immunohistochemistry, quantitative polymerase chain reaction, fluorescence-activated cell sorting, and electrophysiological measurements. Afterward, 2×10 6 iPSC-CMs derived from a cell line transduced with a vector expressing firefly luciferase and green fluorescent protein were transplanted into adult NOD/SCID mice with acute left anterior descending artery ligation. Control animals received PBS injection. Bioluminescence imaging showed limited engraftment on transplantation into ischemic myocardium. However, magnetic resonance imaging of animals transplanted with iPSC-CMs showed significant functional improvement and attenuated cardiac remodeling compared with PBS-treated control animals. To understand the underlying molecular mechanism, microfluidic single-cell profiling of harvested iPSC-CMs, laser capture microdissection of host myocardium, and in vitro ischemia stimulation were used to demonstrate that the iPSC-CMs could release significant levels of proangiogenic and antiapoptotic factors in the ischemic microenvironment. Conclusions— Transplantation of human iPSC-CMs into an acute mouse myocardial infarction model can improve left ventricular function and attenuate cardiac remodeling. Because of limited engraftment, most of the effects are possibly explained by paracrine activity of these cells.

Parathyroid hormone (PTH) is well-known as the principal regulator of calcium homeostasis in the human body and controls bone metabolism via actions on the survival and activation of osteoblasts. The intermittent administration of PTH has been shown to stimulate bone production in mice and men and therefore PTH administration has been recently approved for the treatment of osteoporosis. Besides to its physiological role in bone remodelling PTH has been demonstrated to influence and expand the bone marrow stem cell niche where hematopoietic stem cells, capable of both self-renewal and differentiation, reside. Moreover, intermittent PTH treatment is capable to induce mobilization of progenitor cells from the bone marrow into the bloodstream. This novel function of PTH on modulating the activity of the stem cell niche in the bone marrow as well as on mobilization and regeneration of bone marrow-derived stem cells offers new therapeutic options in bone marrow and stem cell transplantation as well as in the field of ischemic disorders.

Nearly 8% of the human population carries an inactivating point mutation in the gene that encodes the cardioprotective enzyme aldehyde dehydrogenase 2 (ALDH2). This genetic polymorphism (ALDH2*2) is linked to more severe outcomes from ischemic heart damage and an increased risk of coronary artery disease (CAD), but the underlying molecular bases are unknown. We investigated the ALDH2*2 mechanisms in a human model system of induced pluripotent stem cell–derived cardiomyocytes (iPSC-CMs) generated from individuals carrying the most common heterozygous form of the ALDH2*2 genotype. We showed that the ALDH2*2 mutation gave rise to elevated amounts of reactive oxygen species and toxic aldehydes, thereby inducing cell cycle arrest and activation of apoptotic signaling pathways, especially during ischemic injury. We established that ALDH2 controls cell survival decisions by modulating oxidative stress levels and that this regulatory circuitry was dysfunctional in the loss-of-function ALDH2*2 genotype, causing up-regulation of apoptosis in cardiomyocytes after ischemic insult. These results reveal a new function for the metabolic enzyme ALDH2 in modulation of cell survival decisions. Insight into the molecular mechanisms that mediate ALDH2*2-related increased ischemic damage is important for the development of specific diagnostic methods and improved risk management of CAD and may lead to patient-specific cardiac therapies.

Granulocyte-colony stimulating factor (G-CSF) has been shown to promote mobilization of bone marrow-derived stem cells (BMCs) into the bloodstream associated with improved survival and cardiac function after myocardial infarction. Therefore, the aim of the present study was to investigate whether G-CSF is able to attenuate cardiac remodelling in a mouse model of pressure-induced LV hypertrophy focusing on mobilization and migration of BMCs. LV hypertrophy was induced by transverse aortic constriction (TAC) in C57BL/6J mice. Four weeks after TAC procedure. Mice were treated with G-CSF (100 μg/kg/day; Amgen Biologicals) for 2 weeks. The number of migrated BMCs in the heart was analysed by flow cytometry. mRNA expression and protein level of different growth factors in the myocardium were investigated by RT-PCR and ELISA. Functional analyses assessed by echocardiography and immunohistochemical analysis were performed 8 weeks after TAC procedure. G-CSF-treated animals revealed enhanced homing of VLA-4(+) and c-kit(+) BMCs associated with increased mRNA expression and protein level of the corresponding homing factors Vascular cell adhesion protein 1 and Stem cell factor in the hypertrophic myocardium. Functionally, G-CSF significantly preserved LV function after TAC procedure, which was associated with a significantly reduced area of fibrosis compared to control animals. Furthermore, G-CSF-treated animals revealed a significant improvement of survival after TAC procedure. In summary, G-CSF treatment preserves cardiac function and is able to diminish cardiac fibrosis after induction of LV hypertrophy associated with increased homing of VLA-4(+) and c-kit(+) BMCs and enhanced expression of their respective homing factors VCAM-1 and SCF.

Background In primary hyperparathyroidism (PHPT), the increased levels of parathyroid hormone (PTH) result in mobilisation of bone-marrow-derived cells (BMCs) into peripheral blood. However, the fate of these cells is still unknown. Materials and methods In this study, we sought to investigate cells with typical surface markers of BMCs within parathyroid adenomas (PA) of patients with primary hyperparathyroidism. We therefore investigated PA and normal parathyroid glands (NPG) of 15 patients with PHPT by immunohistochemistry and PCR. Results mRNA levels for CD31, CD34 and CD45 were significantly increased in PA compared to NPG. Immunohistochemical staining for CD31 and CD34 revealed a significantly higher vessel density in PA. Furthermore, scattered single cells expressing CD31, CD34 or CD45 were significantly augmented compared to normal parathyroid glands and directly correlated with vessel density. mRNA levels of SDF-1 was increased whereas its major inhibitor dipeptidylpeptidase IV (DPP IV) is decreased in PA, suggesting that the SDF-1 axis plays a role in the migration of BMCs into PA. Conclusion These data indicate a possible role of BMCs in the pathophysiology of PA of patients with PHPT.

Aims Our pre-clinical studies demonstrated that G-CSF based stem cell mobilization in combination with genetic or pharmaceutical CD26/DPP-IV inhibition after acute myocardial infarction leads to improved cardiac homing of stem cells, enhanced heart function and increased survival. Thereupon, we initiated a phase III, multi-centre, randomised, placebo-controlled efficacy and safety study ( n =100) analyzing the effect of combined application of G-CSF and Sitagliptin, which is a clinically admitted, anti-diabetic DPP-IV-inhibitor, after acute myocardial infarction ("SITAGRAMI-Trial"; EudraCT Number: 2007-003941-34). Methods The primary objective of the study is to assess myocardial regeneration by improved myocardial homing of mobilized stem cells, as measured by cardiac function using MRI analysis. In this paper, we report on the study design and a planned first interim-analysis on safety issues without unblinding. Results During the first 6weeks of follow-up, only two major adverse cardiac events occurred (one de novo stenosis and one instent-restenosis) in the first 36 patients. Presumably, they were not related to any study medication. No other side effects like headache, bone pain, hypoglycaemias etc. were observed. Furthermore, no myocardial infarction or death occurred in any patient. Thus, the rate of serious adverse events lay within the expected range. Conclusions Our data demonstrate that the combined application of Sitagliptin and G-CSF seems to be safe on the short term and feasible after acute myocardial infarction and may represent a new therapeutic option in future.

Rationale: Human embryonic stem cell (hESC) derivatives are attractive candidates for therapeutic use. The engraftment and survival of hESC derivatives as xenografts or allografts require effective immunosuppression to prevent immune cell infiltration and graft destruction. Objective: To test the hypothesis that a short-course, dual-agent regimen of two costimulation-adhesion blockade agents can induce better engraftment of hESC derivatives compared to current immunosuppressive agents. Methods and Results: We transduced hESCs with a double fusion reporter gene construct expressing firefly luciferase (Fluc) and enhanced green fluorescent protein, and differentiated these cells to endothelial cells (hESC-ECs). Reporter gene expression enabled longitudinal assessment of cell engraftment by bioluminescence imaging. Costimulation-adhesion therapy resulted in superior hESC-EC and mouse EC engraftment compared to cyclosporine therapy in a hind limb model. Costimulation-adhesion therapy also promoted robust hESC-EC and hESC-derived cardiomyocyte survival in an ischemic myocardial injury model. Improved hESC-EC engraftment had a cardioprotective effect after myocardial injury, as assessed by magnetic resonance imaging. Mechanistically, costimulation-adhesion therapy is associated with systemic and intragraft upregulation of T-cell immunoglobulin and mucin domain 3 (TIM3) and a reduced proinflammatory cytokine profile. Conclusions: Costimulation-adhesion therapy is a superior alternative to current clinical immunosuppressive strategies for preventing the post-transplant rejection of hESC derivatives. By extending the window for cellular engraftment, costimulation-adhesion therapy enhances functional preservation following ischemic injury. This regimen may function through a TIM3-dependent mechanism.

Existing methodologies for human induced pluripotent stem cell (hiPSC) cardiac differentiation are efficient but require the use of complex, undefined medium constituents that hinder further elucidation of the molecular mechanisms of cardiomyogenesis. Using hiPSCs derived under chemically defined conditions on synthetic matrices, we systematically developed a highly optimized cardiac differentiation strategy, employing a chemically defined medium consisting of just three components: the basal medium RPMI 1640, L-ascorbic acid 2-phosphate, and rice-derived recombinant human albumin. Along with small molecule-based differentiation induction, this protocol produced contractile sheets of up to 95% TNNT2+ cardiomyocytes at a yield of up to 100 cardiomyocytes for every input pluripotent cell, and was effective in 11 hiPSC lines tested. This is the first fully chemically defined platform for cardiac specification of hiPSCs, and allows the elucidation of cardiomyocyte macromolecular and metabolic requirements whilst providing a minimally complex system for the study of maturation and subtype specification.