A new derivatizing reagent, N-hydroxysuccinimidyl-α-naphthylacetate (SINA), has been used as a precolumn derivatizing reagent for the separation and determination of amino acids (AAs) and oligopeptides with HPLC. The spectral properties of SINA derivatives with AAs and oligopeptides have been studied. The derivatization and separation conditions of SINA derivatives with most amino acids and some oligopeptides have been investigated. With spectrophotometric detection at 280 nm, the detection limits were in the range of 0.49–2.76 pmol; with fluorescence detection at λex/λem = 299/338 nm, the detection limits were in the range of 19–376 fmol when the ratio of signal to noise (S/N = 3) was 3.
Exposure to cadmium (Cd), a toxic metal, is epidemiologically linked to nonalcoholic steatohepatitis (NASH) in humans. However, the role of Cd in NASH remains to be fully elucidated. This study employed a novel murine NASH model to investigate the effects of chronic low-dose Cd on hepatic pathology and its underlying mechanisms. NASH is characterized by lipid accumulation, extensive cell death, and persistent inflammation in the liver. We found that treatment with Cd in drinking water (10 mg/L) for 6 or 12 weeks significantly boosted hepatic fat deposition, increased hepatocyte destruction, and amplified inflammatory responses in mice, confirming that low-dose Cd can facilitate NASH development in vivo. Mechanistically, chronic Cd exposure reshaped the hepatic transcriptional landscape, with PPAR-mediated fatty acid metabolic pathways being the most significantly altered. In particular, Cd repressed fatty acid desaturation, leading to the accumulation of saturated fatty acids whose lipotoxicity exacerbated cell death and, consequently, inflammatory activation. In summary, we validated the causal effects of chronic low-dose Cd on NASH in vivo and identified the fatty acid desaturation program as a novel target for Cd to instigate hepatopathological alterations.
Arjunolic acid (AA), as the most abundant triterpenoid component in Cyclocarya paliurus (Batal) Iljinskaja, previously displayed delipidating effects in free fatty acid (FFA)-induced HepG2 steatosis cells. However, whether AA still possesses the ameliorative effects on nonalcoholic fatty liver disease (NAFLD) in normal hepatocytes and in vivo remains vacant and the detailed mechanisms are not defined. In vitro, AA dose-dependently alleviated lipid accumulation in FFA-challenged primary hepatocytes without cytotoxicity. In vivo, AA showed pleiotropic benefits, including attenuating adiposity, mitigating hepatic steatosis and inflammation, improving lipid disorders and insulin resistance, and restoring the impaired gut barrier. Mechanically, we found that AA indirectly activated Sirt1/AMPK-modulated lipid metabolism through elevating NAMPT-mediated NAD+ level, and triggering autophagy, together mediating the lipid-lowering effects. Collectively, our results convey that AA can substantially mitigate NAFLD via indirectly activating Sirt1/AMPK signaling, inducing autophagy and restoring gut barrier, and will be considered as a promising candidate for NAFLD therapy.
Climate change has intensified the frequency of extreme drought events in desert ecosystems, accompanied by uneven distribution of annual precipitation. Whether extreme precipitation events at different phenophases have equivalent impacts on desert plants is an unverified topic, yet it is crucial for understanding the mechanisms of vegetation adaptation to changes in precipitation. This study focuses on the typical desert plant Artemisia ordosica and employs in situ precipitation control experiments using rain shelters to simulate extreme drought events (30 consecutive days of precipitation removal) at three phenophases: the sprouting stage, vegetative growth stage, and flowering and fruiting stage. Against this backdrop, phenological differences in the leaf photosynthetic physiological regulatory mechanisms that affect the accumulation of Aboveground Net Primary Productivity (ANPP) in A. ordosica under extreme drought events were explored, including parameters such as photosynthetic gas exchange, chlorophyll fluorescence, and antioxidant enzymes. The findings reveal that: (1) Extreme drought events at different phenophases markedly reduced the photosynthesis of A. ordosica leaves, subsequently leading to the significantly reduction in ANPP accumulation (p<0.05). With the impact degree ordered as follows: flowering and fruiting stage > sprouting stage > vegetative growth stage; (2) During extreme drought events, A. ordosica experiences a decrease in photosynthetic gas exchange capacity and an enhancement in water use efficiency, which are stomatal regulatory responses. Additionally, there is an increase in thermal dissipation, a decline in photochemical activity parameters (such as potential photosynthetic activity of PSII, initial light energy conversion efficiency, actual photochemical quantum yield, and photochemical quenching), and an augmentation of the antioxidant enzyme system, which are non-stomatal regulatory responses; (3) During extreme drought events at different phenophases, the dominant factor leading to a decline in the photosynthetic rate of A. ordosica leaves is stomatal regulation. However, there are phenological differences in the sensitivity of stomatal and non-stomatal regulation. The stomatal regulation of A. ordosica leaves during the sprouting stage is more sensitive compared to other phenophases. Non-stomatal regulation is most sensitive during the vegetative growth stage, with a heightened sensitivity in the modulation of chlorophyll fluorescence. The study reveals differences in the photosynthetic physiological regulation of desert vegetation in response to extreme drought events at different phenophases, offering an innovative perspective on the physiological and ecological regulatory mechanisms of desert ecosystems in the face of climate change.
Breast cancer patients are usually treated with multiple fractions of radiotherapy (RT) to the whole breast after lumpectomy. We hypothesized that repeated fractions of RT would progressively activate the autotaxin-lysophosphatidate-inflammatory cycle. To test this, a normal breast fat pad and a fat pad containing a mouse 4T1 tumor were irradiated with X-rays using a small-animal "image-guided" RT platform. A single RT dose of 7.5 Gy and three daily doses of 7.5 Gy increased ATX activity and decreased plasma adiponectin concentrations. The concentrations of IL-6 and TNFα in plasma and of VEGF, G-CSF, CCL11 and CXCL10 in the irradiated fat pad were increased, but only after three fractions of RT. In 4T1 breast tumor-bearing mice, three fractions of 7.5 Gy augmented tumor-induced increases in plasma ATX activity and decreased adiponectin levels in the tumor-associated mammary fat pad. There were also increased expressions of multiple inflammatory mediators in the tumor-associated mammary fat pad and in tumors, which was accompanied by increased infiltration of CD45+ leukocytes into tumor-associated adipose tissue. This work provides novel evidence that increased ATX production is an early response to RT and that repeated fractions of RT activate the autotaxin-lysophosphatidate-inflammatory cycle. This wound healing response to RT-induced damage could decrease the efficacy of further fractions of RT.
Abstract Early diagnosis of cirrhosis is crucial for improving patient prognosis. This study aims to investigate signature genes and their correlation with immune cell infiltration in cirrhosis. We utilized a liver cirrhosis patient dataset obtained from the GEO database to identify differentially expressed genes (DEGs). Weighted gene co-expression network analysis (WGCNA), least absolute shrinkage and selection operator (LASSO), and random forest analysis were employed to identify signature genes, including RGS1, DEFB1, and ANOS2P. Subsequently, gene set enrichment analysis (GSEA) revealed that these signature genes are associated with positive correlations with allograft rejection and the focal adhesion pathway. Moreover, CIBERSORT analysis suggested potential involvement of these signature genes in immune cell infiltration within cirrhotic conditions. This study enhances our understanding of cirrhosis pathogenesis and may contribute to the development of early diagnostic tools and therapeutic strategies.
Hyperandrogenism is a key pathological characteristic of polycystic ovary syndrome (PCOS). Tumor necrosis factor α (TNF-α) is both an adipokine and a chronic inflammatory factor, which has been proven to be involved in the pathologic process of PCOS. This study aimed to determine how TNF-α affects glucose uptake in human granulosa cells in the presence of high testosterone concentration.KGN cell line was treated with testosterone and TNF-α alone or co-culture combination for 24 hr, or starved for 24 hr. Quantitative real-time polymerase chain reaction (qPCR) and western blot were performed to measure glucose transporter type 4 (GLUT4) message RNA (mRNA) and protein expression in treated KGN cells. Glucose uptake and GLUT4 expression were detected by immunofluorescence (IF). Furthermore, western blot was performed to measure the contents in the nuclear factor kappa-B (NF-κB) pathway. Meantime, upon addition of TNF-α receptor II (TNFRII) inhibitor or Inhibitor of nuclear factor kappa-B kinase subunit beta (IKKβ) antagonist to block the TNFRII-IKKβ-NF-κB signaling pathway, the glucose uptake in KGN cells and GLUT4 translocation to cytomembrane were detected by IF, and related proteins in TNFRII-IKKβ-NF-κB were detected by western blot.The glucose uptake in Testosterone + TNF-α group was lowered significantly, and Total GLUT4 mRNA and proteins were reduced significantly. GLUT4 translocation to cytomembrane was tarnished visibly; concurrently, the phosphorylated proteins in the TNFRII-IKKβ-NF-κB signaling pathway were enhanced significantly. Furthermore, upon addition of TNFRII inhibitor or IKKβ inhibitor to block the TNFRII-IKKβ-NF-κB signaling pathway, the glucose uptake of treated granulosa cells was improved.TNFRII and IKKβ antagonists may improve glucose uptake in granulosa cells induced by TNF-α by blocking the TNFRII-IKKβ-NF-κB signaling pathway under high androgen conditions.
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