Biotechnological Plastic Degradation and Valorization Using Systems Metabolic Engineering.

Various kinds of plastics have been developed over the past century, vastly improving the quality of life. However, the indiscriminate production and irresponsible management of plastics have led to the accumulation of plastic waste, emerging as a pressing environmental concern. To establish a clean and sustainable plastic economy, plastic recycling becomes imperative to mitigate resource depletion and replace non-eco-friendly processes, such as incineration. Although chemical and mechanical recycling technologies exist, the prevalence of composite plastics in product manufacturing complicates recycling efforts. In recent years, the biodegradation of plastics using enzymes and microorganisms has been reported, opening a new possibility for biotechnological plastic degradation and bio-upcycling. This review provides an overview of microbial strains capable of degrading various plastics, highlighting key enzymes and their role. In addition, recent advances in plastic waste valorization technology based on systems metabolic engineering are explored in detail. Finally, future perspectives on systems metabolic engineering strategies to develop a circular plastic bioeconomy are discussed.

Targeted Delivery of Recombinant Heat Shock Protein 27 to Cardiomyocytes Promotes Recovery from Myocardial Infarction.

Ischemic heart disease, especially myocardial infarction (MI), is the leading cause of death worldwide. Apoptotic mechanisms are thought to play a significant role in cardiomyocyte death after MI. Increased production of heat shock proteins (Hsps) in cardiomyocytes is a normal response to promote tolerance and to reduce cell damage. Hsp27 is considered to be a therapeutic option for the treatment of ischemic heart disease due to its protective effects on hypoxia-induced apoptosis. Despite its antiapoptotic effects, the lack of strategies to deliver Hsp27 to the heart tissue in vivo limits its clinical applicability. In this study, we utilized an antibody against the angiotensin II type 1 (AT1) receptor, which is expressed immediately after ischemia/reperfusion in the heart of MI rats. To achieve cardiomyocyte-targeted Hsp27 delivery after ischemia/reperfusion, we employed the immunoglobulin-binding dimer ZZ, a modified domain of protein A, in conjunction with the AT1 receptor antibody. Using the AT1 receptor antibody, we achieved systemic delivery of ZZ-TAT-GFP fusion protein into the heart of MI rats. This approach enabled selective delivery of Hsp27 to cardiomyocytes, rescued cells from apoptosis, reduced the area of fibrosis, and improved cardiac function in the rat MI model, thus suggesting its applicability as a cardiomyocyte-targeted protein delivery system to inhibit apoptosis induced by ischemic injury.

Upregulation of FZD5 in Eosinophilic Chronic Rhinosinusitis with Nasal Polyps by Epigenetic Modification.

Eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) is one of the most challenging problems in clinical rhinology. FZD5 is a receptor for Wnt5A, and its complex with Wnt5A contributes to activating inflammation and tissue modification. Nasal polyps and eosinophil/non-eosinophil counts are reported to be directly correlated. This study investigated the expression and distribution of FZD5, and the role of eosinophil infiltration and FZD5 in eosinophilic CRSwNP pathogenesis. The prognostic role of eosinophil levels was evaluated in seven patients with CRSwNP. Fifteen patients with CRS were classified based on the percentage of eosinophils in nasal polyp tissue. Methylated genes were detected using methyl-CpG-binding domain sequencing, and qRT-PCR and immunohistochemistry were used to detect FZD5 expression in nasal polyp tissue samples. The results showed that mRNA expression of FZD5 was upregulated in nasal polyps. FZD5 expression was significantly higher in nasal polyp samples from patients with eosinophilic CRSwNP than in those from patients with non-eosinophilic CRSwNP, as indicated by immunohistochemistry. Furthermore, inflammatory cytokine levels were higher in eosinophilic CRSwNP-derived epithelial cells than in normal tissues. In conclusion, FZD5 expression in nasal mucosal epithelial cells is correlated with inflammatory cells and might play a role in the pathogenesis of eosinophilic CRSwNP.

Curcumin Treatment in Combination with Glucose Restriction Inhibits Intracellular Alkalinization and Tumor Growth in Hepatoma Cells.

Dysregulation of cellular energy metabolism is closely linked to cancer development and progression. Calorie or glucose restriction (CR or GR) inhibits energy-dependent pathways, including IGF-1/PI3K/Akt/mTOR, in cancer cells. However, alterations in proton dynamics and reversal of the pH gradient across the cell membrane, which results in intracellular alkalinization and extracellular acidification in cancer tissues, have emerged as important etiopathogenic factors. We measured glucose, lactate, and ATP production after GR, plant-derived CR-mimetic curcumin treatment, and curcumin plus GR in human hepatoma cells. Intracellular pH regulatory effects, in particular, protein-protein interactions within mTOR complex-1 and its structural change, were investigated. Curcumin treatment or GR mildly inhibited Na+/H+ exchanger-1 (NHE1). vATPase, monocarboxylate transporter (MCT)-1, and MCT4 level. Combination treatment with curcumin and GR further enhanced the inhibitory effects on these transporters and proton-extruding enzymes, with intracellular pH reduction. ATP and lactate production decreased according to pH change. Modeling of mTOR protein revealed structural changes upon treatments, and curcumin plus GR decreased binding of Raptor and GßL to mTOR, as well as of Rag A and Rag B to Raptor. Consequently, 4EBP1 phosphorylation was decreased and cell migration and proliferation were inhibited in a pH-dependent manner. Autophagy was increased by curcumin plus GR. In conclusion, curcumin treatment combined with GR may be a useful supportive approach for preventing intracellular alkalinization and cancer progression.

Corrigendum: Small molecule-mediated up-regulation of microRNA targeting a key cell death modulator BNIP3 improves cardiac function following ischemic injury.

This corrects the article DOI: 10.1038/srep23472.

TAK-733 inhibits inflammatory neointimal formation by suppressing proliferation, migration, and inflammation in vitro and in vivo.

As a potent and selective allosteric inhibitor of MEK, TAK-733 has been shown to exert anti-cancer effects for a wide range of cancers both in vitro and in vivo. However, its effects on inhibiting growth have never been investigated in the cardiovascular system, where regulation of abnormal vascular smooth muscle cell growth in neointimal hyperplasia is an important area of focus. Angiotensin II was used to mimic inflammatory neointimal hyperplasia in an in vitro environment, and balloon catheter-induced injury with an infusion of angiotensin II was used to generate an in vivo rat restenosis model under inflammatory conditions. TAK-733 exerted anti-proliferative and anti-migratory effects on human vascular smooth muscle cells. These multiple effects of TAK-733 were evaluated using various assays, such as cell cycle analysis and wound healing. Interestingly, TAK-733 did not induce apoptosis in smooth muscle cells but only reduced the proliferation rate; additionally, it did not affect EC viability. TAK-733 also exhibited anti-inflammatory activity, as observed by attenuated monocyte adhesion to smooth muscle cells via inhibition of ICAM1 and VCAM1 overexpression. The in vivo study demonstrated that neointimal hyperplasia after balloon injury and angiotensin II stimulation was suppressed by TAK-733, and downregulation of the inflammatory signal and enhanced re-endothelialization were observed. TAK-733 may have therapeutic potential for treating neointimal hyperplasia by attenuating smooth muscle cell proliferation, migration, and inflammation. Thus, TAK-733 could be a promising drug candidate for treating patients with restenosis.

Role of epigenetics in the pathogenesis of chronic rhinosinusitis with nasal polyps.

Chronic rhinosinusitis (CRS) is a highly prevalent disease characterized by mucosal inflammation of the nose and paranasal sinuses. CRS can be divided into two main categories, CRS with nasal polyps (NPs; CRSwNP) and CRS without NPs (CRSsNP). Although the pathophysiology of CRS remains unclear, DNA methylation has been implicated in the etiology of CRSwNP. The aim of the present study was to elucidate whether DNA methylation of specific genes is involved in the development of NPs. In total, 18 individuals were included in the present study, and were divided into three groups: CRSwNP (n=7), CRSsNP (n=7) and healthy controls (n=4). NP tissues were obtained from the seven patients with CRSwNP and biopsies of the inferior turbinate mucosa from all three groups were used as controls. Methylated genes detected by methyl­CpG­binding domain sequencing were validated by methylation­specific polymerase chain reaction (PCR), bisulfite sequencing, and reverse transcription­quantitative PCR (RT­qPCR). Methyl­CpG­binding domain sequencing identified 43,674 CpG islands in 518 genes. The promotor regions of 10 and 30 genes were hypermethylated and hypomethylated, respectively, in NP samples compared with controls. The top four genes with altered hypomethylation in NP tissues were, Keratin 19 (KRT19), nuclear receptor subfamily 2 group F member 2 (NR2F2), A Disintegrin­like And Metallopeptidase (Reprolysin Type) with Thrombospondin type 1 motif 1 (ADAMTS1) and zinc finger protein 222 (ZNF222). RT­qPCR demonstrated that the expression levels of KRT19, NR2F2 and ADAMTS1 were significantly increased in NP tissues; however, there was no difference in the levels of ZNF222 between NP and control tissues. Further studies are required to confirm the relevance of these epigenetic modifications in the mechanisms underlying NP formation.

Factors that contribute to disagreement in satisfaction between surgeons and patients after corrective septorhinoplasty.

BACKGROUND: Corrective septorhinoplasty is one of the most common facial plastic surgeries. However, surgeons and patients sometimes disagree about postoperative-outcome satisfaction after corrective septorhinoplasty. OBJECTIVE: We investigated the factors that influenced the disagreement in satisfaction between surgeons and patients after corrective septorhinoplasty. METHODS: Surgeon satisfaction was assessed by other plastic surgeons by comparing patient photographs taken at the preoperative and 12-month postoperative periods. Patient satisfaction was assessed by the Rhinoplasty Outcome Evaluation Questionnaire (ROEQ) before surgery and 12 months after surgery. The dissatisfied group was defined as showing a negative change or no change in the ROEQ quartile between baseline and 12 months after surgery. RESULTS: A total of 70 patients were included. No significant differences were observed between the satisfied and dissatisfied groups in sex, marital status, depression history, and major anesthetic problems. However, the dissatisfied group was significantly younger, more likely to be employed, and better educated than the satisfied group. In addition, a multivariate logistic regression analysis indicated that being highly educated was a predictor of disagreement in satisfaction between surgeons and patients. CONCLUSION: Our findings indicated that highly educated patients who underwent corrective septorhinoplasty required more detailed preoperative guidance, including more complete information on the limitations of the surgery.

Potential therapeutic application of small molecule with sulfonamide for chondrogenic differentiation and articular cartilage repair.

The restoration of damaged articular cartilage is a long-pursued goal in regenerative medicine. Chondrocyte-specific differentiation of mesenchymal stem cells (MSCs) may be an effective means of repairing damaged cartilage. We identified small molecule 6 with sulfonamide as an agent that promotes specific chondrogenic differentiation of human adipose-derived MSCs (hASCs). Unlike other chondrogenic differentiation media composed of various defined components, simply adding compound 6 into culture medium was sufficient to induce chondrogenesis in this study. In an animal osteoarthritis model, both the small molecule 6 and the 6-treated hASCs exhibited enhanced recovery of injured articular cartilage. This work provides new insight into MSC differentiation induced by small molecules and potential new therapeutic approaches for articular cartilage injury.

Small molecule-mediated up-regulation of microRNA targeting a key cell death modulator BNIP3 improves cardiac function following ischemic injury.

Genetic ablation of BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3), an essential regulator of cardiac cell death, is an effective way to prevent cardiac cell death triggered by pathologic conditions. However, currently there exists no known means, such as inhibitors, to down-regulate BNIP3 in mature heart. Here, we report that a small molecule inducer of microRNA-182 (miR-182) suppressed ischemia/reperfusion (I/R)-induced cardiac cell death by down-regulating BNIP3. We first selected miR-182 as a potent BNIP3-targeting miRNA based on miRNA-target prediction databases and empirical data. The subsequent screening of small molecules for inducing miR-182 expression identified Kenpaullone as a hit compound. Both exogenous miR-182 and Kenpaullone significantly suppressed hypoxia-induced cardiomyocyte death in vitro. To investigate the effect of changing substituents of Kenpaullone on miR-182 expression, we synthesized 9 derivatives of Kenpaullone. Among these derivatives, compound 5 showed significantly improved ability to induce miR-182 expression. The results of the in vivo study showed that compound 5 significantly improved heart function following I/R-injury in rats. Our study provides strong evidence that the small molecule-mediated up-regulation of miRNAs is a viable strategy to down-regulate target proteins with no known chemical inhibitor and that compound 5 may have potential to prevent I/R-inflicted cardiac cell death.

The microRNA-dependent cell fate of multipotent stromal cells differentiating to endothelial cells.

In the endothelial recovery process, bone marrow-derived MSCs are a potential source of cells for both research and therapy, and their capacities to self-renew and to differentiate into all the cell types in the human body make them a promising therapeutic agent for remodeling cellular differentiation and a valuable resource for the treatment of many diseases. Based on the results provided in a miRNA database, we selected miRNAs with unique targets in cell fate-related signaling pathways. The tested miRNAs targeting GSK-3ß (miR-26a), platelet-derived growth factor receptor, and CD133 (miR-26a and miR-29b) induced MSC differentiation into functional ECs, whereas miRNAs targeting VEGF receptor (miR-15, miR-144, miR-145, and miR-329) inhibited MSC differentiation into ECs through VEGF stimulation. In addition, the expression levels of these miRNAs were correlated with in vivo physiological endothelial recovery processes. These findings indicate that the miRNA expression profile is distinct for cells in different stages of differentiation from MSCs to ECs and that specific miRNAs can function as regulators of endothelialization.

Impact of miRNAs on cardiovascular aging.

Aging is a multidimensional process that leads to an increased risk of developing severe diseases, such as cancer and cardiovascular, neurodegenerative, and immunological diseases. Recently, small non-coding RNAs known as microRNAs (miRNAs) have been shown to regulate gene expression, which contributes to many physiological and pathophysiological processes in humans. Increasing evidence suggests that changes in miRNA expression profiles contribute to cellular senescence, aging and aging-related diseases. However, only a few miRNAs whose functions have been elucidated have been associated with aging and/or aging-related diseases. This article reviews the currently available findings regarding the roles of aging-related miRNAs, with a focus on cardiac and cardiovascular aging.

Looking for Pyroptosis-Modulating miRNAs as a Therapeutic Target for Improving Myocardium Survival.

Pyroptosis is the most recently identified type of regulated cell death with inflammatory response and has characteristics distinct from those of apoptosis or necrosis. Recently, independent studies have reported that small noncoding RNAs termed microRNAs (miRNAs) are involved in the regulation of pyroptosis. Nevertheless, only a handful of empirical data regarding miRNA-dependent regulation of pyroptosis is currently available. This review is aimed to provide a current update on the role of miRNAs in pyroptosis and to offer suggestions for future studies probing miRNAs as a linker connecting pyroptosis to various cardiovascular diseases (CVDs) and their potential as a therapeutic target for preventing excessive cell death of myocardium during CVDs.

ROS-mediated bidirectional regulation of miRNA results in distinct pathologic heart conditions.

Under distinct pathological heart conditions, the expression of a single miRNA can display completely opposite patterns. However, the mechanism underlying the bidirectional regulation of a single miRNA and the clinical implications of this regulation remain largely unknown. To address this issue, we examined the regulation of miR-1, one of the most abundant miRNAs in the heart, during cardiac hypertrophy and ischemia/reperfusion (I/R). Our data indicated that different magnitudes and chronicities of ROS levels in cardiomyocytes resulted in differential expression of miR-1, subsequently altering the expression of myocardin. In animal models, the administration of a miR-1 mimic attenuated cardiac hypertrophy by suppressing the transverse aortic constriction-induced increase in myocardin expression, whereas the administration of anti-miR-1 ameliorated I/R-induced cardiac apoptosis and deterioration of heart function. Our findings indicated that a pathologic stimulus such as ROS can bidirectionally alter the expression of miRNA to contribute to the development of pathological conditions exhibiting distinct phenotypes and that the meticulous adjustment of the pathological miRNA levels is required to improve clinical outcomes.

let-7b suppresses apoptosis and autophagy of human mesenchymal stem cells transplanted into ischemia/reperfusion injured heart 7by targeting caspase-3.

INTRODUCTION: Mesenchymal stem cells (MSCs) have therapeutic potential for the repair of myocardial injury. The efficacy of MSC therapy for myocardial regeneration mainly depends on the survival of cells after transplantation into the infarcted heart. In the transplanted regions, reactive oxygen species (ROS) can cause cell death, and this process depends on caspase activation and autophagosome formation. METHODS: A Software TargetScan was utilized to search for microRNAs (miRNAs) that target caspase-3 mRNA. Six candidate miRNAs including let-7b were selected and transfected into human MSCs in vitro. Expression of MEK-EKR signal pathways and autophagy-related genes were detected. Using ischemia/reperfusion model (I/R), the effect of MSCs enriched with let-7b was determined after transplantation into infarcted heart area. Miller catheter was used to evaluate cardiac function. RESULTS: Here, we report that let-7b targets caspase-3 to regulate apoptosis and autophagy in MSCs exposed to ROS. Let-7b-transfected MSCs (let-7b-MSCs) showed high expression of survival-related proteins, including p-MEK, p-ERK and Bcl-2, leading to a decrease in Annexin V/PI- and TUNEL-positive cells under ROS-rich conditions. Moreover, autophagy-related genes, including Atg5, Atg7, Atg12 and beclin-1, were significantly downregulated in let-7b-MSCs. Using a rat model of acute myocardial infarction, we found that intramyocardial injection of let-7b-MSCs markedly enhanced left ventricular (LV) function and microvessel density, in accordance with a reduced infarct size and the expression of caspase-3. CONCLUSIONS: Taken together, these data indicate that let-7b may protect MSCs implanted into infarcted myocardium from apoptosis and autophagy by directly targeting caspase-3 signaling.

Induction of hematopoietic and endothelial cell program orchestrated by ETS transcription factor ER71/ETV2.

The ETS factor ETV2 (aka ER71) is essential for the generation of the blood and vascular system, as ETV2 deficiency leads to a complete block in blood and endothelial cell formation and embryonic lethality in the mouse. However, the ETV2-mediated gene regulatory network and signaling governing hematopoietic and endothelial cell development are poorly understood. Here, we map ETV2 global binding sites and carry out in vitro differentiation of embryonic stem cells, and germ line and conditional knockout mouse studies to uncover mechanisms involved in the hemangiogenic fate commitment from mesoderm. We show that ETV2 binds to enhancers that specify hematopoietic and endothelial cell lineages. We find that the hemangiogenic progenitor population in the developing embryo can be identified as FLK1(high)PDGFRα(-). Notably, these hemangiogenic progenitors are exclusively sensitive to ETV2-dependent FLK1 signaling. Importantly, ETV2 turns on other Ets genes, thereby establishing an ETS hierarchy. Consequently, the hematopoietic and endothelial cell program initiated by ETV2 is maintained partly by other ETS factors through an ETS switching mechanism. These findings highlight the critical role that transient ETV2 expression plays in the regulation of hematopoietic and endothelial cell lineage specification and stability.

Cell adhesion and long-term survival of transplanted mesenchymal stem cells: a prerequisite for cell therapy.

The literature provides abundant evidence that mesenchymal stem cells (MSCs) are an attractive resource for therapeutics and have beneficial effects in regenerating injured tissues due to their self-renewal ability and broad differentiation potential. Although the therapeutic potential of MSCs has been proven in both preclinical and clinical studies, several questions have not yet been addressed. A major limitation to the use of MSCs in clinical applications is their poor viability at the site of injury due to the harsh microenvironment and to anoikis driven by the loss of cell adhesion. To improve the survival of the transplanted MSCs, strategies to regulate apoptotic signaling and enhance cell adhesion have been developed, such as pretreatment with cytokines, growth factors, and antiapoptotic molecules, genetic modifications, and hypoxic preconditioning. More appropriate animal models and a greater understanding of the therapeutic mechanisms of MSCs will be required for their successful clinical application. Nevertheless, the development of stem cell therapies using MSCs has the potential to treat degenerative diseases. This review discusses various approaches to improving MSC survival by inhibiting anoikis.

MicroRNA-29b inhibits migration and proliferation of vascular smooth muscle cells in neointimal formation.

The proliferation and migration of smooth muscle cells (SMCs) are considered to be key steps in the progression of atherosclerosis and restenosis. Certain stimuli, such as, interleukin-3 (IL-3) are known to stimulate proliferation and migration in vascular diseases. Meanwhile, microRNAs (miRs) have been revealed as critical modulators of various diseases in which miR-29b is known to regulate cell growth by targeting Mcl-1 and MMP2. However, roles of miR-29b in vascular smooth muscle cells remain almost unknown. We hypothesized that miR-29b may control the proliferation and migration processes induced by IL-3 stimulation by inhibiting its own specific targets in SMCs. MiR-29b significantly suppressed the proliferation and migration of SMCs through the inhibition of the signaling pathway related to Mcl-1 and MMP2. We also found that miR-29b expression levels significantly declined in balloon-injured rat carotid arteries and that the overexpression of miR-29b by local oligonucleotide delivery can inhibit neointimal formation. Consistent with the critical role of miR-29b in vitro, we observed down-regulated expression levels of Mcl-1 and MMP2 from the neointimal region. These results indicate that miR-29b suppressed the proliferation and migration of SMCs, possibly through the inhibition of Mcl-1 and MMP2, and suggest that miR-29b may serve as a useful therapeutic tool to treat cardiovascular diseases such as, atherosclerosis and restenosis.

Modulation of Fas-Fas Ligand Interaction Rehabilitates Hypoxia-Induced Apoptosis of Mesenchymal Stem Cells in Ischemic Myocardium Niche.

Mesenchymal stem cells (MSCs) have the potential to repair and regenerate ischemic heart tissue; however, the poor viability of transplanted MSCs in the ischemic region is a major obstacle to their therapeutic use. This cell death is caused by Fas and Fas ligand (FasL) interactions under harsh conditions. To investigate improving the survival and therapeutic effects of MSCs, we focused our research on Fas-FasL-mediated cell death. In this study, we found that the poor viability of transplanted MSCs was caused by Fas-FasL interactions between host ischemic myocardial cells and implanted MSCs. In addition, we found that increased Fas expression and the corresponding decrease of cell survival were in close relation to hypoxic MSCs treated with FasL and H2O2. When MSCs were treated with a recombinant Fas/Fc chimera (Fas/Fc) inhibiting Fas-FasL interactions, the expressions of proapoptotic proteins including caspase-8, caspase-3, Bax, and cytochrome-c were attenuated, and the survival of MSCs was recovered. In ischemia-reperfusion injury models, the interaction between FasL in ischemic heart and Fas in implanted MSCs caused a loss of transplanted MSCs, whereas the inhibition of this interaction by Fas/Fc treatment improved cell survival and restored heart function. Thus, our study suggests that Fas-FasL interactions are responsible for activating cell death signaling in implanted stem cells and could be a potential target for improving therapeutic efficacy of stem cells in treating ischemic heart diseases.

Combination of a peroxisome proliferator-activated receptor-gamma agonist and an angiotensin II receptor blocker attenuates myocardial fibrosis and dysfunction in type 2 diabetic rats.

AIMS/INTRODUCTION: We aimed to examine the effect of an angiotensin II receptor blocker (ARB), a peroxisome proliferator-activated receptor (PPAR)-gamma agonist, and their combination on myocardial fibrosis and function in type 2 diabetic rats. MATERIALS AND METHODS: Five male Long-Evans Tokushima Otsuka (LETO) rats and 20 male Otsuka Long-Evans Tokushima Fatty (OLETF) rats were used. OLETF rats were assigned to four groups (n = 5 per group) at 28 weeks-of-age: untreated, losartan-treated, rosiglitazone-treated and combination-treated. The ARB, losartan, was administered at a dose of 5 mg/kg/day, and the PPAR-gamma agonist, rosiglitazone, was administered at a dose of 3 mg/kg/day by oral gavage for 12 weeks. Urine and blood samples were collected, and two-dimensional echocardiograms and strain rate imaging were obtained at 28 and 40 weeks. Cytokines were evaluated by reverse transcriptase polymerase chain reaction, and histological analysis was carried out at 40 weeks. RESULTS: At 40 weeks, the global radial strains of the losartan-treated (55.7 ± 4.5%, P = 0.021) and combination-treated groups (59.3 ± 6.7%, P = 0.001) were significantly higher compared with the untreated OLETFs (44.3 ± 10.5%). No difference was observed when compared with LETO rats. Although the rosiglitazone-treated group showed a better metabolic profile than the untreated OLETF group, there was no difference in the global radial strain (49.8 ± 6.0 vs 44.3 ± 10.5, P = 0.402). The expression of pro-inflammatory cytokines, and collagen type I and III were consistently attenuated in the losartan-treated and combination-treated OLETF groups, but not in the rosiglitazone-treated group. CONCLUSIONS: A combination of rosiglitazone and losartan attenuates myocardial fibrosis and dysfunction in type 2 diabetic rats.