Sally K. Hammad

To compare the therapeutic potential of rat bone marrow-derived mesenchymal stem cells (BM-MSCs) preconditioned ex-vivo with resveratrol (MCR) and BM-MSCs isolated from resveratrol-pre-treated rats (MTR) in type-1 diabetic rats. Type-1 diabetes was induced by a single streptozotocin injection (50 mg/kg; ip) in 24 rats. Following the confirmation of T1DM, diabetic rats were randomly divided into four groups: diabetic control (DC), diabetic rats treated with insulin subcutaneous (7.5 IU/kg/day), diabetic rats treated with MCR cells (3 × 10⁶cells/rat, intravenous) and diabetic rats treated with MTR cells (3 × 10⁶cells/rat, intravenous). Rats were sacrificed 4 weeks following cellular transplantation. Untreated diabetic rats suffered from pancreatic cell damage, had high blood glucose levels, increased apoptotic, fibrosis, and oxidative stress markers and decreased survival and pancreatic regeneration parameters. Both MSCs preconditioned ex-vivo with RES and MSCs isolated from rats pre-treated with RES homed successfully in injured pancreas and showed therapeutic potential in the treatment of STZ-induced T1DM. MCR cells showed better efficiency than MTR cells. The pre-conditioning of BM-MSCs with resveratrol may be a promising therapeutic possibility in T1DM. Resveratrol-preconditioned BM-MSCs encouraged effects almost comparable to that of exogenous insulin with the advantages of cured pancreas and restored islets not attained by insulin.

Vanillin (Van) and pentoxifylline (PTX) ameliorated isoproterenol-induced myocardial injury; reduced cardiac oxidative stress, inflammation, and apoptosis; and promoted cardiac angiogenesis via Akt/HIF-1α/VEGF signaling.

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: Chronic kidney disease (CKD) is a major public health problem associated with high mortality. The therapeutic effects of pachymic in CKD management and its underlying mechanisms have not been studied. Therefore, we aimed to investigate the possible inhibitory effect of PA on renal Wnt/β-catenin signalling in CKD. Methods: CKD was induced in rats by doxorubicin (DOX; 3.5 mg/kg i.p., twice weekly for 3 weeks). Rats were treated orally with PA (10 mg/kg/day), LOS (10 mg/kg/day) or their combination (PA + LOS) for 4 weeks starting after the last dose of DOX. Key findings: DOX-induced renal injury was characterized by high serum cystatin-C, and urine albumin/creatinine ratio, renal content of podocin and klotho were decreased. Tumour necrosis factor-α, interleukin-6, interleukin-1β, Wnt1, active β-catenin/total β-catenin ratio and fibronectin along with mRNA expression of RENIN, ACE and AT1 were increased in renal tissues. Treatment with either PA or LOS ameliorated all DOX-induced changes. The combined treatment was more effective in improving all changes than monotherapy. Conclusions: These results suggest a new therapeutic benefit of PA in ameliorating CKD in rats through its up-regulatory effect on renal klotho thereby preventing Wnt/β-catenin reactivation and RAS gene expression. PA/LOS combination provided an additional inhibition of Wnt/β-catenin signalling and its downstream targets.

Postmenopausal women are at an increased risk of vascular calcification which is defined as the pathological deposition of minerals in the vasculature, and is strongly linked with increased cardiovascular disease risk. Since estrogen-replacement therapy is associated with increased cancer risk, there is a strong need for safer therapeutic approaches. In this study we aimed to investigate the protective and therapeutic effects of the phytoestrogen resveratrol against vascular calcification in ovariectomized rats, a preclinical model of postmenopause. Furthermore, we aimed to compare the effects of resveratrol to those of estrogen and to explore the mechanisms underpinning those effects. Treatment with resveratrol or estrogen ameliorated aortic calcification in ovariectomized rats, as shown by reduced calcium deposition in the arterial wall. Mechanistically, the effects of resveratrol and estrogen were mediated via the activation of SIRT1 signaling. SIRT1 protein expression was downregulated in the aortas of ovariectomized rats, and upregulated in rats treated with resveratrol or estrogen. Moreover, resveratrol and estrogen reduced the levels of the osteogenic markers: runt-related transcription factor 2 (RUNX2), osteocalcin and alkaline phosphatase (ALP) which have been shown to play a role during vascular calcification. Additionally, the senescence markers (p53, p16 and p21) which were also reported to play a role in the pathogenesis of vascular calcification, were reduced upon treatment with resveratrol and estrogen. In conclusion, the phytoestrogen resveratrol may be a safer alternative to estrogen, as a therapeutic approach against the progression of vascular calcification during postmenopause.

Bone is a mineralized structure that is mainly made of a matrix that supports the various types of bone cells; osteoblasts, osteoclasts, osteocytes and bone lining cells. Bone mass is preserved as a result of the balance between bone forming osteoblasts and bone resorbing osteoclasts, in a process known as bone remodeling. Bone remodeling process occurs mainly in three steps: resorption, reversal and formation. These steps are controlled locally and systemically by numerous regulatory factors. Among these regulatory factors, wingless-related MMTV integration site (Wnt) signaling pathway plays a significant role in maintainig bone mass as well as regulating many cellular processes. Based on whether β-catenin is involved or not, Wnt signaling is categorized into two main pathways; the canonical and the non-canonical pathways. The actions exerted by the Wnt signaling pathway are achieved when Wnt ligands bind to specific transmembrane receptors such as the Frizzled family (Frz) members and low density lipoprotein receptor-related proteins (LRPs) and are inhibited when these ligands or receptors bind to Wnt signaling inhibitors such as Wnt inhibitory factor 1 (WIF1), secreted Frizzled-related proteins (sFRPs), Dickkopf 1 (DKK1) and sclerostin. Improper synthesis of any of these ligands, receptors or inhibitors leads to disruption of different body functions and progression of various diseases including skeletal diseases. Therefore, the components of the Wnt signaling pathway can be targeted for developing novel therapeutic agents to manage different diseases.

Wingless-integrated/β-catenin (Wnt/β-catenin) signaling pathway is an evolutionarily conserved signaling which is not only important for regulation of embryogenesis and organ development, but also for injury repair, homeostasis and tissue remodeling. Dysregulation of this pathway either by upregulation or even downregulation is highly implicated in various diseases such as; liver diseases, kidney diseases, lung fibrosis, heart failure, vascular calcification, osteoporosis, cellular senescence, neurodegeneration, Alzheimer's disease and cancers. Thus, targeting Wnt/β-catenin signaling has attracted scientific research as a good strategy ameliorating several diseases. In this review we discussed Wnt/β-catenin components, the Wnt-on state and the Wnt-off state. Furthermore, we summarized the effects of Wnt/β-catenin signaling in several distinct organs including brain, bone, liver, heart, lung and kidney. We also discussed various molecules that act as modulators of Wnt/β-catenin signaling pathway via targeting its components (Wnt, Frizzled, LRP5/6, Porcupine, Disheveled, β-catenin destruction complex and β-catenin activity) aiming to show their possible therapeutic potential in several diseases.