Exploring the role of botulinum toxin in crucial proper care

From Selfless
Jump to navigation Jump to search

PM2.5 is a well-known air pollutant threatening public health, and long-term exposure to PM2.5 increases the risk of cardiovascular diseases. Nrf2 plays a pivotal role in the amelioration of PM2.5-induced lung injury. However, if Nrf2 is involved in PM2.5-induced heart injury, and the underlying molecular mechanisms have not been explored. In this study, wild type (Nrf2+/+) and Nrf2 knockout (Nrf2-/-) mice were exposed to PM2.5 for 6 months. After PM2.5 exposure, Nrf2-/- mice developed severe physiological changes, lung injury and cardiac dysfunction. In the PM2.5-exposed hearts, Nrf2 deficiency caused significant collagen accumulation through promoting the expression of fibrosis-associated signals. Additionally, Nrf2-/- mice exhibited greater oxidative stress in cardiac tissues after PM2.5 exposure. Furthermore, PM2.5-induced inflammation in heart samples were accelerated in Nrf2-/- mice through promoting inhibitor of α/nuclear factor κB (IκBα/NF-κB) signaling pathways. We also found that Nrf2-/- aggravated autophagy initiation and glucose metabolism disorder in hearts of mice with PM2.5 challenge. Cardiac receptor-interacting protein kinase 3 (RIPK3) expression triggered by PM2.5 was further enhanced in mice with the loss of Nrf2. Collectively, these results suggested that strategies for enhancing Nrf2 could be used to treat PM2.5-induced cardiovascular diseases.Interleukin 18 (IL-18) promotes inflammation and apoptosis in chondrocytes, thereby contributing to the development and progression of osteoarthritis (OA). Here, we investigated the effects of IL-18 treatment and inhibition in rat chondrocytes in vitro and in vivo. We used RT-PCR and Western blotting to measure the mRNA and protein levels of the chondrocyte-specific genes Collagen II and Aggrecan as well as the protein levels of apoptosis-related (Bax, Bcl2, Caspase3/9), autophagy-related (Atg5, Atg7, Beclin1, LC3), and mTOR pathway-related genes (PI3K, Akt, mTOR). We observed a decrease in Collagen II and Aggrecan mRNA and protein levels, upregulation of chondrocyte apoptosis, downregulation of chondrocyte autophagy, and activation of the PI3K/Akt/mTOR pathway upon IL-18 treatment. PI3K/Akt/mTOR pathway activation and inhibition tests using rat 740Y-P (PI3K activator), SC79 (AKT activator), 3BDO (mTOR activator), or LY294002 (PI3K inhibitor) revealed that activation of the PI3K/Akt/mTOR pathway enhances chondrocyte-specific gene degradation induced by IL-18, while its inhibition has protective effects on chondrocytes. We also found that treatment with rapamycin (a selective mTOR inhibitor) also exerts chondro-protective effects that ameliorate OA by promoting autophagy. These results suggest that inhibition of the mTOR pathway could be exploited for therapeutic benefits in the treatment of OA.Mitochondria putatively regulate the aging process, in part, through the small regulatory peptide, mitochondrial open reading frame of the 12S rRNA-c (MOTS-c) that is encoded by the mitochondrial genome. Here we investigated the regulation of MOTS-c in the plasma and skeletal muscle of healthy aging men. Circulating MOTS-c reduced with age, but older (70-81 y) and middle-aged (45-55 y) men had ~1.5-fold higher skeletal muscle MOTS-c expression than young (18-30 y). Plasma MOTS-c levels only correlated with plasma in young men, was associated with markers of slow-type muscle, and associated with improved muscle quality in the older group (maximal leg-press load relative to thigh cross-sectional area). Using small mRNA assays we provide evidence that MOTS-c transcription may be regulated independently of the full length 12S rRNA gene in which it is encoded, and expression is not associated with antioxidant response element (ARE)-related genes as previously seen in culture. Our results suggest that plasma and muscle MOTS-c are differentially regulated with aging, and the increase in muscle MOTS-c expression with age is consistent with fast-to-slow type muscle fiber transition. learn more Further research is required to determine the molecular targets of endogenous MOTS-c in human muscle but they may relate to factors that maintain muscle quality.Although assessing clinical reasoning is almost universally considered central to medical education it is not a straightforward issue. In the past decades, our insights into clinical reasoning as a phenomenon, and consequently the best ways to assess it, have undergone significant changes. In this article, we describe how the interplay between fundamental research, practical applications, and evaluative research has pushed the evolution of our thinking and our practices in assessing clinical reasoning.The infectious life cycle of human papillomaviruses (HPVs) is tightly linked to keratinocyte differentiation. Evidence suggests a sophisticated interplay between host gene regulation and virus replication. Alternative splicing is an essential process for host and viral gene expression, and is generally upregulated by serine arginine-rich splicing factors (SRSFs). SRSF activity can be positively or negatively controlled by cycles of phosphorylation/dephosphorylation. Here we show that HPV16 infection leads to accumulation of the paradigm SRSF protein, SRSF1, in the cytoplasm in a keratinocyte differentiation-specific manner. Moreover, HPV16 infection leads to increased levels of cytoplasmic and nuclear phosphorylated SRSF1. SR protein kinase 1 (SRPK1) phosphorylates SRSF1. Similar to HPV upregulation of SRSF1, we demonstrate HPV upregulation of SRPK1 via the viral E2 protein. SRPK1 depletion or drug inhibition of SRPK1 kinase activity resulted in reduced levels of SRSF1, suggesting that phosphorylation stabilizes the protein in differentiated HPV-infected keratinocytes. Together, these data indicate HPV infection stimulates the SRPK1-SRSF axis in keratinocytes.Oral infection of caterpillars by baculoviruses is initiated by occlusion-derived virus particles (ODVs) that infect midgut epithelium cells. The ODV envelope therefore contains at least ten different proteins, which are called per os infectivity factors (PIFs). Nine of these PIFs form the so-called ODV entry complex that consists of a stable core formed by PIF1, 2, 3 and 4, to which the other PIFs [PIF0, 6, 7, 8 and 9 (ac108)] bind with lower affinity. PIF1 and 2 are not only essential for complex formation, but also mediate ODV-binding to the epithelial brush border, probably via the C-termini. To study the involvement of these PIFs during midgut infection in greater detail, we assessed the oral infectivity and the ability to form the complex of a series of PIF1 and PIF2 C-terminal truncation mutants of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), which were constructed in this study. Limited truncation of either PIF1 or 2 already severely impaired the ODV oral infectivity, but did not affect the formation of the core complex.