Background: The regenerative capacity of the heart after myocardial infarction (MI) is limited. Our previous study showed that ectopic introduction of Cdk1/CyclinB1 and Cdk4/CyclinD1 complexes (4F) promotes cardiomyocyte proliferation in 15-20% of infected cardiomyocytes in vitro and in vivo and improves cardiac function after MI in mice. Methods: Here, using temporal single-cell RNAseq we aimed to identify the necessary reprogramming stages during the forced cardiomyocyte proliferation with 4F on a single cell basis. Also, using rat and pig models of ischemic heart failure, we aimed to start the first preclinical testing to introduce 4F gene therapy as a candidate for the treatment of ischemia-induced heart failure. Results: Temporal bulk and single-cell RNAseq and further biochemical validations of mature hiPS-CMs treated with either LacZ or 4F adenoviruses revealed full cell cycle reprogramming in 15% of the cardiomyocyte population at 48 h post-infection with 4F, which was mainly associated with sarcomere disassembly and metabolic reprogramming (n=3/timepoint/group). Transient overexpression of 4F, specifically in cardiomyocytes, was achieved using a polycistronic non-integrating lentivirus (NIL) encoding the 4F; each is driven by a TNNT2 promoter (TNNT2-4Fpolycistronic-NIL). TNNT2-4Fpolycistronic-NIL or control virus was injected intramyocardially one week after MI in rats (n=10/group) or pigs (n=6-7/group). Four weeks post-injection, TNNT2-4Fpolycistronic-NIL treated animals showed significant improvement in left ventricular ejection fraction and scar size compared with the control virus treated animals. At four months after treatment, rats that received TNNT2-4Fpolycistronic-NIL still showed a sustained improvement in cardiac function and no obvious development of cardiac arrhythmias or systemic tumorigenesis (n=10/group). Conclusions: This study provides mechanistic insights into the process of forced cardiomyocyte proliferation and advances the clinical feasibility of this approach by minimizing the oncogenic potential of the cell cycle factors thanks to the use of a novel transient and cardiomyocyte-specific viral construct.

Objectives: To determine the prevalence of type-2 diabetes mellitus (DM) in patients with hepatitis C virus (HCV) and B virus (HBV) infections. Materials and Methods: A cross-sectional study of HCV- and HBV-positive patients admitted to King Abdul Aziz University Hospital, Jeddah, Saudi Arabia, was conducted from January 1999 to September 2000. The following data were collected and analysed: demographic data, the presence and type of DM, details of the treatment, body mass index (BMI), family history of DM, serum transaminases, thrombocytopenia, and presence of liver cirrhosis on liver biopsy. A total of 399 patients were included in the study. Results: 165 (41%) were anti-HCV positive and 234 (59%) were HBsAg positive. Type-2 diabetes was present in 35 of 165 (21.2%) patients with HCV infection, and 33 of 234 (14.1%) with HBV infection. 94% of anti-HCV-positive type-2 diabetes were older than 40 years and 6% were younger, while for nondiabetics the corresponding percentages were 55 and 45%, respectively. 76% of HBsAg-positive type-2 diabetics were older than 40 and 24% were younger, while the corresponding percentages for nondiabetics were 27 and 73%, respectively. Anti-HCV-positive type-2 diabetics, when compared to nondiabetics, had a higher BMI, a frequent family history of DM, elevated serum transaminases, thrombocytopenia, and liver cirrhosis on biopsy. HBsAg-positive type-2 diabetics had only a more frequent family history of DM than did nondiabetics. Conclusion: Our findings indicate that type-2 diabetes is more common in patients with an HCV than with an HBV infection.

The regenerative capacity of the heart after myocardial infarction (MI) is limited. Our previous study showed that ectopic introduction of Cdk1/CyclinB1 and Cdk4/CyclinD1 complexes (4F) promotes cardiomyocyte proliferation in 15-20% of infected cardiomyocytes in vitro and in vivo and improves cardiac function after MI. Here, we aim to identify the necessary reprogramming stages during the forced cardiomyocyte proliferation with 4F on a single cell basis. Also, we aim to start the first preclinical testing to introduce 4F gene therapy as a candidate for the treatment of ischemia-induced heart failure. Temporal bulk and single-cell RNAseq and further biochemical validations of mature hiPS-CMs treated with either LacZ or 4F adenoviruses revealed full cell cycle reprogramming in 15% of the cardiomyocyte population after 48 h post-infection with 4F, which was associated with sarcomere disassembly and metabolic reprogramming. Transient overexpression of 4F, specifically in cardiomyocytes, was achieved using a polycistronic non-integrating lentivirus (NIL) encoding the 4F; each is driven by a TNNT2 promoter (TNNT2-4F-NIL). TNNT2-4F-NIL or control virus was injected intramyocardially one week after MI in rats or pigs. TNNT2-4F-NIL treated animals showed significant improvement in left ventricular ejection fraction and scar size compared with the control virus treated animals four weeks post-injection. In conclusion, the present study provides a mechanistic demonstration of the process of forced cardiomyocyte proliferation and advances the clinical feasibility of this approach by minimizing the oncogenic potential of the cell cycle factors using a novel transient and cardiomyocyte-specific viral construct.

Background Bronchial anastomotic dehiscence is considered one of the most catastrophic early airway complications post-transplant. The presence of a partial dehiscence can also cause further complications such as a fistula between the bronchus and the pleural membrane. Platelet-rich plasma (PRP) is known to significantly enhance the healing process and is being used in the treatment of various conditions, however, so far, there are no reports of the use of PRP in the treatment of bronchial anastomotic dehiscence fistula. Case presentation We present a 37-year-old male, with non-cystic fibrosis bronchiectasis underwent bilateral lung transplantation. The patient developed partial dehiscence of the right bronchial anastomosis that was complicated by a small bronchopleural fistula. Two bronchoscopic applications of autologous platelet-rich plasma were carried out. Follow-up a few weeks later showed complete closure and healing of the fistula. Conclusions This case report suggests that the treatment of post-lung transplant small bronchial anastomotic partial dehiscence fistula with PRP is safe and effective.

Rationale: The regenerative capacity of the heart to repair itself after myocardial infarction (MI)is limited. Our previous study showed that ectopic introduction of Cdk1/CyclinB1 andCdk4/CyclinD1 complexes (4F) promotes cardiomyocyte proliferation in vitro and in vivo andimproves cardiac function after MI. However, its clinical application is limited due to the concernsfor tumorigenic potential in other organs. Objectives: To first, identify on a single cell transcriptomic basis the necessary reprogrammingsteps that cardiomyocytes need to undertake to progress through the proliferation processfollowing 4F overexpression, and then, to determine the pre-clinical efficacy of transient andcardiomyocyte specific expression of 4F in improving cardiac function after MI in small and largeanimals. Methods and Results: Temporal bulk and single cell RNAseq of mature hiPS-CMs treated with4F or LacZ control for 24, 48, or 72 h revealed full cell cycle reprogramming in 15% of thecardiomyocyte population which was associated with sarcomere disassembly and metabolicreprogramming. Transient overexpression of 4F specifically in cardiomyocytes was achievedusing non-integrating lentivirus (NIL) driven by TNNT2 (TNNT2-4F-NIL). One week after inductionof ischemia-reperfusion injury in rats or pigs, TNNT2-4F-NIL or control virus was injectedintramyocardially. Compared with controls, rats or pigs treated with TNNT2-4F-NIL showed a 20-30% significant improvement in ejection fraction and scar size four weeks after treatment, asassessed by echocardiography and histological analysis. Quantification of cardiomyocyteproliferation in pigs using a novel cytokinesis reporter showed that ~10% of the cardiomyocyteswithin the injection site were labelled as daughter cells following injection with TNNT2-4F-NILcompared with ~0.5% background labelling in control groups. Conclusions: We provide the first understanding of the process of forced cardiomyocyteproliferation and advanced the clinical applicability of this approach through minimization ofoncogenic potential of the cell cycle factors using a novel transient and cardiomyocyte-specificviral construct.