Sodium butyrate attenuates peritoneal fibroproliferative process in mice

NEW FINDINGS

What is the central question of this study? Peritoneal injury can result in a persistent fibroproliferative process in the abdominal cavity, causing pain and loss of function of internal organs. This study aimed to demonstrate the use of sodium butyrate (NaBu) as a potential agent to attenuate peritoneal fibrosis induced by a synthetic matrix. What is the main finding and its importance? Our findings provide the first evidence that NaBu attenuates the inflammatory, angiogenesis and fibrogenesis axes involved in the formation of peritoneal fibrovascular tissue, indicating the potential of this compound to ameliorate peritoneal fibrosis.

ABSTRACT

The aim of this study was to identify the bio-efficacy of sodium butyrate (NaBu) on preventing the development of peritoneal fibrovascular tissue induced by implantation of a synthetic matrix in the abdominal cavity. Polyether-polyurethane sponge discs were implanted in the peritoneal cavity of mice, which were treated daily with oral administration of NaBu (100 mg/kg). Control animals received water (100 μl). After 7 days, the implants were removed for assessment of inflammatory, angiogenic and fibrogenic markers. Compared with control values, NaBu treatment decreased mast cell recruitment/activation, inflammatory enzyme activities, levels of pro-inflammatory cytokines, and the proteins p65 and p50 of the nuclear factor-κB pathway. Angiogenesis, as determined by haemoglobin content, vascular endothelial growth factor levels and the number of blood vessels in the implant, was reduced by the treatment. In NaBu-treated animals, the predominant collagen present in the abdominal fibrovascular tissue was thin collagen, whereas in control implants it was thick collagen. Transforming growth factor-β1 levels were also lower in implants of treated animals. Sodium butyrate downregulated the inflammatory, angiogenesis and fibrogenesis axes of the fibroproliferative tissue induced by the intraperitoneal synthetic matrix. This compound has potential to control/regulate chronic inflammation and adverse healing processes in the abdominal cavity.

Sulfonamide-Functionalized Polymeric Nanoparticles For Enhanced In Vivo Colorectal Cancer Therapy

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer in the world. 5-Fluorouracil (5-FU) is a conventional and most effective drug used in the clinic for the treatment of CRC. However, the clinical use of 5-FU is limited due to the acquired resistance and systemic toxicity, such as hepatotoxicity and gastrointesti-nal toxicity.

OBJECTIVE

Recent advances in nanomedicine are being exploited to develop nanoparticle platforms to overcome resistance and therapeutic delivery of active molecules. Here, we develop 5-FU loaded sulfadiazine-poly(lactide-co-glycolide) nanoparticles (SUL-PLGA NPs) to be applied in the colorectal cancer model.

METHODS

We assessed the in vivo efficacy of the SUL-PLGA NPs to enhance the antitumor effect of 5-FU.

RESULTS

In vivo treatment with 5-FU-SUL-PLGA NPs significantly reduced tumor growth in a colon cancer xen-ograft model compared to free 5-FU and 5-FU loaded non-targeted NPs. Treatment with 5-FU-SUL-PLGA NPs also increased blood vessel diameters within tumors, which could act in conjunction to enhance antitumor effi-cacy. In addition, 5-FU-SUL-PLGA NPs significantly reduced liver mass and lung mass, which are the most common metastasis sites of CRC, and decreased liver hepatotoxicity compared to free 5-FU drug and 5-FU loaded non-targeted NPs.

CONCLUSION

Our findings suggest that the use of 5-FU-SUL-PLGA NPs is a promising strategy to enhance 5-FU efficacy against CRC.

Correlation between circadian rhythm related genes, type 2 diabetes, and cancer: Insights from metanalysis of transcriptomics data

Clock genes work as an auto-regulated transcription-translational loop of circadian genes that drives the circadian rhythms in each cell and they are essential to physiological requests. Since metabolism is a dynamic process, it involves several physiological variables that circadian cycling. The clock genes alterations can affect multiple systems concomitantly, because they constitute the promoter factors for relevant metabolic pathways. Considering the intertwined structure of signaling, regulatory, and metabolic processes within a cell, we employed a genome-scale biomolecular network. Accordingly, a meta-analysis of diabetic-associated transcriptomic datasets was performed, and the core information on differentially expressed genes (DEGs) was obtained by statistical analyses. In the current study, meta-analysis was performed on type 2 diabetes, circadian rhythm-related genes, and breast, bladder, liver, pancreas, colon and rectum cancer-associated transcriptome data using the integration of gene expression profiles with genome-scale biomolecular networks in diabetes samples. First, we detected downregulated and upregulated DEGs in mouse cortex and hypothalamus samples of mice with sleep deprivation. In summary, upregulated genes active genes associated with oxidative phosphorylation, cancer and diabetes, mainly in hypothalamus specimens. In cortex, we observed mainly downregulation of immune system. DEGs were combined with 214 circadian rhythm related genes to type 2 DM and cancer samples. We observed that several common genes deregulated in both diseases. Klf10, Ntkr3, Igf1, Usp2, Ezh2 were both downregulated in type 2 DM and cancer samples, while Arntl2 and Agrp were upregulated. It seems that the changes in mRNA are contributing to the phenotypic changes in type 2 DM, resulting in phenotypic changes associated with the malignant transformation. Taking those genes to perform a survival analysis, we found only Igf1, Usp2 and Arntl2 genes associated with patient outcomes. While Igf1 and Usp2 downregulation had a negative impact, Arntl2 upregulation was associated with poor survival both in BLCA and BRCA cancer samples. Our data stimulate efforts in news studies to achieve the experimental and clinical validation about these biomolecules.

Factors Associated with Mortality among Hospitalized Patients with COVID-19: A Retrospective Cohort Study

Information on the risk factors for COVID-19 mortality in low- and middle-income countries is still scarce. In this retrospective cohort study, we analyzed the factors associated with COVID-19 mortality in hospitalized patients in a poor area of Brazil. Logistic regression was used to identify factors independently associated with mortality, including gender, age, and the presence of underlying medical conditions. A total of 1,207 patients were included in the analysis, and a 1.5-fold increase in COVID-19 mortality was found among patients aged > 65 years with hypertension and diabetes (odds ratio [OR]: 1.50, 95% CI: 1.02–2.19). Moreover, infectious disease (OR: 4.31, 95% CI: 1.39–13.39), kidney disease (OR: 2.59, 95% CI: 1.27–5.27), and heart disease (OR: 2.00, 95% CI: 1.31–3.04) were also predictive for COVID-19 in-hospital death. This large cohort provides important data on potential factors associated with COVID-19 mortality in Brazil.

Implant-induced inflammatory angiogenesis is up-regulated in obese mice

The damaging effects of obesity extend to multiple pre-existing tissue/organs. However, the influence of this condition on key components (inflammation and angiogenesis) of fibrovascular connective proliferating tissue, essential in repair processes, has been neglected. Our objective in this study was to investigate whether obesity would influence inflammatory-angiogenesis induced by synthetic matrix of polyether-polyurethane implanted subcutaneously in high-fat-fed obese C57/BL6 mice. Fourteen days after implantation, the inflammatory and angiogenic components of the newly formed tissue intra-implant were evaluated. The pro-inflammatory enzyme activities, myeloperoxidase (MPO) and N-acetyl-β-D-glucosaminidase (NAG), the levels of TNF-α, CXCL1/KC and CCL2 and NF-κB transcription factor were examined. Angiogenesis was determined by morphometric analysis of implant blood vessels, intra-implant levels of hemoglobin content, VEGF levels, and western blot for VEGFR2. All inflammatory and angiogenic markers were increased in the implants of obese mice compared with their non-obese counterparts. Similarly, activation of the NF-κB pathway and phosphorylation of VEGFR2 were higher in implants of obese mice (1.60 ± 0.28 Np65/Cp65; 0.96 ± 0.08 p-VEGFR2/VEGFR2-T) compared with implants of non-obese animals (1.40 ± 0.14; 0.49 ± 0.08). These observations suggest that obesity exerts critical role in sponge-induced inflammatory-angiogenesis, possibly by activating fibrovascular components in the inflamed microenvironment. Thus, this pathological condition causes damage not only to pre-existing tissues/organs but also to newly formed proliferating fibrovascular tissue. This is relevant to the development of therapeutic approaches to improve healing processes in patients with obesity.

Schwann cell reprogramming and lung cancer progression: a meta-analysis of transcriptome data

Schwann cells were identified in the tumor surrounding area prior to initiate the invasion process underlying connective tissue. These cells promote cancer invasion through direct contact, while paracrine signaling and matrix remodeling are not sufficient to proceed. Considering the intertwined structure of signaling, regulatory, and metabolic processes within a cell, we employed a genome-scale biomolecular network. Accordingly, a meta-analysis of Schwann cells associated transcriptomic datasets was performed, and the core information on differentially expressed genes (DEGs) was obtained by statistical analyses. Gene set over-representation analyses was performed on core DEGs to identify significantly functional and pathway enrichment analysis between Schwann cells and, lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC). DEGs were further integrated with genome-scale human biomolecular networks. miRNAs were proposed by the reconstruction of a transcriptional and post-transcriptional regulatory network. Moreover, microarray-based transcriptome profiling was performed, and the prognostic power of selected dedifferentiated Schwann cell biomolecules was predicted. We observed that pathways associated with Schwann cells dedifferentiation was overexpressed in lung cancer samples. However, genes associated with Schwann cells migration inhibition system were downregulated. Besides, miRNA targeting those pathways were also deregulated. In this study, we report valuable data for further experimental and clinical analysis, because the proposed biomolecules have significant potential as systems biomarkers for screening or for therapeutic purposes in perineural invasion of lung cancer.

Correlation between renin-angiotensin system (RAS) related genes, type 2 diabetes, and cancer: Insights from metanalysis of transcriptomics data

Although studies have provided significant evidence about the role of RAS in mediating cancer risk in type 2 diabetes mellitus (DM), conclusions about the central molecular mechanisms underlying this disease remain to be reached, because this type of information requires an integrative multi-omics approach. In the current study, meta-analysis was performed on type 2 diabetes and breast, bladder, liver, pancreas, colon and rectum cancer-associated transcriptome data, and reporter biomolecules were identified at RNA, protein, and metabolite levels using the integration of gene expression profiles with genome-scale biomolecular networks in diabetes samples. This approach revealed that RAS biomarkers could be associated with cancer initiation and progression, which include metabolites (particularly, aminoacyl-tRNA biosynthesis and ABC transporters) as novel biomarker candidates and potential therapeutic targets. We detected downregulation and upregulation of differentially expressed genes (DEGs) in blood, pancreatic islets, liver and skeletal muscle from normal and diabetic patients. DEGs were combined with 211 renin-angiotensin-system related genes. Upregulated genes were enriched using Pathway analysis of cancer in pancreatic islets, blood and skeletal muscle samples. It seems that the changes in mRNA are contributing to the phenotypic changes in carcinogenesis, or that they are as a result of the phenotypic changes associated with the malignant transformation. Our analyses showed that Ctsg and Ednrb are downregulated in cancer samples. However, by immunohistochemistry experiments we observed that EDNRB protein showed increased expression in tumor samples. It is true that alterations in mRNA expression do not always reflect alterations in protein expression, since post-translational changes can occur in proteins. In this study, we report valuable data for further experimental and clinical analysis, because the proposed biomolecules have significant potential as systems biomarkers for screening or for therapeutic purposes in type 2 diabetes and cancer-associated pathways.

Double immunofluorescence labeling for CD31 and CD105 as a marker for polyether polyurethane-induced angiogenesis in mice

A crucial component of the integration between foreign implants and the host is angiogenesis. However, to date, none of the available techniques and/or endothelial markers employed to assess angiogenesis in the implant/host interface seems to be able to highlight vascular structures convincingly. In the present study we investigated and compared the expression of two endothelial cell markers: platelet endothelial cell adhesion molecule (PECAM-1) (CD31) and endoglin (CD105) using immunohistochemistry (IHC) and immunofluorescence (IF) to identify and quantify newly formed blood vessels in subcutaneous implants of polyether-polyurethane sponge of formalin-fixed paraffin-embedded tissue. At day 14 post implantation the discs of the synthetic matrix were removed and processed for histological and morphometric analysis. In IHC staining for CD31 antibody the number of vessels was 2.27±0.69 and 5.25±0.46 for CD105. In IF for CD31 the number of vessels was 15.36±1.295 and 10.54±0.8213 for CD105. The level of cross-reaction was lesser in IF images compared with IHC images. Co-localization of CD31/CD105 using confocal images showed positive correlation (Pearson's co-relation and Manders' equation). The double labeling for blood vessels using the IF technique for CD31/CD105 may be an important tool for evaluation of angiogenesis in biomaterial/host integration.

Upregulation of Foreign Body Response in Obese Mice

OBJECTIVE

Obesity is a highly prevalent multifactorial metabolic condition in which the need for functional bioengineered substitutes (e.g., scaffolds for tissue engineering) is likely to occur. However, the adverse foreign body response (FBR) that invariably takes place adjacent to implant devices impairing their function is poorly characterized in this condition. This study investigated the influence of obesity on the host response to a synthetic matrix implanted subcutaneously in high-fat-fed obese mice.

METHODS

Histological analysis of 14-day-old implants was performed to identify collagen deposition, capsule thickness, fibroblast-like cells, foreign body giant cells, and mast cells. In addition, transforming growth factor β1 (TGF-β1) levels in the implants and serum were determined.

RESULTS

All fibrogenic markers (and TGF-β1 levels) increased in the implants of obese mice compared with their nonobese counterparts. Particularly relevant was the fibrous capsule thickness in implants of obese mice (234.2 ± 22.1 µm vs. 109.2 ± 13.4 µm in implants of nonobese animals).

CONCLUSIONS

The study results showing that obesity upregulates the main features of the FBR induced by subcutaneous implants in mice may be relevant in understanding biomaterial integration and performance in this condition. This is crucial to the development of strategies to maintain the integrity and function of implantable devices.

Kinetics of pancreatic tissue proliferation in a polymeric platform in mice

BACKGROUND/OBJECTIVES

Pancreas regenerative capacity after injury is not always sufficient to comply with the body's requirement of digestive enzymes and hormones. We present an alternative system to induce pancreas parenchyma proliferation (exocrine and endocrine components), rather than regeneration or remodeling in normoglycemic mice.

METHODS

Porous discs of polyether-polyurethane were surgically placed adjacent to the native pancreas and removed at days 15, 30 and 45 after implantation. No exogenous growth factors or extracellular matrix components were added to the platform. The synthetic matrix provided a platform that was filled with parenchymal and non-parenchymal pancreas tissue as detected by histological analysis. Immunohistochemistry analysis were performed to identify insulin positive cells in the newly formed tissue. In addition, angiogenic, inflammatory and metabolic parameters were carried out in those mice.

RESULTS

At day 15, the pores of the platform were filled with inflammatory cells, spindled-shaped like fibroblasts, extracellular matrix components, blood vessels and clusters of pancreatic parenchyma (acini, ducts and islet-like structures). At days 30 and 45 the pancreas features remained well organized; its organization resembled that of a native pancreas. Interestingly, besides islet-like structures that showed positive cells to insulin, some ductal cells were also positive for insulin immunostaining. No significant differences in serum glucose and c-peptide concentrations during the experimental period were detected.

CONCLUSIONS

The plain synthetic porous platform (without addition of exogenous molecules) placed adjacent to the native organ exhibits potential to restore and/or expand exocrine (acini, ducts) and endocrine (β-cell mass) components in pancreatic injuries and in high metabolic demand.

Induction of liver proliferation using a polymeric platform in mice

AIMS

Currently, animal models of liver regeneration are based on extensive lesions of the native organ and on cellular approaches using biomaterials to host growth factors and extracellular components to create artificial liver systems. We report a polymeric biological platform, minimally invasive, that induced sequential proliferation of liver parenchyma inside the scaffold in mice.

MAIN METHODS

Porous discs of polyether-polyurethane were surgically placed under the left liver lobe and removed at days 4, 8, 12 and 25 after implantation. No exogenous growth factors or extracellular matrix components were added to the scaffold. Histological analysis of the implants was performed to identify hepatocytes, liver vascular structures and bile ducts in the newly formed tissue. In addition, systemic markers for hepatic function were determined.

KEY FINDINGS

This biohybrid device provided a scaffold that was gradually filled with parenchymal and non-parenchymal liver tissue as detected by histological analysis. At day 4, the pores of the scaffold were filled with inflammatory cells and spindled-shaped like fibroblasts, and extracellular matrix components. At day 8, hepatocytes clusters, central lobular hepatic veins, portal space containing arteries, veins and biliary ducts were detected. By days 12 and 25 a liver-like structure filled 2/3 of the scaffold. Its organization resembled that of a mature liver. Serum concentration of ALT increased three-fold initially after implantation, returning gradually to control levels.

SIGNIFICANCE

The plain synthetic scaffold (without addition of exogenous molecules) placed under the intact left liver lobe exhibits the potential to investigate physiological mechanisms that regulate liver parenchyma proliferation.

Synthetic matrix of polyether-polyurethane as a biological platform for pancreatic regeneration

AIMS

Several alternative cellular approaches using biomaterials to host insulin-producing cells derived from stem cells have been developed to overcome the limitations of type 1 diabetes treatment (exogenous insulin injection). However, none seem to fulfill all requirements needed to induce pancreatic cells successful colonization of the scaffolds. Here, we report a polymeric platform adherent to the native mice pancreas filled with human adipose stem cells (hASCs) that was able to induce growth of pancreatic parenchyma.

MAIN METHODS

Synthetic polyether-polyurethane discs were placed adjacent to pancreas of normoglycemic and streptozotocin-induced diabetic mice. At day 4 post implantation, 1×10⁶ hASCs were injected intra-implant in groups of normoglycemic and diabetic mice. Immunohistochemistry analysis of the implants was performed to identify insulin positive cells in the newly formed tissue. In addition, metabolic, inflammatory and angiogenic parameters were carried out in those mice.

KEY FINDINGS

This study provides evidence of the ability of a biohybrid device to induce the growth of differentiated pancreas parenchyma in both normoglycemic and streptozotocin-induced diabetic mice as detected by histological analysis. Glucose metabolism and body weight of hyperglycemic mice bearing hASCs implants improved.

SIGNIFICANCE

The synthetic porous scaffold bearing hASC cells placed adjacent to the native animal pancreas exhibits the potential to be exploited in future cell-based type 1 diabetes therapies.