Metabolism and phospholipid assembly of polyunsaturated fatty acids in human bone marrow mesenchymal stromal cells

High arachidonic acid (20:4n-6) and low n-3 PUFA levels impair the capacity of cultured human bone marrow mesenchymal stromal cells (hBMSCs) to modulate immune functions. The capacity of the hBMSCs to modify PUFA structures was found to be limited. Therefore, different PUFA supplements given to the cells resulted in very different glycerophospholipid (GPL) species profiles and substrate availability for phospholipases, which have preferences for polar head group and acyl chains when liberating PUFA precursors for production of lipid mediators. When supplemented with 20:4n-6, the cells increased prostaglandin E2 secretion. However, they elongated 20:4n-6 to the less active precursor, 22:4n-6, and also incorporated it into triacylglycerols, which may have limited the proinflammatory signaling. The n-3 PUFA precursor, 18:3n-3, had little potency to reduce the GPL 20:4n-6 content, while the eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acid supplements efficiently displaced the 20:4n-6 acyls, and created diverse GPL species substrate pools allowing attenuation of inflammatory signaling.(Jlr) The results emphasize the importance of choosing appropriate PUFA supplements for in vitro hBMSC expansion and suggests that for optimal function they require an exogenous fatty acid source providing 20:5n-3 and 22:6n-3 sufficiently, but 20:4n-6 moderately, which calls for specifically designed optimal PUFA supplements for the cultures.Peer reviewe

Structural and Functional Support by Left Atrial Appendage Transplant to the Left Ventricle after a Myocardial Infarction

The left atrial appendage (LAA) of the adult heart has been shown to contain cardiac and myeloid progenitor cells. The resident myeloid progenitor population expresses an array of pro-regenerative paracrine factors. Cardiac constructs have been shown to inhibit deleterious remodeling of the heart using physical support. Due to these aspects, LAA holds promise as a regenerative transplant. LAAs from adult mT/mG mice were transplanted to the recipient 129X1-SvJ mice simultaneously as myocardial infarction (MI) was performed. A decellularized LAA patch was implanted in the control group. Two weeks after MI, the LAA patch had integrated to the ventricular wall, and migrated cells were seen in the MI area. The cells had two main phenotypes: small F4/80+ cells and large troponin C+ cells. After follow-up at 8 weeks, the LAA patch remained viable, and the functional status of the heart improved. Cardiac echo demonstrated that, after 6 weeks, the mice in the LAA-patch-treated group showed an increasing and statistically significant improvement in cardiac performance when compared to the MI and MI + decellularized patch controls. Physical patch-support (LAA and decellularized LAA patch) had an equal effect on the inhibition of deleterious remodeling, but only the LAA patch inhibited the hypertrophic response. Our study demonstrates that the LAA transplantation has the potential for use as a treatment for myocardial infarction. This method can putatively combine cell therapy (regenerative effect) and physical support (inhibition of deleterious remodeling).Peer reviewe

Structural and Functional Support by Left Atrial Appendage Transplant to the Left Ventricle after a Myocardial Infarction

The left atrial appendage (LAA) of the adult heart has been shown to contain cardiac and myeloid progenitor cells. The resident myeloid progenitor population expresses an array of pro-regenerative paracrine factors. Cardiac constructs have been shown to inhibit deleterious remodeling of the heart using physical support. Due to these aspects, LAA holds promise as a regenerative transplant. LAAs from adult mT/mG mice were transplanted to the recipient 129X1-SvJ mice simultaneously as myocardial infarction (MI) was performed. A decellularized LAA patch was implanted in the control group. Two weeks after MI, the LAA patch had integrated to the ventricular wall, and migrated cells were seen in the MI area. The cells had two main phenotypes: small F4/80+ cells and large troponin C+ cells. After follow-up at 8 weeks, the LAA patch remained viable, and the functional status of the heart improved. Cardiac echo demonstrated that, after 6 weeks, the mice in the LAA-patch-treated group showed an increasing and statistically significant improvement in cardiac performance when compared to the MI and MI + decellularized patch controls. Physical patch-support (LAA and decellularized LAA patch) had an equal effect on the inhibition of deleterious remodeling, but only the LAA patch inhibited the hypertrophic response. Our study demonstrates that the LAA transplantation has the potential for use as a treatment for myocardial infarction. This method can putatively combine cell therapy (regenerative effect) and physical support (inhibition of deleterious remodeling).Peer reviewe

Epicardial transplantation of autologous atrial appendage micrografts : evaluation of safety and feasibility in pigs after coronary artery occlusion

Objectives. Several approaches devised for clinical utilization of cell-based therapies for heart failure often suffer from complex and lengthy preparation stages. Epicardial delivery of autologous atrial appendage micrografts (AAMs) with a clinically used extracellular matrix (ECM) patch provides a straightforward therapy alternative. We evaluated the operative feasibility and the effect of micrografts on the patch-induced epicardial foreign body inflammatory response in a porcine model of myocardial infarction. Design. Right atrial appendages were harvested and mechanically processed into AAMs. The left anterior descending coronary artery was ligated to generate acute infarction. Patches of ECM matrix with or without AAMs were transplanted epicardially onto the infarcted area. Four pigs received the ECM and four received the AAMs patch. Cardiac function was studied by echocardiography both preoperatively and at 3-week follow-up. The primary outcome measures were safety and feasibility of the therapy administration, and the secondary outcome was the inflammatory response to ECM. Results. Neither AAMs nor ECM patch-related complications were detected during the follow-up time. AAMs patch preparation was feasible according to time and safety. Inflammation was greatly reduced in AAMs when compared with ECM patches as measured by the amount of infiltrated inflammatory cells and area of inflammation. Immunohistochemistry demonstrated an increased CD3+ cell density in the AAMs patch infiltrate. Conclusions. Epicardial AAMs transplantation demonstrated safety and clinical feasibility. The use of micrografts significantly inhibited ECM-induced foreign body inflammatory reactivity. Transplantation of AAMs shows good clinical applicability as adjuvant therapy to cardiac surgery and can suppress acute inflammatory reactivity.Peer reviewe

The effects of culture conditions on the functionality of efficiently obtained mesenchymal stromal cells from human cord blood

Background aims. Cord blood (CB) is an attractive source of mesenchymal stromal cells (MSCs) because of its abundant availability and ease of collection. However, the success rate of generating CB-MSCs is low. In this study, our aim was to demonstrate the efficiency of our previously described method to obtain MSCs from CB and further characterize them and to study the effects of different culture conditions on MSCs. Methods. CB-MSC cultures were established in low oxygen (3%) conditions on fibronectin in 10% fetal bovine serum containing culture medium supplemented with combinations of growth factors. Cells were characterized for their adipogenic, osteogenic and chondrogenic differentiation capacity; phenotype; and HOX gene expression profile. The functionality of the cells cultured in different media was tested in vitro with angiogenesis and T-cell proliferation assays. Results. We demonstrate 87% efficacy in generating MSCs from CB. The established cells had typical MSC characteristics with reduced adipogenic differentiation potential and a unique HOX gene fingerprint. Growth factor rich medium and a 3% oxygen condition enhanced cell proliferation; however, the growth factor rich medium had a negative effect on the expression of CD90. Dexamethasone-containing medium improved the capacity of the cells to suppress T-cell proliferation, whereas the cells grown without dexamethasone were more able to support angiogenesis. Conclusions. Our results demonstrate that the composition of expansion medium is critical for the functionality of MSCs and should always be appropriately defined for each purpose.Peer reviewe

Ischemic Heart Disease Selectively Modifies the Right Atrial Appendage Transcriptome

Background: Although many pathological changes have been associated with ischemic heart disease (IHD), molecular-level alterations specific to the ischemic myocardium and their potential to reflect disease severity or therapeutic outcome remain unclear. Currently, diagnosis occurs relatively late and evaluating disease severity is largely based on clinical symptoms, various imaging modalities, or the determination of risk factors. This study aims to identify IHD-associated signature RNAs from the atrial myocardium and evaluate their ability to reflect disease severity or cardiac surgery outcomes.Methods and Results: We collected right atrial appendage (RAA) biopsies from 40 patients with invasive coronary angiography (ICA)-positive IHD undergoing coronary artery bypass surgery and from 8 patients ICA-negative for IHD (non-IHD) undergoing valvular surgery. Following RNA sequencing, RAA transcriptomes were analyzed against 429 donors from the GTEx project without cardiac disease. The IHD transcriptome was characterized by repressed RNA expression in pathways for cell-cell contacts and mitochondrial dysfunction. Increased expressions of the CSRNP3, FUT10, SHD, NAV2-AS4, and hsa-mir-181 genes resulted in significance with the complexity of coronary artery obstructions or correlated with a functional cardiac benefit from bypass surgery.Conclusions: Our results provide an atrial myocardium-focused insight into IHD signature RNAs. The specific gene expression changes characterized here, pave the way for future disease mechanism-based identification of biomarkers for early detection and treatment of IHD.Peer reviewe

Ribonucleotide reductase is not limiting for mitochondrial DNA copy number in mice

Peer reviewe

Epicardial transplantation of atrial appendage micrograft patch salvages myocardium after infarction

Iskeeminen sydänsairaus, toiselta nimeltään sepelvaltimotauti, on suomalainen kansansairaus, joka useista hoitomuodoistaan huolimatta on edelleen maailmanlaajuisesti yleisin yksittäinen kuolinsyy. Sepelvaltimoiden ohitusleikkaus on revaskularisoiva sepelvaltimotaudin kirurginen hoitomuoto, josta on kertynyt jo vuosikymmenien vankka kokemus. Ohitusleikkauksen vaikuttavuutta on pyritty tehostamaan sen yhteydessä annosteltavien soluhoitojen tai kudosteknologian avulla rakennettujen siirteiden avulla . Valitettavasti nämä nk. adjuvanttihoidot ovat kustannuksiltaan ja toteutukseltaan niin raskaita, että niiden kliininen toteutettavuus ja vaikuttavuus ovat jääneet odotetusta. Tutkimuksessa arvioimme sydänlihaksen akuutin hapenpuutteen, eli sydäninfarktin, kokeellisessa mallissa sydämien vauriopinnalle asetettujen pienien eteiskorvakudospalojen toiminnallista, kudosopillista sekä mekanistista vaikuttavuutta. Pienet eteiskorvakekudospalat kerättiin saman hiirilinjan hiiristä, pilkottiin mekaanisesti ja siirrettiin sydämen pinnalle vauriopintaa vasten. Ultraäänitutkimusseurannan perusteella kudospalat tehostivat toiminnallista paranemista alkuvaiheen ensivaurion jälkeen kontrolliryhmiin (lumeoperoitu, pelkkä sydäninfarkti sekä infarkti ja pelkkä paikkamateriaali) nähden. Sydänkudoksen histologiset värjäystutkimukset paljastivat vähentyneen kollageeniarpipitoisuuden, lisääntyneen sydänlihassolujen troponiinipitoisuuden sekä kokonaisuutena ilmeisen sydänlihaksen säilymisen. Anatomisesti kohdennetut proteomiikka-analyysit paljastivat kudospalahoitoon assosioituvien useiden kudosparanemisen kannalta keskeisien biologisten prosessien aktivoitumisia juuri sydämen vaurioalueella vielä viikkojakin vaurion jälkeen. Näitä prosesseja olivat mm. lisääntynyt uudisverisuonitus, sydänlihassolujen jakaantuminen sekä vähentynyt ohjelmoitunut solukuolema. Sydämen pinnalle sydäninfarktin aikana kirurgista paikkamateraalia hyödyntäen asetetut eteiskorvakekudospalat suojaavat sydänlihasta iskeemiseltä vauriolta. Hoitomuodon tulokset ja selkeä toteutusprotokolla tukevat sen kliinistä soveltuvuutta ohitusleikkauksen adjuvanttihoidoksi

Epicardial transplantation of atrial appendage micrograft patch salvages myocardium after infarction

Iskeeminen sydänsairaus, toiselta nimeltään sepelvaltimotauti, on suomalainen kansansairaus, joka useista hoitomuodoistaan huolimatta on edelleen maailmanlaajuisesti yleisin yksittäinen kuolinsyy. Sepelvaltimoiden ohitusleikkaus on revaskularisoiva sepelvaltimotaudin kirurginen hoitomuoto, josta on kertynyt jo vuosikymmenien vankka kokemus. Ohitusleikkauksen vaikuttavuutta on pyritty tehostamaan sen yhteydessä annosteltavien soluhoitojen tai kudosteknologian avulla rakennettujen siirteiden avulla . Valitettavasti nämä nk. adjuvanttihoidot ovat kustannuksiltaan ja toteutukseltaan niin raskaita, että niiden kliininen toteutettavuus ja vaikuttavuus ovat jääneet odotetusta. Tutkimuksessa arvioimme sydänlihaksen akuutin hapenpuutteen, eli sydäninfarktin, kokeellisessa mallissa sydämien vauriopinnalle asetettujen pienien eteiskorvakudospalojen toiminnallista, kudosopillista sekä mekanistista vaikuttavuutta. Pienet eteiskorvakekudospalat kerättiin saman hiirilinjan hiiristä, pilkottiin mekaanisesti ja siirrettiin sydämen pinnalle vauriopintaa vasten. Ultraäänitutkimusseurannan perusteella kudospalat tehostivat toiminnallista paranemista alkuvaiheen ensivaurion jälkeen kontrolliryhmiin (lumeoperoitu, pelkkä sydäninfarkti sekä infarkti ja pelkkä paikkamateriaali) nähden. Sydänkudoksen histologiset värjäystutkimukset paljastivat vähentyneen kollageeniarpipitoisuuden, lisääntyneen sydänlihassolujen troponiinipitoisuuden sekä kokonaisuutena ilmeisen sydänlihaksen säilymisen. Anatomisesti kohdennetut proteomiikka-analyysit paljastivat kudospalahoitoon assosioituvien useiden kudosparanemisen kannalta keskeisien biologisten prosessien aktivoitumisia juuri sydämen vaurioalueella vielä viikkojakin vaurion jälkeen. Näitä prosesseja olivat mm. lisääntynyt uudisverisuonitus, sydänlihassolujen jakaantuminen sekä vähentynyt ohjelmoitunut solukuolema. Sydämen pinnalle sydäninfarktin aikana kirurgista paikkamateraalia hyödyntäen asetetut eteiskorvakekudospalat suojaavat sydänlihasta iskeemiseltä vauriolta. Hoitomuodon tulokset ja selkeä toteutusprotokolla tukevat sen kliinistä soveltuvuutta ohitusleikkauksen adjuvanttihoidoksi