Role of the Mitochondria in Immune-Mediated Apoptotic Death of the Human Pancreatic β Cell Line βLox5

Mitochondria are indispensable in the life and death of many types of eukaryotic cells. In pancreatic beta cells, mitochondria play an essential role in the secretion of insulin, a hormone that regulates blood glucose levels. Unregulated blood glucose is a hallmark symptom of diabetes. The onset of Type 1 diabetes is preceded by autoimmune-mediated destruction of beta cells. However, the exact role of mitochondria has not been assessed in beta cell death. In this study, we examine the role of mitochondria in both Fas- and proinflammatory cytokine-mediated destruction of the human beta cell line, βLox5. IFNγ primed βLox5 cells for apoptosis by elevating cell surface Fas. Consequently, βLox5 cells were killed by caspase-dependent apoptosis by agonistic activation of Fas, but only after priming with IFNγ. This beta cell line undergoes both apoptotic and necrotic cell death after incubation with the combination of the proinflammatory cytokines IFNγ and TNFα. Additionally, both caspase-dependent and -independent mechanisms that require proper mitochondrial function are involved. Mitochondrial contributions to βLox5 cell death were analyzed using mitochondrial DNA (mtDNA) depleted βLox5 cells, or βLox5 ρ0 cells. βLox5 ρ0 cells are not sensitive to IFNγ and TNFα killing, indicating a direct role for the mitochondria in cytokine-induced cell death of the parental cell line. However, βLox5 ρ0 cells are susceptible to Fas killing, implicating caspase-dependent extrinsic apoptotic death is the mechanism by which these human beta cells die after Fas ligation. These data support the hypothesis that immune mediators kill βLox5 cells by both mitochondrial-dependent intrinsic and caspase-dependent extrinsic pathways

Pancreatic β-Cell Death in Response to Pro-Inflammatory Cytokines Is Distinct from Genuine Apoptosis

A reduction in functional β-cell mass leads to both major forms of diabetes; pro-inflammatory cytokines, such as interleukin-1beta (IL-1β) and gamma-interferon (γ-IFN), activate signaling pathways that direct pancreatic β-cell death and dysfunction. However, the molecular mechanism of β-cell death in this context is not well understood. In this report, we tested the hypothesis that individual cellular death pathways display characteristic phenotypes that allow them to be distinguished by the precise biochemical and metabolic responses that occur during stimulus-specific initiation. Using 832/13 and INS-1E rat insulinoma cells and isolated rat islets, we provide evidence that apoptosis is unlikely to be the primary pathway underlying β-cell death in response to IL-1β+γ-IFN. This conclusion was reached via the experimental results of several different interdisciplinary strategies, which included: 1) tandem mass spectrometry to delineate the metabolic differences between IL-1β+γ-IFN exposure versus apoptotic induction by camptothecin and 2) pharmacological and molecular interference with either NF-κB activity or apoptosome formation. These approaches provided clear distinctions in cell death pathways initiated by pro-inflammatory cytokines and bona fide inducers of apoptosis. Collectively, the results reported herein demonstrate that pancreatic β-cells undergo apoptosis in response to camptothecin or staurosporine, but not pro-inflammatory cytokines

Sugar and sugar-free liquid formulations of delamanid for patients with rifampicin-resistant TB

BACKGROUND: Delamanid (DLM) tablets are recommended for the treatment of rifampicin-resistant TB. However, no liquid or dispersible tablet formulation of DLM is currently commercially available for patients with challenges ingesting these tablets. The aim of this study was to develop stable extemporaneous liquid formulations of DLM that can be stored at room temperature for several weeks.METHODS: DLM tablets were suspended in 1) simple syrup and 2) a specially formulated sugar-free vehicle. These suspensions containing DLM 5 mg/mL were stored in plastic prescription bottles at room temperature or 30°C for 30 days. These suspensions were evaluated for appearance, potency, pH, and microbial counts at Days 0, 15, and 30.RESULTS: The potency of DLM in each formulation remained at 98–104% of the theoretical concentration for 30 days. The appearance, pH, and microbial count did not change for the sugar-free formulation during the 30-day storage period. Microbial growth, however, was observed in the simple syrup formulation on Day 30 but not on Day 15.CONCLUSION: DLM can be formulated in sugar or sugar-free suspensions and stored at room temperature or 30°C for at least 15 and 30 days, respectively.</jats:p

Stable, compounded bedaquiline suspensions to support practical implementation of pediatric dosing in the field

BACKGROUND: Bedaquiline (BDQ) tablets are indicated as part of a combination regimen for the treatment of multidrug-resistant TB in adults, adolescents and children. A dispersible tablet formulation is now approved but is not currently available in all settings. The aim of this study was to develop stable extemporaneous liquid formulations of BDQ that can be stored at room temperature or 30°C for several weeks, to support pragmatic pediatric dosing in the field and reduce wastage.METHODS: BDQ tablets were suspended in simple syrup and a sugar-free vehicle. Each 20 mg/mL formulation was stored at room temperature or 30°C for 30 days in amber dispensing bottles. Appearance, BDQ potency, pH and microbial counts were determined on Days 0, 15 and 30.RESULTS: The BDQ potency in both formulations remained at 98–101% of the theoretical concentration for 30 days. The appearance, pH and microbial count of sugar-free formulation did not change during the 30-day storage. The simple syrup formulation was stable for 15 days as microbial growth was observed on Day 30.CONCLUSIONS: BDQ may be prepared in syrup or sugar-free suspensions: syrup suspensions can be stored for 15 days at room temperature and 30C, whereas sugar-free suspensions can be stored for 30 days at room temperature and 30C. This information will support practical BDQ dosing for children in the field.</jats:p

Extemporaneously compounded liquid formulations of clofazimine

BACKGROUND: Clofazimine (CFZ) is routinely used worldwide for the treatment of leprosy and TB. However, no liquid or dispersible tablet formulations of CFZ are currently available commercially for patients with challenges ingesting soft gelatin capsules or solid formulations. The aim of this research was to develop stable extemporaneous liquid formulations of CFZ that can be stored at room temperature for several weeks to enable practical dosing in the field.METHODS: Two formulations were prepared in syrup and sugar-free vehicles with CFZ tablets using a simple method that can be used in a routine pharmacy. Suspensions were stored at room temperature and at 30°C for 30 days. Formulation aliquots were tested on Days 0, 15 and 30 for appearance, pH, potency and microbial counts.RESULTS: Appearance remained unchanged during storage. The pH of both formulations was between 4.0 and 6.0. Potency was between 90% and 110% for 30 days in the syrup formulation and for 15 days in the sugar-free formulation. Microbial counts met United States Pharmacopeia &lt;1111&gt; limits for oral aqueous liquids and specific organisms were absent.CONCLUSIONS: A simple field-friendly method was successfully developed for the preparation of CFZ liquid formulations using commonly available ingredients. This will permit practical dosing and titration for children and other patients with swallowing challenges.</jats:p

Repair of Nitric Oxide-damaged DNA in β-Cells Requires JNK-dependent GADD45α Expression*

Proinflammatory cytokines induce nitric oxide-dependent DNA damage and ultimately β-cell death. Not only does nitric oxide cause β-cell damage, it also activates a functional repair process. In this study, the mechanisms activated by nitric oxide that facilitate the repair of damaged β-cell DNA are examined. JNK plays a central regulatory role because inhibition of this kinase attenuates the repair of nitric oxide-induced DNA damage. p53 is a logical target of JNK-dependent DNA repair; however, nitric oxide does not stimulate p53 activation or accumulation in β-cells. Further, knockdown of basal p53 levels does not affect DNA repair. In contrast, expression of growth arrest and DNA damage (GADD) 45α, a DNA repair gene that can be regulated by p53-dependent and p53-independent pathways, is stimulated by nitric oxide in a JNK-dependent manner, and knockdown of GADD45α expression attenuates the repair of nitric oxide-induced β-cell DNA damage. These findings show that β-cells have the ability to repair nitric oxide-damaged DNA and that JNK and GADD45α mediate the p53-independent repair of this DNA damage

Crise ecológica, escassez hídrica e ideologias: uma análise crítica da Carta de 2070

This article analyzes the relationship between geography and ideologies, through what has been called “ecological crisis”, focusing discussions around the water scarcity. The article is divided into three parts. At first, we describe the predominant approaches to water since the late twentieth century, worldwide. Then, we present some forms of relationship between ideologies and approaches to nature, in different historical moments and we focus on analyzing the speeches about the nature building on the “Development Ideology”, the “Progress Ideology” and “Sustainable Development Ideology”. In these discussions we present the different approaches given to water from these philosophies. Finally, we outline some considerations that aim to stimulate critical thinking about the current characteristics of social reproduction space