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OBJECTIVE: To determine whether the ratio of hepatocyte growth factor (HGF) to transforming growth factor beta1 (TGFbeta1) in systemic lupus erythematosus (SLE) nephritis could be a prognostic factor for response to therapy with cyclophosphamide (CYC) and steroids at 6 months, and to examine whether the molecular ratio of HGF to TGFbeta1 correlates with the activity index (AI) and chronicity index (CI) and has predictive value for remission at the sixth month. METHODS: Thirty-six SLE patients with new-onset nephritis, 25 of whom were treated with CYC and steroids, entered into a prospective observational cohort trial at a tertiary university referral center. Renal biopsy findings and clinical parameters were recorded for all patients. Histopathologic, clinical, and immunohistochemical data at baseline served to define the predictive value for the outcome at 6 months. RESULTS: AI and CI at baseline did not distinguish patients who had achieved remission from those who had not achieved remission after receiving CYC plus steroids. HGF and TGFbeta1 were expressed in the tubuli, not in the glomeruli. The CI correlated directly with the TGFbeta1 extension score (TGFbeta1-ES) (r = 0.43, P = 0.008), but correlated indirectly with the HGF intensity score (HGF-IS) (r = -0.39, P = 0.02) and the HGF-ES (r = -0.45, P = 0.006). An HGF-ES:TGFbeta1-ES ratio of >or=1 at baseline distinguished patients who had achieved remission from those who had not achieved remission, with a predictive value of 94%. CONCLUSION: These findings indicate that baseline expression of renal HGF and TGFbeta1 predicts short-term renal outcome after therapy with CYC and steroids. [ABSTRACT FROM AUTHOR]

Purpose: Cellular senescence associated with ageing and disease hampers the functional properties of human c-Kit+ Cardiac Stem Cells (CSC) in vitro. Aim of the study was to identify molecular mechanisms associated with CSC senescence and to pharmacologically modulate this latter, at the aim to improve the therapeutic potential of CSC in vivo.Methods: c-Kit+ CSC were isolated from atrial specimens of end-stage failing hearts (E-CSC, n=20) and hearts donated for transplantation (D-CSC, n=14). D- and E-CSC were compared in vitro for the expression of senescence markers and secretome. The ability of CSC's secretome to protect rat adult cardiomyocytes (CM) in vitro from a simulated ischemia-reperfusion injury was analysed. 3 molecular signalling pathways associated with cell senescence were investigated. A 3-days pharmacologic treatment with a cocktail of 10nM Rapamycin and 0.5μM Resveratrol was employed to revert E-CSC senescence in vitro. The functional recovery of SCID-Beige mice infarcted hearts injected with Vehicle (n=17), D-CSC (n=17), E-CSC (n=18) or drug-conditioned-E-CSC (n=18) (300,000 cells/heart) was compared 14 days post-transplantation.Results: with respect to D-CSC, E-CSC show, in vitro, higher levels of senescence markers (p16, γH2AX), a blunted proliferation and a secretome strongly enriched in the pro-inflammatory IL-1β, unable to protect rat CM from apoptosis and senescence in vitro. Neutralisation of IL-1β restored E-CSC's secretome protective effect. At the molecular level, E-CSC are characterized by an hyper-activation of the canonical NFB pathway and of Caspase1, an increased activity of the TORC1 complex, an impairment of the authophagic flux and a reduction of AMPK, Akt and CREB activation. All these alterations could be successfully reverted employing a cocktail of Rapamycin and Resveratrol. The drug treatment reduced the fraction of senescent E-CSC and the amount of IL-1β secreted in vitro, thus restoring the protective effect on rat CM. Last, D-CSC but not E-CSC were able to enhance myocardial healing when injected in a mouse infarcted heart. However, the ex vivo preconditioning of E-CSC with Rapamycin and Resveratrol, prior to the in vivo transplantation, restored their reparative potential to D-CSC levels.Conclusions: we first demonstrate that senescent c-Kit+ CSC resident in human failing hearts display an impaired in vivo reparative ability; importantly, senescent CSC can be rejuvenated in vitro with a short pharmacologic conditioning, finally boosting the in vivo cardiac regeneration. These findings open new avenues to improve autologous CSC therapy in heart failure. [ABSTRACT FROM PUBLISHER]

Background: The scarring of the heart that results from myocardial infarction has been interpreted as evidence that the heart is composed of myocytes that are unable to divide. However, recent observations have provided evidence of proliferation of myocytes in the adult heart. Therefore, we studied the extent of mitosis among myocytes after myocardial infarction in humans.Methods: Samples from the border of the infarct and from areas of the myocardium distant from the infarct were obtained from 13 patients who had died 4 to 12 days after infarction. Ten normal hearts were used as controls. Myocytes that had entered the cell cycle in preparation for cell division were measured by labeling of the nuclear antigen Ki-67, which is associated with cell division. The fraction of myocyte nuclei that were undergoing mitosis was determined, and the mitotic index (the ratio of the number of nuclei undergoing mitosis to the number not undergoing mitosis) was calculated. The presence of mitotic spindles, contractile rings, karyokinesis, and cytokinesis was also recorded.Results: In the infarcted hearts, Ki-67 expression was detected in 4 percent of myocyte nuclei in the regions adjacent to the infarcts and in 1 percent of those in regions distant from the infarcts. The reentry of myocytes into the cell cycle resulted in mitotic indexes of 0.08 percent and 0.03 percent, respectively, in the zones adjacent to and distant from the infarcts. Events characteristic of cell division--the formation of the mitotic spindles, the formation of contractile rings, karyokinesis, and cytokinesis--were identified; these features demonstrated that there was myocyte proliferation after myocardial infarction.Conclusions: Our results challenge the dogma that the adult heart is a postmitotic organ and indicate that the regeneration of myocytes may be a critical component of the increase in muscle mass of the myocardium. [ABSTRACT FROM AUTHOR]