Liver Nuclear Activation of Carbon Tetrachloride or Bromotrichloromethane to Trichloromethyl and Trichloromethylperoxyl Free Radicals.Their Reactions With Lipids and Proteins

The formation of·CCl3 radicals in liver nuclei was suggested by spin trapping of them with N-t-butyl-α-phenylnitrone followed by GC/MS detection of the resulting adduct. Comparison of its formation in microsomal biotransformation of CCl4 was made. In aerobic nuclear activation mixtures containing NADPH and CCl4, significant decrease in the arachidonic acid content of nuclear lipids was observed (27. 8%, compared to control), the intensity of this decrease was lower than that occurring in the corresponding microsomal incubation mixtures (29.1%). Significant decreases in arachidonic acid content of nuclear and endoplasmic reticulum lipids were also observed in animals at 6 hours of poisoning with the haloalkane. During aerobic nuclear metabolism of CCl4 or CBrCl3, cholesterol oxidation products were detected: a ketocholesterol, an epoxide like structure and 7-ketocholesterol. Nuclear protein carbonyl formation was not promoted during nuclear CCl4 biotransformation. NADPH by itself may lead to protein carbonyl formation during prolonged periods of incubation. CBrCl3 in contrast, led to decreased protein carbonyl formation. No increase in nuclear protein carbonyl formation was observed in CCl4 intoxicated animals during periods of time between 1 to 6 hours after treatment. The results indicate that during nuclear biotransformation of CCl4 or CBrCl3 reactive free radicals, PUFA degradation, reactive aldehydes and cholesterol oxidation products are formed, nearby DNA and regulatory proteins.

Transition-metal-catalyzed C-H functionalization for late-stage modification of peptides and proteins

Late-stage modification of peptides and proteins meets the increasing demand in biochemical and pharmaceutical communities. These modification strategies could provide functionalized nonproteinogenic analogues with enhanced biological activities or improved therapeutic capabilities compared to their natural counterparts. Recent years, transition-metal-promoted functionalization of ubiquitous C-H bonds has been emerged as a powerful and tunable tool in this area, both for backbone diversifications and labeling of specific moieties. These reactions were flexible and expedient in both academic and industrial laboratories, especially considering their atom and step-economy, good functional group compatibility, accurate site selectivity. This review surveys the progress achieved in the late-stage modification of peptides and proteins utilizing transition-metal-catalyzed C-H functionalization with C-C and C-X(F, Cl, O, N, B, etc.) bonds formation.

Expert systems for HPLC in biochemistry—The knowledge base for selection of HPLC column system in the separation of amino acids, peptides and proteins

The strategy of expert system for high performance liquid chromatography was discussed, the attentions are mainly placed on the knowledge base for selection of column system, separation modes and detection modes in the analysis of amino acids, peptides and proteins.

Analysis of Proteotranscriptomics Landscape Reveals Differentially Regulated Pathways in Toxoplasma gondii Infected Mouse Liver

Toxoplasma gondii (T. gondii) an intracellular protozoan parasite, infects mammals including human population world-wide. Upon primary infection, the parasite contributes to mild flu like symptoms in immune competent host, but life threatening complication is seen in immune compromised patients and in pregnant women. Understanding the host-parasite interaction is critical for understanding the pathogenesis and biology parasite reactivation in the host. In this study, we used proteotrasncriptomics analyses by integrating the transcriptomics and proteomics data of T. gondii infected mouse liver to uncover the effector molecules responsible for disease pathogenesis that can be used as candidate markers for diagnosis and drug target. With this aim, we systematically integrated transcriptomicand proteomic data, representing the parasite infected mouse liver. Out of 2758 differentially expressed genes (DEGs) and 301 differentially expressed proteins (DEPs), 159 overlapping genes were identified. Among them, 86 genes were upregulated and 72 were downregulated in their respective mRNA and protein levels in the infected condition. Gene Ontology (GO) analysis revealed that the upregulated genes were mostly associated with immune system processes whereas the downregulated genes were involved in oxidation-reduction process and metabolism of lipid, and fatty acids. Protein-protein interaction (PPI) network analysis uncovered an interaction-hub including, Psmb8, Psmb9 and Tap1 for upregulated proteins and Cyp1A2, Cyp4A10 and Cyp3A11 for down-regulated proteins. Further studies are needed to validating these effector molecules. These molecules are likely to play a vital role in disease pathogenesis, as well as can be used as potential diagnostic marker and drug target candidates.

COVID-19,liver dysfunction and pathophysiology:A conceptual discussion

The intra and extracellular pathways of hepatic injury by coronavirus disease 2019(COVID-19)are still being studied.Understanding them is important to treat this viral disease and other liver and biliary tract disorders.Thus,this paper aims to present three hypotheses about liver injury caused by COVID-19:(1)The interactions between severe acute respiratory syndrome coronavirus 2 spike protein and membrane receptors in the hepatocyte;(2)The dysbiosis and"gutliver axis"disruption in patients with serious clinical presentations of COVID-19;and(3)The inflammatory response exacerbated through the production of interleukins such as interleukin-6.However,despite these new perspectives,the pathophysiological process of liver injury caused by COVID-19 is still complex and multifactorial.Thus,understanding all these variables is a challenge to science but also the key to propose individualized and effective patient therapies.

Expression and significance of the vascular permeability factor in nasal polyps

目的探讨血管通透性因子(vascular permeability factor, VPF)在鼻息肉组织中的表达及意义.方法将9例鼻息肉标本及8例下鼻甲粘膜标本行VPF及其受体flk-1的免疫组化染色,光镜观查.结果 VPF在鼻息肉组织的血管内皮细胞和腺体细胞的表达明显高于下鼻甲组织(P<0.01,P<0.05),flk-1在血管内皮细胞的表达明显高于下鼻甲组织(P<0.01).结论 VPF对鼻息肉发生过程中组织极度水肿的产生可能有非常重要的作用.

Extracellular domain of kinase domain region mediated by adeno-associated virus inhibits growth and angiogenesis of bladder cancer in Balb-c mice

OBJECTIVE: To verify whether the extracellular domain of kinase domain region (KDR) has anti-angiogenesis activity in vivo. METHODS: cDNA was cloned into adeno-associated virus (AAV) vector pSNAV and transfected to baby hamster kidney (BHK) cells. Recombinant AAV was obtained from the cell culture supernatant after adding helper virus. Recombinant AAV-infected human bladder cancer EJ cell line (EJ cells) were injected subcutaneously into Balb-c nude mice. Tumor specimens were removed from the mice, paraffin-embedded and sliced, then stained by immunohistochemistry. Microvessel density (MVD) was determined under a microscope. RESULTS: The tumor volume developed by EJ cells transfected with the extracellular domain of KDR was significantly smaller (1.70 +/- 0.18 cm(3)) compared with that in the control (5.62 +/- 0.67 cm(3)) (P

Tumor Interstitial Fluid and Gastric Cancer Metastasis:An Experimental Study to Verify the Hypothesis of "Tumor-Phlegm Microenvironment"

Objective： To extract tumor interstitial fluid （TIF） from MKN-45 gastric cancer which is similar to ＂muddy phlegm＂ in Chinese medicine and observe influences of MKN-45 tumor interstitial fluid （MKN-45 TIF） intervention on metastasis of gastric cancer and on the expressions of vascular endothelial growth factor （VEGF）, kinase insert domain containing receptor （KDR）, epithelial-cadherin （E-cad）, cyclooxygenase-2 （COX-2）, intercellular adhesion molecule-1 （ICAM-1） and telomerase genes and proteins in primary tumor tissue. Methods： An MKN-45 tumor-bearing model was established in 50 nude mice. The modeled animals were equally randomized to 5 groups： the simple tumor-bearing group （model group）, the normal saline （NS） via tail vein injection （i.v.） group （NS i.v. group）, MKN-45 TIF i.v. group （TIF i.v. group）, NS intraperitoneal injection （i.p.） group （NS i.p. group）, and MKN-45 TIF i.p. group （TIF i.p. group）. The TIF and NS intervention groups received injection （i.p. or i.v.） of MKN-45 TIF or NS twice a week, 0.2 mL at a time. After 8 weeks, the primary tumors were removed, weighed and HE stained to observe tumor metastasis. The primary tumor tissues were analyzed by immunohistochemistry and real-time quantitative PCR to detect expressions of VEGF, KDR, E-cad, COX-2, ICAM-1, and telomerase genes and proteins in different groups. Results： There were significant differences in tumor weight between TIF intervention groups and the model and NS intervention groups. Tumor metastasis was observed in all 5 groups, but the tumor metastasis rate in TIF intervention groups was significantly higher than those in the model and NS intervention groups. The gene and protein expressions of gastric cancer-related factors VEGF, KDR, COX-2, ICAM-1 and telomerase were unregulated while the gene and protein expressions of E-cad were downregulated in TIF intervention groups. Conclusions： TIF promotes tumor growth, invasion and metastasis of gastric cancer. These findings provide preliminary experimental clues for verifying the hypothesis of ＂tumor-phlegm microenvironment＂.