Effect of electroacupuncture intervention on angiogenesis in psoriasis mice. / ç”µé’ˆå¯¹é“¶å±‘ç— å°é¼ è¡€ç®¡ç”Ÿæˆçš„å½±å“åŠæœºåˆ¶ç ”ç©¶.

OBJECTIVES: To observe the effect of electroacupuncture (EA) stimulation of "Zusanli"(ST36) and"Xuehai"(SP10) on the angiogenesis of the local injured skin tissue in mice with psoriasis, so as to explore its mechanisms underlying improvement of psoriasis-induced skin lesions. METHODS: A total of 24 female BALB/c mice aged 6-8 weeks were randomly divided into control, model and EA groups, with 8 mice in each group. The psoriasis-like skin lesion model was established by application of 5% imiquimod (IMQ) cream to the mice's back skin, 62.5 mg/d, for 7 days after local depilation, and the mice of the control group received local application of an equal amount of petroleum jelly once a day for 7 days. EA stimulation (2 Hz/100 Hz) was applied to ST36 and SP10 for 30 min, once daily for 7 consecutive days. Photos of the topical injured skin at the back were taken every day, and the severity of psoriasis lesions (psoriasis area and severity index ï¼»PASIï¼½) was scaled. Following H.E. staining, the morphological changes in the injured skin tissue were observed with epidermal thickness analyzed, and the Masson staining was used to observe the proportion of collagen fibers in the injured skin tissues. Immunohistochemical method was used to detect the expression of microvascular markers CD31 and vascular endothelial growth factor (VEGF) and the microvascular density (MVD) was calculated. Western blot was used to detect the expression levels of CD31, VEGF proteins and mitogen activated protein kinases (MAPK) signaling pathway related proteins p38, phosphorylated p38 (p-p38), extracellular regulated protein kinases (ERK), p-ERK, c-Jun N-terminal kinase (JNK) and p-JNK in the injured skin tissue. RESULTS: Compared with the control group, the mice in the model group showed an evident increase in the erythema score, scales score, skin thickening score and PASI score, epidermal thickness, proportion of the collagen fibers, MVD value of CD31 and VEGF, and expression levels of CD31 and VEGF proteins, and p-p38/p38, p-ERK/ERK and p-JNK/JNK ratios in the injured skin tissue (P<0.001, P<0.01). In contrast to the model group, the EA group had a significant decrease in the levels of all the indexes mentioned above (P<0.05, P<0.01, P<0.001). CONCLUSIONS: EA intervention can improve the psoriasis-like skin lesions induced by IMQ in mice, which may be related with its functions in down-regulating the expression of angiogenic related factors CD31 and VEGF proteins and MAPK signaling pathway related proteins in the topical injured skin tissue.

Catalytic NO Reduction by Noble-Metal-Free Vanadium-Aluminum Oxide Cluster Anions.

By using state-of-the-art mass spectrometry and guided by the newly discovered single-electron mechanism (SEM; e.g., Ti3+ + 2NO → Ti4+-O•- + N2O), we determined experimentally that the vanadium-aluminum oxide clusters V4-xAlxO10-x- (x = 1-3) can catalyze the reduction of NO by CO and substantiated theoretically that the SEM still prevails in driving the catalysis. This finding marks an important step in cluster science in which a noble metal had been demonstrated to be indispensable in NO activation mediated by heteronuclear metal clusters. The results provide new insights into the SEM in which active V-Al cooperative communication favors the transfer of an unpaired electron from the V atom to NO attached to the Al atom on which the reduction reaction actually takes place. This study provides a clear picture for improving our understanding of related heterogeneous catalysis, and the electron hopping behavior induced by NO adsorption could be a fundamental chemistry for driving NO reduction.

Filtration of the preferred catalyst for reverse water-gas shift among Rhn- (n = 3-11) clusters by mass spectrometry under variable temperatures.

The key to optimizing energy-consuming catalytic conversions lies in acquiring a fundamental understanding of the nature of the active sites and the mechanisms of elementary steps at an atomically precise level, while it is challenging to capture the crucial step that determines the overall temperature of a real-life catalytic reaction. Herein, benefiting from a newly-developed high-temperature ion trap reactor, the reverse water-gas shift (CO2 + H2 → CO + H2O) reaction catalyzed by the Rhn- (n = 3-11) clusters was investigated under variable temperatures (298-783 K) and the critical temperature that each elementary step (Rhn- + CO2 and RhnO- + H2) requires to take place was identified. The Rh4- cluster strikingly surpasses other Rhn- clusters to drive the catalysis at a mild starting temperature (∼440 K). This finding represents the first example that a specifically sized cluster catalyst that works under an optimum condition can be accurately filtered by using state-of-the-art mass spectrometric experiments and rationalized by quantum-chemical calculations.

Physical exercise suppresses hepatocellular carcinoma progression by alleviating hypoxia and attenuating cancer stemness through the Akt/GSK-3ß/ß-catenin pathway.

OBJECTIVE: Physical exercise, a common non-drug intervention, is an important strategy in cancer treatment, including hepatocellular carcinoma (HCC). However, the mechanism remains largely unknown. Due to the importance of hypoxia and cancer stemness in the development of HCC, the present study investigated whether the anti-HCC effect of physical exercise is related to its suppression on hypoxia and cancer stemness. METHODS: A physical exercise intervention of swimming (30 min/d, 5 d/week, for 4 weeks) was administered to BALB/c nude mice bearing subcutaneous human HCC tumor. The anti-HCC effect of swimming was assessed in vivo by tumor weight monitoring, hematoxylin and eosin (HE) staining, and immunohistochemistry (IHC) detection of proliferating cell nuclear antigen (PCNA) and Ki67. The expression of stemness transcription factors, including Nanog homeobox (NANOG), octamer-binding transcription factor 4 (OCT-4), v-Myc avian myelocytomatosis viral oncogene homolog (C-MYC) and hypoxia-inducible factor-1α (HIF-1α), was detected using real-time reverse transcription polymerase chain reaction. A hypoxia probe was used to explore the intratumoral hypoxia status. Western blot was used to detect the expression of HIF-1α and proteins related to protein kinase B (Akt)/glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin signaling pathway. The IHC analysis of platelet endothelial cell adhesion molecule-1 (CD31), and the immunofluorescence co-location of CD31 and desmin were used to analyze tumor blood perfusion. SMMC-7721 cells were treated with nude mice serum. The inhibition effect on cancer stemness in vitro was detected using suspension sphere experiments and the expression of stemness transcription factors. The hypoxia status was inferred by measuring the protein and mRNA levels of HIF-1α. Further, the expression of proteins related to Akt/GSK-3ß/ß-catenin signaling pathway was detected. RESULTS: Swimming significantly reduced the body weight and tumor weight in nude mice bearing HCC tumor. HE staining and IHC results showed a lower necrotic area ratio as well as fewer PCNA or Ki67 positive cells in mice receiving the swimming intervention. Swimming potently alleviated the intratumoral hypoxia, attenuated the cancer stemness, and inhibited the Akt/GSK-3ß/ß-catenin signaling pathway. Additionally, the desmin+/CD31+ ratio, rather than the number of CD31+ vessels, was significantly increased in swimming-treated mice. In vitro experiments showed that treating cells with the serum from the swimming intervention mice significantly reduced the formation of SMMC-7721 cell suspension sphere, as well as the mRNA expression level of stemness transcription factors. Consistent with the in vivo results, HIF-1α and Akt/GSK-3ß/ß-catenin signaling pathway were also inhibited in cells treated with serum from swimming group. CONCLUSION: Swimming alleviated hypoxia and attenuated cancer stemness in HCC, through suppression of the Akt/GSK-3ß/ß-catenin signaling pathway. The alleviation of intratumoral hypoxia was related to the increase in blood perfusion in the tumor. Please cite this article as: Xiao CL, Zhong ZP, Lü C, Guo BJ, Chen JJ, Zhao T, Yin ZF, Li B. Physical exercise suppresses hepatocellular carcinoma progression by alleviating hypoxia and attenuating cancer stemness through the Akt/GSK-3ß/ß-catenin pathway. J Integr Med. 2023; 21(2): 184-193.

Water-Gas Shift Catalyzed by Iridium-Vanadium Oxide Clusters IrVO2- with Iridium in a Rare Oxidation State of -II.

The discovery of compounds containing transition metals with an unusual and well-established oxidation state is vital to enrich our horizon on formal oxidation state. Herein, benefiting from the study of the water-gas shift reaction (CO + H2O → CO2 + H2) mediated with the iridium-vanadium oxide cluster IrVO2-, the missing -II oxidation state of iridium was identified. The reactions were performed by using our newly developed double ion trap reactors that can spatially separate the addition of reactants and are characterized by mass spectrometry and quantum-chemical calculations. This finding makes an important step that all the proposed 13 oxidation states of iridium (+IX to -III) have been known. The iridium atom in the IrVO2- cluster features the Ir═V double bond and resembles chemically the coordinated oxygen atom. A reactivity study demonstrated that the flexible role switch of iridium between an oxygen-atom like (Ir-IIVO2-) and a transition-metal-atom like behavior (Ir+IIVO3-) in different species can drive the water-gas shift reaction in the gas phase under ambient conditions. This result parallels and well rationalizes the extraordinary reactivity of oxide-supported iridium single-atom catalysts in related condensed-phase reactions.

Reverse water-gas shift reaction catalyzed by diatomic rhodium anions.

The reverse water-gas shift (RWGS, CO2 + H2 → CO + H2O, ΔH298 = +0.44 eV) reaction mediated by the diatomic anion Rh2- was successfully constructed. The generation of a gas-phase H2O molecule and ion product [Rh2(CO)ads]- was identified unambiguously at room temperature and the only elementary step that requires extra energy to complete the catalysis is the desorption of CO from [Rh2(CO)ads]-. This experimentally identified Rh2- anion represents the first gas-phase species that can drive the RWGS reaction because it is challenging to design effective routes to yield H2O from CO2 and H2. The reactions were performed by using our newly developed double ion trap reactors and characterized by mass spectrometry, photoelectron spectroscopy, and high-level quantum-chemical calculations. We found that the order that the reactants (CO2 or D2) were fed into the reactor did not have a pronounced impact on the reactivity and the final product distribution (D2O and Rh2CO-). The atomically precise insights into the key steps to guide the reaction toward the RWGS direction were provided.

Aerobic exercise suppresses hepatocellular carcinoma by downregulating dynamin-related protein 1 through PI3K/AKT pathway.

OBJECTIVE: Exercise, as a common non-drug intervention, is one of several lifestyle choices known to reduce the risk of cancer. Mitochondrial division has been reported to play a key role in the occurrence and transformation of hepatocellular carcinoma (HCC). This study investigated whether exercise could regulate the occurrence and development of HCC through mitosis. METHODS: Bioinformatics technology was used to analyze the expression level of dynamin-related protein 1 (DRP1), a key protein of mitochondrial division. The effects of DRP1 and DRP1 inhibitor (mdivi-1) on the proliferation and migration of liver cancer cells BEL-7402 were observed using cell counting kit-8, plate colony formation, transwell cell migration, and scratch experiments. Enzyme-linked immunosorbent assay, Western blot and real-time polymerase chain reaction were used to detect the expression of DRP1 and its downstream phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway. A treadmill exercise intervention was tested in a nude mouse human liver cancer subcutaneous tumor model expressing different levels of DRP1. The size and weight of subcutaneous tumors in mice were detected before and after exercise. RESULTS: The expression of DRP1 in liver cancer tissues was significantly upregulated compared with normal liver tissues (P < 0.001). The proliferation rate and the migration of BEL-7402 cells in the DRP1 over-expression group were higher than that in the control group. The mdivi-1 group showed an inhibitory effect on the proliferation and migration of BEL-7402 cells at 50 µmol/L. Aerobic exercise was able to inhibit the expression of DRP1 and decrease the size and weight of subcutaneous tumors. Moreover, the expression of phosphorylated PI3K (p-PI3K) and phosphorylated AKT (p-AKT) decreased in the exercise group. However, exercise could not change p-PI3K and p-AKT levels after knocking down DRP1 or using mdivi-1 on subcutaneous tumor. CONCLUSION: Aerobic exercise can suppress the development of tumors partially by regulating DRP1 through PI3K/AKT pathway.

Water Gas Shift Reaction Catalyzed by Rhodium-Manganese Oxide Cluster Anions.

Fundamental understanding of the nature of active sites in real-life water gas shift (WGS) catalysts that can convert CO and H2O into CO2 and H2 is crucial to engineer related catalysts performing under ambient conditions. Herein, we identified that the WGS reaction can be, in principle, catalyzed by rhodium-manganese oxide clusters Rh2MnO1,2- in the gas phase at room temperature. This is the first example of the construction of such a potential catalysis in cluster science because it is challenging to discover clusters that can abstract the oxygen from H2O and then supply the anchored oxygen to oxidize CO. The WGS reaction was characterized by mass spectrometry, photoelectron spectroscopy, and quantum-chemical calculations. The coordinated oxygen in Rh2MnO1,2- is paramount for the generation of an electron-rich Mn+-Rh- bond that is critical to capture and reduce H2O and giving rise to a polarized Rh+-Rh- bond that functions as the real redox center to drive the WGS reaction.

CTRP1 decreases ABCA1 expression and promotes lipid accumulation through the miR-424-5p/FoxO1 pathway in THP-1 macrophage-derived foam cells.

Prevention of ATP binding cassette transporter A1 (ABCA1)-dependent cholesterol efflux leads to lipid accumulation in macrophages and atherosclerosis development. C1q tumor necrosis factor-related protein 1 (CTRP1), a conserved paralog of adiponectin, has been shown to aggravate atherosclerosis via its proinflammatory property. However, very little is known about its effects on ABCA1 expression and macrophage lipid accumulation. In the current studies, we found that CTRP1 downregulated ABCA1 expression, inhibited cholesterol efflux to apoA-I and promoted lipid accumulation in THP-1 macrophage-derived foam cells. Forkhead box O1 (FoxO1), a transcriptional repressor of ABCA1, was identified as a direct target of miR-424-5p. Mechanistically, CTRP1 attenuated miR-424-5p levels and then augmented FoxO1 expression in the nucleus, which led to downregulation of ABCA1 expression and inhibition of cholesterol efflux. In conclusion, these findings suggest that CTRP1 restrains cholesterol efflux and facilitates macrophage lipid accumulation through the miR-424-5p/FoxO1/ABCA1 signaling pathway, thereby providing a novel mechanistical insight into its proatherosclerotic action.

CTRP12 ameliorates atherosclerosis by promoting cholesterol efflux and inhibiting inflammatory response via the miR-155-5p/LXRα pathway.

C1q tumor necrosis factor-related protein 12 (CTRP12), a conserved paralog of adiponectin, is closely associated with cardiovascular disease. However, little is known about its role in atherogenesis. The aim of this study was to examine the influence of CTRP12 on atherosclerosis and explore the underlying mechanisms. Our results showed that lentivirus-mediated CTRP12 overexpression inhibited lipid accumulation and inflammatory response in lipid-laden macrophages. Mechanistically, CTRP12 decreased miR-155-5p levels and then increased its target gene liver X receptor α (LXRα) expression, which increased ATP binding cassette transporter A1 (ABCA1)- and ABCG1-dependent cholesterol efflux and promoted macrophage polarization to the M2 phenotype. Injection of lentiviral vector expressing CTRP12 decreased atherosclerotic lesion area, elevated plasma high-density lipoprotein cholesterol levels, promoted reverse cholesterol transport (RCT), and alleviated inflammatory response in apolipoprotein E-deficient (apoE-/-) mice fed a Western diet. Similar to the findings of in vitro experiments, CTRP12 overexpression diminished miR-155-5p levels but increased LXRα, ABCA1, and ABCG1 expression in the aortas of apoE-/- mice. Taken together, these results suggest that CTRP12 protects against atherosclerosis by enhancing RCT efficiency and mitigating vascular inflammation via the miR-155-5p/LXRα pathway. Stimulating CTRP12 production could be a novel approach for reducing atherosclerosis.

[Effect of low-frequency electrical acupoint stimulation on gastrointestinal motility function following radical gastrectomy in patients with gastric cancer].

OBJECTIVE: To observe the effect of low-frequency electrical acupoint stimulation on gastrointestinal motility in patients undergoing radical gastrectomy, and its impact on regulation of inflammatory response, so as to evaluate its clinical value. METHODS: A total of 177 patients undergoing radical gastrectomy were randomly divided into conventional group (n＝43), low-frequency electrical acupoint stimulation (LEAS) group (n＝45), fast track surgery (FTS) group (n＝46) and FTS＋LEAS group (n＝43). Patients of the conventional group received conventional treatment (pre-surgical mechanical bowel preparation, post-surgical fasting, and indwelling abdominal drainage tube, etc.). Patients in the LEAS group were treated by low-frequency electrical stimulation at bilateral Zusanli (ST36), Shangjuxu(ST37), Xiajuxu(ST39) and Sanyinjiao(SP6) for 30 min, once daily from 1 day after the operation to first postoperative flatus. FTS group was given fast track surgery treatment, such as preoperative education, preoperative nutritional support, early oral feeding, early removal of abdominal drainage tube, etc. The FTS＋LEAS group was given low-frequency electrical acupoint stimulation on the basis of the FTS treatment. Levels of white blood cells (WBC), neutrophils (N), C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) at 1, 3, and 6 d after the operation in the 4 groups were assayed. The first postoperative flatus and defecation time were recorded. RESULTS: After the treatment, the first postoperative flatus and defecation time in the LEAS, FTS and FTS＋LEAS groups were significantly shorter than those of the conventional group (P<0.05), and the first flatus time of the FTS＋LEAS group was even earlier than that of the FTS group (P<0.05). No significant differences were found among the 3 groups in the postoperative defecation time (P>0.05). The CRP levels in the 4 groups on 3 and 6 d after operation were higher than those on the 1st postoperative day, and the highest level was on 3 d after the operation. Compared with the conventional group, CRP level on 3 d and CRP and IL-6 levels on 3 and 6 d in the LEAS and FTS＋LEAS groups were significantly lower (P<0.05). Compared with the LEAS group, the levels of N, CRP on 3 d and the levels of N, CRP, IL-6 on 6 d in the FTS group were significantly increased (P<0.05). Compared with the FTS group, the level of CRP on 3 d and the levels of N, CRP, IL-6 on 6 d in the FTS＋LEAS group were significantly decreased (P<0.05). CONCLUSION: FTS combined with LEAS is superior to simple FTS or LEAS treatment in shortening the first flatus and defecation time and promoting the recovery of gastrointestinal motility function in patients undergoing radical gastrectomy, which may be associated with its effect in alleviating postoperative inflammatory responses.

Inhibition of the ox-LDL-Induced Pyroptosis by FGF21 of Human Umbilical Vein Endothelial Cells Through the TET2-UQCRC1-ROS Pathway.

Fibroblast growth factor 21 (FGF21) is a hormone-like member of the FGF family that is associated with cell death in atherosclerosis. However, its underlying mechanisms remain unclear. In this study, the effect of FGF21 on endothelial cell pyroptosis and its potential mechanisms were investigated. Results showed that FGF21 inhibits oxidized low-density lipoprotein (ox-LDL)-induced pyroptosis and related molecular expression in human umbilical vein endothelial cells (HUVECs). Mitochondrial function was damaged by ox-LDL and restored by FGF21. A mechanism proved that ubiquinol cytochrome c reductase core protein I (UQCRC1) was downregulated by ox-LDL and upregulated by FGF21. Further, the silencing of UQCRC1 aggravated HUVEC pyroptosis and impaired mitochondrial function and reactive oxygen species (ROS) production. Moreover, Tet methylcytosine dioxygenase (TET2) was involved in the regulation of UQCRC1 expression and pyroptosis. In summary, FGF21 inhibited ox-LDL-induced HUVEC pyroptosis through the TET2-UQCRC1-ROS pathway.

Infliximab therapy and outcomes in patients with polyarticular juvenile idiopathic arthritis: a single-center study in China.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is a chronic inflammatory disease that includes seven heterogeneous subgroups with different prognoses. In particular, polyarticular JIA (pJIA) has a longer period of active disease and a poorer prognosis. Tumor necrosis factor (TNF)-alpha inhibitors are effective in patients with pJIA, but the therapeutic regimen remains controversial. Here, we performed a single-center study to determine the potential correlation between TNF-alpha inhibitor (infliximab) therapy and outcomes in these patients. METHODS: Clinical data of 40 pJIA patients were collected at our center from January 1, 2010 to January 1, 2018, and patients were grouped according to the timing of infliximab therapy. The erythrocyte sedimentation rate (ESR), the number of joints with active disease, and the 27-point juvenile arthritis disease activity score (JADAS-27) were analyzed. RESULTS: The ESR, the active joint count, and the JADAS-27 decreased significantly in all groups after 3 months (P = 0.041/0.415/0.008, 0.022/0.030/ < 0.001, and 0.05/0.012/ < 0.001, respectively) and 6 months (P = 0.036/0.045/0.041, 0.076/0.037/ < 0.001, and 0.096/0.006/ < 0.001, respectively) of infliximab treatment, although the rates of change of these parameters were similar. However, after 12 months, only patients treated with infliximab within 3 months of disease onset had a stable ESR, active joint count, and JADAS-27, while these parameters increased sharply when infliximab was administered 3 months and especially 1 year after disease onset. CONCLUSIONS: TNF-alpha is a pleiotropic pro-inflammatory cytokine of crucial importance in the pathogenesis of JIA. Infliximab can improve the outcomes of patients with pJIA significantly, and should be introduced early during the clinical course.

The 5-Lipoxygenase Inhibitor Zileuton Protects Pressure Overload-Induced Cardiac Remodeling via Activating PPARα.

Zileuton has been demonstrated to be an anti-inflammatory agent due to its well-known ability to inhibit 5-lipoxygenase (5-LOX). However, the effects of zileuton on cardiac remodeling are unclear. In this study, the effects of zileuton on pressure overload-induced cardiac remodeling were investigated and the possible mechanisms were examined. Aortic banding was performed on mice to induce a cardiac remodeling model, and the mice were then treated with zileuton 1 week after surgery. We also stimulated neonatal rat cardiomyocytes with phenylephrine (PE) and then treated them with zileuton. Our data indicated that zileuton protected mice from pressure overload-induced cardiac hypertrophy, fibrosis, and oxidative stress. Zileuton also attenuated PE-induced cardiomyocyte hypertrophy in a time- and dose-dependent manner. Mechanistically, we found that zileuton activated PPARα, but not PPARγ or PPARθ, thus inducing Keap and NRF2 activation. This was confirmed with the PPARα inhibitor GW7647 and NRF2 siRNA, which abolished the protective effects of zileuton on cardiomyocytes. Moreover, PPARα knockdown abolished the anticardiac remodeling effects of zileuton in vivo. Taken together, our data indicate that zileuton protects against pressure overload-induced cardiac remodeling by activating PPARα/NRF2 signaling.

miR-23b-3p and miR-125b-5p downregulate apo(a) expression by targeting Ets1 in HepG2 cells.

High concentrations of plasma lipoprotein(a) [Lp(a)] have been inferred to be an independent risk factor for cardiovascular and cerebrovascular diseases, such as coronary artery diseases, restenosis, and stroke. Apolipoprotein(a) [apo(a)] is one of the most important components of Lp(a) and contributes greatly to the increased concentration of plasma Lp(a). As a critical positive transacting factor of apo(a) gene, Ets1 has been proven as a target gene of several miRNAs, such as miR-193b, miR-125b-5p, miR-200b, miR-1, and miR-499. In this study, a series of experiments on miRNAs and relative miRNAs inhibitor delivered HepG2 cells were conducted, and two miRNAs that downregulate the apo(a) by targeting the 3'-UTR of Ets1 were identified. Results showed that apo(a) and Ets1 were differentially expressed in SMMC7721 and HepG2 cell lines. Meanwhile, apo(a) and Ets1 were inversely correlated with several hepatic endogenous miRNAs, such as miR-125b-5p, miR-23b-3p, miR-26a-5p, and miR-423-5p, which were predicted to bind to Ets1. Results show that miR-125b-5p and miR-23b-3p mimics could inhibit the synthesis of apo(a) by directly targeting Ets1 in HepG2, thereby reducing the plasma Lp (a) concentration.

Size-Dependent Reactivity of Nano-Sized Neutral Manganese Oxide Clusters toward Ethylene.

Neutral manganese oxide clusters with the general composition Mn2 N O3 N+x (N=2-22; x=-1, 0, 1) with dimensions up to a nanosize were prepared by laser ablation and reacted with C2 H4 in a fast flow reactor. The size-dependent reactivity of C2 H4 adsorption on these clusters was experimentally identified and the adsorption reactivity decreases generally with an increase of the cluster size. Density functional theory calculations were performed to study the geometrical and electronic structures of the Mn2 N O3 N (N=1-6) clusters. The calculated results indicated that the coordination number and the charge distribution of the metal centers are responsible for the experimentally observed size-dependent reactivity. The highly charged Mn atoms with low coordination are preferential to adsorb C2 H4 . In contrast, the neutral manganese oxide clusters are completely inert toward the saturated hydrocarbon molecule C2 H6 . This work provides new perspectives to design related materials in the separation of hydrocarbon molecules.

Molecular signal networks and regulating mechanisms of the unfolded protein response.

Within the cell, several mechanisms exist to maintain homeostasis of the endoplasmic reticulum (ER). One of the primary mechanisms is the unfolded protein response (UPR). In this review, we primarily focus on the latest signal webs and regulation mechanisms of the UPR. The relationships among ER stress, apoptosis, and cancer are also discussed. Under the normal state, binding immunoglobulin protein (BiP) interacts with the three sensors (protein kinase RNA-like ER kinase (PERK), activating transcription factor 6 (ATF6), and inositol-requiring enzyme 1α (IRE1α)). Under ER stress, misfolded proteins interact with BiP, resulting in the release of BiP from the sensors. Subsequently, the three sensors dimerize and autophosphorylate to promote the signal cascades of ER stress. ER stress includes a series of positive and negative feedback signals, such as those regulating the stabilization of the sensors/BiP complex, activating and inactivating the sensors by autophosphorylation and dephosphorylation, activating specific transcription factors to enable selective transcription, and augmenting the ability to refold and export. Apart from the three basic pathways, vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR)-phospholipase C-γ (PLCγ)-mammalian target of rapamycin complex 1 (mTORC1) pathway, induced only in solid tumors, can also activate ATF6 and PERK signal cascades, and IRE1α also can be activated by activated RAC-alpha serine/threonine-protein kinase (AKT). A moderate UPR functions as a pro-survival signal to return the cell to its state of homeostasis. However, persistent ER stress will induce cells to undergo apoptosis in response to increasing reactive oxygen species (ROS), Ca2+ in the cytoplasmic matrix, and other apoptosis signal cascades, such as c-Jun N-terminal kinase (JNK), signal transducer and activator of transcription 3 (STAT3), and P38, when cellular damage exceeds the capacity of this adaptive response.