Clinical and pulmonary function analysis in long-COVID revealed that long-term pulmonary dysfunction is associated with vascular inflammation pathways and metabolic syndrome.

Introduction: Long-term pulmonary dysfunction (L-TPD) is one of the most critical manifestations of long-COVID. This lung affection has been associated with disease severity during the acute phase and the presence of previous comorbidities, however, the clinical manifestations, the concomitant consequences and the molecular pathways supporting this clinical condition remain unknown. The aim of this study was to identify and characterize L-TPD in patients with long-COVID and elucidate the main pathways and long-term consequences attributed to this condition by analyzing clinical parameters and functional tests supported by machine learning and serum proteome profiling. Methods: Patients with L-TPD were classified according to the results of their computer-tomography (CT) scan and diffusing capacity of the lungs for carbon monoxide adjusted for hemoglobin (DLCOc) tests at 4 and 12-months post-infection. Results: Regarding the acute phase, our data showed that L-TPD was favored in elderly patients with hypertension or insulin resistance, supported by pathways associated with vascular inflammation and chemotaxis of phagocytes, according to computer proteomics. Then, at 4-months post-infection, clinical and functional tests revealed that L-TPD patients exhibited a restrictive lung condition, impaired aerobic capacity and reduced muscular strength. At this time point, high circulating levels of platelets and CXCL9, and an inhibited FCgamma-receptor-mediated-phagocytosis due to reduced FcγRIII (CD16) expression in CD14+ monocytes was observed in patients with L-TPD. Finally, 1-year post infection, patients with L-TPD worsened metabolic syndrome and augmented body mass index in comparison with other patient groups. Discussion: Overall, our data demonstrated that CT scan and DLCOc identified patients with L-TPD after COVID-19. This condition was associated with vascular inflammation and impair phagocytosis of virus-antibody immune complexes by reduced FcγRIII expression. In addition, we conclude that COVID-19 survivors required a personalized follow-up and adequate intervention to reduce long-term sequelae and the appearance of further metabolic diseases.

Metabolomics profiling and chemoresistance mechanisms in ovarian cancer cell lines: Implications for targeting glutathione pathway.

Ovarian cancer presents a significant challenge due to its high rate of chemoresistance, which complicates the effectiveness of drug-response therapy. This study provides a comprehensive metabolomic analysis of ovarian cancer cell lines OVCAR-3 and SK-OV-3, characterizing their distinct metabolic landscapes. Metabolomics coupled with chemometric analysis enabled us to discriminate between the metabolic profiles of these two cell lines. The OVCAR-3 cells, which are sensitive to doxorubicin (DOX), exhibited a preference for biosynthetic pathways associated with cell proliferation. Conversely, DOX-resistant SK-OV-3 cells favored fatty acid oxidation for energy maintenance. Notably, a marked difference in glutathione (GSH) metabolism was observed between these cell lines. Our investigations further revealed that GSH depletion led to a profound change in drug sensitivity, inducing a shift from a cytostatic to a cytotoxic response. The results derived from this comprehensive metabolomic analysis offer potential targets for novel therapeutic strategies to overcome drug resistance. Our study suggests that targeting the GSH pathway could potentially enhance chemotherapy's efficacy in treating ovarian cancer.

Humoral immunity against SARS-CoV-2 evoked by heterologous vaccination groups using the CoronaVac (Sinovac) and BNT162b2 (Pfizer/BioNTech) vaccines in Chile.

Introduction: Severe acute respiratory syndrome virus 2 (SARS-CoV-2) has caused over million deaths worldwide, with more than 61,000 deaths in Chile. The Chilean government has implemented a vaccination program against SARS-CoV-2, with over 17.7 million people receiving a complete vaccination scheme. The final target is 18 million individuals. The most common vaccines used in Chile are CoronaVac (Sinovac) and BNT162b2 (Pfizer-Biotech). Given the global need for vaccine boosters to combat the impact of emerging virus variants, studying the immune response to SARS-CoV-2 is crucial. In this study, we characterize the humoral immune response in inoculated volunteers from Chile who received vaccination schemes consisting of two doses of CoronaVac [CoronaVac (2x)], two doses of CoronaVac plus one dose of BNT162b2 [CoronaVac (2x) + BNT162b2 (1x)], and three doses of BNT162b2 [BNT162b2 (3x)]. Methods: We recruited 469 participants from Clínica Dávila in Santiago and the Health Center Víctor Manuel Fernández in the city of Concepción, Chile. Additionally, we included participants who had recovered from COVID-19 but were not vaccinated (RCN). We analyzed antibodies, including anti-N, anti-S1-RBD, and neutralizing antibodies against SARS-CoV-2. Results: We found that antibodies against the SARS-CoV-2 nucleoprotein were significantly higher in the CoronaVac (2x) and RCN groups compared to the CoronaVac (2x) + BNT162b2 (1x) or BNT162b2 (3x) groups. However, the CoronaVac (2x) + BNT162b2 (1x) and BNT162b2 (3x) groups exhibited a higher concentration of S1-RBD antibodies than the CoronaVac (2x) group and RCN group. There were no significant differences in S1-RBD antibody titers between the CoronaVac (2x) + BNT162b2 (1x) and BNT162b2 (3x) groups. Finally, the group immunized with BNT162b2 (3x) had higher levels of neutralizing antibodies compared to the RCN group, as well as the CoronaVac (2x) and CoronaVac (2x) + BNT162b2 (1x) groups. Discussion: These findings suggest that vaccination induces the secretion of antibodies against SARS-CoV-2, and a booster dose of BNT162b2 is necessary to generate a protective immune response. In the current state of the pandemic, these data support the Ministry of Health of the Government of Chile's decision to promote heterologous vaccination as they indicate that a significant portion of the Chilean population has neutralizing antibodies against SARS-CoV-2.

Phenolic compounds as Nrf2 inhibitors: potential applications in cancer therapy.

Cancer is a leading cause of death worldwide and involves an oxidative stress mechanism. The transcription factor Nrf2 has a crucial role in cytoprotective response against oxidative stress, including cancer growth and progression and therapy resistance. For this reason, inhibitors of Nrf2 are new targets to be studied. Traditional plant-based remedies rich in phytochemicals have been used against human cancers and phenolic compounds are known for their chemopreventive properties. This comprehensive review offers an updated review of the role of phenolic compounds as anticancer agents due to their action on Nrf2 inhibition. In addition, the role of naturally-occurring bioactive anticancer agents are covered in the clinical applications of polyphenols as Nrf2 inhibitors. Video Abstract.

Adenosine promoted angiogenesis mediated by the release of small extracellular vesicles from human endothelial progenitor cells.

Endothelial progenitor cells (EPCs) are stem cells mainly derived from bone marrow; from where they migrate to repair and regenerate damaged tissues. eEPCs have been classified into two sub-populations, early (eEPC) and late EPCs (lEPC), depending on maturation stages in vitro. In addition, eEPC release endocrine mediators, including small extracellular vesicles (sEVs), which in turn may enhance the eEPC-mediated wound healing properties. Nevertheless, adenosine contributes to angiogenesis by recruiting eEPC at the injury site. However, whether ARs may enhance the secretome of eEPC, including sEVs, is unknown. Therefore, we aimed to investigate whether AR activation increase the release of sEVs in eEPC, which in turn has paracrine effects on recipient endothelial cells. Results shown that 5'-N-ethylcarboxamidoadenosine (NECA), a non-selective agonist, increase both the protein levels of the vascular endothelial growth factor (VEGF), and the number of sEVs released to the conditioned medium (CM) in primary culture of eEPC. Importantly, CM and EVs harvested from NECA-stimulated eEPC promote in vitro angiogenesis, without changes in cell proliferation, in recipient ECV-304 endothelial cells. This constitutes the first evidence showing that adenosine enhances sEVs release from eEPC, which has pro-angiogenic capacity on recipient endothelial cells.

Can Probiotics, Particularly Limosilactobacillus fermentum UCO-979C and Lacticaseibacillus rhamnosus UCO-25A, Be Preventive Alternatives against SARS-CoV-2?

COVID-19, an infection produced by the SARS-CoV-2 virus in humans, has rapidly spread to become a high-mortality pandemic. SARS-CoV-2 is a single-stranded RNA virus characterized by infecting epithelial cells of the intestine and lungs, binding to the ACE2 receptor present on epithelial cells. COVID-19 treatment is based on antivirals and antibiotics against symptomatology in addition to a successful preventive strategy based on vaccination. At this point, several variants of the virus have emerged, altering the effectiveness of treatments and thereby attracting attention to several alternative therapies, including immunobiotics, to cope with the problem. This review, based on articles, patents, and an in silico analysis, aims to address our present knowledge of the COVID-19 disease, its symptomatology, and the possible beneficial effects for patients if probiotics with the characteristics of immunobiotics are used to confront this disease. Moreover, two probiotic strains, L. fermentum UCO-979C and L. rhamnosus UCO-25A, with different effects demonstrated at our laboratory, are emphasized. The point of view of this review highlights the possible benefits of probiotics, particularly those associated with immunomodulation as well as the production of secondary metabolites, and their potential targets during SARS-CoV-2 infection.

Loxin Reduced the Inflammatory Response in the Liver and the Aortic Fatty Streak Formation in Mice Fed with a High-Fat Diet.

Oxidized low-density lipoprotein (ox-LDL) is the most harmful form of cholesterol associated with vascular atherosclerosis and hepatic injury, mainly due to inflammatory cell infiltration and subsequent severe tissue injury. Lox-1 is the central ox-LDL receptor expressed in endothelial and immune cells, its activation regulating inflammatory cytokines and chemotactic factor secretion. Recently, a Lox-1 truncated protein isoform lacking the ox-LDL binding domain named LOXIN has been described. We have previously shown that LOXIN overexpression blocked Lox-1-mediated ox-LDL internalization in human endothelial progenitor cells in vitro. However, the functional role of LOXIN in targeting inflammation or tissue injury in vivo remains unknown. In this study, we investigate whether LOXIN modulated the expression of Lox-1 and reduced the inflammatory response in a high-fat-diet mice model. Results indicate that human LOXIN blocks Lox-1 mediated uptake of ox-LDL in H4-II-E-C3 cells. Furthermore, in vivo experiments showed that overexpression of LOXIN reduced both fatty streak lesions in the aorta and inflammation and fibrosis in the liver. These findings were associated with the down-regulation of Lox-1 in endothelial cells. Then, LOXIN prevents hepatic and aortic tissue damage in vivo associated with reduced Lox-1 expression in endothelial cells. We encourage future research to understand better the underlying molecular mechanisms and potential therapeutic use of LOXIN.

Impact of Obstructive Sleep Apnea (OSA) in COVID-19 Survivors, Symptoms Changes Between 4-Months and 1 Year After the COVID-19 Infection.

Objective: To determine the association between Obstructive Sleep Apnea (OSA) with long-term symptoms and inflammatory cytokines, exploring the changes between 4-months and 1-year after COVID-19 infection. Methods: We conducted an observational, prospective cohort study, including patients ≥18 years old with confirmed diagnosis of COVID-19 between April to July 2020. All participants underwent two clinical follow-up visits, the first at 4-months (Visit 1) and the second at 1 year, after SARS-CoV-2 infection (Visit 2). Plasma glucose, total cholesterol, HDL, and triglycerides. Regarding pulmonary function, spirometry and lung diffusion capacity tests were assessed. For mental and neurocognitive evaluation, a short-form (SF-12), Beck depression and Hospital-Anxiety depression questionnaires were conducted at both time-points, whereas the Montreal Cognitive assessment was conducted during the second follow-up. Regarding to sleep evaluation, Epworth Sleepiness Scale, Insomnia Severity index and STOP-BANG questionnaire were conducted. Additionally, a home sleep apnea test and 7-day wrist actigraphy were performed in all participants. Inflammatory cytokines were measured using an inflammatory cytokine bead array kit. p-values < 0.05 were considered statistically significant and statistical analyses were performed using R software. Results: A total of 60 patients were included in the first follow-up, from which 57 completed the second follow-up. The mean age was 46.4 years-old (SD ± 13.1) and 53.3% were male. 30% of cases reported mild COVID-19 infection, 28.3% with moderate illness, and 41.6% with severe illness. Moreover, 56.6% of them were admitted to the ICU. Regarding to metabolic values, the OSA group showed higher values of insulin resistance (IR) (27%), systolic blood pressure (SBP) 135.2 (±19.1), dyslipidemia (67.5%), total cholesterol 202.1 (±60.5), triglycerides 176.1 (±119.0) and HOMA-IR 9.0 (±18.8) in comparison with the non-OSA group. 1 year after COVID-19 infection, DLCO test remains abnormal in OSA patients (25% OSA vs. 3.6% non-OSA, p = 0.02). Finally, those participants with OSA who develop ARDS reported an adjusted OR 20.4 (95%-CI, 1.04-504) risk of neurocognitive impairment. Discussion: Among patients with previous COVID-19, OSA impact the development of incident glycemic, neurocognitive impairment, and abnormal functional pulmonary changes that persist up to 1 year since acute phase.

Secretome from Human Mesenchymal Stem Cells-Derived Endothelial Cells Promotes Wound Healing in a Type-2 Diabetes Mouse Model.

Tissue regeneration is often impaired in patients with metabolic disorders such as diabetes mellitus and obesity, exhibiting reduced wound repair and limited regeneration capacity. We and others have demonstrated that wound healing under normal metabolic conditions is potentiated by the secretome of human endothelial cell-differentiated mesenchymal stem cells (hMSC-EC). However, it is unknown whether this effect is sustained under hyperglycemic conditions. In this study, the wound healing effect of secretomes from undifferentiated human mesenchymal stem cells (hMSC) and hMSC-EC in a type-2 diabetes mouse model was analyzed. hMSC were isolated from human Wharton's jelly and differentiated into hMSC-EC. hMSC and hMSC-EC secretomes were analyzed and their wound healing capacity in C57Bl/6J mice fed with control (CD) or high fat diet (HFD) was evaluated. Our results showed that hMSC-EC secretome enhanced endothelial cell proliferation and wound healing in vivo when compared with hMSC secretome. Five soluble proteins (angiopoietin-1, angiopoietin-2, Factor de crecimiento fibroblástico, Matrix metallopeptidase 9, and Vascular Endothelial Growth Factor) were enriched in hMSC-EC secretome in comparison to hMSC secretome. Thus, the five recombinant proteins were mixed, and their pro-healing property was evaluated in vitro and in vivo. Functional analysis demonstrated that a cocktail of these proteins enhanced the wound healing process similar to hMSC-EC secretome in HFD mice. Overall, our results show that hMSC-EC secretome or a combination of specific proteins enriched in the hMSC-EC secretome enhanced wound healing process under hyperglycemic conditions.

An environmental measurement for a dynamic and endogenous global environmental Kuznets curve in the global context.

Planetary boundaries (PB) is a novel conceptual framework that assesses the state of processes fundamental to the stability of the Earth system. Studies argue a non-linear relationship between economy and environmental degradation, known as the environmental Kuznets curve (EKC). We postulate this inverted-U association between PB and economic output in a worldwide sample. This paper, therefore, examines the correlation between changes in environmental conditions and global economic growth, incorporating the growth rate of key control variables (population, financial development, merchandise trade and regulations). Thus, we intend to identify and address the main gaps in these EKC studies and analyse the impacts of worldwide economic growth on global environmental change. PB variables are identified as the more integrated perspective with regard to this change. These planetary boundaries include various proxies: global CO2 concentration as a climate change proxy, threatened species for biodiversity loss, the total ozone for ozone depletion, mean surface ocean hydrogen ion concentration for ocean acidification and global fertiliser consumption for biochemical cycles. Under this integrated perspective, the EKC hypothesis is supported for climate change and ocean acidification panels using a dynamic system generalized method of moments (GMM) approach. Meanwhile, biochemical cycles, ozone depletion and freshwater use, land change and biodiversity loss boundaries do not support the existence of the EKC shape using the same methodology. The results provide an additional and novel view to be factored into the decisions of policymaker and investment institutions to contribute to sustainable development in all countries.

Immunomodulation of T Helper Cells by Tumor Microenvironment in Oral Cancer Is Associated With CCR8 Expression and Rapid Membrane Vitamin D Signaling Pathway.

The immune system plays a key role in the protective response against oral cancer; however, the tumor microenvironment (TME) impairs this anti-cancer response by modulating T helper (Th) responses and promoting an anti-inflammatory environment. Regulatory T cells (Tregs) and Th2 effector cells (Teff) are associated with poor prognosis in oral squamous cell carcinoma (OSCC). However, the main immunomodulatory mechanisms associated with the enrichment of these subsets in OSCC remain unknown. We characterized Th-like lineages in Tregs and Teff and evaluated immunomodulatory changes induced by the TME in OSCC. Our phenotypic data revealed a higher distribution of tumour-infiltrating CCR8+ and Th2-like Treg in OSCC compared with non-malignant samples, whereas the percentages of Th1 cells were reduced in cancer. We then analyzed the direct effect of the TME by exposing T cell subsets to cancer secretomes and observed the OSCC secretome induced CCR8 expression and reduced cytokine production from both subsets. Transcriptomic analysis showed that the co-culture with OSCC secretome induced several gene changes associated with the vitamin D (VitD) signaling pathway in T cells. In addition, proteomic analysis identified the presence of several proteins associated with prostaglandin E2 (PGE2) production by rapid membrane VitD signaling and a reduced presence of the VitD binding protein. Thus, we analyzed the effect of VitD and PGE2 and observed that VitD promotes a regulatory Th2-like response with CCR8 expression whilst PGE2 also modulated CCR8 but inhibited cytokine production in combination with VitD. Finally, we evaluated the presence of CCR8 ligand in OSCC and observed increased chemokine CCL18, which was also able to upregulate CCR8 in activated Th cells. Overall, our data showed the immunomodulatory changes induced by the TME involving CCR8 expression and regulatory Th2 phenotypes, which are associated with PGE2 mediated VitD signaling pathway and CCL18 expression in OSCC.

Synthesis and Cytotoxic Analysis of Novel Myrtenyl Grafted Pseudo-Peptides Revealed Potential Candidates for Anticancer Therapy.

Myrtenal is a natural monoterpene isolated from essential oils of several plants and their derivates have shown to have several biological properties including cytotoxicity. The cytotoxic activity of these derivates are being investigated for their antitumor effect leading to the development of potential anticancer agents. In this study, novels Myrtenyl grafted pseudo-peptides were designed, synthesized and functionally characterized as possible therapeutic agents for cancer treatment. Thirteen novel Myrtenyl grafted pseudo-peptides were prepared in high atom economy and efficiency by a classic Ugi-4CR and sequential post-modification. Their structures were confirmed by NMR, and ESI-MS, and its cytotoxic activity was evaluated in three cancer cell lines and primary CD4+ T cells at different proliferative cycles. Our results revealed that some of these compounds showed significant cytotoxicity against human gastric, breast and colon adenocarcinoma cells lines, but not against human dermal fibroblast cell line. Moreover, from the thirteen novel myrtenyl synthesized the compound (1R,5S)-N-{[1-(3-chlorophenyl)-1H-1,2,3-triazol-4-yl]methyl}-N-[2-(cyclohexylamino)-2-oxoethyl]-6,6-dimethylbicyclo[3.1.1]hept-2-ene-2-carboxamide (3b) proved to be the best candidate in terms of acceptable EC50, and Emax values in cancer cell lines and at inducing cytotoxicity in CD4+ T cells undergoing active proliferation, without affecting non-proliferating T cells. Overall, the synthesis and characterization of our Myrtenyl derivates revealed novel potential anticancer candidates with selective cytotoxic activity.

Association between insulin resistance and the development of cardiovascular disease.

For many years, cardiovascular disease (CVD) has been the leading cause of death around the world. Often associated with CVD are comorbidities such as obesity, abnormal lipid profiles and insulin resistance. Insulin is a key hormone that functions as a regulator of cellular metabolism in many tissues in the human body. Insulin resistance is defined as a decrease in tissue response to insulin stimulation thus insulin resistance is characterized by defects in uptake and oxidation of glucose, a decrease in glycogen synthesis, and, to a lesser extent, the ability to suppress lipid oxidation. Literature widely suggests that free fatty acids are the predominant substrate used in the adult myocardium for ATP production, however, the cardiac metabolic network is highly flexible and can use other substrates, such as glucose, lactate or amino acids. During insulin resistance, several metabolic alterations induce the development of cardiovascular disease. For instance, insulin resistance can induce an imbalance in glucose metabolism that generates chronic hyperglycemia, which in turn triggers oxidative stress and causes an inflammatory response that leads to cell damage. Insulin resistance can also alter systemic lipid metabolism which then leads to the development of dyslipidemia and the well-known lipid triad: (1) high levels of plasma triglycerides, (2) low levels of high-density lipoprotein, and (3) the appearance of small dense low-density lipoproteins. This triad, along with endothelial dysfunction, which can also be induced by aberrant insulin signaling, contribute to atherosclerotic plaque formation. Regarding the systemic consequences associated with insulin resistance and the metabolic cardiac alterations, it can be concluded that insulin resistance in the myocardium generates damage by at least three different mechanisms: (1) signal transduction alteration, (2) impaired regulation of substrate metabolism, and (3) altered delivery of substrates to the myocardium. The aim of this review is to discuss the mechanisms associated with insulin resistance and the development of CVD. New therapies focused on decreasing insulin resistance may contribute to a decrease in both CVD and atherosclerotic plaque generation.

Expression and purification of the surface proteins from Andes virus.

Andes virus is the main causative agent of Hantavirus cardiopulmonary syndrome in South America. There are currently no vaccines or treatments against Andes virus. However, there are several evidences suggesting that antibodies against Andes virus envelope glycoproteins may be enough to confer full protection against Hantavirus cardiopulmonary syndrome. The goal of the present work was to express, purify and characterize the extracellular domains of Andes virus glycoproteins Gn and Gc. We generated two adenoviral vectors encoding the extracellular domains of Andes virus glycoproteins Gn and Gc. Both molecules were expressed by adenoviral transduction in SiHa cells. We found that sGc ectodomain was mainly secreted into the culture medium, whereas sGn was predominantly retained inside the cells. Both molecules were expressed at very low concentrations (below 1 µg/mL). Treatment with the proteasome inhibitor ALLN raised sGc concentration in the cell culture medium, but did not affect expression levels of sGn. Both ectodomains were purified by immobilized metal ion affinity chromatography, and were recognized by sera from persons previously exposed to Andes virus. To our knowledge, this is the first work that addresses the expression and purification of Andes virus glycoproteins Gn and Gc. Our results demonstrate that sGn and sGc maintain epitopes that are exposed on the surface of the viral envelope. However, our work also highlights the need to explore new strategies to achieve high-level expression of these proteins for development of a vaccine candidate against Andes virus.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Promote Angiogenesis: Potencial Clinical Application.

Mesenchymal stem cells (MSCs) are adult multipotent stem cells that are able to differentiate into multiple specialized cell types including osteocytes, adipocytes, and chondrocytes. MSCs exert different functions in the body and have recently been predicted to have a major clinical/therapeutic potential. However, the mechanisms of self-renewal and tissue regeneration are not completely understood. It has been shown that the biological effect depends mainly on its paracrine action. Furthermore, it has been reported that the secretion of soluble factors and the release of extracellular vesicles, such as exosomes, could mediate the cellular communication to induce cell-differentiation/self-renewal. This review provides an overview of MSC-derived exosomes in promoting angiogenicity and of the clinical relevance in a therapeutic approach.

Endothelium trans differentiated from Wharton's jelly mesenchymal cells promote tissue regeneration: potential role of soluble pro-angiogenic factors.

BACKGROUND: Mesenchymal stem cells have a high capacity for trans-differentiation toward many adult cell types, including endothelial cells. Feto-placental tissue, such as Wharton's jelly is a potential source of mesenchymal stem cells with low immunogenic capacity; make them an excellent source of progenitor cells with a potential use for tissue repair. We evaluated whether administration of endothelial cells derived from mesenchymal stem cells isolated from Wharton's jelly (hWMSCs) can accelerate tissue repair in vivo. METHODS: Mesenchymal stem cells were isolated from human Wharton's jelly by digestion with collagenase type I. Endothelial trans-differentiation was induced for 14 (hWMSC-End14d) and 30 (hWMSC-End30d) days. Cell phenotyping was performed using mesenchymal (CD90, CD73, CD105) and endothelial (Tie-2, KDR, eNOS, ICAM-1) markers. Endothelial trans-differentiation was demonstrated by the expression of endothelial markers and their ability to synthesize nitric oxide (NO). RESULTS: hWMSCs can be differentiated into adipocytes, osteocytes, chondrocytes and endothelial cells. Moreover, these cells show high expression of CD73, CD90 and CD105 but low expression of endothelial markers prior to differentiation. hWMSCs-End express high levels of endothelial markers at 14 and 30 days of culture, and also they can synthesize NO. Injection of hWMSC-End30d in a mouse model of skin injury significantly accelerated wound healing compared with animals injected with undifferentiated hWMSC or injected with vehicle alone. These effects were also observed in animals that received conditioned media from hWMSC-End30d cultures. CONCLUSION: These results demonstrate that mesenchymal stem cells isolated from Wharton's jelly can be cultured in vitro and trans-differentiated into endothelial cells. Differentiated hWMSC-End may promote neovascularization and tissue repair in vivo through the secretion of soluble pro-angiogenic factors.

Lectin-like oxidized LDL receptor-1 is an enhancer of tumor angiogenesis in human prostate cancer cells.

Altered expression and function of lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been associated with several diseases such as endothelial dysfunction, atherosclerosis and obesity. In these pathologies, oxLDL/LOX-1 activates signaling pathways that promote cell proliferation, cell motility and angiogenesis. Recent studies have indicated that olr1 mRNA is over-expressed in stage III and IV of human prostatic adenocarcinomas. However, the function of LOX-1 in prostate cancer angiogenesis remains to be determined. Our aim was to analyze the contribution of oxLDL and LOX-1 to tumor angiogenesis using C4-2 prostate cancer cells. We analyzed the expression of pro-angiogenic molecules and angiogenesis on prostate cancer tumor xenografts, using prostate cancer cell models with overexpression or knockdown of LOX-1 receptor. Our results demonstrate that the activation of LOX-1 using oxLDL increases cell proliferation, and the expression of the pro-angiogenic molecules VEGF, MMP-2, and MMP-9 in a dose-dependent manner. Noticeably, these effects were prevented in the C4-2 prostate cancer model when LOX-1 expression was knocked down. The angiogenic effect of LOX-1 activated with oxLDL was further demonstrated using the aortic ring assay and the xenograft model of tumor growth on chorioallantoic membrane of chicken embryos. Consequently, we propose that LOX-1 activation by oxLDL is an important event that enhances tumor angiogenesis in human prostate cancer cells.

Role of lectin-like oxidized low density lipoprotein-1 in fetoplacental vascular dysfunction in preeclampsia.

The bioavailability of nitric oxide (NO) represents a key marker in vascular health. A decrease in NO induces a pathological condition denominated endothelial dysfunction, syndrome observed in different pathologies, such as obesity, diabetes, kidney disease, cardiovascular disease, and preeclampsia (PE). PE is one of the major risks for maternal death and fetal loss. Recent studies suggest that the placenta of pregnant women with PE express high levels of lectin-like oxidized LDL receptor-1 (LOX-1), which induces endothelial dysfunction by increasing reactive oxygen species (ROS) and decreasing intracellular NO. Besides LOX-1 activation induces changes in migration and apoptosis of syncytiotrophoblast cells. However, the role of this receptor in placental tissue is still unknown. In this review we will describes the physiological roles of LOX-1 in normal placenta development and the potential involvement of this receptor in the pathophysiology of PE.

Essential role of intracellular glutathione in controlling ascorbic acid transporter expression and function in rat hepatocytes and hepatoma cells.

Although there is in vivo evidence suggesting a role for glutathione in the metabolism and tissue distribution of vitamin C, no connection with the vitamin C transport systems has been reported. We show here that disruption of glutathione metabolism with buthionine-(S,R)-sulfoximine (BSO) produced a sustained blockade of ascorbic acid transport in rat hepatocytes and rat hepatoma cells. Rat hepatocytes expressed the Na(+)-coupled ascorbic acid transporter-1 (SVCT1), while hepatoma cells expressed the transporters SVCT1 and SVCT2. BSO-treated rat hepatoma cells showed a two order of magnitude decrease in SVCT1 and SVCT2 mRNA levels, undetectable SVCT1 and SVCT2 protein expression, and lacked the capacity to transport ascorbic acid, effects that were fully reversible on glutathione repletion. Interestingly, although SVCT1 mRNA levels remained unchanged in rat hepatocytes made glutathione deficient by in vivo BSO treatment, SVCT1 protein was absent from the plasma membrane and the cells lacked the capacity to transport ascorbic acid. The specificity of the BSO treatment was indicated by the finding that transport of oxidized vitamin C (dehydroascorbic acid) and glucose transporter expression were unaffected by BSO treatment. Moreover, glutathione depletion failed to affect ascorbic acid transport, and SVCT1 and SVCT2 expression in human hepatoma cells. Therefore, our data indicate an essential role for glutathione in controlling vitamin C metabolism in rat hepatocytes and rat hepatoma cells, two cell types capable of synthesizing ascorbic acid, by regulating the expression and subcellular localization of the transporters involved in the acquisition of ascorbic acid from extracellular sources, an effect not observed in human cells incapable of synthesizing ascorbic acid.

The glucose transporter-2 (GLUT2) is a low affinity dehydroascorbic acid transporter.

We studied the acquisition of dehydroascorbic acid by rat hepatocytes, H4IIE rat hepatoma cells and Xenopus laevis oocytes. Transport kinetics and competition and inhibition studies revealed that rat hepatocytes transport oxidized dehydroascorbic acid through a single functional component possessing the functional and kinetic properties expected for the glucose transporter GLUT2. On the other hand, rat hepatoma cells showed expression of at least two dehydroascorbic acid transporters with the expected functional and kinetic properties expected for GLUT1 and GLUT2. Expression studies of GLUT2 in X. laevis oocytes followed by transport kinetics and competition and inhibition studies revealed that GLUT2 is a low affinity dehydroascorbic transporter whose kinetic and functional properties match those observed for the endogenous GLUT2 transporter in rat hepatocytes and rat hepatoma cells. Therefore, GLUT2, a transporter known as a low affinity transporter of glucose and fructose and a high affinity transporter of glucosamine is also a low affinity dehydroascorbic acid transporter.