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Trastuzumab (Trz) is a humanized monoclonal antibody targeting epidermal growth factor receptor 2 (HER2; ErbB2). The combined administration of Trz and doxorubicin (DOX) has shown potent anti-cancer efficacy; however, this regimen may be accompanied by severe cardiac toxicity. Mesenchymal stem cells (MSCs)-derived exosomes are nanosized vesicles that play a crucial role in cell–cell communication and have shown efficacy in the treatment of various diseases. In this study, we aim to investigate the cardioprotective effects of MSCs-derived exosomes in a DOX/Trz- mediated cardiotoxicity model, and the possible mechanisms underlying these effects are elucidated. Forty-nine male rats were randomly assigned into four groups: Group I (control); Group II (Dox/Trz); Group III (protective group); and Group IV (curative group). Cardiac hemodynamic parameters, serum markers of cardiac injury, oxidative stress indices, and cardiac histopathology were investigated. Further, transcript profile of specific cardiac tissue injury markers, apoptotic markers, and fibrotic markers were analyzed using qRT-PCR, while the protein expressions of pAkt/Akt, pERK/ERK, pJNK/JNK, pJNK/JNK, and pSTAT3/STAT3 were evaluated by ELISA. Additionally, cardiac mirR-21 and miR-26a were assessed. A combined administration of DOX/Trz disrupted redox and Ca2+ homeostasis in cardiac tissue induced myocardial fibrosis and myofibril loss and triggered cardiac DNA damage and apoptosis. This cardiotoxicity was accompanied by decreased NRG-1 mRNA expression, HER2 protein expression, and suppressed AKT and ERK phosphorylation, while triggering JNK phosphorylation. Histological and ultra-structural examination of cardiac specimens revealed features typical of cardiac tissue injury. Moreover, a significant decline in cardiac function was observed through biochemical testing of serum cardiac markers and echocardiography. In contrast, the intraperitoneal administration of MSCs-derived exosomes alleviated cardiac injury in both protective and curative protocols; however, superior effects were observed in the protective protocol. The results of the current study indicate the ability of MSCs-derived exosomes to protect from and attenuate DOX/Trz-induced cardiotoxicity. The NRG-1/HER2, MAPK, PI3K/AKT, PJNK/JNK, and PSTAT/STAT signaling pathways play roles in mediating these effects.

Background. Liver transplantation remains the only viable therapy for liver failure but has a severely restricted utility. Here, we aimed to decellularize rat livers to form acellular 3D bio-scaffolds suitable for seeding with induced pluripotent cells (iPSCs) as a tool to investigate the role of Wnt/β-catenin signaling in liver development and generation. Methods. Dissected rat livers were randomly divided into three groups: I (control), II (decellularized scaffolds) and III (recellularized scaffolds). Liver decellularization was established via an adapted perfusion procedure and assessed through the measurement of extracellular matrix (ECM) proteins and DNA content. Liver recellularization was assessed through histological examination and measurement of transcript levels of Wnt/β-catenin pathway, hepatogenesis, liver-specific microRNAs and growth factors essential for liver development. Adult rat liver decellularization was confirmed by the maintenance of ECM proteins and persistence of growth factors essential for liver regeneration. Results. iPSCs seeded rat decellularized livers displayed upregulated transcript expression of Wnt/β-catenin pathway-related, growth factors, and liver specification genes. Further, recellularized livers displayed restored liver-specific functions including albumin secretion and urea synthesis. Conclusion. This establishes proof-of-principle for the generation of three-dimensional liver organ scaffolds as grafts and functional re-establishment.

Diabetic retinopathy (DR) is a serious microvascular complication of diabetes mellitus. Mesenchymal stem cells are currently studied as therapeutic strategy for management of DR. Exosomes, considered as a promising cell-free therapy option, display biological functions similar to those of their parent cells. In retinal development, Wnt/b-catenin signaling provides key cues for functional progression. The present study aimed to evaluate the potential efficacy of bone marrow-derived mesenchymal stem cell-derived exosomes (BM-MSCs-Ex) in diabetes-induced retinal injury via modulation of the Wnt/ b-catenin signaling pathway.Eighty-one rats were allocated into 6 groups (control, DR, DR + DKK1, DR + exosomes, DR + Wnt3a and DR + exosomes+Wnt3a). Evaluation of each group was via histopathological examination, assessment of gene and/or protein expression concerned with oxidative stress (SOD1, SOD2, Nox2, Nox4, iNOS), inflammation (TNF-α, ICAM-1, NF-κB) and angiogenesis (VEGF, VE-cadherin).Results demonstrated that exosomes blocked the wnt/b-catenin pathway in diabetic retina concomitant with significant reduction of features of DR as shown by downregulation of retinal oxidants, upregulation of antioxidant enzymes, suppression of retinal inflammatory and angiogenic markers. These results were further confirmed by histopathological results, fundus examination and optical coherence tomography. Additionally, exosomes ameliorative effects abrogated wnt3a-triggered retinal injury in DR.Collectively, these data demonstrated that exosomes ameliorated diabetes-induced retinal injury via suppressing Wnt/ b-catenin signaling with subsequent reduction of oxidative stress, inflammation and angiogenesis.

Background Diabetic foot ulceration is a serious chronic complication of diabetes mellitus characterized by high disability, mortality, and morbidity. Platelet-rich plasma (PRP) has been widely used for diabetic wound healing due to its high content of growth factors. However, its application is limited due to the rapid degradation of growth factors. The present study aimed to evaluate the efficacy of combined adipose-derived mesenchymal stem cells (ADSCs) and PRP therapy in promoting diabetic wound healing in relation to the Notch signaling pathway. Methods Albino rats were allocated into 6 groups [control (unwounded), sham (wounded but non-diabetic), diabetic, PRP-treated, ADSC-treated, and PRP+ADSCs-treated groups]. The effect of individual and combined therapy was evaluated by assessing wound closure rate, epidermal thickness, dermal collagen, and angiogenesis. Moreover, gene and protein expression of key elements of the Notch signaling pathway (Notch1, Delta-like canonical Notch ligand 4 (DLL4), Hairy Enhancer of Split-1 (Hes1), Hey1, Jagged-1), gene expression of angiogenic marker (vascular endothelial growth factor and stromal cell-derived factor 1) and epidermal stem cells (EPSCs) related gene (ß1 Integrin) were assessed. Results Our data showed better wound healing of PRP+ADSCs compared to their individual use after 7 and 14 days as the combined therapy caused reepithelialization and granulation tissue formation with a marked increase in area percentage of collagen, epidermal thickness, and angiogenesis. Moreover, Notch signaling was significantly downregulated, and EPSC proliferation and recruitment were enhanced compared to other treated groups and diabetic groups. Conclusions These data demonstrated that PRP and ADSCs combined therapy significantly accelerated healing of diabetic wounds induced experimentally in rats via modulating the Notch pathway, promoting angiogenesis and EPSC proliferation.

Background Very small embryonic-like stem cells (VSELs) are a rare population within the ovarian epithelial surface. They contribute to postnatal oogenesis as they have the ability to generate immature oocytes and resist the chemotherapy. These cells express markers of pluripotent embryonic and primordial germ cells. Objective We aimed to explore the capability of VSELs in restoring the postnatal oogenesis of chemo-ablated rat ovaries treated with bone marrow-derived mesenchymal stem cells (BM-MSCs) combined with pregnant mare serum gonadotropin (PMSG). Methods Female albino rats were randomly assigned across five groups: I (control), II (chemo-ablation), III (chemo-ablation + PMSG), IV (chemo-ablation + MSCs), and V (chemo-ablation + PMSG + MSCs). Postnatal oogenesis was assessed through measurement of OCT4, OCT4A, Scp3, Mvh, Nobox, Dazl4, Nanog, Sca-1, FSHr, STRA8, Bax, miR143, and miR376a transcript levels using qRT-PCR. Expression of selected key proteins were established as further confirmation of transcript expression changes. Histopathological examination and ovarian hormonal assessment were determined. Results Group V displayed significant upregulation of all measured genes when compared with group II, III or IV. Protein expression confirmed the changes in transcript levels as group V displayed the highest average density in all targeted proteins. These results were confirmed histologically by the presence of cuboidal germinal epithelium, numerous primordial, unilaminar, and mature Graafian follicles in group V. Conclusion VSELs can restore the postnatal oogenesis in chemo-ablated ovaries treated by BM-MSCs combined with PMSG.

Introduction Curcumin is an inducer of heme oxygenase enzyme-1 (HO-1) that is involved in erectile signaling via elevating cyclic guanosine monophosphate (cGMP)levels. Aim To assess the effect of oral administration of a water-soluble long-acting curcumin derivative on erectile signaling. Methods Two hundred and thirty six male white albino rats were divided into four groups; group 1 (N = 20) includes control. Group 2 (N = 72) was equally divided into four subgroups; subgroup 1 received pure curcumin (10 mg/kg), subgroup 2 received the long-acting curcumin derivative (2 mg/kg), subgroup 3 received the long-acting curcumin derivative (10 mg/kg), and subgroup 4 received sildenafil (4 mg/kg). Subgroups were sacrificed after the first, second, and third hour. Group 3 (N = 72) was equally divided into the same four subgroups already mentioned and were sacrificed after 24 hours, 48 hours, and 1 week. Group 4 (N = 72) was subjected to intracavernosal pressure (ICP) measurements 1 hour following oral administration of the same previous doses in the same rat subgroups. Main Outcome Measure Cavernous tissue HO enzyme activity, cGMP, and ICP. Results In group 2, there was a significant progressive maintained elevation of HO activity and cGMP tissue levels starting from the first hour in subgroups 3 and 4, whereas, the rise in HO activity and cGMP started from second hour regarding the other rat subgroups. Sildenafil effect decreased after 3 hours. In group 3, there was a significant maintained elevation of HO activity and cGMP tissue levels extended to 1 week as compared to controls for all rat subgroups that received both forms of curcumin. In group 4, long-acting curcumin derivative exhibited more significant potentiation of intracavernosal pressure as compared to control and to the pure curcumin. Conclusion Water-soluble long-acting curcumin derivative could mediate erectile function via upregulating cavernous tissue cGMP. Abdel Aziz MT, El Asmer MF, Rezq A, Kumosani TA, Mostafa S, Mostafa T, Atta H, Abdel Aziz Wassef M, Fouad HH, Rashed L, Sabry D, Hassouna AA, Senbel A, and Abdel Aziz A. Novel water-soluble curcumin derivative mediating erectile signaling

Curcumin exerts a hypoglycemic action and induces heme-oxygenase-1 (HO-1). We evaluated the effect of curcumin on isolated islets of Langerhans and studied whether its action on insulin secretion is mediated by inducible HO-1. Islets were isolated from rats and divided into control islets, islets incubated in different curcumin concentrations, islets incubated in hemin, islets incubated in curcumin and HO inhibitor, stannous mesoporphyrin (SnMP), islets incubated in hemin and SnMP, islets incubated in SnMP only, and islets incubated in 16.7 mmol/L glucose. Heme-oxygenase activity, HO-1 expression, and insulin estimation was assessed. Insulin secretion, HO-1 gene expression and HO activity were significantly increased in islets incubated in curcumin, hemin, and glucose compared with controls. This increase in insulin secretion was significantly decreased by incubation of islets in SnMP. The action of curcumin on insulin secretion from the isolated islets may be, in part, mediated through increased HO-1 gene expression.

Introduction Activation of the renin‐angiotensin system which is common in diabetes mellitus might affect heme oxygenase (HO‐1) gene expression. Aim Assessment of the effects of administration of angiotensin II (Ang II) receptor antagonist (losartan) with HO‐1 inducer or inhibitor on erectile signaling in diabetic rats. Materials and Methods Seventy male rats were divided equally into seven groups; healthy controls, streptozotocin‐induced diabetic rats, rats on citrate buffer, diabetic rats on losartan, diabetic rats on HO‐1 inducer (cobalt protoporphyrin [CoPP]), diabetic rats on losartan and CoPP, and diabetic rats on losartan and HO‐1 inhibitor (stannus mesoporphyrin [SnMP]). Main Outcome Measure HO enzyme activity, HO‐1 gene expression, cyclic guanosine monophosphate (cGMP) assay, intracavernosal pressure (ICP), and cavernous tissue sinusoids surface area. Results HO‐1 gene expression, HO enzymatic activity, and cGMP were significantly decreased in the cavernous tissue of diabetic rats. These parameters were significantly elevated with the use of CoPP that restored the normal control levels of HO enzyme activity. Administration of losartan exhibited a significant enhancing effect on these parameters compared with the diabetic group, but not restored to the control levels, whereas administration of CoPP combined with losartan led to the restoration of their normal levels. ICP demonstrated significant decline in diabetic rats. The use of CoPP and/or losartan led to its significant improvement compared with diabetic rats. Administration of either losartan and/or CoPP led to a significant increase in the cavernous sinusoids surface area of diabetic rats. Administration of losartan with SnMP significantly decreased the enhancing effect of losartan on the studied parameters. Conclusion The decline in erectile function in diabetes mellitus could be attributed to the downregulation of HO‐1 gene expression. HO‐1 induction added to Ang II receptor antagonist could improve erectile function. Abdel Aziz MT, El Asmer MF, Mostafa T, Atta H, Mahfouz S, Fouad H, Rashed L, Sabry D, Hassouna A, Abdel Aziz AT, Senbel A, and Demery A. Effects of losartan, HO‐1 inducers or HO‐1 inhibitors on erectile signaling in diabetic rats.

Estrogen (E(2)) and progesterone (P) hormones have a pro-inflammatory and an anti-inflammatory role under different conditions. The current study explored this phenomenon in the context of septic inflammation.This study involved 48 female albino rats. E(2) (4 mg/100 g body weight (b.w.) and P (5 mg/kg b.w.) were administered to ovariectomized (OVX) rats after systemic inflammation (SI) induced by puncturing the caecum I cm from its end with a single hole by using a 21-gauge needle. Key indices of inflammation and apoptosis were evaluated.OVX animals subjected to SI showed significantly increased levels of serum tumor necrosis factor-alpha (TNF-u), C reactive protein (CRP) and alanine aminotransferase (ALT). They also showed higher levels of expression of the enzyme inducible nitric oxide synthase (iN OS); 312 ± 43 mg/ml; in the liver, and the activity of both cyclooxygenase 2 (COX-2); 59.4 ± 3.2 U/ml; and caspase 3 enzymes; 6.3 ± 0.54 ng/ml; when compared to non-OVX animals subjected to (SI), (180 ± 3 mg/ml, 16.4 ± 1.69 U/ml, 0.98 ± 0.23 ng/ml respectively). Administration of E(2) resulted in a significant reduction of all serum and liver tissue parameters of inflammation (e.g.decreased iNOS; 193 ± 28 mg/ml and COX-2; 27.6 ± 3.91 U/ml) and decreased apoptosis (Caspase 3; 1.18 ± 0.21 ng/ml). In contrast, OVX animals injected with P before induction of SI showed a significant rise of all measured parameters.E(2) and Pin physiological levels have contrasting though complementary roles in regulation of the immune system possibly allowing a limited inflammatory response while preventing excessive damage to the tissues.

Novel water-soluble curcumin derivatives have been developed to overcome low in vivo bioavailability of curcumin. The aim of this work is to assess the potential utility of certain downstream targets as bioavailability indicators of systemic activity of pure curcumin and two novel water-soluble curcumin derivatives (NCD) by constructing dose-dependent response curves and to prove whether this novel curcumin derivatives retained, improved, or abolished biological activity of pure curcumin when applied in vivo. Pure curcumin (CUR), curcumin-carboxy derivative (NCD-1), and curcumin protein conjugate (NCD-2) were administered orally to rats at escalating doses: 37, 74, 148, and 296 μM/kg body weight, respectively. Plasma levels of GST activity, cavernous tissue levels of cGMP, and enzymatic activity of both HO-1 and GST were assessed one and half and 24 hours after oral administration of curcumin formulae. This study showed that there was a progressive elevation of cavernous tissue levels of cGMP and enzymatic activity of both HO-1 and GST in a dose-dependent manner that was maintained for 24 h with CUR, NCD-1, and NCD-2. Plasma GST activity was decreased by the lowest doses on the curve. The three dose-dependent bioavailability indicators as surrogates of curcumin and two of its novel derivatives are valid in the studied range of concentration and extended time. The novel curcumin derivatives still conserve with improvement the biological activity of natural curcumin when applied in vivo.

Summary This work postulated that heme oxygenase (HO) is partly responsible for controlling phosphodiesterase-5 inhibitor actions by modulating cyclic guanosine monophosphate (cGMP) cavernous tissue levels. Five hundred and four male Sprague–Dawley rats, divided into five groups, were investigated. Group 1 (n = 72) included controls, group 2 (n = 72) received sildenafil citrate (ViagraR) orally, group 3 (n = 72) received vardenafil hydrochloride (LevitraR), group 4 (n = 72) received tadalafil (CialisR). Group 5 (n = 216), subdivided into three subgroups (A, B and C, 72 each), received the same dose of each drug with the HO inhibitor, Zn protoporphyrin. Eight rats from each group/subgroup were killed at 0.5, 1, 2, 3, 4, 6, 18, 24 and 36 h when cGMP levels in the cavernous tissues were estimated. Cavernous tissue cGMP levels increased significantly in sildenafil, vardenafil and tadalafil-treated rats compared to the controls with significant decreases after HO inhibition. It is concluded that the effects of these PDE-5 inhibitors in rat cavernous tissue are partly mediated through HO activity via the cGMP signalling pathway.

To study the effect of mesenchymal stem cells (MSC) on experimental liver fibrosis in rats.MSC were derived from bone marrow obtained from femoral and tibial bones of male albino rats. MSC were separated, grown, and propagated in culture for 4 weeks and were characterized morphologically and by detection of CD29 by RT-PCR. They were then infused into the tail vein of female rats that received CCl4 injection to induce liver fibrosis. Rats were divided into 4 groups: control, CCl4, CCl4 plus MSC, and MSC. Liver tissue was examined histopathologically and liver functions (ALT and serum albumin) were estimated for all groups. Y-chromosome gene (sry) was assessed by PCR in liver tissue of the female rats to confirm uptake of the male stem cells. Hydroxyproline content in liver tissue was assessed by chemical methods and expression of the collagen gene (type I) was detected as a marker for liver fibrosis. Results of the present study showed that MSC have a significant antifibrotic effect as evidenced by the significant decrease in liver collagen gene expression as well as the decrease in hydroxyproline content in the CCl4/MSC group (p0.001) compared to the CCl4 group. The Y-chromosome gene (sry) was detected by RT-PCR in the CCl4/MSC group, but was not detected in control group and other groups. The CD29 gene was expressed in MSC culture, and this confirmed the efficiency of isolation and propagation of MSC in culture. With regard to liver function, there was also a significant improvement and elevation of serum albumin in the CCl4/MSC group compared to the CCl4 group (p0.05). As regard to the liver enzyme ALT, there was a decrease of its level in the CCl4/MSC group compared to the CCl4 group. However, this was statistically nonsignificant (p0.05). In conclusion, MSC have a potential therapeutic effect against the fibrotic process through their effect in minimizing collagen deposition in addition to their capacity to differentiate into hepatocytes.

Background The present study was conducted to evaluate the tumor suppressive effects of bone marrow derived mesenchymal stem cells (MSCs) in an experimental hepatocellular carcinoma (HCC) model in rats and to investigate the possible role of Wnt signaling in hepato-carcinogenesis. Methods Ninety rats were included in the study and were divided equally into: Control group, rats which received MSCs only, rats which received MSCs vehicle only, HCC group induced by diethylnitroseamine (DENA) and CCl 4 , rats which received MSCs after HCC induction, rats which received MSCs before HCC induction. Histopathological examination and gene expression of Wnt signaling target genes by real time, reverse transcription-polymerase chain reaction (RT-PCR) in rat liver tissue, in addition to serum levels of ALT, AST and alpha fetoprotein were performed in all groups. Results Histopathological examination of liver tissue from animals which received DENA-CCl4 only, revealed the presence of anaplastic carcinoma cells and macro-regenerative nodules type II with foci of large and small cell dysplasia. Administration of MSCs into rats after induction of experimental HCC improved the histopathological picture which showed minimal liver cell damage, reversible changes, areas of cell drop out filled with stem cells. Gene expression in rat liver tissue demonstrated that MSCs downregulated β-catenin, proliferating cell nuclear antigen (PCNA), cyclin D and survivin genes expression in liver tissues after HCC induction. Amelioration of the liver status after administration of MSCs has been inferred by the significant decrease of ALT, AST and Alpha fetoprotein serum levels. Administration of MSCs before HCC induction did not show any tumor suppressive or protective effect. Conclusions Administration of MSCs in chemically induced HCC has tumor suppressive effects as evidenced by down regulation of Wnt signaling target genes concerned with antiapoptosis, mitogenesis, cell proliferation and cell cycle regulation, with subsequent amelioration of liver histopathological picture and liver function.