Fumarate inhibits PTEN to promote tumorigenesis and therapeutic resistance of type2 papillary renal cell carcinoma.

Fumarate is an oncometabolite. However, the mechanism underlying fumarate-exerted tumorigenesis remains unclear. Here, utilizing human type2 papillary renal cell carcinoma (PRCC2) as a model, we show that fumarate accumulates in cells deficient in fumarate hydratase (FH) and inhibits PTEN to activate PI3K/AKT signaling. Mechanistically, fumarate directly reacts with PTEN at cysteine 211 (C211) to form S-(2-succino)-cysteine. Succinated C211 occludes tethering of PTEN with the cellular membrane, thereby diminishing its inhibitory effect on the PI3K/AKT pathway. Functionally, re-expressing wild-type FH or PTEN C211S phenocopies an AKT inhibitor in suppressing tumor growth and sensitizing PRCC2 to sunitinib. Analysis of clinical specimens indicates that PTEN C211 succination levels are positively correlated with AKT activation in PRCC2. Collectively, these findings elucidate a non-metabolic, oncogenic role of fumarate in PRCC2 via direct post-translational modification of PTEN and further reveal potential stratification strategies for patients with FH loss by combinatorial AKTi and sunitinib therapy.

A new approach for reducing pollutants level: a longitudinal cohort study of physical exercises in young people.

BACKGROUND: The present study aimed to evaluate the elimination of three common pollutants (dimethoate, benzo(a)pyrene (BaP) and bisphenol A (BPA) by different physical exercises and to assess the possible factors which could affect the pollutants elimination. METHODS: A total of 200 individuals who chose different kinds of exercises in accordance to their own wish were recruited. The levels of urinary pollutants were measured using ß-glucuronidase hydrolysis followed by a high-performance liquid chromatography tandem mass spectrometry-based method. RESULTS: Totally, the levels of dimethoate, BaP and BPA were reduced after physical exercises. However, the elimination of BaP in male was higher than that in female but the elimination of BPA in female was higher than that in male. Multivariate logistic regression showed that the degree of heart rate (HR) change was a protective factor affecting the improvement effect of dimethoate, BaP and BPA while BMI (body mass index) was a risk factor. Nevertheless, sex was a risk factor affecting the improvement of dimethoate and BaP but had a lower efficacy on BPA improvement. CONCLUSION: The present findings indicate that physical exercises can be considered as a novel approach to eliminate pollutants level in human body and can also give suggestions for choosing specific physical exercises to male and female individuals. Moreover, those who are with higher BMI need to lose weight before eliminating pollutant level through physical exercises.

Role of Ezrin in Asthma-Related Airway Inflammation and Remodeling.

Ezrin is an actin binding protein connecting the cell membrane and the cytoskeleton, which is crucial to maintaining cell morphology, intercellular adhesion, and cytoskeleton remodeling. Asthma involves dysfunction of inflammatory cells, cytokines, and airway structural cells. Recent studies have shown that ezrin, whose function is affected by extensive phosphorylation and protein interactions, is closely associated with asthma, may be a therapeutic target for asthma treatment. In this review, we summarize studies on ezrin and discuss its role in asthma-related airway inflammation and remodeling.

Urinary levels of dimethoate, bisphenol A and benzo[a]pyrene in first-year students of Hohai University from different geographical regions.

BACKGROUND: The objective of this study was to detect the urinary levels of dimethoate, benzo(a) pyrene (BaP), and bisphenol A (BPA) in first-year Hohai University students with different geographic origins. METHODS: First-morning urine samples were collected from 540 healthy freshmen aged 17 to 19 years. Chemical levels were measured using ß-glucuronidase hydrolysis followed by a high-performance liquid chromatography-tandem mass spectrometry-based method. Geometric means (GMs) of these three chemicals are presented by body mass index (BMI) and location in a volume-based and creatinine-standardized way. RESULTS: GM concentrations of omethoate, BPA and 3-OHBaP were 9.47 µg/L (10.80 µg/g creatinine), 3.54 µg/L (4.04 µg/g creatinine) and 0.34 ng/L (0.39 ng/g creatinine), respectively. The GM concentration of omethoate in males was significantly higher than that in females. The individuals with a BMI higher than 23.9 had higher GM concentrations of omethoate, BPA, and 3-OHBaP. The inhabitants of Southwest China had significantly lower GM concentrations of omethoate, BPA, and 3-OHBaP than those who lived in other locations in China. CONCLUSION: The average level of environmental chemical accumulation in freshmen is lower in Southwest China and differs in youth who live in different regions. In addition, obesity is correlated with higher toxin levels in youth.

Integrative proteomics and immunochemistry analysis of the factors in the necrosis and repair in acetaminophen-induced acute liver injury in mice.

Acetaminophen (APAP) overdose-induced acute liver injury (AILI) is a significant clinical problem worldwide, the hepatotoxicity mechanisms are well elucidated, but the factors involved in the necrosis and repair still remain to be investigated. APAP was injected intraperitoneally in male Institute of Cancer Research (ICR) mice. Quantitative proteome analysis of liver tissues was performed by 2-nitrobenzenesulfenyl tagging, two-dimensional-nano high-performance liquid chromatography separation, and matrix-assisted laser desorption/ionization-time of flight mass spectrometry analysis. Diffrenetial proteins were verified by the immunochemistry method. 36 and 44 differentially expressed proteins were identified, respectively, at 24 hr after APAP (200 or 300 mg·kg -1 ) administration. The decrease in the mitochondrial protective proteins Prdx6, Prdx3, and Aldh2 accounted for the accumulation of excessive reactive oxygen species (ROS) and aldehydes, impairing mitochondria structure and function. The Gzmf combined with Bax and Apaf-1 jointly contributed to the necrosis. The blockage of Stat3 activation led to the overexpression of unphosphorylated Stat3 and the overproduction of Bax. The overexpression of unphosphorylated Stat3 represented necrosis; the alternation from Stat3 to p-Stat3 in necrotic regions represented hepatocytes from death to renewal. The high expressions of P4hα1, Ncam, α-SMA, and Cygb were involved in the liver repair, they were not only the markers of activated HSC but also represented an intermediate stage of hepatocytes from damage or necrosis to renewal. Our data provided a comprehensive report on the profile and dynamic changes of the liver proteins in AILI; the involvement of Gzmf and the role of Stat3 in necrosis were revealed; and the role of hepatocyte in liver self-repair was well clarified.

Inhibition of GGPPS1 attenuated LPS-induced acute lung injury and was associated with NLRP3 inflammasome suppression.

Inhibition of the mevalonate pathway using statins has been shown to be beneficial in the treatment of acute lung injury (ALI). Here, we investigated whether partial inhibition of this pathway by targeting geranylgeranyl pyrophosphate synthase large subunit 1 (GGPPS1), a catalase downstream of the mevalonate pathway, was effective at treating lung inflammation in ALI. Lipopolysaccharide (LPS) was intratracheally instilled to induce ALI in lung-specific GGPPS1-knockout and wild-type mice. Expression of GGPPS1 in lung tissues and alveolar epithelial cells was examined. The severity of lung injury and inflammation was determined in lung-specific GGPPS1 knockout and wild-type mice by measuring alveolar exudate, neutrophil infiltration, lung injury, and cell death. Change in global gene expression in response to GGPPS1 depletion was measured using mRNA microarray and verified in vivo and in vitro. We found that GGPPS1 levels increased significantly in lung tissues and alveolar epithelial cells in LPS-induced ALI mice. Compared with wild-type and simvastatin treated mice, the specific deletion of pulmonary GGPPS1 attenuated the severity of lung injury by inhibiting apoptosis of AECs. Furthermore, deletion of GGPPS1 inhibited LPS-induced inflammasome activation, in terms of IL-1ß release and pyroptosis, by downregulating NLRP3 expression. Finally, downregulation of GGPPS1 reduced the membrane expression of Ras-related protein Rab10 and Toll-like receptor 4 (TLR4) and inhibited the phosphonation of IκB. This effect might be attributed to the downregulation of GGPP levels. Our results suggested that inhibition of pulmonary GGPPS1 attenuated LPS-induced ALI predominantly by suppressing the NLRP3 inflammasome through Rab10-mediated TLR4 replenishment.

Click-Chemistry-Mediated Rapid Microbubble Capture for Acute Thrombus Ultrasound Molecular Imaging.

Bioorthogonal coupling chemistry has been studied as a potentially advantageous approach for molecular imaging because it offers rapid, efficient, and strong binding, which might also benefit stability, production, and chemical conjugation. The inverse-electron-demand Diels-Alder reaction between a 1,2,4,5-tetrazine and trans-cyclooctene (TCO) is an example of a highly selective and rapid bioorthogonal coupling reaction that has been used successfully to prepare targeted molecular imaging probes. Here we report a fast, reliable, and highly sensitive approach, based on a two-step pretargeting bioorthogonal approach, to achieving activated-platelet-specific CD62p-targeted thrombus ultrasound molecular imaging. Tetrazine-modified microbubbles (tetra-MBs) could be uniquely and rapidly captured by subsequent click chemistry of thrombus tagged with a trans-cyclooctene-pretreated CD62p antibody. Moreover, such tetra-MBs showed great long-term stability under physiological conditions, thus offering the ability to monitor thrombus changes in real time. We demonstrated for the first time that a bioorthogonal targeting molecular ultrasound imaging strategy based on tetra-MBs could be a simple but powerful tool for rapid diagnosis of acute thrombosis.

The alteration of protein prenylation induces cardiomyocyte hypertrophy through Rheb-mTORC1 signalling and leads to chronic heart failure.

G protein-regulated cell function is crucial for cardiomyocytes, and any deregulation of its gene expression or protein modification can lead to pathological cardiac hypertrophy. Herein, we report that protein prenylation, a lipidic modification of G proteins that facilitates their association with the cell membrane, might control the process of cardiomyocyte hypertrophy. We found that geranylgeranyl diphosphate synthase (GGPPS), a key enzyme involved in protein prenylation, played a critical role in postnatal heart growth by regulating cardiomyocyte size. Cardiac-specific knockout of GGPPS in mice led to spontaneous cardiac hypertrophy, beginning from week 4, accompanied by the persistent enlargement of cardiomyocytes. This hypertrophic effect occurred by altered prenylation of G proteins. Evaluation of the prenylation, membrane association and hydrophobicity showed that Rheb was hyperactivated and increased mTORC1 signalling pathway after GGPPS deletion. Protein farnesylation or mTORC1 inhibition blocked GGPPS knockdown-induced mTORC1 activation and suppressed the larger neonatal rat ventricle myocyte size and cardiomyocyte hypertrophy in vivo, demonstrating a central role of the FPP-Rheb-mTORC1 axis for GGPPS deficiency-induced cardiomyocyte hypertrophy. The sustained cardiomyocyte hypertrophy progressively provoked cardiac decompensation and dysfunction, ultimately causing heart failure and adult death. Importantly, GGPPS was down-regulated in the hypertrophic hearts of mice subjected to transverse aortic constriction (TAC) and in failing human hearts. Moreover, HPLC-MS/MS detection revealed that the myocardial farnesyl diphosphate (FPP):geranylgeranyl diphosphate (GGPP) ratio was enhanced after pressure overload. Our observations conclude that the alteration of protein prenylation promotes cardiomyocyte hypertrophic growth, which acts as a potential cause for pathogenesis of heart failure and may provide a new molecular target for hypertrophic heart disease clinical therapy.

GSTpi protects against angiotensin II-induced proliferation and migration of vascular smooth muscle cells by preventing signal transducer and activator of transcription 3 activation.

Angiotensin II (Ang II)-elicited excessive proliferation, hypertrophy and migration of vascular smooth muscle cells (VSMCs) are vital to the pathogenesis of atheroclerosis. Glutathione S-transferase pi (GSTpi) exists extensively in various kinds of cells and protects cells against different stresses. However, knowledge remains limited about what GSTpi acts in VSMCs. We investigated the effect of GSTpi on Ang II-induced VSMC proliferation, hypertrophy and migration and its latent mechanism. Overexpression and RNAi experiments demonstrated that GSTpi inhibited Ang II-induced proliferation, hypertrophy and migration of VSMCs and arrested progression of cell cycle from G0/G1 to S phase. Immunoprecipitation, mass spectrometry and confocal microscopy analyses showed that GSTpi directly associated with signal transducer and activator of transcription 3 (STAT3) to prevent Ang II-triggered binding of Src to STAT3 and thus suppressed Ang II-stimulated phosphorylation and nuclear translocation of STAT3, as well as cyclin D1 expression. In contrast, GSTpi didn't affect Ang II-activated extracellular signal-regulated kinase (ERK1/2). GSTpi acts as a negative regulator to prevent Ang II-triggered proliferative signaling in VSMCs, suggesting that it may protect vessels against the stresses associated with atherosclerosis formation.

Reactivating PTEN to impair glioma stem cells by inhibiting cytosolic iron-sulfur assembly.

Glioblastoma, the most lethal primary brain tumor, harbors glioma stem cells (GSCs) that not only initiate and maintain malignant phenotypes but also enhance therapeutic resistance. Although frequently mutated in glioblastomas, the function and regulation of PTEN in PTEN-intact GSCs are unknown. Here, we found that PTEN directly interacted with MMS19 and competitively disrupted MMS19-based cytosolic iron-sulfur (Fe-S) cluster assembly (CIA) machinery in differentiated glioma cells. PTEN was specifically succinated at cysteine (C) 211 in GSCs compared with matched differentiated glioma cells. Isotope tracing coupled with mass spectrometry analysis confirmed that fumarate, generated by adenylosuccinate lyase (ADSL) in the de novo purine synthesis pathway that is highly activated in GSCs, promoted PTEN C211 succination. This modification abrogated the interaction between PTEN and MMS19, reactivating the CIA machinery pathway in GSCs. Functionally, inhibiting PTEN C211 succination by reexpressing a PTEN C211S mutant, depleting ADSL by shRNAs, or consuming fumarate by the US Food and Drug Administration-approved prescription drug N-acetylcysteine (NAC) impaired GSC maintenance. Reexpressing PTEN C211S or treating with NAC sensitized GSC-derived brain tumors to temozolomide and irradiation, the standard-of-care treatments for patients with glioblastoma, by slowing CIA machinery-mediated DNA damage repair. These findings reveal an immediately practicable strategy to target GSCs to treat glioblastoma by combination therapy with repurposed NAC.

Hypoxanthine phosphoribosyl transferase 1 metabolizes temozolomide to activate AMPK for driving chemoresistance of glioblastomas.

Temozolomide (TMZ) is a standard treatment for glioblastoma (GBM) patients. However, TMZ has moderate therapeutic effects due to chemoresistance of GBM cells through less clarified mechanisms. Here, we demonstrate that TMZ-derived 5-aminoimidazole-4-carboxamide (AICA) is converted to AICA ribosyl-5-phosphate (AICAR) in GBM cells. This conversion is catalyzed by hypoxanthine phosphoribosyl transferase 1 (HPRT1), which is highly expressed in human GBMs. As the bona fide activator of AMP-activated protein kinase (AMPK), TMZ-derived AICAR activates AMPK to phosphorylate threonine 52 (T52) of RRM1, the catalytic subunit of ribonucleotide reductase (RNR), leading to RNR activation and increased production of dNTPs to fuel the repairment of TMZ-induced-DNA damage. RRM1 T52A expression, genetic interruption of HPRT1-mediated AICAR production, or administration of 6-mercaptopurine (6-MP), a clinically approved inhibitor of HPRT1, blocks TMZ-induced AMPK activation and sensitizes brain tumor cells to TMZ treatment in mice. In addition, HPRT1 expression levels are positively correlated with poor prognosis in GBM patients who received TMZ treatment. These results uncover a critical bifunctional role of TMZ in GBM treatment that leads to chemoresistance. Our findings underscore the potential of combined administration of clinically available 6-MP to overcome TMZ chemoresistance and improve GBM treatment.

Sterol regulatory element-binding protein 2 maintains glioblastoma stem cells by keeping the balance between cholesterol biosynthesis and uptake.

BACKGROUND: Glioblastomas (GBMs) display striking dysregulation of metabolism to promote tumor growth. Glioblastoma stem cells (GSCs) adapt to regions of heterogeneous nutrient availability, yet display dependency on de novo cholesterol biosynthesis. The transcription factor Sterol Regulatory Element-Binding Protein 2 (SREBP2) regulates cholesterol biosynthesis enzymes and uptake receptors. Here, we investigate adaptive behavior of GSCs under different cholesterol supplies. METHODS: In silico analysis of patient tumors demonstrated enrichment of cholesterol synthesis associated with decreased angiogenesis. Comparative gene expression of cholesterol biosynthesis enzymes in paired GBM specimens and GSCs were performed. In vitro and in vivo loss-of-function genetic and pharmacologic assays were conducted to evaluate the effect of SREBP2 on GBM cholesterol biosynthesis, proliferation, and self-renewal. Chromatin immunoprecipitation quantitative real-time PCR was leveraged to map the regulation of SREBP2 to cholesterol biosynthesis enzymes and uptake receptors in GSCs. RESULTS: Cholesterol biosynthetic enzymes were expressed at higher levels in GBM tumor cores than in invasive margins. SREBP2 promoted cholesterol biosynthesis in GSCs, especially under starvation, as well as proliferation, self-renewal, and tumor growth. SREBP2 governed the balance between cholesterol biosynthesis and uptake in different nutrient conditions. CONCLUSIONS: SREBP2 displays context-specific regulation of cholesterol biology based on its availability in the microenvironment with induction of cholesterol biosynthesis in the tumor core and uptake in the margin, informing a novel treatment strategy for GBM.

Dual Role of CXCL8 in Maintaining the Mesenchymal State of Glioblastoma Stem Cells and M2-Like Tumor-Associated Macrophages.

PURPOSE: The dynamic interplay between glioblastoma stem cells (GSC) and tumor-associated macrophages (TAM) sculpts the tumor immune microenvironment (TIME) and promotes malignant progression of glioblastoma (GBM). However, the mechanisms underlying this interaction are still incompletely understood. Here, we investigate the role of CXCL8 in the maintenance of the mesenchymal state of GSC populations and reprogramming the TIME to an immunosuppressive state. EXPERIMENTAL DESIGN: We performed an integrative multi-omics analyses of RNA sequencing, GBM mRNA expression datasets, immune signatures, and epigenetic profiling to define the specific genes expressed in the mesenchymal GSC subsets. We then used patient-derived GSCs and a xenograft murine model to investigate the mechanisms of tumor-intrinsic and extrinsic factor to maintain the mesenchymal state of GSCs and induce TAM polarization. RESULTS: We identified that CXCL8 was preferentially expressed and secreted by mesenchymal GSCs and activated PI3K/AKT and NF-κB signaling to maintain GSC proliferation, survival, and self-renewal through a cell-intrinsic mechanism. CXCL8 induced signaling through a CXCR2-JAK2/STAT3 axis in TAMs, which supported an M2-like TAM phenotype through a paracrine, cell-extrinsic pathway. Genetic- and small molecule-based inhibition of these dual complementary signaling cascades in GSCs and TAMs suppressed GBM tumor growth and prolonged survival of orthotopic xenograft-bearing mice. CONCLUSIONS: CXCL8 plays critical roles in maintaining the mesenchymal state of GSCs and M2-like TAM polarization in GBM, highlighting an interplay between cell-autonomous and cell-extrinsic mechanisms. Targeting CXCL8 and its downstream effectors may effectively improve GBM treatment.

Analysis of the differentially expressed low molecular weight peptides in human serum via an N-terminal isotope labeling technique combining nano-liquid chromatography/matrix-assisted laser desorption/ionization mass spectrometry.

RATIONALE: Peptidomics analysis of human serum is challenging due to the low abundance of serum peptides and interference from the complex matrix. This study analyzed the differentially expressed (DE) low molecular weight peptides in human serum integrating a DMPITC-based N-terminal isotope labeling technique with nano-liquid chromatography and matrix-assisted laser desorption/ionization mass spectrometry (nano-LC/MALDI-MS). METHODS: The workflow introduced a [d(6)]-4,6-dimethoxypyrimidine-2-isothiocyanate (DMPITC)-labeled mixture of aliquots from test samples as the internal standard. The spiked [d(0)]-DMPITC-labeled samples were separated by nano-LC then spotted on the MALDI target. Both quantitative and qualitative studies for serum peptides were achieved based on the isotope-labeled peaks. RESULTS: The DMPITC labeling technique combined with nano-LC/MALDI-MS not only minimized the errors in peptide quantitation, but also allowed convenient recognition of the labeled peptides due to the 6 Da mass difference. The data showed that the entire research procedure as well as the subsequent data analysis method were effective, reproducible, and sensitive for the analysis of DE serum peptides. CONCLUSIONS: This study successfully established a research model for DE serum peptides using DMPITC-based N-terminal isotope labeling and nano-LC/MALDI-MS. Application of the DMPITC-based N-terminal labeling technique is expected to provide a promising tool for the investigation of peptides in vivo, especially for the analysis of DE peptides under different biological conditions.

Oleanolic Acid (OA) Targeting UNC5B Inhibits Proliferation and EMT of Ovarian Cancer Cell and Increases Chemotherapy Sensitivity of Niraparib.

OBJECTIVE: To investigate the effect of OA on proliferation, migration, and epithelial-mesenchymal transition (EMT) of ovarian cancer cells by inhibiting UNC5B and to study its mechanism. METHODS: TCGA database was used to analyze the expression of UNC5B in ovarian cancer and its relationship with prognosis. The expression of UNC5B in ovarian cancer cells was detected by qPCR assay. qRT-PCR was used to detect the changes of EMT markers after different treatments. CCK-8 assay was used to detect cell proliferation, transwell assay was used to evaluate cell migration, and clonogenesis assay was used to evaluate the effect of UNC5B on ovarian cancer cell proliferation. Meanwhile, the synergistic effect of OA on niraparib was evaluated. RESULTS: UNC5B was highly expressed in ovarian cancer, and its expression was negatively correlated with the prognosis of ovarian cancer patients. UNC5B was highly expressed in ovarian cancer cells SKOV3 and OVCA420 compared with normal ovarian epithelial cells. In addition, silencing UNC5B inhibits the proliferation, invasion, clonogenesis, and EMT processes of ovarian cancer cells. OA inhibits proliferation, invasion, and clonogenesis of ovarian cancer cells by inhibiting UNC5B and increases the antitumor activity of niraparib. CONCLUSION: UNC5B acts as an oncogenic gene in ovarian cancer. OA inhibits ovarian cancer cell proliferation, migration, and EMT by targeting UNC5B and increases the antitumor effect of niraparib. UNC5B is expected to be a new potential therapeutic target for ovarian cancer. OA may be used as an antitumor drug and deserves further study.

Salidroside reduces neuropathology in Alzheimer's disease models by targeting NRF2/SIRT3 pathway.

BACKGROUND: Neurite dystrophy is a pathologic hallmark of Alzheimer's disease (AD). However, drug discovery targeting neurite protection in AD remains largely unexplored. METHODS: Aß-induced neurite and mitochondrial damage assays were used to evaluate Aß toxicity and the neuroprotective efficacy of a natural compound salidroside (SAL). The 5×FAD transgenic mouse model of AD was used to study the neuroprotective function of SAL. To verify the direct target of SAL, we used surface plasmon resonance and cellular thermal shift assays to analyze the drug-protein interaction. RESULTS: SAL ameliorates Aß-mediated neurite damage in cell culture. We further reveal that SAL represses mitochondrial damage in neurites by promoting mitophagy and maintaining mitochondrial homeostasis, dependent on an NAD-dependent deacetylase SIRT3. In AD mice, SAL protects neurite morphology, mitigates Aß pathology, and improves cognitive function, which are all SIRT3-dependent. Notably, SAL directly binds to transcription factor NRF2, inhibits its degradation by blocking its interaction with KEAP1 ubiquitin ligase, and then advances NRF2-mediated SIRT3 transcription. CONCLUSIONS: Overall, we demonstrate that SAL, a potential anti-aging drug candidate, attenuates AD pathology by targeting NRF2/SIRT3 pathway for mitochondrial and neurite protection. Drug discovery strategies focusing on SAL may thus provide promising therapeutics for AD.

A Buthus martensii Karsch scorpion sting targets Nav1.7 in mice and mimics a phenotype of human chronic pain.

ABSTRACT: Gain-of-function and loss-of-function mutations in Nav1.7 cause chronic pain and pain insensitivity, respectively. The preferential expression of Nav1.7 in the peripheral nervous system and its role in human pain signaling make Nav1.7 a promising target for next-generation pain therapeutics. However, pharmacological agents have not fully recapitulated these pain phenotypes, and because of the lack of subtype-selective molecular modulators, the role of Nav1.7 in the perception of pain remains poorly understood. Scorpion venom is an excellent source of bioactive peptides that modulate various ion channels, including voltage-gated sodium (Nav) channels. Here, we demonstrate that Buthus martensii Karsch scorpion venom (BV) elicits pain responses in mice through direct enhancement of Nav1.7 activity and have identified Makatoxin-3, an α-like toxin, as a critical component for BV-mediated effects on Nav1.7. Blocking other Nav subtypes did not eliminate BV-evoked pain responses, supporting the pivotal role of Nav1.7 in BV-induced pain. Makatoxin-3 acts on the S3-S4 loop of voltage sensor domain IV (VSD4) of Nav1.7, which causes a hyperpolarizing shift in the steady-state fast inactivation and impairs inactivation kinetics. We also determined the key residues and structure-function relationships for the toxin-channel interactions, which are distinct from those of other well-studied α toxins. This study not only reveals a new mechanism underlying BV-evoked pain but also enriches our knowledge of key structural elements of scorpion toxins that are pivotal for toxin-Nav1.7 interactions, which facilitates the design of novel Nav1.7 selective modulators.

Characterization and sequence identification of angiotensin II by a novel method involving ultra-fast liquid chromatography assay coupled with matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight five tandem mass spectrometry analysis.

High-throughput proteomics aims to investigate dynamically changing proteins expressed by a full organism, specific tissue or cellular compartment under certain conditions. High-sensitivity mass spectrometry has gradually become a significant tool for characterizing peptides. Here, we analyzed angiotensin II using ultra-fast liquid chromatography (UFLC) coupled with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-ToF MS). First, we applied UFLC in isolating and collecting the angiotensin II, and then Axima-Resonance (MALDI-QIT-ToF MS(5)) was adopted, which enables collision-induced dissociation-MS(5) analysis for fine structural characterization of angiotensin II. Resultant MS, MS(2), MS(3) and MS(4) spectra of interested [M+H](+) ions selected as precursor ions yielded detailed information about the sites of fragmentation as well as the amino acid sequence for angiotensin II; meanwhile, the average deviation between theoretical mass and actually measured mass from MS to MS(5) spectra was only 0.32 Da. It indicated that Axima-Resonance was capable of analyzing the peptide sequence accurately and provide the corresponding fragmentation information thoroughly, thus suggesting a potential strategy involving UFLC assay coupled with MALDI-QIT-ToF MS(5) analysis on high-throughput proteomics study in future.

Repeated Herbal Acupoint Sticking Relieved the Recurrence of Allergic Asthma by Regulating the Th1/Th2 Cell Balance in the Peripheral Blood.

Allergic asthma is an inflammatory disease involving the Th1/Th2 cell imbalance in the peripheral blood. Repeated herbal acupoint sticking (RHAS) has been used for hundreds of years in China to relieve the recurrence of allergic asthma, and it is still practiced today. Thus, we explored the effect on allergic asthma relapse and the underlying immunoregulatory mechanism in this study. Here, we enrolled 50 allergic asthma participants, and 38 of them completed the treatment and follow-up (the allergic asthma group). In addition, 13 healthy participants (the control group) were enrolled. The recurrence number of allergic asthma participants and asthma control test (ACT) were used to evaluate the effect of treatment on relieving allergic asthma recurrence. Flow cytometry was performed to analyze the levels of Th1 and Th2 cells in the peripheral blood. The serum levels of IgE, IFN-γ, and IL-4 were detected by ELISA. (1) In the allergic asthma group, compared to before the first treatment, the recurrence number of allergic asthma participants decreased and the ACT score increased at end of the last treatment, 18 and 30 weeks of the trial (P < 0.05). At 18 and 30 weeks of the trial, the recurrence number of allergic asthma participants was less and the ACT score was higher than the ones from the same period last year in the allergic asthma group (P < 0.05). Compared to before the first treatment, the percentage of Th1 cell did not change significantly, the percentage of Th2 cell decreased, and the Th1/Th2 cell ratio increased in the allergic asthma group by the end of the last treatment (P < 0.05). Meanwhile, the release of IgE and IL-4 reduced (P < 0.05), and the release of IFN-γ did not significantly change in the allergic asthma group. (2) Compared with the control group, the serum levels of IgE and IL-4 and the percentage of Th2 cell were higher, and the Th1/Th2 cell ratio was lower in the allergic asthma group (P < 0.05). There was no significant difference between Th1 cell and IFN-γ before the first treatment. (3) Compared with the control group, the IgE levels and the percentage of Th2 cell were higher in the allergic asthma group (P < 0.01). Simultaneously, there was no significant difference between Th1 cell, the Th1/Th2 cell ratio, and the serum levels of IFN-γ and IL-4 by the end of the last treatment. The data suggested that RHAS reduced the amount of Th2 cell and elevated the Th1/Th2 cell ratio, thereby alleviating the inflammatory responses in the allergic asthma participants.