Mitochondria-Modulating Liposomes Reverse Radio-Resistance for Colorectal Cancer.

Complete remission of colorectal cancer (CRC) is still unachievable in the majority of patients by common fractionated radiotherapy, leaving risks of tumor metastasis and recurrence. Herein, clinical CRC samples demonstrated a difference in the phosphorylation of translation initiation factor eIF2α (p-eIF2α) and the activating transcription factor 4 (ATF4), whose increased expression by initial X-ray irradiation led to the resistance to subsequent radiotherapy. The underlying mechanism is studied in radio-resistant CT26 cells, revealing that the incomplete mitochondrial outer membrane permeabilization (iMOMP) triggered by X-ray irradiation is key for the elevated expression of p-eIF2α and ATF4, and therefore radio-resistance. This finding guided to discover that metformin and 2-DG are synergistic in reversing radio resistance by inhibiting p-eIF2α and ATF4. Liposomes loaded with metformin and 2-DG (M/D-Lipo) are thus prepared for enhancing fractionated radiotherapy of CRC, which achieved satisfactory therapeutic efficacy in both local and metastatic CRC tumors by reversing radio-resistance and preventing T lymphocyte exhaustion.

The PTB and PRR domains of numb regulate neurite outgrowth by influencing voltage-gated calcium channel expression and kinetics.

Numb is an evolutionarily conserved protein that regulates the differentiation of neuronal progenitor cells through unknown mechanisms. Numb has four alternative splice variants with different lengths of phosphotyrosine-binding (PTB) and proline-rich regions (PRR) domains. In this study, we demonstrated that Numb expression was increased in the primary cultures of rat cortical and hippocampal neurons over time in vitro, and Numb antisense inhibited neurite outgrowth. We verified that cells overexpressing short PTB (SPTB) or long PTB (LPTB) domains exhibited differentiation or proliferation, respectively. SPTB-mediated differentiation was related to the PRR domains, as cells expressing SPTB/LPRR had longer dendrites and more branched dendrites than cells expressing SPTB/SPRR. The differentiation of both cell types was completely blocked by the Ca2+ chelator. Western blot analysis revealed the increased total protein expression of voltage-gated calcium channel (VGCC) subunit α1C and α1D in cells expressing SPTB and LPTB Numb. The increased expression of the VGCC ß3 subunit was only observed in cells expressing SPTB Numb. Immunocytochemistry further showed that SPTB-mediated cell differentiation was associated with increased membrane expression of VGCC subunits α1C, α1D and ß3, which corresponded to the higher Ca2+ current (ICa) densities. Furthermore, we found that VGCC of cells transfected with SPTB/SPRR or SPTB/LPRR Numb isoforms exhibit steady-state inactivation (SSI) in both differentiated and undifferentiated phenotypes. A similar SSI of VGCC was observed in the differentiated cells transfected with SPTB/SPRR or SPTB/LPRR Numb isoforms, whereas a left shift SSI of VGCC in cells expressing SPTB/LPRR was detected in the undifferentiated cells. Collectively, these data indicate that SPTB domain is essential for neurite outgrowth involving in membrane expression of VGCC subunits, and LPRR plays a role in neuronal branching and the regulation of VGCC inactivation kinetics.

A Polymeric Hydrogel to Eliminate Programmed Death-Ligand 1 for Enhanced Tumor Radio-Immunotherapy.

Programmed death-ligand 1 (PD-L1) is a specialized shield on tumor cells that evades the immune system. Even inhibited by PD-L1 antibodies, a cycling process constantly transports PD-L1 from inside to outside of cells, facilitating the renewal and replenishment of PD-L1 on the cancer cell membrane. Herein, we develop a sodium alginate hydrogel consisting of elesclomol-Cu and galactose to induce persistent cuproptosis, leading to the reduction of PD-L1 for radio-immunotherapy of colon tumors. First, a prefabricated hydrogel is synthesized by immobilizing elesclomol onto a sodium alginate saccharide chain through the coordination with bivalent copper ions (Cu2+), followed by incorporation of galactose. After implantation into the tumors, this prefabricated hydrogel can be further cross-linked in the presence of physiological calcium ions (Ca2+), resulting in the formation of a hydrogel with controlled release of elesclomol-Cu2+ (ES-Cu) and galactose. The hydrogel effectively induces the oligomerization of DLAT and cuproptosis in colorectal cancer cells. Interestingly, radiation-induced PD-L1 upregulation is abrogated in the presence of the hydrogel, releasing ES-Cu and galactose. Consequently, the sensitization of tumor to radiotherapy and immunotherapy is significantly improved, further prolonging the survival of tumor-bearing mice in both local and metastatic tumors. Our study introduces an approach that combines cuproptosis with immunotherapy and radiotherapy.

(P)ppGpp synthetase Rsh participates in rifampicin tolerance of persister cells in Brucella abortus in vitro.

Brucella abortus is facultative intracellular pathogen that causes chronic persistent infections and results in abortion and infertility in food animals. Recurrent infections can be one of the results of persister cells formation that transiently displays phenotypic tolerance to high dose of antibiotics treatment. We examined persister cells formation of B. abortus strain A19 in stationary phase and investigated a potential role for the (p)ppGpp synthetase Rsh in this process. We found that B. abortus stationary phase cells can produce higher levels of multi-drugs tolerant persister cells in vitro under high dose of antibiotics (20 × MIC) exposure than do exponential phase cells. Persister cell formation was also induced with environmental stressors pH 4.5, 0.01 M PBS (pH7.0), 2% NaCl and 25 °C, upon exposure to ampicillin, enrofloxacin and rifampicin. Persister cells were not formed following exposure to 1 mM H2O2. The numbers of persister cells were significantly increased following uptake of B. abortus stationary phase cells by RAW264.7 macrophages in contrast with cultures in TSB liquid medium. Environmental stressors to B. abortus significantly increased expression of rsh mRNA level. The rsh null mutant (Δrsh) formed significantly fewer persister cells than the complemented (CΔrsh) and wildtype (WT) strains under high dose of rifampicin in vitro. These data for the first time demonstrate that B. abortus can produce multi-drug tolerant persister cells in stationary phase. The (p)ppGpp synthetase Rsh is necessary for persister cell formation in B. abortus in the presence of rifampicin. On this basis, a new understanding of the recurrent infections of Brucella was advanced, thus provided a new basis for revelation of pathogenic mechanism of the chronic persistent infection in Brucella.

Alr Gene in Brucella suis S2: Its Role in Lipopolysaccharide Biosynthesis and Bacterial Virulence in RAW264.7.

Brucella suis, the causative agent of brucellosis, poses a significant public health and animal husbandry threat. However, the role of the alanine racemase (alr) gene, which encodes alanine racemase in Brucella, remains unclear. Here, we analyzed an alr deletion mutant and a complemented strain of Brucella suis S2. The knockout strain displayed an unaltered, smooth phenotype in acriflavine agglutination tests but lacked the core polysaccharide portion of lipopolysaccharide (LPS). Genes involved in the LPS synthesis were significantly upregulated in the deletion mutant. The alr deletion strain exhibited reduced intracellular viability in the macrophages, increased macrophage-mediated killing, and upregulation of the apoptosis markers. Bcl2, an anti-apoptotic protein, was downregulated, while the pro-apoptotic proteins, Bax, Caspase-9, and Caspase-3, were upregulated in the macrophages infected with the deletion strain. The infected macrophages showed increased mitochondrial membrane permeability, Cytochrome C release, and reactive oxygen species, activating the mitochondrial apoptosis pathway. These findings revealed that alanine racemase was dispensable in B. suis S2 but influenced the strain's rough features and triggered the mitochondrial apoptosis pathway during macrophage invasion. The deletion of the alr gene reduced the intracellular survival and virulence. This study enhances our understanding of the molecular mechanism underlying Brucella's survival and virulence and, specifically, how alr gene affects host immune evasion by regulating bacterial LPS biosynthesis.

Exogenous AMPA downregulates gamma-frequency network oscillation in CA3 of rat hippocampal slices.

Pharmacologically-induced persistent hippocampal γ oscillation in area CA3 requires activation of α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors (AMPARs). However, we demonstrated that exogenous AMPA dose-dependently inhibited carbachol (CCH)-induced γ oscillation in the CA3 area of rat hippocampal slices, but the underlying mechanism is not clear. Application of AMPARs antagonist NBQX (1 µM) did not affect γ oscillation power (γ power), nor AMPA-mediated γ power reduction. At 3 µM, NBQX had no effect on γ power but largely blocked AMPA-mediated γ power reduction. Ca2+-permeable AMPA receptor (CP-AMPAR) antagonist IEM1460 or CaMKK inhibitor STO-609 but not CaMKIIα inhibitor KN93 enhanced γ power, indicating that activation of CP-AMPAR or CaMKK negatively modulated CCH-induced γ oscillation. Either CP-AMPAR antagonist or CaMKK inhibitor alone did not affected AMPA-mediated γ power reduction, but co-administration of IEM1460 and NBQX (1 µM) largely prevented AMPA-mediated downregulation of γ suggesting that CP-AMPARs and CI-AMPARs are involved in AMPA downregulation of γ oscillation. The recurrent excitation recorded at CA3 stratum pyramidale was significantly reduced by AMPA application. Our results indicate that AMPA downregulation of γ oscillation may be related to the reduced recurrent excitation within CA3 local neuronal network due to rapid CI-AMPAR and CP-AMPAR activation.

Factors Influencing Patient and Caregiver Preferences for Antipsychotic Treatment of Schizophrenia in China: A Discrete Choice Experiment.

Purpose: This study aimed to quantify the preferences of Chinese patients with schizophrenia and their caregivers for antipsychotic treatment. Patients and Methods: Patients with schizophrenia (aged 18-35) and their caregivers were recruited via six outpatient mental health clinics in Shanghai, People's Republic of China. In a discrete choice experiment (DCE), participants chose between two hypothetical treatment scenarios that varied regarding the type of treatment, rate of hospitalization, severity of positive symptoms, treatment cost and rates of improvement in daily and social functioning. Data for each group were analyzed using the modelling approach that yielded the lower deviance information criterion. The relative importance score (RIS) for each treatment attribute was also determined. Results: A total of 162 patients and 167 caregivers participated. Frequency of hospital admission was the most important treatment attribute for patients (average scaled RIS=27%), followed by mode and frequency of treatment administration (24%). Improvement in ability to carry out daily activities (8%) and improvement in social functioning (8%) were least important. Patients in full-time employment placed more importance on the frequency of hospital admission than unemployed patients (p<0.01). Frequency of hospital admission was also the most important attribute for caregivers (RIS=33%), followed by improvement in positive symptoms (20%), while improvement in daily activities (7%) was the least important. Conclusion: Patients with Schizophrenia in China prefer treatments that help reduce the number of times they are admitted to hospital, as do their caregivers. These results may bring insight for physicians and health authorities in China regarding the treatment characteristics that patients value the most.

Study on the mechanism of oral administration of tetrandrine during neoadjuvant chemotherapy for colon cancer.

Colon cancer is a digestive tract tumor with one of the highest frequencies worldwide, and with a high fatality rate. The present study aimed to investigate the expression and regulation of inflammatory factors in tumor tissues, monocytes and blood samples in patients with colon cancer (n=46) following treatment with neoadjuvant chemotherapy combined with tetrandrine. All patients underwent tumor resection after neoadjuvant chemotherapy. In the experimental group, 20 cases took tetrandrine during chemotherapy, while in the control group, 26 cases underwent chemotherapy without tetrandrine. Reverse transcription-quantitative PCR and western blotting were performed to detect the mRNA and protein expression levels of TNF-α. ELISA was used to detect the cytokine/chemokine expression levels [IL-15, IL-1ß and IL-6, as well as chemokine ligand (CCL)2, CCL5, CCL20, chemokine (C-X-C motif) ligand CXCL1, CXCL2, CXCL3, CXCL5 and CXCL10 in the culture supernatant of colon cancer tissue]. Human blood mononuclear cells were cultured, and cytokine release was determined by ELISA. Cell proliferation ability was assessed using the MTT assay. Compared with the control group, the mRNA and protein expression levels of tumor necrosis factor-α (TNF-α) were downregulated in tumor tissues and serum and the serum levels of IL-15, IL-1ß and IL-6 were relatively low in the experimental group. The expression levels of CCL5, CXCL2 and CXCL10 in the supernatant of cancer tissue culture were relatively low, compared with the conditioned medium prepared from tumor tissues of patients not receiving tetrandrine. When the cultured blood mononuclear cells were stimulated by the tissue culture supernatant from the experimental group, less IL-15, IL-1ß and IL-6 were released, compared with the medium of tumor tissues of patients not taking tetrandrine. Following stimulation with the tissue culture supernatant from the experimental group, the proliferation ability of HCT116 colon cancer cells significantly declined. During chemotherapy of patients with colon cancer, tetrandrine may inhibit the expression of TNF-α in cancer tissues and blood, reduce the release of inflammatory factors and chemokines and decrease cancer cell proliferation. These findings provide a theoretical basis for the treatment of colon cancer in the clinic.

CNTN1 Aggravates Neuroinflammation and Triggers Cognitive Deficits in Male Mice by Boosting Crosstalk between Microglia and Astrocytes.

A wealth of knowledge regarding glial cell-mediated neuroinflammation, which contributes to cognitive deficits in Alzheimer's disease (AD) has emerged in recent years. Contactin 1(CNTN1), a member of the cell adhesion molecule and immunoglobulin supergene family, is centrally involved in axonal growth regulation and is also a key player in inflammation-associated disorders. However, whether CNTN1 plays a role in inflammation-related cognitive deficits and how this process is triggered and orchestrated remain to be fully elucidated. In this study, we examined postmortem brains with AD. CNTN1 immunoreactivity was markedly increased, particularly in the CA3 subregion, as compared with non-AD brains. Furthermore, by applying an adeno-associated virus-based approach to overexpress CNTN1 directly via stereotactic injection in mice, we demonstrated that hippocampal CNTN1 overexpression triggered cognitive deficits detected by novel object-recognition, novel place-recognition and social cognition tests. The mechanisms underlying these cognitive deficits could be attributed to hippocampal microglia and astrocyte activation, which led to aberrant expression of excitatory amino acid transporters (EAAT)1/EAAT2. This resulted in long-term potentiation (LTP) impairment that could be reversed by minocyline, an antibiotic and the best-known inhibitor of microglial activation. Taken together, our results identified Cntn1 as a susceptibility factor involved in regulating cognitive deficits via functional actions in the hippocampus. This factor correlated with microglial activation and triggered astrocyte activation with abnormal EAAT1/EAAT2 expression and LTP impairment. Overall, these findings may significantly advance our understanding of the pathophysiological mechanisms underlying the risk of neuroinflammation related cognitive deficits.

Soybean GmSAUL1, a Bona Fide U-Box E3 Ligase, Negatively Regulates Immunity Likely through Repressing the Activation of GmMPK3.

E3 ubiquitin ligases play important roles in plant immunity, but their role in soybean has not been investigated previously. Here, we used Bean pod mottle virus (BPMV)-mediated virus-induced gene silencing (VIGS) to investigate the function of GmSAUL1 (Senescence-Associated E3 Ubiquitin Ligase 1) homologs in soybean. When two closely related SAUL1 homologs were silenced simultaneously, the soybean plants displayed autoimmune phenotypes, which were significantly alleviated by high temperature, suggesting that GmSAUL1a/1b might be guarded by an R protein. Interestingly, silencing GmSAUL1a/1b resulted in the decreased activation of GmMPK6, but increased activation of GmMPK3 in response to flg22, suggesting that the activation of GmMPK3 is most likely responsible for the activated immunity observed in the GmSAUL1a/1b-silenced plants. Furthermore, we provided evidence that GmSAUL1a is a bona fide E3 ligase. Collectively, our results indicated that GmSAUL1 plays a negative role in regulating cell death and immunity in soybean.

Early cerebral hemodynamic changes following unilateral carotid artery stenting in patients with different degrees of carotid stenosis.

Background: Few studies have focused on cerebral hemodynamics in the early stage following carotid artery stenting (CAS). This retrospective cohort study aimed to investigate cerebral hemodynamic changes within 6 hours of unilateral CAS in patients with different degrees of carotid stenosis. Methods: A total of 104 patients who underwent CAS accompanied by transcranial color-code Doppler or transcranial Doppler were enrolled in the study. The participants were divided into the following 3 groups based on the degree of carotid stenosis: severe stenosis group, extreme stenosis group, and near occlusion group. Bilateral middle cerebral artery (MCA) peak systolic velocity (PSV) and pulsatility index (PI) were measured using transcranial color-code Doppler before and 1 and 3 hours following CAS. Blood pressure, MCA-PSV, and PI were compared among the 3 groups. Results: At 1 hour following CAS, ipsilateral MCA-PSV increased compared to the baseline in the severe stenosis group [84±21 vs. 93±27 cm/s; 8.1%; interquartile range (IQR), 1.4-20.1%; P<0.001]. A similar hemodynamic change, but of a larger magnitude, was observed in the extreme stenosis group (83±24 vs. 100±29 cm/s; 20.8%; IQR, 5.3-33.1%; P<0.001) and near occlusion group (73±24 vs. 109±29 cm/s, 45.8%; IQR, 24.3-73.1%; P<0.001). At 3 hours after CAS, the hemodynamic changes were the same as those at 1 hour. PI increased in all 3 groups following CAS. A subgroup analysis was performed according to symptoms, sex, smoking status, history of hypertension, and presence of hyperlipidemia or diabetes, and the increase in ipsilateral MCA-PSV was not significant. In terms of adverse events, only 4 patients in the near occlusion group experienced transient post-CAS hyperperfusion. Conclusions: The ipsilateral MCA-PSV and PI in patients following unilateral CAS increased significantly in the initial hours. The increase in ipsilateral MCA-PSV was considerably higher in patients with a severe degree of stenosis. Near occlusion of the carotid artery was an independent risk factor for hyperperfusion after unilateral CAS.

Hsa_circ_0046430 promotes the progression of colorectal cancer by targeting miR-6785-5p/SRCIN1 axis as a ceRNA.

The correlation among circular RNAs (circRNAs), microRNAs, and messenger RNAs have gained increasing attention in recent years. However, the mechanism of such discoveries in colorectal cancer (CRC) is not yet elucidated. The present study aimed to clarify whether the novel circRNAs regulate the prognosis-related genes through the competing endogenous RNAs (ceRNA). An analysis of the Weighted Gene Co-Expression Network Analysis was conducted to screen a module-trait circRNAs, and other big data mining technologies were used to predict the related microRNAs and the downstream genes. Prognosis-related gene model was built using the Cox regression analysis for the 138 messenger RNAs associated with hsa circ 0046430. The qRT-PCR was adopted to verify ceRNA network. Immunohistochemistry verified the correlation between SRCIN1 and patient prognosis. In summary, these results demonstrated that hsa_circ_0046430 is a tumor-related circRNA based on the clinical characteristics module of Weighted Gene Co-Expression Network Analysis. The prognostic risk score signature model analysis indicated that CRC risk was independently related to the risk score and SRCIN1 was independently associated with overall survival. Therefore, the hsa_circ_0046430/miR-6785-5p/SRCIN1 axis was constructed. Hsa_circ_0046430/miR-6785-5p/SRCIN1 axis relative expression level was determined by qRT-PCR. Immunohistochemical staining further validated that SCRIN1 was significantly higher in cancer than in adjacent normal tissues. Our study identified and primarily validated the hsa_circ_0046430/miR-6785-5p/SRCIN1 regulatory axis impacted on CRC prognosis, suggesting novel biomarkers and therapeutic targets for CRC patients. Further in-depth studies are essential to confirm the underlying ceRNA mechanism.

Comparison of pain relief and limb function improvement after extracorporeal shock wave therapy and thermomagnetic therapy in the treatment of low back pain.

Objective: To compare the rehabilitation effects of extracorporeal shock wave therapy (ESWT) and thermomagnetic therapy (TMT) in patients with low back pain (LBP). Methods: As a single-centre retrospective observational study, clinical data of patients with LBP who received rehabilitation treatment in our hospital from January 2020 to May 2021 were retrospectively collected. Based on the treatment mode, the patients were retrospectively divided into two groups: the control group (patients received core muscle training + TMT, n=51) and the observation group (patients received core muscle training + ESWT, n=56). The general data of the patients were collected and the groups were matched for age, gender and pain duration. The visual analogue scale (VAS) score of pain, improvement of limb function, ß-endorphin (ß-EP), prostaglandin E2 (PGE2) and nitric oxide (NO) were compared between the two groups before and after treatment. Results: The VAS scores of the observation group were lower than those of the control group at one, two weeks and one month after the treatment (P<0.05). After the treatment, the proportion of mild limb dysfunction in the observation group was 57.14% (32/56), which was higher than 35.29% (1 /51) in the control group. The proportion of patients with severe and obvious disorders was 0 and 5.36% (3/56), respectively, which was lower than 11.76% (6/51) and 5.88% (3/51) in the control group (P<0.05). After the treatment, levels of NO and PGE2 in the observation group were lower, and the level of ß-EP was significantly lower than in the control group (P<0.05). Conclusions: A combination of core muscle training and ESWT can effectively improve the analgesic effect of the treatment and promote greater improvement of limb function in patients with LBP.

[Interaction of Chinese and western medicines in treatment of cardiovascular diseases].

Cardiovascular diseases are a global public health problem, and the combination of Chinese and western medicine tends to be a major solution in China. However, the complex components in traditional Chinese medicine may interact with the therapeutic western medicines for the diseases, which will lead to the herb-drug interaction(HDI). The information on the interaction can serve as a reference for the rational combination of the Chinese and western medicines in the clinical treatment of cardiovascular diseases and help avoid the occurrence of clinical safety events. However, the research on the interaction of Chinese medicine is limited as compared with that on western medicine, and no systematic review on HDI in the treatment of cardiovascular diseases is available. Therefore, this study first introduced the mechanism of HDI, then summarized the research on HDI for the commonly used drugs for cardiovascular diseases, analyzed the problems in the available studies, and put forward suggestions on the application, regulation, and research. This study aims to highlight HDI in clinical drug use and provide a reference for rational use of combination of Chinese and western medicines in the treatment of cardiovascular diseases.

Brucella BtpB Manipulates Apoptosis and Autophagic Flux in RAW264.7 Cells.

Brucella transfers effectors into host cells, manipulating cellular processes to its advantage; however, the mechanism by which effectors regulate cellular processes during infection is poorly understood. A growing number of studies have shown that apoptosis and autophagy are critical mechanisms for target cells to cope with pathogens and maintain cellular homeostasis. BtpB is a Brucella type IV secretion system effector with a complex mechanism for manipulating host infection. Here, we show that the ectopic expression of BtpB promoted DNA fragmentation. In contrast, an isogenic mutant strain, ΔbtpB, inhibited apoptosis compared to the wild-type strain B. suis S2 in RAW264.7 cells. In addition, BtpB inhibited autophagy, as determined by LC3-II protein levels, the number of LC3 puncta, and p62 degradation. We also found that BtpB reduced autophagolysosome formation and blocked the complete autophagic flux. Moreover, our results revealed that the autophagy inhibitor, chloroquine, reduces Brucella's intracellular survival. Overall, our data unveil new mechanisms of virulence implicating the effector BtpB in regulating host intracellular infection.

Metabolic Homeostasis-Regulated Nanoparticles for Antibody-Independent Cancer Radio-Immunotherapy.

The special metabolic traits of cancer cells and tumor-associated macrophages (TAMs) in the tumor microenvironment (TME) are promising targets for developing novel cancer therapy strategies, especially the glycolysis and mitochondrial energy metabolism. However, therapies targeting a singular metabolic pathway are always counteracted by the metabolic reprogramming of cancer, resulting in unsatisfactory therapeutic effect. Herein, this work employs poly(ethylene glycol)-coated (PEGylated) liposomes as the drug delivery system for both mannose and levamisole hydrochloride to simultaneously inhibit glycolysis and restrain mitochondrial energy metabolism and thus inhibit tumor growth. In combination with radiotherapy, the liposomes can not only modulate the immunosuppressive TME by cellular metabolism regulation to achieve potent therapeutic effect for local tumors, but also suppress the M2 macrophage proliferation triggered by X-ray irradiation and thus enhance the immune response to inhibit metastatic lesions. In brief, this work provides a new therapeutic strategy targeting the special metabolic traits of cancer cells and immunosuppressive TAMs to enhance the abscopal effect of radiotherapy for cancer.

BtpB inhibits innate inflammatory responses in goat alveolar macrophages through the TLR/NF-κB pathway and NLRP3 inflammasome during Brucella infection.

Brucella species are infectious facultative intracellular pathogens. They have evolved multiple strategies to thwart immune responses and replicate in macrophages for chronic persistence in the host. As a Brucella effector, BtpB is transferred into target cells through the type IV secretion system. BtpB, a Toll/interleukin-1 receptor domain-containing protein, blocks host innate immune responses by interfering with Toll-like receptor signaling. However, the intracellular targets and their activated downstream pathways remain unclear. In this study, we constructed a strain of Brucella suis S2 with a deletion in the gene for BtpB, ΔbtpB, and the complemented strain, C-ΔbtpB with a restored copy of the btpB gene. The bacterial growth curves and stress resistance results showed that BtpB did not affect B. suis S2 growth. Infection of alveolar macrophages with WT and ΔbtpB strains showed that BtpB inhibited TLR2 and TLR4 expression and attenuated NLRP3 inflammasome activation. BtpB also attenuated secretion of the Brucella-induced proinflammatory cytokines, IL-1ß, IL-6, and TNF-α, in alveolar macrophages while up-regulating IL-10 expression. In general, the results confirmed that BtpB specifically inhibits TLR2/TLR4 and disrupts NLRP3 signaling pathways to inhibit host immune responses in early Brucella infections.

A LysR Transcriptional Regulator Manipulates Macrophage Autophagy Flux During Brucella Infection.

Brucella, the intracellular bacteria, have evolved subtle strategies to efficiently survive and replicate in macrophages. However, the virulence effector proteins involved are still unclear. LysR-type transcriptional regulators (lttrs) are the largest regulator family with diverse function in prokaryotes. However, very little is known about the role of LysR regulators in the Brucella spp. Here, a BSS2_II0858 gene, encoded as one of the LysR-type regulators, was studied. We successfully constructed a BSS2_II0858 deletion mutant, Δ0858, and complementation strain CΔ0858 in Brucella suis S2. The cell apoptosis induced by B. suis S2 and its derivatives were detected by flow cytometry. The autophagy was then assessed by immunoblot analysis using the IL3I/II and p62 makers. In addition, the autophagy flux was evaluated by double fluorescent labeling method for autophagy marker protein LC3. Our studies demonstrated that B. suis S2 and its derivatives inhibited the programmed cell death in early stage and promoted apoptosis in the later stage during infection in RAW264.7 cells. The BSS2_II0858 gene was found to play no role during apoptosis according to these results. Compared with the wild-type strain, Δ0858 mutant can stimulate the conversion of LC3-I to LC3-II and markedly inhibited the autophagy flux at early stage leading to obvious autophagosome accumulation. This study explored the function of BSS2_II0858 gene and may provide new insights for understanding the mechanisms involved in the survival of Brucella in macrophages.

A 4-Benzene-Indol Derivative Alleviates LPS-Induced Acute Lung Injury Through Inhibiting the NLRP3 Inflammasome.

Acute lung injury (ALI) is a common complication of critical illness that could frequently lead to acute respiratory distress syndrome and other serious clinical consequences. Sepsis is one of the major and most common inducements among all causes of ALI. Due to its high incidence and mortality rate and also the complexity in treatment, sepsis-related ALI has become an urgent clinical problem waiting to be solved effectively. At present, only the protective ventilation strategy, restrictive fluid management, and antibiotics application are measures that can improve the prognosis with evidence-based medical proof. No pharmacological treatment is currently available to protect or significantly reverse the prognosis. Seeking for effective interventions measures for sepsis-related ALI is one of the most necessitous research directions. In this research, a conspicuous discovery of treatment-related translational use for a 4-benzene-indol derivative was elaborated by screening a large number of chemical compounds. The results showed that 4-benzene-indol derivative could not only suppress the activation of NLRP3 inflammasome both in vitro and alleviate LPS-induced ALI in vivo but also suppress the NLRP3 inflammasome in human myeloid leukemia mononuclear cells (THP-1) cell lines. Mechanistically, 1,2-diol blocks the NLRP3 inflammasome activation by disrupting NLRP3-NEK7 interaction and the subsequent NLRP3 inflammasome assembly and activation. To summarize, this research indicated that the newly-discovered 4-benzene-indol derivative targets NLRP3 inflammasome signaling, which consequently alleviates sepsis-related ALI. Collectively, the 4-benzene-indol derivative may serve as a potential therapeutic drug and NLRP3 inflammasome signaling would be a novel pharmaceutical target for clinical treatment of sepsis-related ALI.

A study on the temperature profile of bifurcation tunnel fire under natural ventilation.

This study simulated a series of bifurcation tunnel fire scenarios using the numerical code to investigate the temperature profile of bifurcation tunnel fire under natural ventilation. The bifurcation tunnel fire scenarios considered three bifurcation angles (30°, 45°, and 60°) and six heat release rates (HRRs) (5, 10, 15, 20, 25, and 30 MW). According to the simulation results, the temperature profile with various HRRs and bifurcation angles was described. Furthermore, the effects of bifurcation angles and HRRs on the maximum temperature under the bifurcation tunnel ceiling and the temperature decay along the longitudinal direction of the branch were investigated. According to the theoretical analysis, two prediction models were proposed. These models can predict a bifurcation tunnel fire's maximum temperature and longitudinal temperature decay in the branch. The results of this study could be valuable for modelling a bifurcation tunnel fire and benefit the fire engineering design of bifurcation tunnels.