Exceptional capture of methane at low pressure by an iron-based metal-organic framework.

The selective capture of methane (CH4) at low concentrations and its separation from N2 are extremely challenging owing to the weak host-guest interactions between CH4 molecules and any sorbent material. Here, we report the exceptional adsorption of CH4 at low pressure and the efficient separation of CH4/N2 by MFM-300(Fe). MFM-300(Fe) shows a very high uptake for CH4 of 0.85 mmol g-1 at 1 mbar and 298 K and a record CH4/N2 selectivity of 45 for porous solids, representing a new benchmark for CH4 capture and CH4/N2 separation. The excellent separation of CH4/N2 by MFM-300(Fe) has been confirmed by dynamic breakthrough experiments. In situ neutron powder diffraction, and solid-state nuclear magnetic resonance and diffuse reflectance infrared Fourier transform spectroscopies, coupled with modelling, reveal a unique and strong binding of CH4 molecules involving Fe-OH⋯CH4 and C⋯phenyl ring interactions within the pores of MFM-300(Fe), thus promoting the exceptional adsorption of CH4 at low pressure.

Direct Synthesis of N-formamides by Integrating Reductive Amination of Ketones and Aldehydes with CO2 Fixation in a Metal-Organic Framework.

Formamides are important feedstocks for the manufacture of many fine chemicals. State-of-the-art synthesis of formamides relies on the use of an excess amount of reagents, giving copious waste and thus poor atom-economy. Here, we report the first example of direct synthesis of N-formamides by coupling two challenging reactions, namely reductive amination of carbonyl compounds, particularly biomass-derived aldehydes and ketones, and fixation of CO2 in the presence of H2 over a metal-organic framework supported ruthenium catalyst, Ru/MFM-300(Cr). Highly selective production of N-formamides has been observed for a wide range of carbonyl compounds. Synchrotron X-ray powder diffraction reveals the presence of strong host-guest binding interactions via hydrogen bonding and parallel-displaced π⋅⋅⋅π interactions between the catalyst and adsorbed substrates facilitating the activation of substrates and promoting selectivity to formamides. The use of multifunctional porous catalysts to integrate CO2 utilisation in the synthesis of formamide products will have a significant impact in the sustainable synthesis of feedstock chemicals.

mPPTMP195 nanoparticles enhance fracture recovery through HDAC4 nuclear translocation inhibition.

Delayed repair of fractures seriously impacts patients' health and significantly increases financial burdens. Consequently, there is a growing clinical demand for effective fracture treatment. While current materials used for fracture repair have partially addressed bone integrity issues, they still possess limitations. These challenges include issues associated with autologous material donor sites, intricate preparation procedures for artificial biomaterials, suboptimal biocompatibility, and extended degradation cycles, all of which are detrimental to bone regeneration. Hence, there is an urgent need to design a novel material with a straightforward preparation method that can substantially enhance bone regeneration. In this context, we developed a novel nanoparticle, mPPTMP195, to enhance the bioavailability of TMP195 for fracture treatment. Our results demonstrate that mPPTMP195 effectively promotes the differentiation of bone marrow mesenchymal stem cells into osteoblasts while inhibiting the differentiation of bone marrow mononuclear macrophages into osteoclasts. Moreover, in a mouse femur fracture model, mPPTMP195 nanoparticles exhibited superior therapeutic effects compared to free TMP195. Ultimately, our study highlights that mPPTMP195 accelerates fracture repair by preventing HDAC4 translocation from the cytoplasm to the nucleus, thereby activating the NRF2/HO-1 signaling pathway. In conclusion, our study not only proposes a new strategy for fracture treatment but also provides an efficient nano-delivery system for the widespread application of TMP195 in various other diseases.

Experience of patients with diabetic retinopathy: A qualitative study.

AIMS: To understand the status quo and needs of self-management of patients with diabetic retinopathy (DR) and to provide a reference for formulating management programs that meet the needs of these patients. DESIGN: A qualitative interview study. METHODS: Semi-structured, in-depth interviews were conducted between November and December 2021. A purposive sample of 15 patients with DR who were hospitalized in the Retinal Department of Eye Hospital was recruited. Colaizzi's analysis was used to organize and analyse the interview data. This study followed the Consolidated Criteria for Reporting Qualitative Research (COREQ) checklist. RESULTS: The experience of patients with DR can be summarized into four themes: (1) lack of DR knowledge, (2) low quality of life, (3) poor self-management behaviour and (4) seek for support from many aspects. CONCLUSION: Patients with DR lack disease knowledge and have poor self-management abilities and adherence. Medical staff should provide personalized care according to the patient's self-management status and needs, promote the establishment of self-management behaviours and prevent and delay disease progression. IMPACT: This study helps assist medical staff in the early management of patients with DR and provides a reference for the construction of prevention programs for patients.

A novel 4 immune-related genes as diagnostic markers and correlated with immune infiltrates in major depressive disorder.

BACKGROUND: Immune response is prevalently related with major depressive disorder (MDD) pathophysiology. However, the study on the relationship between immune-related genes (IRGs) and immune infiltrates of MDD remains scarce. METHODS: We extracted expression data of 148 MDD patients from 2 cohorts, and systematically characterized differentially expressed IRGs by using limma package in R software. Then, the LASSO and multivariate logistic regression analysis was used to identify the most powerful IRGs. Next, we analyzed the relationship between IRGs and immune infiltrates of MDD. Finally, GSE76826 was used to to verificate of IRGs as a diagnostic markers in MDD. RESULTS: 203 different IRGs s in MDD has been identified (P < 0.05). GSEA revealed that the different IRGs was more likely to be enriched in immune-specific pathways. Then, a 9 IRGs was successfully established to predict MDD based on LASSO. Next, 4 IRGs was obtained by multivariate logistic regression analysis, and AUC for CD1C, SPP1, CD3D, CAMKK2, and IRGs model was 0.733, 0.767, 0.816, 0.800, and 0.861, suggesting that they have a good diagnostic performance. Furthermore, the proportion of T cells CD8, T cells γδ, macrophages M0, and NK cells resting in MDD group was lower than that in the healthy controls, suggesting that the immune system in MDD group is impaired. Simultaneously, CD3D was validated a reliable marker in MDD, and was positively correlated with T cells CD8. GSEA revealed high expression CD3D was more likely to be enriched in immune-specific pathways, and low expression CD3D was more likely to be enriched in glucose metabolism metabolism-specific pathways. CONCLUSIONS: We applied bioinformatics approaches to suggest that a 4 IRGs could serve as diagnostic markers to provide a novel direction to explore the pathogenesis of MDD.

Histone H4 induces heparan sulfate degradation by activating heparanase in chlorine gas-induced acute respiratory distress syndrome.

BACKGROUND: Heparan sulfate (HS) degradation mediates pulmonary endothelial hyper-permeability and acute pulmonary edema during acute respiratory distress syndrome (ARDS). The aim of this study was to examine whether histone H4 induced HS degradation by activating heparanase (HPSE) in chlorine gas (Cl2)-induced ARDS. METHODS: Acute lung injury was induced by Cl2 exposure or histone H4 injection in C57BL/6 mice. Histone H4 in bronchoalveolar lavage fluid (BALF) and plasma was measured by ELISA. HS degradation was measured by immunostaining, ELISA, and flow cytometry. HPSE mRNA and protein were measured by real-time qPCR and western blot analysis, respectively, at preset timepoints. The HPSE inhibitor OGT2115 and specific siRNAs were used to study the role of HPSE during HS degradation caused by Cl2 exposure or histone H4 challenge. Blocking antibodies against TLR1, TLR2, TLR4, or TLR6 were used in vitro to investigate which signaling pathway was involved. The transcriptional regulation of HPSE was studied vis-à-vis NF-κB, which was assessed by nuclear translocation of NF-κB p65 and phosphorylation of I-κBα protein. RESULTS: Histone H4 in BALF and plasma increased evidently after Cl2 inhalation. Cl2 exposure or histone H4 challenge caused obvious acute lung injury in mice, and the pulmonary glycocalyx was degraded evidently as observed from endothelial HS staining and measurement of plasma HS fragments. Pretreatment with OGT2115, an HPSE inhibitor, relieved the acute lung injury and HS degradation caused by Cl2 exposure or histone H4 challenge. Targeted knockdown of HPSE by RNA interference (RNAi) significantly inhibited histone H4 induced HS degradation in HPMECs, as measured by immunofluorescence and flow cytometry. By inducing phosphorylation of I-κB α and nuclear translocation of NF-κB p65, histone H4 directly promoted mRNA transcription and protein expression of HPSE in a dose-dependent manner. Additionally, a blocking antibody against TLR4 markedly inhibited both activation of NF-κB and expression of HPSE induced by histone H4. CONCLUSIONS: Histone H4 is a major pro-inflammatory mediator in Cl2-induced ARDS in mice, and induces HS degradation by activating HPSE via TLRs- and NF-κB-signaling pathways.

Effects of rifampicin on the pharmacokinetics of alflutinib, a selective third-generation EGFR kinase inhibitor, and its metabolite AST5902 in healthy volunteers.

Background Alflutinib is a novel irreversible and highly selective third-generation EGFR inhibitor currently being developed for the treatment of non-small cell lung cancer patients with activating EGFR mutations and EGFR T790M drug-resistant mutation. Alflutinib is mainly metabolized via CYP3A4 to form its active metabolite AST5902. Both alflutinib and AST5902 contribute to the in vivo pharmacological activity. The aim of this study was to investigate the effects of rifampicin (a strong CYP3A4 inducer) on the pharmacokinetics of alflutinib and AST5902 in healthy volunteers, thus providing important information for drug-drug interaction evaluation and guiding clinical usage. Methods This study was designed as a single-center, open-label, and single-sequence trial over two periods. The volunteers received a single dose of 80 mg alflutinib on Day 1/22 and continuous doses of 0.6 g rifampicin on Day 15-30. Blood sampling was conducted on Day 1-10 and Day 22-31. The pharmacokinetics of alflutinib, AST5902, and the total active ingredients (alflutinib and AST5902) with or without rifampicin co-administration were respectively analyzed. Results Co-administration with rifampicin led to 86% and 60% decreases in alflutinib AUC0-∞ and Cmax, respectively, as well as 17% decrease in AST5902 AUC0-∞ and 1.09-fold increase in AST5902 Cmax. The total active ingredients (alflutinib and AST5902) exhibited 62% and 39% decreases in AUC0-∞ and Cmax, respectively. Conclusions As a strong CYP3A4 inducer, rifampicin exerted significant effects on the pharmacokinetics of alflutinib and the total active ingredients (alflutinib and AST5902). The results suggested that concomitant strong CYP3A4 inducers should be avoided during alflutinib treatment. This trial was registered at http://www.chinadrugtrials.org.cn . The registration No. is CTR20191562, and the date of registration is 2019-09-12.

Alcohol use among patients with epilepsy in western China. A hospital-based study.

AMIS: Alcohol consumption has multiple negative consequences for people with epilepsy, including precipitation of seizure or status epilepticus, worsening of seizure control, increased adverse effects of anti-seizure medications, increased sudden unexpected death in epilepsy, and premature mortality. The aim of this study was to investigate alcohol use and explore the sociodemographic and clinical factors associated with alcohol use among patients with epilepsy in western China. METHODS: A face-to-face questionnaire on alcohol use was conducted at Sichuan Provincial People's Hospital from December 2020 to June 2021. All adult patients who came to our epilepsy center (inpatient and outpatient) were invited to participate in this study. Logistic regression was used to evaluate the possible risk factors associated with alcohol use within the last 12 months. RESULTS: A total of 425 patients completed this study, 24.2% of patients with epilepsy had used alcohol within the last 12 months, being male and having a history of alcohol use were independently associated factors. Among patients who had used alcohol within the last 12 months, 52.4% complained of worsening of seizure control, heavy alcohol use, and frequent alcohol use were independently associated with worsening of seizure control after alcohol use in patients with epilepsy. CONCLUSION: This study revealed that the rate of alcohol use among patients with epilepsy was high. Male patients with a history of alcohol use were more prone to alcohol use after a diagnosis of epilepsy. Heavy alcohol use and frequent alcohol use were independently associated with worsening of seizure control after alcohol use in patients with epilepsy. Patient education on the destructive effects of alcohol use is needed for patients with epilepsy.

N,N'-1,10-Bis(Naringin) Triethylenetetraamine, Synthesis and as a Cu(II) Chelator for Alzheimer's Disease Therapy.

The bis-Schiff base of N,N'-1,10-bis(naringin) triethylenetetraamine (1) was prepared, as a copper(II) ion chelator, compound 1 was used for Alzheimer's disease therapy in vitro. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay of compound 1 showed that this Schiff base could promote PC12 cells proliferation, and also, compound 1 could inhibit Cu2+-amyloid-ß (Aß)1-42 mediated cytotoxicity on PC12 cells. The thioflavine T (ThT) assay showed that 1 can effectively attenuate Cu2+-induced Aß1-42 aggregation. In addition, compound 1 is determined to be potent antioxidants on the basis of in vitro antioxidant assay, it can effectively decease the level of reactive oxygen species (ROS) in Cu2+-Aß1-42-treated PC12 cells and elevate the superoxide dismutase (SOD) activity in Cu2+-Aß1-42-treated PC12 cells. The results show that N,N'-1,10-bis(naringin) triethylenetetraamine is a potential agent for therapy of Alzheimer's disease.

Heavy metal accumulation and health risk assessment of crayfish in the middle and lower reaches of Yangtze River during 2015-2017.

This study performed statistical analysis and risk assessment of five heavy metals (As, Cd, Cr, Hg, Pb) in crayfish samples collected from six provinces in the middle and lower reaches of Yangtze River during 2015-2017. The Spearman correlation test and the results of hierarchical cluster analysis (HCA) indicated that As, Pb, and Cd in crayfish were significantly correlated, and the results of HCA showed that Jiangxi, Jiangsu, and Zhejiang were clustered into one group; Hubei, Hunan, and Anhui were clustered into another group; and provinces in the same group had spatial similarities in heavy metals. The pollution index (PI) values of five heavy metals in all provinces were below 1, implying that crayfish samples in this area were not highly contaminated. The target hazard quotient (THQ) values of five heavy metals were mainly below 1 except Hg in Anhui (2.9709), which was far beyond 1, indicating that the health risk posed by Hg exposure should not be ignored in Anhui.

Genetic dereplication driven discovery of a tricinoloniol acid biosynthetic pathway in Trichoderma hypoxylon.

A genetic dereplication approach in combination with differential gene expression led to the discovery of three new sesquiterpenes, tricinoloniol acids (TRAs) A-C (1-3) and the known fusidilactone A (4) from T. hypoxylon. Comparative transcriptomic analysis and targeted deletion identified the biosynthetic route for TRAs. Our results demonstrate an alternative application of the genetic dereplication method for exploring the biosynthesis of cryptic secondary metabolites (SMs), which utilizes the coordinated expression of trichothecene (tri) and tra cluster genes.

A survey of Chinese consumers' knowledge, beliefs and behavioural intentions regarding salt intake and salt reduction.

OBJECTIVE: Globally, China is among the 'saltiest' nations. In order to support current nationwide salt reduction initiatives, we investigated Chinese consumers' knowledge, beliefs and behaviours related to salt intake and salt reduction. DESIGN: A cross-sectional face-to-face survey was carried out, focusing on salt knowledge, beliefs and behaviours related to salt intake and salt reduction, perceptions of salt reduction responsibility and support for different national strategies. SETTING: The survey was carried out in China mainland. PARTICIPANTS: Consumers (n 2444) from six of seven major geographical regions in China participated in the survey. After data cleaning, a sample of 2430 was included in the final analysis. RESULTS: A majority of Chinese consumers believed that salt added during home cooking was the biggest contributor to their salt intake. Knowledge gaps existed in the awareness of salt hidden in certain foods and flavouring products. Chinese consumers in general were interested in lowering their salt intake. They were aware of salt reduction tools, but the adoption level was low. Consumers expressed strong support for promotion of salt-restriction spoons and public education, but not fiscal policies (e.g. salt-related tax or subsidies). In terms of individual differences, education status demonstrated a substantial impact on salt reduction knowledge and behaviour. CONCLUSIONS: There is still big room to 'shake' Chinese consumers' salt habit. The present study provides important evidence and consumer insights to support China's efforts to meet its salt reduction targets.

Macroautophagy Regulates Nuclear NOTCH1 Activity Through Multiple p62 Binding Sites.

NOTCH1 is the prototype of the NOTCH family of single-pass transmembrane receptors and regulates many basic processes during embryonic development and human pathogenesis. In core to NOTCH1 activation are proteolytic cleavages that release its intracellular domain (NICD1), which in turn translocates to the nucleus to regulate gene transcription. Macroautophagy (hereafter autophagy) has been shown to promote the degradation of NOTCH1, but the underlying mechanisms remain elusive. Here, we show that autophagy promotes the degradation of NOTCH1 by p62-dependent binding between NICD1 and LC3, a component of the autophagosomes that execute autophagy. Strikingly, deleting any of the structural NICD1 domains fails to block the degradation of NICD1 by autophagy, and p62 binds to almost all these domains independently, indicating that p62 binds to multiple sites on NICD1 to promote its degradation. Intriguingly, inhibition of autophagy induces the accumulation of NICD1 in not only the cytoplasm but also the nucleus and increases the transcriptional activity of NICD1, and such regulation of nuclear NICD1 by autophagy is unique to NICD1 and not observed for all other NICDs (NICD2-4). Collectively, our results suggest that autophagy tightly controls nuclear NOTCH1 activity through multiple p62 binding sites, and that modulating autophagy activity may be useful for treating NOTCH1 related human diseases. © 2018 IUBMB Life, 70(10):985-994, 2018.

Peroxisome proliferator-activated receptor δ promotes colonic inflammation and tumor growth.

Although epidemiologic and experimental evidence strongly implicates chronic inflammation and dietary fats as risk factors for cancer, the mechanisms underlying their contribution to carcinogenesis are poorly understood. Here we present genetic evidence demonstrating that deletion of peroxisome proliferator-activated receptor δ (PPARδ) attenuates colonic inflammation and colitis-associated adenoma formation/growth. Importantly, PPARδ is required for dextran sodium sulfate induction of proinflammatory mediators, including chemokines, cytokines, COX-2, and prostaglandin E2 (PGE2), in vivo. We further show that activation of PPARδ induces COX-2 expression in colonic epithelial cells. COX-2-derived PGE2 stimulates macrophages to produce proinflammatory chemokines and cytokines that are responsible for recruitment of leukocytes from the circulation to local sites of inflammation. Our results suggest that PPARδ promotes colonic inflammation and colitis-associated tumor growth via the COX-2-derived PGE2 signaling axis that mediates cross-talk between tumor epithelial cells and macrophages.

Whole-genome sequencing uncovers the genetic basis of chronic mountain sickness in Andean highlanders.

The hypoxic conditions at high altitudes present a challenge for survival, causing pressure for adaptation. Interestingly, many high-altitude denizens (particularly in the Andes) are maladapted, with a condition known as chronic mountain sickness (CMS) or Monge disease. To decode the genetic basis of this disease, we sequenced and compared the whole genomes of 20 Andean subjects (10 with CMS and 10 without). We discovered 11 regions genome-wide with significant differences in haplotype frequencies consistent with selective sweeps. In these regions, two genes (an erythropoiesis regulator, SENP1, and an oncogene, ANP32D) had a higher transcriptional response to hypoxia in individuals with CMS relative to those without. We further found that downregulating the orthologs of these genes in flies dramatically enhanced survival rates under hypoxia, demonstrating that suppression of SENP1 and ANP32D plays an essential role in hypoxia tolerance. Our study provides an unbiased framework to identify and validate the genetic basis of adaptation to high altitudes and identifies potentially targetable mechanisms for CMS treatment.

Prostaglandin E2 Promotes Colorectal Cancer Stem Cell Expansion and Metastasis in Mice.

BACKGROUND & AIMS: Inflammation may contribute to the formation, maintenance, and expansion of cancer stem cells (CSCs), which have the capacity for self-renewal, differentiation, and resistance to cytotoxic agents. We investigated the effects of the inflammatory mediator prostaglandin E2 (PGE2) on colorectal CSC development and metastasis in mice and the correlation between levels of PGE2 and CSC markers in human colorectal cancer (CRC) specimens. METHODS: Colorectal carcinoma specimens and matched normal tissues were collected from patients at the Mayo Clinic (Scottsdale, AZ) and analyzed by mass spectrometry and quantitative polymerase chain reaction. Human primary CRC cells and mouse tumor cells were isolated using microbeads or flow cytometry and analyzed for sphere-formation and by flow cytometry assays. LS-174T cells were sorted by flow cytometry (for CD133(+)CD44(+) and CD133(-)CD44(-) cells) and also used in these assays. NOD-scidIL-2Rγ(-/-) (NSG) mice were given cecal or subcutaneous injections of LS-174T or human primary CRC cells. Apc(Min/+) mice and NSG mice with orthotopic cecal tumors were given vehicle (controls), PGE2, celecoxib, and/or Ono-AE3-208. PGE2 downstream signaling pathways were knocked down with small hairpin RNAs, expressed from lentiviral vectors in LS-174T cells, or blocked with inhibitors in human primary CRC cells. RESULTS: Levels of PGE2 correlated with colonic CSC markers (CD133, CD44, LRG5, and SOX2 messenger RNAs) in human colorectal carcinoma samples. Administration of PGE2 to Apc(Min/+) mice increased tumor stem cells and tumor burden, compared with controls. NSG mice given PGE2 had increased numbers of cecal CSCs and liver metastases compared with controls after intracecal injection of LS-174T or human primary CRC cells. Alternatively, celecoxib, an inhibitor of prostaglandin-endoperoxide synthase 2, reduced polyp numbers in Apc(Min/+) mice, liver metastasis in NSG mice with orthotopic tumors, and numbers of CSCs in Apc(Min/+) and NSG mice. Inhibitors or knockdown of PGE2 receptor 4 (EP4), phosphoinositide 3-kinase (PI3K) p85α, extracellular signal-regulated kinase 1 (ERK1), or nuclear factor (NF)-κB reduced PGE2-induced sphere formation and expansion of LS-174T and/or human primary CRC cells. Knockdown of ERK1 or PI3K p85α also attenuated PGE2-induced activation of NF-κB in LS-174T cells. An EP4 antagonist reduced the ability of PGE2 to induce CSC expansion in orthotopic tumors and to accelerate the formation of liver metastases. Knockdown experiments showed that NF-κB was required for PGE2 induction of CSCs and metastasis in mice. CONCLUSIONS: PGE2 induces CSC expansion by activating NF-κB, via EP4-PI3K and EP4-mitogen-activated protein kinase signaling, and promotes the formation of liver metastases in mice. The PGE2 signaling pathway therefore might be targeted therapeutically to slow CSC expansion and colorectal cancer progression.

Geniposide Suppresses Hepatic Glucose Production via AMPK in HepG2 Cells.

Geniposide is one of the main compounds in Gardenia jasminoides ELLIS and has many pharmacological activities, but its anti-hyperglycemic activity has not yet been fully explored. This study was designed to determine, for the first time, how geniposide from G. jasminoides regulates hepatic glucose production, and the underlying mechanisms. During in vitro study, we found the inhibitory effect of geniposide on the hepatic glucose production is partly through AMP-activated protein kinase (AMPK) activation in HepG2 cells. Geniposide significantly inhibited hepatic glucose production in a dose-dependent manner. AMPK, acetyl coenzyme A synthetase (ACC) and forkhead box class O1 (FoxO1) phosphorylation were stimulated by different concentrations of geniposide. In addition, the enzyme activities of phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase) were all significantly suppressed. What is important is that these effects were partly reversed by (1) inhibition of AMPK activity by compound C, a selective AMPK inhibitor, and by (2) suppression of AMPKα expression by small interfering RNA (siRNA). In summary, geniposide potentially ameliorates hyperglycemia through inhibition of hepatic gluconeogenesis by modulation of the AMPK-FoxO1 signaling pathway. Geniposide or geniposide-containing medicinal plants could represent a promising therapeutic agent to prevent type 2 diabetes on gluconeogenesis.

Involvement of protein kinase ζ in the maintenance of hippocampal long-term potentiation in rats with chronic visceral hypersensitivity.

The hippocampal long-term potentiation (LTP) was implicated in the formation of visceral hypersensitivity in rats with irritable bowel syndrome in our previous study. Recent studies have shown that protein kinase M ζ (PKMζ) may be responsible for the maintenance of LTP in memory formation. However, it remains unclear whether PKMζ is involved in the visceral hypersensitivity. In this study, a rat model of visceral hypersensitivity was generated by neonatal maternal separation (NMS). The visceral hypersensitivity was assessed by recording responses of the external oblique abdominal muscle to colorectal distension. Our results demonstrated that hippocampal LTP and visceral hypersensitivity were enhanced significantly in rats of NMS. ζ-Pseudosubstrate inhibitory peptide (ZIP) could dose dependently inhibit the maintenance of Cornu Ammonis area 1 LTP in rats of NMS. Furthermore, Western blot data showed that the expression of hippocampal phosphorylated PKMζ (p-PKMζ) significantly increased in rats of NMS. In addition, bilateral intrahippocampal injections of ZIP attenuated the visceral hypersensitivity dose dependently in rats of NMS. The maximal inhibition was observed at 30 min, and significant inhibition lasted for 1.5-2 h after ZIP application. Besides, data from the open-field test and Morris water maze showed that ZIP did not influence the movement and spatial procedural memory in rats of NMS. In conclusion, p-PKMζ might be a critical protein in the maintenance of hippocampal LTP, which could result in visceral hypersensitivity.

MicroRNA-200 promotes lung cancer cell growth through FOG2-independent AKT activation.

MicroRNA-200 (miR-200) has emerged as a regulator of the PI3K/AKT pathway and cancer cell growth. It was reported that miR-200 can activate PI3K/AKT by targeting FOG2 (friend of GATA 2), which directly binds to the p85α regulatory subunit of PI3K. We found that miR-200 was elevated in early stage lung adenocarcinomas when compared with normal lung tissues, and the expression of miR-200 promoted the tumor spheroid growth of lung adenocarcinoma cells. We show that AKT activation was essential for such oncogenic action of miR-200. However, depletion of FOG2 had little effect on AKT activation. By performing a reverse-phase protein array, we found that miR-200 not only activated AKT but also concomitantly inactivated S6K and increased IRS-1, an S6K substrate that is increased on S6K inactivation. Depletion of IRS-1 partially inhibited the miR-200-dependent AKT activation. Taken together, our results suggest that miR-200 may activate AKT in lung adenocarcinoma cells through a FOG2-independent mechanism involving IRS-1. Our findings also provide evidence that increased miR-200 expression may contribute to early lung tumorigenesis and that AKT inhibitors may be useful for the treatment of miR-200-dependent tumor cell growth.

Atomic structure of the autosomal recessive hypercholesterolemia phosphotyrosine-binding domain in complex with the LDL-receptor tail.

Hypercholesterolemia, high serum cholesterol in the form of LDL, is a major risk factor for atherosclerosis. LDL is mostly degraded in the liver after its cellular internalization with the LDL receptor (LDLR). This clathrin-mediated endocytosis depends on the protein autosomal recessive hypercholesterolemia (ARH), which binds the LDLR cytoplasmic tail. Mutations in either the LDLR tail or in ARH lead to hypercholesterolemia and premature atherosclerosis. Despite the significance of this interaction for cholesterol homeostasis, no structure of either ARH or the LDLR tail is available to determine its molecular basis. We report the crystal structure at 1.37-Å resolution of the phosphotyrosine-binding (PTB) domain of ARH in complex with an LDLR tail peptide containing the FxNPxY(0) internalization signal. Surprisingly, ARH interacts with a longer portion of the tail than previously recognized, which extends to I(-7)xF(-5)xNPxY(0)QK(+2). The LDLR tail assumes a unique "Hook"-like structure with a double ß-turn conformation, which is accommodated in distinctive ARH structural determinants (i.e., an extended backbone hydrogen-bonding platform, three hydrophobic helical grooves, and a hydrophobic pocket for Y(0)). This unique complementarity differs significantly in related PTB proteins and may account for the unique physiological role of these partners in the hepatic uptake of cholesterol LDL. Moreover, the unusual hydrophobic pocket for Y(0) explains the distinctive ability of ARH to internalize proteins containing either FxNPxY(0) or FxNPxF(0) sequences. Biophysical measurements reveal how mutations associated with hypercholesterolemia destabilize ARH and its complex with LDLR and illuminate LDL internalization defects seen in patients.