Epigenetic regulation of pyroptosis in cancer: Molecular pathogenesis and targeting strategies

Immune checkpoint blockade therapy has revolutionized the field of cancer treatment, leading to durable responses in patients with advanced and metastatic cancers where conventional therapies were insufficient. However, factors like immunosuppressive cells and immune checkpoint molecules within the tumor microenvironment (TME) can suppress the immune system and thus negatively affect the efficiency of immune checkpoint inhibitors. Pyroptosis, a gasdermin-induced programmed cell death, could transform "cold tumors" to "hot tumors" to improve the milieu of TME, thus enhancing the immune response and preventing tumor growth. Recently, evidence showed that epigenetics could regulate pyroptosis, which further affects tumorigenesis, suggesting that epigenetics-based tumor cells pyroptosis could be a promising therapeutic strategy. Hence, this review focuses on the pyroptotic mechanism and summarizes three common types of epigenetics, DNA methylation, histone modification, and non-coding RNA, all of which have a role in regulating the expression of transcription factors and proteins involved in pyroptosis in cancer. Especially, we discuss targeting strategies on epigenetic-regulated pyroptosis and provide insights on the future trend of cancer research which may fuel cancer therapies into a new step.

Efficacy and mechanism of Wuzi Yanzong pill on the prevention and treatment of EAE

Objective

Studies have shown that Wuzi Yanzong Pill (WYP) can be used to treat neurological diseases, but its mechanisms for multiple sclerosis (MS) remain unclear. This study aims to determine the effect of WYP on MS in an animal model of experimental autoimmune encephalomyelitis (EAE), and explore its mechanism. To provide theoretical basis for the clinical treatment of MS with WYP.

Methods

C57BL/6 female mice were randomly divided into Blank control, EAE control, low dose WYP, medium dose WYP, and high dose WYP groups. One week before model generation, the mice were gavaged with saline (50 mL/kg/d) in Blank control and EAE control groups. The treatment groups was gavaged with different doses of WYP solution (4, 8, or 16 g/kg/d respectively) Clinical scores were recorded daily. Sample collection was conducted on the 14th and 28th days, respectively The expressions of IL-10, IL-17, IL-12, TNF-α and IFN-γ in spleen were detected by ELISA. The expressions of ROCKII, P-MYPT1, TLR4, NF-κB/p65, MCP-1, CCR2 in spleen, brain and spinal cord were detected by Western Blot. The types of macrophages and the contents of intracellular IL-10 and IL-12 were detected by Flow Cytometry. The contents of TNF-α and TLR4 mRNA in the spleen were detected by RT-PCR.

Results

WYP treatment improved the clinical score of EAE mice in a significant dose-dependent manner, with the WYP high-dose group showed the most significant improvement in clinical score. Compared with the EAE control group, WYP high dose group had significantly lower levels of IL-17, IFN-γ, ROCKII, P-MYPT1, TLR4, NF-κB/p65, MCP-1, and CCR2 as well as TNF-α and TLR4 mRNA, but increased the number of M2 macrophages and IL-10.

Conclusion

WYP treatment relieves clinical symptoms in EAE mice, which may be related to regulate inflammatory pathway and inhibiting expressions of inflammatory cytokines.

[Postpartum fatal pulmonary embolism with F5 gene mutation: a case report]

Pulmonary embolism (PE) is one of the leading causes of maternal death. Various clinical and environmental risk factors can cause PE. Here, we reported an uncommon PE case with multiple etiological causes, including caesarean section, overweight, anti-cardiolipin antibody positive, and factor 5 gene mutation. The patient was a 25-year-old woman who developed cardiac asystole and apnea one day after cesarean delivery due to pulmonary embolism. After cardiopulmonary resuscitation and thrombolytic therapy, high doses of epinephrine were still needed to maintain blood pressure and heart rate, so we treated her with venoarterial extracorporeal membrane oxygenation (ECMO) to maintain systemic circulation. She progressively improved and was discharged on oral warfarin treatment. Comprehensive laboratory tests revealed a positive anticardiolipin antibody. Through whole exon gene sequencing, we identified a novel mutation (A2032➝G) in the F5 gene. This mutation was predicted to result in the replacement of lysine with glutamate at position 678, close to one of the APC cleavage sites. P.Lys678Glu was found to be a detrimental mutation by SIFT software and suspected detrimental by Polyphen-2 software. Attention should be paid to the etiological screening of young patients with pulmonary embolism, which is helpful in guiding the anticoagulant scheme and anticoagulant duration, and is of great significance in preventing thrombosis recurrence and complications.

β-Elemene enhances erlotinib sensitivity through induction of ferroptosis by upregulating lncRNA H19 in EGFR-mutant non-small cell lung cancer

Nearly half of all Asian non-small cell lung cancer (NSCLC) patients harbour epidermal growth factor receptor (EGFR) mutations, and first-generation EGFR tyrosine kinase inhibitors (TKIs) are one of the first-line treatments that have improved the outcomes of these patients. Unfortunately, 20% of these patients can not benefit from the treatment. The basis of this primary resistance is poorly understood. Therefore, overcoming EGFR-TKI primary resistance and maintaining the efficacy of TKIs has become a key issue. β-Elemene, a sesquiterpene compound extracted from Curcuma aromatica Salisb. (wenyujing), has shown potent antitumor effects. In this research, we found that β-elemene combined with erlotinib enhanced the cytotoxicity of erlotinib to primary EGFR-TKI-resistant NSCLC cells with EGFR mutations and that ferroptosis was involved in the antitumor effect of the combination treatment. We found that lncRNA H19 was significantly downregulated in primary EGFR-TKI-resistant NSCLC cell lines and was upregulated by the combination treatment. Overexpression or knockdown of H19 conferred sensitivity or resistance to erlotinib, respectively, in both in vitro and in vivo studies. The high level of H19 enhanced the cytotoxicity of erlotinib by inducing ferroptosis. In conclusion, our data showed that β-elemene combined with erlotinib could enhance sensitivity to EGFR-TKIs through induction of ferroptosis via H19 in primary EGFR-TKI-resistant lung cancer, providing a promising strategy to overcome EGFR-TKI resistance in NSCLC patients.

Preoperative computed tomography enterography-based radiomics signature: A potential predictor of postoperative anastomotic recurrence in patients with Crohn's disease

BACKGROUND

More than half of patients with Crohn's disease (CD) require at least one surgery for symptom management; however, approximately half of the patients may experience postoperative anastomotic recurrence (PAR).

OBJECTIVES

This study aims to develop and validate a preoperative computed tomography enterography (CTE)-based radiomics signature to predict early PAR in CD.

DESIGN

A total of 186 patients with CD (training cohort, n = 134; test cohort, n = 52) who underwent preoperative CTE and surgery between January 2014 and June 2020 were included in this retrospective multi-centre study.

METHODS

106 radiomic features were initially extracted from intestinal lesions and peri-intestinal mesenteric fat, respectively; significant radiomic features were selected from them and then used to develop intestinal or mesenteric radiomics signatures, using the least absolute shrinkage and selection operator and a Cox regression model. A radiomics-based nomogram incorporating these signatures with clinical-radiological factors was created for comparison with a model based on clinical-radiological features alone.

RESULTS

68 of 134 patients in training cohort and 16 of 52 patients in test cohort suffered from PAR. The intestinal radiomic signature (hazard ratio [HR]: 2.17; 95% confidence interval [CI]: 1.32-3.58; P = 0.002) and mesenteric radiomic signature (HR: 2.19; 95% CI: 1.14-4.19; P = 0.018) were independent risk factors for PAR in the training cohort as per a multivariate analysis. The radiomics-based nomogram (C-index: 0.710; 95% CI: 0.672-0.748) yielded superior predictive performance than the clinical-radiological model (C-index, 0.607; 95% CI: 0.582-0.632) in the test cohort. Decision curve analysis demonstrated that the radiomics-based nomogram outperformed the clinical-radiological model in terms of clinical usefulness.

CONCLUSIONS

Preoperative mesenteric and intestinal CTE radiomics signatures are potential non-invasive predictors of PAR in postoperative patients with CD.

PCGF6/MAX/KDM5D facilitates MAZ/CDK4 axis expression and pRCC progression by hypomethylation of the DNA promoter

Polycomb group RING finger protein 6 (PCGF6) plays an important role as a regulator of transcription in a variety of cellular processes, including tumorigenesis. However, the function and expression of PCGF6 in papillary RCC (pRCC) remain unclear. In the present study, we found that PCGF6 expression was significantly elevated in pRCC tissues, and high expression of PCGF6 was associated with poor survival of patients with pRCC. The overexpression of PCGF6 promoted while depletion of PCGF6 depressed the proliferation of pRCC cells in vitro. Interestingly, myc-related zinc finger protein (MAZ), a downstream molecular of PCGF6, was upregulated in pRCC with hypomethylation promoter. Mechanically, PCGF6 promoted MAZ expression by interacting with MAX and KDM5D to form a complex, and MAX recruited PCGF6 and KDM5D to the CpG island of the MAZ promoter and facilitated H3K4 histone demethylation. Furthermore, CDK4 was a downstream molecule of MAZ that participated in PCGF6/MAZ-regulated progression of pRCC. These results indicated that the upregulation of PCGF6 facilitated MAZ/CDK4 axis expression and pRCC progression by hypomethylation of the MAZ promoter. The PCGF6/MAZ/CDK4 regulatory axis may be a potential target for the treatment of ccRCC.

The spatiotemporal matching pattern of Ezrin/Periaxin involved in myoblast differentiation and fusion and Charcot-Marie-Tooth disease-associated muscle atrophy

BACKGROUND

Clinically, Charcot-Marie-Tooth disease (CMT)-associated muscle atrophy still lacks effective treatment. Deletion and mutation of L-periaxin can be involved in CMT type 4F (CMT4F) by destroying the myelin sheath form, which may be related to the inhibitory role of Ezrin in the self-association of L-periaxin. However, it is still unknown whether L-periaxin and Ezrin are independently or interactively involved in the process of muscle atrophy by affecting the function of muscle satellite cells.

METHOD

A gastrocnemius muscle atrophy model was prepared to mimic CMT4F and its associated muscle atrophy by mechanical clamping of the peroneal nerve. Differentiating C2C12 myoblast cells were treated with adenovirus-mediated overexpression or knockdown of Ezrin. Then, overexpression of L-periaxin and NFATc1/c2 or knockdown of L-periaxin and NFATc3/c4 mediated by adenovirus vectors were used to confirm their role in Ezrin-mediated myoblast differentiation, myotube formation and gastrocnemius muscle repair in a peroneal nerve injury model. RNA-seq, real-time PCR, immunofluorescence staining and Western blot were used in the above observation.

RESULTS

For the first time, instantaneous L-periaxin expression was highest on the 6th day, while Ezrin expression peaked on the 4th day during myoblast differentiation/fusion in vitro. In vivo transduction of adenovirus vectors carrying Ezrin, but not Periaxin, into the gastrocnemius muscle in a peroneal nerve injury model increased the numbers of muscle myosin heavy chain (MyHC) I and II type myofibers, reducing muscle atrophy and fibrosis. Local muscle injection of overexpressed Ezrin combined with incubation of knockdown L-periaxin within the injured peroneal nerve or injection of knockdown L-periaxin into peroneal nerve-injured gastrocnemius muscle not only increased the number of muscle fibers but also recovered their size to a relatively normal level in vivo. Overexpression of Ezrin promoted myoblast differentiation/fusion, inducing increased MyHC-I⁺ and MyHC-II + muscle fiber specialization, and the specific effects could be enhanced by the addition of adenovirus vectors for knockdown of L-periaxin by shRNA. Overexpression of L-periaxin did not alter the inhibitory effects on myoblast differentiation and fusion mediated by knockdown of Ezrin by shRNA in vitro but decreased myotube length and size. Mechanistically, overexpressing Ezrin did not alter protein kinase A gamma catalytic subunit (PKA-γ cat), protein kinase A I alpha regulatory subunit (PKA reg Iα) or PKA reg Iβ levels but increased PKA-α cat and PKA reg II α levels, leading to a decreased ratio of PKA reg I/II. The PKA inhibitor H-89 remarkably abolished the effects of overexpressing-Ezrin on increased myoblast differentiation/fusion. In contrast, knockdown of Ezrin by shRNA significantly delayed myoblast differentiation/fusion accompanied by an increased PKA reg I/II ratio, and the inhibitory effects could be eliminated by the PKA reg activator N6-Bz-cAMP. Meanwhile, overexpressing Ezrin enhanced type I muscle fiber specialization, accompanied by an increase in NFATc2/c3 levels and a decrease in NFATc1 levels. Furthermore, overexpressing NFATc2 or knocking down NFATc3 reversed the inhibitory effects of Ezrin knockdown on myoblast differentiation/fusion.

CONCLUSIONS

The spatiotemporal pattern of Ezrin/Periaxin expression was involved in the control of myoblast differentiation/fusion, myotube length and size, and myofiber specialization, which was related to the activated PKA-NFAT-MEF2C signaling pathway, providing a novel L-Periaxin/Ezrin joint strategy for the treatment of muscle atrophy induced by nerve injury, especially in CMT4F.

Rb3B5O8F2 and K0.6Rb2.4B5O8F2: Two New Deep-Ultraviolet Transparent Nonlinear Optical Fluorooxoborates Designed by Cations Regulation

Two new fluorooxoborates Rb3B5O8F2 and K0.6Rb2.4B5O8F2 were successfully obtained by cation regulation. Both of them crystallize in non-centrosymmetric space group P21. The structural evolution from Li2Na0.9K0.1B5O8F2 to Rb3B5O8F2, as well...

Pyroptosis in inflammatory bone diseases: Molecular insights and targeting strategies

Inflammatory bone diseases include osteoarthritis (OA) and rheumatoid arthritis (RA), which can cause severe bone damage in a chronic inflammation state, putting tremendous pressure on the patients' families and government agencies regarding medical costs. In addition, the complexity of osteoimmunology makes research on these diseases difficult. Hence, it is urgent to determine the potential mechanisms and find effective drugs to target inflammatory bone diseases to reduce the negative effects of these diseases. Recently, pyroptosis, a gasdermin-induced necrotic cell death featuring secretion of pro-inflammatory cytokines and lysis, has become widely known. Based on the effect of pyroptosis on immunity, this process has gradually emerged as a vital component in the etiopathogenesis of inflammatory bone diseases. Herein, we review the characteristics and mechanisms of pyroptosis and then focus on its clinical significance in inflammatory bone diseases. In addition, we summarize the current research progress of drugs targeting pyroptosis to enhance the therapeutic efficacy of inflammatory bone diseases and provide new insights for future directions.

Effects of Selenium Supplementation on the Ion Homeostasis in the Reproductive Organs and Eggs of Laying Hens Fed With the Diet Contaminated With Cadmium, Lead, Mercury, and Chromium

The objective of this study was to explore the toxic effects of different heavy metals in combination with their deposition and ion homeostasis in the reproductive organs and eggs of laying hens, as well as the alleviating action of selenized yeast. A total of 160 Lohmann pink-shell laying hens (63-week-old) were randomly allocated into four treatments with 10 replicates of four hens each. The four dietary treatments were the corn-soybean meal basal dietary (control; CON); the CON dietary supplemented with 0.4 mg/kg selenium from selenized yeast (Se); the CON dietary supplemented with 5 mg/kg Cd + 50 mg/kg Pb +3 mg/kg Hg + 5 mg/kg Cr (HEM), and the HEM dietary supplemented with 0.4 mg/kg selenium from selenized yeast (HEM+Se). The dietary HEM significantly increased Cd, Pb, and Hg deposition in the egg yolk and ovary, and Cd and Hg deposition in the oviduct and in the follicular wall (p < 0.05). The HEM elevated Fe concentration in the egg yolk, ovary, and oviduct (p < 0.05). The HEM decreased Mn concentration in the egg yolk, Fe, Mn, and Zn concentrations in the egg white, Cu concentration in the ovary, Mg concentration in the oviduct, as well as Ca, Cu, Zn, and Mg concentrations in the follicular walls (p < 0.05). Dietary Se addition elevated Se concentration in the egg yolk, oviduct, and follicular walls and Mg concentration (p < 0.05) in the oviduct, whereas it reduced Fe concentration in the oviduct compared with the HEM-treated hens. Some positive or negative correlations among these elements were observed. Canonical Correlation Analysis showed that the concentrations of Pb and Hg in the egg yolk were positively correlated with those in the ovary. The concentration of Cd in the egg white was positively correlated with that in the oviduct. In summary, dietary Cd, Pb, Hg, and Cr in combination caused ion loss and deposition of HEM in reproductive organs of laying hens. Dietary Se addition at 0.4 mg/kg from selenized yeast alleviated the negative effects of HEM on Fe and Mg ion disorder in the oviduct and follicle wall of hens.

A Novel Diagnostic and Therapeutic Strategy for Cancer Patients by Integrating Chinese Medicine Syndrome Differentiation and Precision Medicine

Applying Chinese medicine (CM) is an important strategy for malignant tumor treatment in China. One of the significant characteristics of CM is to treat diseases based on syndrome differentiation. For Western medicine, it is of important clinical significance to formulate guidelines for the diagnosis and treatment of cancer patients based on the characteristics of disease differentiation. In Chinese clinical practice, the combination of disease differentiation and syndrome differentiation is an important feature for cancer treatment in the past. Currently, molecular profiling and genomic analysis-based precision medicine optimizes the anticancer drug design and holds the greatest success in treating cancer patients. Therefore, we want to know which populations of cancer patients can benefit more from CM treatment if the theory of precision medicine is applied to CM clinical practice. So, we developed a novel diagnostic and therapeutic strategy "disease-syndrome differentiation-genomic profiling-prescriptions" for cancer patients by CM syndrome differentiation and precision medicine. As a result, this strategy has greatly enhanced the anti-tumor efficacy of CM and improved clinical outcomes for cancer patients with some gene mutations. Our idea will hopefully establish a novel approach for the inheritance and innovation of CM.

Oncogenic potential of BEST4 in colorectal cancer via activation of PI3K/Akt signaling

BEST4 is a member of the bestrophin protein family that plays a critical role in human intestinal epithelial cells. However, its role and mechanism in colorectal cancer (CRC) remain largely elusive. Here, we investigated the role and clinical significance of BEST4 in CRC. Our results demonstrate that BEST4 expression is upregulated in clinical CRC samples and its high-level expression correlates with advanced TNM (tumor, lymph nodes, distant metastasis) stage, LNM (lymph node metastasis), and poor survival. Functional studies revealed that ectopic expression of BEST4 promoted CRC cell proliferation and metastasis, whereas the depletion of BEST4 had the opposite effect both in vitro and in vivo. Mechanistically, BEST4 binds to the p85α regulatory subunit of phosphatidylinositol-3-kinase (PI3K) and promotes p110 kinase activity; this leads to activation of Akt signaling and expression of MYC and CCND1, which are critical regulators of cell proliferation and metastasis. In clinical samples, the expression of BEST4 is positively associated with the expression of phosphorylated Akt, MYC and CCND1. Pharmacological inhibition of Akt activity markedly repressed BEST4-mediated Akt signaling and proliferation and metastasis of CRC cells. Importantly, the interaction between BEST4 and p85α was also enhanced by epidermal growth factor (EGF) in CRC cells. Therapeutically, BEST4 suppression effectively sensitized CRC cells to gefitinib treatment in vivo. Taken together, our findings indicate the oncogenic potential of BEST4 in colorectal carcinogenesis and metastasis by modulating BEST4/PI3K/Akt signaling, highlighting a potential strategy for CRC therapy.

The Role of TGF-β Signaling Pathways in Cancer and Its Potential as a Therapeutic Target

The transforming growth factor-β (TGF-β) signaling pathway mediates various biological functions, and its dysregulation is closely related to the occurrence of malignant tumors. However, the role of TGF-β signaling in tumorigenesis and development is complex and contradictory. On the one hand, TGF-β signaling can exert antitumor effects by inhibiting proliferation or inducing apoptosis of cancer cells. On the other hand, TGF-β signaling may mediate oncogene effects by promoting metastasis, angiogenesis, and immune escape. This review summarizes the recent findings on molecular mechanisms of TGF-β signaling. Specifically, this review evaluates TGF-β's therapeutic potential as a target by the following perspectives: ligands, receptors, and downstream signaling. We hope this review can trigger new ideas to improve the current clinical strategies to treat tumors related to the TGF-β signaling pathway.

Spatio-temporal model of Meox1 expression control involvement of Sca-1-positive stem cells in neointima formation through the synergistic effect of Rho/CDC42 and SDF-1α/CXCR4

AIMS

Neointimal hyperplasia remains a major obstacle in vascular regeneration. Sca-1-positive progenitor cells residing within the vascular adventitia play a crucial role in the assemblage of vascular smooth muscle cell (VSMC) and the formation of the intimal lesion. However, the underlying mechanisms during vascular injury are still unknown.

METHODS AND RESULTS

Aneointimal formation rat model was prepared by carotid artery injury using 2F-Forgaty. After vascular injury, Meox1 expressions time-dependently increased during the neointima formation, with its levels concurrently increasing in the adventitia, media, and neointima. Meox1 was highly expressed in the adventitia on the first day after vascular injury compared to the expression levels in the media. Conversely, by the 14th day post-injury, Meox1 was extensively expressed more in the media and neointima than the adventitia. Analogous to the change of Meox1 in injured artery, Sca-1+ progenitor cells increased in the adventitia wall in a time-dependent manner and reached peak levels on the 7th day after injury. More importantly, this effect was abolished by Meox1 knockdown with shRNA. The enhanced expression of SDF-1α after vascular injury was associated with the markedly enhanced expression levels of Sca1+ progenitor cell, and these levels were relatively synchronously increased within neointima by the 7th day after vascular injury. These special effects were abolished by the knockdown of Meox1 with shRNA and inhibition of CXCR4 by its inhibitor, AMD3100. Finally, Meox1 concurrently regulated SDF-1α expressions in VSMC via activating CDC42, and CDC42 inhibition abolished these effects by its inhibitor, ZCL278. Also, Meox1 was involved in activation of the CXCR4 expression of Sca-1+ progenitor cells by CDC42.

CONCLUSIONS

Spatio-temporal model of Meox1 expression regulates theSca-1+progenitor cell migration during the formation of the neointima through the synergistic effect of Rho/CDC42 and SDF-1α/CXCR4.

Sexual variation in two species of Helorus Latreille (Hymenoptera, Heloridae) from NW China, with description of female of Helorus caii He amp; Xu

The intra-specific variation of two species of Helorus Latreille (Hymenoptera, Heloridae) from NW China is studied and for the first time the sexual variation in Chinese Helorus species is described. Both sexes of Helorus antefurcalis He Xu, 2015 (new for Shaanxi) and H. caii He Xu, 2015 (up to now only known from one male), are described and illustrated. Helorus xinjiangensis He Xu, [June] 2015, is a new junior synonym of H. alborzicus Izadizadeh, van Achterberg Talebi, [April] 2015 and H. elgoni Risbec, 1950, is re-instated as valid species. A revised key to the Old World species of Helorus Latreille (except Australian region) is included.

Review of the Bobekia-group (Braconidae, Alysiinae, Alysiini), with description of a new genus and a new subgenus

The world genera of the Bobekia-group of Alysiini (Braconidae: Alysiinae) are reviewed and keyed. A new genus (Neodiastagen. nov.) is proposed for Phasmidiastaecuadorensis Fischer, 2006, from Ecuador. One new subgenus (Parabobekoidessubg. nov.; type species Separatatus (Parabobekoides) yinshanisp. nov. from NW China) is described and illustrated. Neosymphanes Belokobylskij, 1998 is a new synonym of Bobekia Niezabitowski, 1910 (syn. nov.).

Functional characterization of short-type peptidoglycan recognition proteins (PGRPs) from silkworm Bombyx mori in innate immunity

Peptidoglycan recognition proteins (PGRPs) are members of an important class of pattern recognition receptors in insects that can specifically recognize peptidoglycan (PGN) in bacterial cell walls and participate in immune regulation and bacterial clearance. Although the role of PGRPs in regulating the innate immune response in Drosophila melanogaster has been studied, little is known regarding PGRPs in Lepidoptera species. In this study, five short (S)-type Bombyx mori PGRPs (BmPGRPs) were cloned, expressed, and evaluated for their function in innate immunity. B. mori larvae that were injected with the gram-positive bacterium Bacillus megaterium or the gram-negative bacterium Escherichia coli exhibited a rapid and significant upregulation in S-type BmPGRP expression. The results showed that the five evaluated BmPGRPs have significant agglutination activity toward E. coli and B. megaterium and more notable amidase activity toward meso-diaminopimelic acid peptidoglycan (DAP-PGN). Furthermore, only in the presence of BmPGRP-S5 did B. mori larval hemocytes exhibit significant phagocytosis against E. coli and B. megaterium.

An ML protein from the silkworm Bombyx mori may function as a key accessory protein for lipopolysaccharide signaling

Lipopolysaccharide (LPS) is a common component of the outermost cell wall in Gram-negative bacteria. In mammals, LPS serves as an endotoxin that can be recognized by a receptor complex of TLR4 (Toll-like receptor 4) and MD-2 (myeloid differentiation-2) and subsequently induce a strong immune response to signal the release of tumor necrosis factor (TNF). In Drosophila melanogaster, no receptors for LPS have been identified, and LPS cannot activate immune responses. Here, we report a protein, BmEsr16, which contains an ML (MD-2-related lipid-recognition) domain, may function as an LPS receptor in the silkworm Bombyx mori. We showed that antibacterial activity in the hemolymph of B. mori larvae was induced by Escherichia coli, peptidoglycan (PGN) and LPS and that the expression of antimicrobial peptide genes was also induced by LPS. Furthermore, both the expression of BmEsr16 mRNA in the fat body and the expression of BmEsr16 protein in the hemolymph were induced by LPS. Recombinant BmEsr16 bound to LPS and lipid A, as well as to PGN, lipoteichoic acid, but not to laminarin or mannan. More importantly, LPS-induced immune responses in the hemolymph of B. mori larvae were blocked when the endogenous BmEsr16 protein was neutralized by polyclonal antibody specific to BmEsr16. Our results suggest that BmEsr16 may function as a key accessory protein for LPS signaling in B. mori.

Laser trapping/confocal Raman spectroscopic characterization of PLGA-PEG nanoparticles

We have immobilized poly(ethylene glycol) (PEG) on the surfaces of poly(lactic-co-glycolic acid) (PLGA) nanoparticles by two different chemical methods, i.e., SOCl2 halogenate-alcoholysis and DCC dehydration. The immobilized PLGA nanoparticles were characterized by DLS, 1H NMR, FT-IR and laser trapping/confocal Raman spectroscopic techniques. As a result, especially the Raman spectra which were measured after optically trapping ca. 10 individual nanoparticles in solution indicated that the PLGA nanoparticles were successfully immobilized with the PEG by the chemical methods.

Hoeflea prorocentri sp. nov., isolated from a culture of the marine dinoflagellate Prorocentrum mexicanum PM01

A Gram-stain negative, aerobic, rod-shaped, non-motile, yellow-pigmented and non-spore-forming bacterial strain, designated PM5-8^T, was isolated from a culture of a marine toxigenic dinoflagellate Prorocentrum mexicanum PM01. Strain PM5-8^T grew at 15-35 °C (optimum, 25-30 °C) and pH 6-11 (optimum, 7.5-8). Cells required at least 1.5% (w/v) NaCl for growth, and can tolerate up to 7.0% with the optimum of 4%. Phylogenetic analysis based on 16S rRNA gene sequence revealed that the strain PM5-8^T is closely related to members of the genus Hoeflea, with high sequence similarities with Hoeflea halophila JG120-1^T (97.06%) and Hoeflea alexandrii AM1V30^T (97.01%). DNA-DNA hybridization values between the isolate and other type strains of recognized species of the genus Hoeflea were between 11.8 and 25.2%, which is far below the value of 70% threshold for species delineation. The DNA G + C content was 50.3 mol%. The predominant cellular fatty acids of the strain were identified as summed feature 8 (C_16:1 ω7c and/or C_16:1 ω6c; 51.5%), C_18:1 ω7c 11-methyl (20.7%), C_16:0 (17.2%) and C_18:0 (5.7%). The major respiratory quinone was Q-10. Polar lipids profiles contained phosphatidylcholine, phosphatidylglycerol, sulfoquinovosyl diacylglycerol, phosphatidylmono- methylethanolamine, phosphatidylethanolamine and four unidentified lipids. On the basis of the polyphasic taxonomic data presented, strain PM5-8^T (= CCTCC AB 2016294^T = KCTC 62490^T) represents a novel species of the genus Hoeflea, for which the name Hoeflea prorocentri sp. nov. is proposed.

The addition of protein-bound amino acids in low-protein diets improves the metabolic and immunological characteristics in fifteen- to thirty-five-kg pigs

This study was to evaluate the effects of supplementation of AA form (crystalline vs. protein bound) in low-protein diets on growth, metabolic, and immunological characteristics of pigs. A total of 80 barrows (PIC 327 × 1050; 15.57 ± 0.13 kg BW and 48 ± 2 d of age), housed in 4 pigs per pen with 5 pens per treatment, were assigned to 4 dietary treatments of 17, 15, and 13% CP and 13% CP plus casein for 28 d. The crystalline AA were supplemented to meet the requirement of indispensable AA in pigs. Results showed that pigs fed the 13% CP diet or the 13% CP plus casein diet had lower ( < 0.01) ADG and ADFI and a greater ( < 0.01) feed:gain ratio than pigs fed the 17% CP or 15% CP diets over the 4-wk study period. Compared with other diets, pigs fed the 13% CP diet had decreased concentrations of plasma urea nitrogen, albumin ( < 0.01), and mRNA expressions of Toll-like receptor 4 (), nuclear factor kappa B (; < 0.05), and Toll-interacting protein (; < 0.01) in the ileum and also increased activity of plasma glutamate-pyruvate transaminase ( < 0.05) and concentrations of IL-1β ( < 0.05) and tumor necrosis factor-α ( < 0.01); however, these characteristics were partly normalized by feeding the 13% CP plus casein diet. Furthermore, the plasma concentration of insulin-like growth factor 1 (IGF-1; < 0.01) and mRNA expressions of protein kinase B (), mammalian target of rapamycin (), and ribosomal protein S6 kinase () in longissimus muscle were increased ( < 0.05) in pigs fed the 13% CP plus casein diet relative to pigs fed the 17% CP or 15% CP diets. In summary, reducing dietary CP level from 17% to 15% had no effect on growth, metabolic, and immunological characteristics of 15- to 35-kg pigs. A further reduction of dietary CP level up to 13% would lead to poor growth performance, but metabolic and immunological characteristics were partly normalized using protein-bound AA to replace synthesized AA in the 13% CP diet.

1, 25(OH)2D3-induced interaction of vitamin D receptor with p50 subunit of NF-κB suppresses the interaction between KLF5 and p50, contributing to inhibition of LPS-induced macrophage proliferation

KLF5 and nuclear factor κB (NF-κB) regulate cell proliferation and inflammation. Vitamin D signaling through vitamin D receptor (VDR) exerts anti-proliferative and anti-inflammatory actions. However, an actual relationship between KLF5, NF-κB and VDR in the inflammation and proliferation of macrophages is still unclear. Here, we showed that LPS and proinflammatory cytokines stimulate KLF5 gene expression in macrophages, and that 1, 25(OH)₂D₃ suppresses LPS-induced KLF5 expression and cell proliferation via upregulation of VDR expression. Mechanistic studies suggested that KLF5 interacts with p50 subunit of NF-κB to cooperatively induce the expressions of positive cell cycle regulators cyclin B1 and Cdk1/Cdc2 in LPS-treated macrophages. Further studies revealed that 1, 25(OH)₂D₃-induced interaction of VDR with p50 decreases LPS-induced interaction of KLF5 with p50. Collectively, we identify a novel regulatory pathway in which 1, 25(OH)₂D₃ induces VDR expression and promotes VDR interaction with p50 subunit of NF-κB, which in turn attenuates the association of KLF5 with p50 subunit of NF-κB and thus exerts anti-inflammatory and anti-proliferative effects on macrophages.

TMEM16A and myocardin form a positive feedback loop that is disrupted by KLF5 during Ang II-induced vascular remodeling

The TMEM16A protein is an important component of Ca(2+)-dependent Cl(-) channels (CaCCs) in vascular smooth muscle cells. A recent study showed that TMEM16A inhibits angiotensin II-induced proliferation in rat basilar smooth muscle cells. However, whether and how TMEM16A is involved in vascular remodeling characterized by vascular smooth muscle cell proliferation remains largely unclear. In this study, luciferase reporter, Western blotting, and qRT-PCR assays were performed. The results suggested that myocardin promotes TMEM16A expression by forming a complex with serum response factor (SRF) on the TMEM16A promoter in human aortic smooth muscle cells (HASMCs). In turn, upregulated TMEM16A promotes expression of myocardin and vascular smooth muscle cell marker genes, thus forming a positive feedback loop that induces cell differentiation and inhibits cell proliferation. Angiotensin II inhibits TMEM16A expression via Krüppel-like factor 5 (KLF5) in cultured HASMCs. Moreover, in vivo experiments show that infusion of angiotensin II into mice causes a marked reduction in TMEM16A expression and vascular remodeling, and angiotensin II-induced effects are largely reversed in KLF5 null (KLF5(-/-)) mice. KLF5 competes with SRF to interact with myocardin, thereby limiting myocardin binding to SRF and the synergistic activation of the TMEM16A promoter by myocardin and SRF. Our studies demonstrated that angiotensin II induces KLF5 expression and facilitates KLF5 association with myocardin to disrupt the myocardin-SRF complex, subsequently leading to inhibition of TMEM16A transcription. Blocking the positive feedback loop between myocardin and TMEM16A may be a novel therapeutic approach for vascular remodeling.

Chinese medicine Tongxinluo reduces atherosclerotic lesion by attenuating oxidative stress and inflammation in microvascular endothelial cells

Oxidative stress and inflammation are the important pathological basis of atherogenesis. So, attenuating oxidative stress and inflammation has a very important significance in the prevention and treatment of atherosclerosis. The aim of present study was to investigate whether anti-atherosclerotic effect of Tongxinluo (TXL), a compound traditional Chinese medicine, is related to its anti-oxidation and anti-inflammation in human cardiac microvascular endothelial cells (HCMEC). We found that TXL treatment significantly reduced serum lipid levels and atherosclerotic plaque formation of apoE-deficient mice, and improved endothelial cell function as evidenced by increased expression of CD31 and eNOS. TXL pretreatment could abrogate the up-regulation of ROS and MDA induced by C16. Further experiments showed that the anti-oxidative effect of TXL may be related to inhibiting the expression of p22(phox), p47(phox) and HO-1 in HCMECs. We also found that TXL could inhibit the release of IL-1β and TNFα induced by C16, which is mediated by inhibiting the expression and activation of NF-κB. In conclusion, TXL decreases atherosclerotic plaque formation and improves endothelial cell function by inhibiting oxidative stress and inflammation in HCMECs. This finding provides a new molecular mechanism for the anti-atherosclerotic effect of TXL.

Expression of perilipin 2 (PLIN2) in porcine oocytes during maturation

Perilipins have been reported to limit the interaction of lipases with neutral lipids within the droplets, thereby regulating neutral lipid accumulation and utilization. This study aimed to identify the location and expression of PLIN1 and PLIN2 in porcine oocytes during maturation. Quantitative real-time polymerase chain reaction (qRT-PCR), immunostaining and Western blot methods were used to characterize the expression and distribution patterns of PLIN1 and PLIN2 in porcine oocytes. The results showed that PLIN1 was not detectable in porcine oocytes. PLIN2 and BODIPY 493/503-detected neutral lipid droplets appeared identical distribution patterns and extensive colocalization in both GV and MII porcine oocytes. PLIN2 protein expression was higher in GV oocytes than that in MII oocytes (p < 0.05), although PLIN2 mRNA expression was similar in both groups. These findings suggested that PLIN2 was a major lipid droplet-associated protein in porcine oocytes.

[Phosphatidylethanolamine-binding protein (PEBP) in basic and clinical study]

Phosphatidylethanolamine-binding protein (PEBP) is a highly conserved group of multifunctional proteins found in a variety of different species. In the same species, it is expressed in numerous tissues and cell types. PEBP plays a pivotal modulatory role in several signal transduction pathways. PEBP inhibits the MAPK pathway through interacting with Raf-1, so it's also known as Raf-1 kinase inhibitor protein (RKIP). PEBP is involved in the regulation of PKC, G-protein-coupled receptor and NF-kappaB signaling pathway as well. In clinical researches, it was found that as the precursor of hippocampal cholinergic neurostimulating peptide (HCNP), PEBP has an important effect on the development of Alzheimer's disease. Recent evidence imply that PEBP function as a metastasis suppressor gene because it can suppress metastasis and promote apoptosis in tumor cells. In colorectal cancer, high methylation of the promoter region of PEBP gene results in the non-expression of PEBP, that maybe the molecular basis of tumor metastasis. The latest studies demonstrate that PEBP regulates the spindle checkpoint in cell cycle and loss of PEBP can leads to chromosomal abnormalities.