823 research outputs found

    Pattern recognition receptors as key players in adrenal gland dysfunction during sepsis

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    Background: Undergoing systemic inflammation, the innate immune system releases excessive proinflammatory mediators, which finally can lead to organ failure. Pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs) and NOD-like receptors (NLRs), form the interface between bacterial and viral toxins and innate immunity. During sepsis, patients with diagnosed adrenal gland insufficiency are at high risk of developing a multiorgan dysfunction syndrome, which dramatically increases the risk of mortality. To date, little is known about the mechanisms leading to adrenal dysfunction under septic conditions. Here, we investigated the sepsis-related activation of the PRRs, cell inflammation, and apoptosis within adrenal glands. Methods: Two sepsis models were performed: the polymicrobial sepsis model (caecal ligation and puncture (CLP)) and the LTA-induced intoxication model. All experiments received institutional approval by the Regierungspräsidium Darmstadt. CLP was performed as previously described [1], wherein one-third of the caecum was ligated and punctured with a 20-gauge needle. For LTA-induced systemic inflammation, TLR2 knockout (TLR2-/-) and WT mice were injected intraperitoneally with pure LTA (pLTA; 1 mg/kg) or PBS for 2 hours. To detect potential direct adrenal dysfunction, mice were additionally injected with adrenocorticotropic hormone (ACTH; 100 μg/kg) 1 hour after pLTA or PBS. Adrenals and plasma samples were taken. Gene expressions in the adrenals (rt-PCR), cytokine release (multiplex assay), and the apoptosis rate (TUNEL assay) within the adrenals were determined. Results: In both models, adrenals showed increased mRNA expression of TLR2 and TLR4, various NLRs, cytokines as well as inflammasome components, NADPH oxidase subunits, and nitric oxide synthases (data not shown). In WT mice, ACTH alone had no effect on inflammation, while pLTA or pLTA/ACTH administration showed increased levels of the cytokines IL-1β, IL-6, and TNFα. TLR2-/- mice indicated no response as expected (Figure 1, left). Interestingly, surviving CLP mice showed no inflammatory adrenal response, whereas nonsurvivors had elevated cytokine levels (Figure 1, right). Additionally, we identified a marked increase in apoptosis of both chromaffin and steroid-producing cells in adrenal glands obtained from mice with sepsis as compared with their controls (Figure 2). ... Conclusion: Taken together, sepsis-induced activation of the PRRs may contribute to adrenal impairment by enhancing tissue inflammation, oxidative stress and culminate in cellular apoptosis, while mortality seems to be associated with adrenal inflammation

    OPA1 mutation and late-onset cardiomyopathy: mitochondrial dysfunction and mtDNA instability.

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    BackgroundMitochondrial fusion protein mutations are a cause of inherited neuropathies such as Charcot-Marie-Tooth disease and dominant optic atrophy. Previously we reported that the fusion protein optic atrophy 1 (OPA1) is decreased in heart failure.Methods and resultsWe investigated cardiac function, mitochondrial function, and mtDNA stability in a mouse model of the disease with OPA1 mutation. The homozygous mutation is embryonic lethal. Heterozygous OPA(+/-) mice exhibit reduced mtDNA copy number and decreased expression of nuclear antioxidant genes at 3 to 4 months. Although initial cardiac function was normal, at 12 months the OPA1(+/-) mouse hearts had decreased fractional shortening, cardiac output, and myocyte contraction. This coincided with the onset of blindness. In addition to small fragmented mitochondria, aged OPA1(+/-) mice had impaired cardiac mitochondrial function compared with wild-type littermates.ConclusionsOPA1 mutation leads to deficiency in antioxidant transcripts, increased reactive oxygen species, mitochondrial dysfunction, and late-onset cardiomyopathy

    Controllable and Switchable Drug Delivery of Ibuprofen from Temperature Responsive Composite Nanofibers

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    Composited electrospun nanofibers made of temperature-responsive poly(N-isopropylacrylamide) (pNIPAM) and biodegradable poly (ε-caprolactone) (PCL) can be utilized for ‘on-demand’ and controlled drug release of ibuprofen without burst effect for potential pharmaceutical applications. Three types of nanofibers, PCL, pNIPAM and pNIPAM/PCL composite NFs containing ibuprofen were fabricated using electrospinning techniques. Ibuprofen release rates from PCL NFs are not affected by the temperature in the range of 22–34°C (less than 10%). In contrast, the ibuprofen release rates from pNIPAM NFs are very sensitive to the change in temperature, which is five times higher at 22°C compared to 34°C. However, there is a serious burst effect at 22°C. Compared to other two types of NFs, pNIPAM/PCL composite NFs prepared demonstrated a variable and controlled release at both room and higher temperature, due to the extra protection from the hydrophobic poly (ε-caprolactone). The rate at 22°C is 75% faster compared to that at 34°C. This kind of composite design can provide a novel approach to suppress the burst effect in drug delivery systems for potential pharmaceutical applications

    Mesenchymal Stem Cell Use in the Treatment of Osteoarthritis: A Literature Review

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    Mesenchymal stem cell (MSC) therapies have been growing in popularity in research due to their anti-inflammatory, immunomodulatory, and regenerative properties. Many ongoing clinical trials are investigating the safety and efficacy of MSC therapies to treat osteoarthritis, also known as “wear and tear” arthritis. As the average life expectancy increases, with age people are more prone to developing this disease, therefore, increasing its prevalence. This condition is progressive and will lead to functional decline, decreased quality of life, and increased medical costs. Our focus is to discuss the efficacy of mesenchymal stem cell injections in alleviating pain, improving functionality, and slowing the disease progression of osteoarthritis in adults. We systematically reviewed studies through multiple databases, including PubMed, ScienceDirect, AccessMedicine, and Iceberg using the search terms mesenchymal stem cells, osteoarthritis, stem cell therapy, and degenerative joint disease. We limited searches to 2018 and newer, studies in English, and human trials. A total of 20 studies that met the criteria out of 65 full-text studies were included in this review. Clinical outcomes such as pain, functionality, and tissue regeneration were assessed using WOMAC, KOOS, and other validated clinical outcome scales, and resonance imaging were used for disease progression rating. Studies reviewing mesenchymal stem cell injections in arthritic joints have shown positive clinical outcomes with results showing pain level, joint function and regeneration. To realize stem cell injections outside of studies, long-term and larger-scale randomized clinical trials are required to strengthen the interpretations and validity of current studies

    The Immunogenicity of the Tumor-Associated Antigen α-Fetoprotein Is Enhanced by a Fusion with a Transmembrane Domain

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    Aim. To investigate the ability of recombinant modified vaccinia virus Ankara (rMVA) vector to induce an immune response against a well-tolerated self-antigen. Methods. rMVA vectors expressing different form of α-fetoprotein (AFP) were produced and characterized. Naïve mice were vaccinated with MVA vectors expressing the AFP antigen in either a secreted, or a membrane-bound, or an intracellular form. The immune response was monitored by an IFNΓ ELISpot assay and antibody detection. Results. Vaccination with the membrane-associated form of AFP induced a stronger CD8+ T-cell response compared to the ones obtained with the MVA encoding the secreted or the intracellular forms of AFP. Moreover, the vaccination with the membrane-bound AFP elicited the production of AFP-specific antibodies. Conclusions. The AFP transmembrane form is more immunogenic. Expressing a membrane-bound form in the context of an MVA vaccination could enhance the immunogenicity of a self-antigen

    Novel genome polymorphisms in BCG vaccine strains and impact on efficacy

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    Bacille Calmette-Guérin (BCG) is an attenuated strain of Mycobacterium bovis currently used as a vaccine against tuberculosis. Global distribution and propagation of BCG has contributed to the in vitro evolution of the vaccine strain and is thought to partially account for the different outcomes of BCG vaccine trials. Previous efforts by several molecular techniques effectively identified large sequence polymorphisms among BCG daughter strains, but lacked the resolution to identify smaller changes. In this study, we have used a NimbleGen tiling array for whole genome comparison of 13 BCG strains. Using this approach, in tandem with DNA resequencing, we have identified six novel large sequence polymorphisms including four deletions and two duplications in specific BCG strains. Moreover, we have uncovered various polymorphisms in the phoP-phoR locus. Importantly, these polymorphisms affect genes encoding established virulence factors including cell wall complex lipids, ESX secretion systems, and the PhoP-PhoR two-component system. Our study demonstrates that major virulence factors are different among BCG strains, which provide molecular mechanisms for important vaccine phenotypes including adverse effect profile, tuberculin reactivity and protective efficacy. These findings have important implications for the development of a new generation of vaccines

    'With this study, we have hope that something is coming': community members' perceptions of HIV cure-related research in Durban, South Africa - a qualitative focus group study

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    BACKGROUND: Developing a cure for HIV remains a global scientific priority. In 2022, the Females Rising through Education, Support and Health (FRESH) cohort launched an HIV cure-related trial involving an analytical treatment interruption (ATI) in Durban, South Africa. OBJECTIVES: To explore community perspectives about HIV cure-related research. METHODS: Between July-August 2022, we conducted three focus groups with community members. We transcribed audio recordings verbatim and used content analysis to analyze the data. RESULTS: Twenty community members (13 women and 7 men) participated in three focus groups (HIV status not included). Participants viewed HIV cure-related research as a way to address the issue of defaulting on (not taking) HIV treatment. Participants expressed hesitancy around ATIs, since these contradict longstanding treatment adherence messages. Participants shared concerns around the risk of side effects from experimental interventions balanced against potential efficacy. They advocated for trial participants to have the right to decide whether to inform their sex partners about their HIV status and ATI participation, rather than research teams making disclosure mandatory. Focus group participants also emphasized the importance of using simple language to explain HIV cure-related research. CONCLUSIONS: With HIV cure trials set to launch across Africa in the future, there is a critical need to better understand and respond to local community needs and preferences and to adopt this as standard practice prior to regional trial implementation

    Triazole Substitution of a Labile Amide Bond Stabilizes Pantothenamides and Improves Their Antiplasmodial Potency

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    The biosynthesis of coenzyme A (CoA) from pantothenate and the utilization of CoA in essential biochemical pathways represent promising antimalarial drug targets. Pantothenamides, amide derivatives of pantothenate, have potential as antimalarials, but a serum enzyme called pantetheinase degrades pantothenamides, rendering them inactive in vivo. In this study, we characterize a series of 19 compounds that mimic pantothenamides with a stable triazole group instead of the labile amide. Two of these pantothenamides are active against the intraerythrocytic stage parasite with 50% inhibitory concentrations (IC50s) of ∼50 nM, and three others have submicromolar IC50s. We show that the compounds target CoA biosynthesis and/or utilization. We investigated one of the compounds for its ability to interact with the Plasmodium falciparum pantothenate kinase, the first enzyme involved in the conversion of pantothenate to CoA, and show that the compound inhibits the phosphorylation of [14C]pantothenate by the P. falciparum pantothenate kinase, but the inhibition does not correlate with antiplasmodial activity. Furthermore, the compounds are not toxic to human cells and, importantly, are not degraded by pantetheinase
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