[Synergistic effect of azacitidine with homoharringtonine by activating the c-MYC/DDIT3/PUMA axis in acute myeloid leukemia]

Objective: This study aimed to explore the synergistic effect and underlying mechanism of azacitidine (AZA) in combination with homoharringtonine (HHT) in acute myeloid leukemia (AML) . Methods: The synergistic effects of AZA and HHT were examined by cell proliferation, apoptosis, and colony formation assays. The synergistic effects were calculated using the combination index (CI) , and the underlying mechanisms were explored using RNA sequencing, pathway inhibitors, and gene knockdown approaches. Results: Compared with the single-drug controls, AZA and HHT combination significantly induced cell proliferation arrest and showed a synergistic effect with CI < 0.9 in AML cells. In the combination group versus the single-drug controls, colony formation was significantly decreased, whereas apoptosis was significantly increased in U937 (P<0.001) and MV4-11 (P<0.001) cells. AZA and HHT combination activated the integrated stress response (ISR) signaling pathway and induced DDIT3-PUMA-dependent apoptosis in cells. Furthermore, it remarkably downregulated the expression of c-MYC. The combination also activated c-MYC/DDIT3/PUMA-mediated ISR signaling to induce synergy on apoptosis. The synergy of AZA+HHT on apoptosis was induced by activating c-MYC/DDIT3/PUMA-mediated ISR signaling. Conclusion: The combination of AZA and HHT exerts synergistic anti-AML effects by inhibiting cellular proliferation and promoting apoptosis through activation of the ISR signaling pathway via the c-MYC/DDIT3/PUMA axis.

Herp regulates intracellular survival of Mycobacterium tuberculosis H37Ra in macrophages by regulating reactive oxygen species-mediated autophagy

IMPORTANCE

Several studies have suggested that endoplasmic reticulum (ER) stress is important in the pathogenesis of infectious diseases; however, the precise function of ER stress regulation and the role of Herp as a regulator in Mtb H37Ra-induced ER stress remain elusive. Therefore, our study investigated ER stress and autophagy associated with Herp expression in Mycobacterium tuberculosis-infected macrophages to determine the role of Herp in the pathogenesis of tuberculosis.

Impaired mitophagy induces antimicrobial responses in macrophages infected with Mycobacterium tuberculosis

BACKGROUND

Mitophagy, mitochondrial selective autophagy, plays a pivotal role in the maintenance of cellular homeostasis in response to cellular stress. However, the role of mitophagy in macrophages during infection has not been elucidated. To determine whether mitophagy regulates intracellular pathogen survival, macrophages were infected with Mycobacterium tuberculosis (Mtb), an intracellular bacterium.

RESULTS

We showed that Mtb-infected macrophages induced mitophagy through BCL2/adenovirus E1B 19 kDa protein-interacting protein 3 (BNIP3) activation. In contrast, BNIP3-deficient macrophages failed to induce mitophagy, resulting in reduced mitochondrial membrane potential in response to Mtb infection. Moreover, the accumulation of damaged mitochondria due to BNIP3 deficiency generated higher levels of mitochondrial reactive oxygen species (mROS) compared to the control, suppressing the intracellular survival of Mtb. We observed that siBNIP3 suppressed intracellular Mtb in mice lungs.

CONCLUSION

We found that BNIP3 plays a critical role in the regulation of mitophagy during Mtb infection. The inhibition of mitophagy suppresses Mtb growth in macrophages through increased mROS production. Therefore, BNIP3 might be a novel therapeutic target for tuberculosis treatment.

Insomnia and multiple health outcomes: umbrella review of meta-analyses of prospective cohort studies

OBJECTIVES

To evaluate existing evidence of prospective cohort studies on associations between insomnia and multiple health outcomes.

STUDY DESIGN

An umbrella review of meta-analyses of prospective cohort studies.

METHODS

A systematic search was undertaken in Pubmed, Embase, Cochrane, and Web of Science from inception to October 2021 to find meta-analyses of prospective cohort studies investigating the association of insomnia with any health outcome. The summary relative risk (SRR) for each meta-analysis was recalculated with random-effects model. The methodological quality and the quality of evidence were assessed by the A Measurement Tool to Assess Systematic Reviews and Grading of Recommendations, Assessment, Development and Evaluation, respectively.

RESULTS

A total of 25 published meta-analyses of prospective cohort studies, reporting 63 SRRs for 29 unique outcomes were included. Insomnia was mainly related to cardiovascular outcomes and mental disorders. The former comprised atrial fibrillation (SRR: 1.30, 95% confidence interval: 1.26 to 1.35), cardiovascular diseases (1.45, 1.29 to 1.64), coronary heart disease (1.28, 1.10 to 1.50), myocardial infarction (1.42, 1.17 to 1.72), and stroke (1.55, 1.39 to 1.72). The latter involved alcohol abuse (1.35, 1.08 to 1.67), all mental disorders (2.16, 1.70 to 3.97), anxiety (3.23, 1.52 to 6.85), depression (2.31, 1.90 to 2.81), suicidal ideation (2.26, 1.79 to 2.86), suicidal attempt (1.99, 1.31 to 3.02), and suicidal death (1.72, 1.42 to 2.08). Besides, insomnia enhanced the risk of Alzheimer's disease (1.51, 1.06 to 2.14) and hyperlipidemia (1.64, 1.53 to 1.76).

CONCLUSION

Insomnia exhibits considerable adverse outcomes, primarily comprises cardiovascular outcomes and mental disorders, but further studies with robustly designed trials are needed to draw firmer conclusions.

[Effects and mechanism of pressure treatment on hemodynamic changes in patients with hypertrophic scar secondary to extensive burns]

Objective: To investigate the hemodynamic changes of the main arteries and veins of the extremities and the heart in patients with hypertrophic scar secondary to extensive burns after pressure treatment, and to analyze the relevant mechanisms. Methods: A retrospective before-after self-control study was conducted. From January 2017 to February 2022, 37 patients with hypertrophic scar secondary to extensive burns who met the inclusion criteria were hospitalized in the Burn Rehabilitation Department of Guangdong Industrial Injury Rehabilitation Hospital, including 25 males and 12 females, aged 23-52 years. The patients were admitted to the hospital within 12 weeks after wound healing, and within one week after admission, rehabilitation therapists, occupational therapists, and tailors custom-made pressure products such as full-body pressure garment, pressure pants, vests, split finger gloves, split finger socks, hoods, and plastic collars, with the pressure at each part maintained at 2.67-4.00 kPa when wearing. Before the first treatment with pressure products (hereinafter referred to as before pressure treatment) and at 1 h of the first treatment with pressure products (hereinafter referred to as 1 h of pressure treatment), color Doppler ultrasonography was performed to check the pulse rate of the axillary artery, the lumen diameter, peak systolic velocity (PSV), and resistance index of the axillary artery and femoral artery on the left side, the lumen diameter, cross-sectional area, and average blood flow velocity of the axillary vein and femoral vein, and the mitral valve E peak, mitral valve A peak, tricuspid valve E peak, aortic valve PSV, and pulmonary valve PSV of the heart; an optical chromatographic skin detector was used to detect the red color, red pigment, and surface brightness of the scar on the back of the hand to reflect the filling and distribution of the scar microvessels. Data were statistically analyzed with paired sample t test. Results: Compared with those before pressure treatment, the PSV of the axillary artery of patients was significantly slowed down at 1 h of pressure treatment (t=55.42, P<0.01); the average blood flow velocity of the axillary vein was significantly accelerated (t=-60.50, P<0.01); the pulse rate, lumen diameter, and resistance index of the axillary artery, as well as the lumen diameter and cross-sectional area of the axillary vein did not change obviously (P>0.05); the average blood flow velocity of the femoral vein was significantly accelerated (t=-80.52, P<0.01); the lumen diameter, PSV, and resistance index of the femoral artery, as well as the lumen diameter and cross-sectional area of the femoral vein had no significant change (P>0.05); the mitral valve E peak and mitral valve A peak of the heart decreased significantly (with t values of 10.71 and 21.96, respectively, P<0.01); the tricuspid valve E peak of the heart increased significantly (t=7.57, P<0.01); the PSV of the aortic valve and pulmonary valve of the heart did not change obviously (P>0.05). At 1 h of pressure treatment, the red color and red pigment values of the scar on the back of the hand of patients were 15.3±1.1 and 16.8±1.2, respectively, which were significantly lower than 24.5±1.3 and 23.8±1.2 before pressure treatment (with t values of 8.32 and 8.04, respectively, P<0.01). The brightness value of the scar surface on the back of the hand of patients at 1 h of pressure treatment was similar to that before pressure treatment (P>0.05). Conclusions: After pressure treatment for the hypertrophic scar in patients secondary to extensive burn, the average blood flow velocity of the axillary vein and femoral vein in patients are obviously accelerated, the PSV of the axillary artery is significantly slowed down, the peak values of mitral valve E and mitral valve A of the heart are significantly decreased, and the tricuspid valve E peak is significantly increased. These hemodynamic changes may be related to the reduction of microvascular blood flow in the local area of scar after systemic pressure treatment.

Lipocalin 2 regulates expression of MHC class I molecules in Mycobacterium tuberculosis-infected dendritic cells via ROS production

Background

Iron has important roles as an essential nutrient for all life forms and as an effector of the host defense mechanism against pathogenic infection. Lipocalin 2 (LCN2), an innate immune protein, plays a crucial role in iron transport and inflammation. In the present study, we examined the role of LCN2 in immune cells during Mycobacterium tuberculosis (Mtb) infection.

Results

We found that infection with Mtb H37Ra induced LCN2 production in bone marrow-derived dendritic cells (BMDCs). Notably, expression of MHC class I molecules was significantly reduced in LCN2^−/− BMDCs during Mtb infection. The reduced expression of MHC class I molecules was associated with the formation of a peptide loading complex through LCN2-mediated reactive oxygen species production. The reduced expression of MHC class I molecules affected CD8⁺ T-cell proliferation in LCN2^−/− mice infected with Mtb. The difference in the population of CD8⁺ effector T cells might affect the survival of intracellular Mtb. We also found a reduction of the inflammation response, including serum inflammatory cytokines and lung inflammation in LCN2^−/− mice, compared with wild-type mice, during Mtb infection.

Conclusions

These data suggest that LCN2-mediated reactive oxygen species affects expression of MHC class I molecules in BMDCs, leading to lower levels of CD8⁺ effector T-cell proliferation during mycobacterial infection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13578-021-00686-2.

Ang II-Induced Hypertension Exacerbates the Pathogenesis of Tuberculosis

It has been known that infection plays a role in the development of hypertension. However, the role of hypertension in the progression of infectious diseases remain unknown. Many countries with high rates of hypertension show geographical overlaps with those showing high incidence rates of tuberculosis (TB). To explore the role of hypertension in tuberculosis, we compared the effects of hypertension during mycobacterial infection, we infected both hypertensive Angiotensin II (Ang II) and control mice with Mycobacterium tuberculosis (Mtb) strain H37Ra by intratracheal injection. Ang II-induced hypertension promotes cell death through both apoptosis and necrosis in Mtb H37Ra infected mouse lungs. Interestingly, we found that lipid accumulation in pulmonary tissues was significantly increased in the hypertension group compared to the normal controls. Ang II-induced hypertension increases the formation of foamy macrophages during Mtb infection and it leads to cell death. Moreover, the hypertension group showed more severe granuloma formation and fibrotic lesions in comparison with the control group. Finally, we observed that the total number of mycobacteria was increased in the lungs in the hypertension group compared to the normal controls. Taken together, these results suggest that hypertension increases intracellular survival of Mtb through formation of foamy macrophages, resulting in severe pathogenesis of TB.

M1 macrophage dependent-p53 regulates the intracellular survival of mycobacteria

Tumor suppressor p53 is not only affects immune responses but also contributes to antibacterial activity. However, its bactericidal function during mycobacterial infection remains unclear. In this study, we found that the p53-deficient macrophages failed to control Mycobacterium tuberculosis (Mtb), manifested as a lower apoptotic cell death rate and enhanced intracellular survival. The expression levels of p53 during Mtb infection were stronger in M1 macrophages than in M2 macrophages. The TLR2/JNK signaling pathway plays an essential role in the modulation of M1 macrophage polarization upon Mtb infection. It facilitates p53-mediated apoptosis through the production of reactive oxygen species, nitric oxide and inflammatory cytokines in Mtb-infected M1 macrophages. In addition, nutlin-3 effectively abrogated the intracellular survival of mycobacteria in both TB patients and healthy controls after H37Ra infection for 24 h, indicating that the enhancement of p53 production effectively suppressed the intracellular survival of Mtb in hosts. These results suggest that p53 can be a new therapeutic target for TB therapy.

KCNQ1 opposite strand/antisense transcript 1 promotes aggressive biological behaviors of cervical cancer cells via regulating microRNA-491-5p and pyruvate kinase M1/2

Long non-coding RNA (lncRNA) KCNQ1 and opposite strand/antisense transcript 1 (KCNQ1OT1) have been validated to be carcinogenic in several cancers. However, the role of KCNQ1OT1 in regulating the malignant biological behavior and radiotherapy resistance of cervical cancer (CC) remains largely unknown. Quantitative real time-polymerase chain reaction (qRT-PCR) was carried out to detect KCNQ1OT1 and miR-491-5p expression in CC tissues and cells. Pyruvate kinase M1/2 (PKM2) expression was detected by Western blot. CC cell proliferation, movement, migration and invasion were monitored by CCK-8, scratch healing and Transwell assay, respectively. The CC cell colony survival was detected by colony formation assay under different doses of radiation. Dual luciferase reporter gene assay, pull-down assay and RIP assay were employed to verify the targeting relationship between KCNQ1OT1, miR-491-5p and PKM2. In this study, KCNQ1OT1 was significantly up-regulated in CC patient cancerous tissues and cell lines, and its high expression was significantly related to tumor volume increase and poor differentiation. KCNQ1OT1 overexpression significantly promoted CC cell proliferation, metastasis and radioresistance. On the contrary, KCNQ1OT1 knockdown compared to the control group inhibited the above biological behavior of CC cells. The underlying mechanism suggested that KCNQ1OT1 promoted progression and radioresistance of CC by modulating the miR-491-5p/PKM2 axis. In conclusion, KCNQ1OT1 enhances CC cell progression through the miR-491-5p/PKM2 axis.

Apamin from bee venom suppresses inflammation in a murine model of gouty arthritis

ETHNOPHARMACOLOGICAL RELEVANCE

Bee venom (BV) has been used for the treatment of inflammatory diseases, such as rheumatoid arthritis, and for the relief of pain in traditional oriental medicine.

AIM OF STUDY

The aim of this study was to determine the anti-inflammatory effect of BV on monosodium urate (MSU)-induced gouty arthritis in a mouse model.

MATERIALS AND METHODS

To develop a mouse model of acute gouty arthritis, 4 mg 50 μL^-1 of MSU crystal suspension was injected intradermally into the right paw. After MSU crystal injection, we evaluated inflammatory cytokine production in mice of the BV-treated (0.5 and 1 mg kg^-1 body weight) and apamin (APM)-treated (0.5 and 1 mg kg^-1 body weight) groups. The positive control group was administered a colchicine (1 mg kg^-1 body weight) injection with MSU crystals.

RESULTS

BV and APM treatment suppressed inflammatory paw edema in MSU-administered mice. It also exerted anti-inflammatory effects in mice with gouty arthritis by inhibiting proinflammatory cytokine production and inflammasome formation. Interestingly, MSU crystal formation was decreased by BV and APM treatment.

CONCLUSIONS

These results suggest that the APM from BV might be useful for the treatment of gouty arthritis due to its anti-inflammatory activities.

Insights Into the Role of Endoplasmic Reticulum Stress in Infectious Diseases

The endoplasmic reticulum (ER) is the major organelle in the cell for protein folding and plays an important role in cellular functions. The unfolded protein response (UPR) is activated in response to misfolded or unfolded protein accumulation in the ER. However, the UPR successfully alleviates the ER stress. If UPR fails to restore ER homeostasis, apoptosis is induced. ER stress plays an important role in innate immune signaling in response to microorganisms. Dysregulation of UPR signaling contributes to the pathogenesis of a variety of infectious diseases. In this review, we summarize the contribution of ER stress to the innate immune response to invading microorganisms and its role in the pathogenesis of infectious diseases.

Different macrophage polarization between drug-susceptible and multidrug-resistant pulmonary tuberculosis

BACKGROUND

Macrophages play a key role in the infection process, and alternatively activated macrophages (M2 polarization) play important roles in persistent infection via the immune escape of pathogens. This suggests that immune escape of pathogens from host immunity is an important factor to consider in treatment failure and multidrug-resistant tuberculosis (MDR-TB)/extensively drug-resistant tuberculosis (XDR-TB). In this study, we investigated the association between macrophage polarization and MDR-TB/XDR-TB and the association between macrophage polarization and the anti-TB drugs used.

METHODS

iNOS and arginase-1, a surface marker of polarized macrophages, were quantified by immunohistochemical staining and imaging analysis of lung tissues of patients who underwent surgical treatment for pulmonary TB. Drug susceptibility/resistance and the type and timing of anti-tuberculosis drugs used were investigated.

RESULTS

The M2-like polarization rate and the ratio of the M2-like polarization rate to the M1-like polarization rate were significantly higher in the MDR-TB/XDR-TB group than in the DS-TB group. The association between a high M2-like polarization rate and MDR-TB/XDR-TB was more pronounced in patients with a low M1-like polarization rate. Younger age and a higher M2-like polarization rate were independent associated factors for MDR-TB/XDR-TB. The M2-like polarization rate was significantly higher in patients who received anti-TB drugs containing pyrazinamide continuously for 4 or 6 weeks than in those who received anti-TB drugs not containing pyrazinamide.

CONCLUSIONS

The M2-like polarization of macrophages is associated with MDR-TB/XDR-TB and anti-TB drug regimens including pyrazinamide or a combination of pyrazinamide, prothionamide and cycloserine.

Differential protein analysis of Heracleum moellendorffii Hance seeds during stratification

Heracleum moellendorffii Hance is a medicinal vegetable species, and the seed dormancy of this species has caused many agricultural problems. One stratification technique involves alternating layers of seeds and substrate to allow post-ripening of dormant seeds under appropriate environmental conditions and to release dormancy. Non-stratified seeds (NS), cotyledon-stage-embryo seeds (CS) and germinated seeds (GS) represent key stages of H. moellendorffii seeds during stratification. To better understand the breaking of dormancy caused by stratification, tandem mass tag (TMT) mass spectrometry (MS)/MS was used to detect proteins among NS, CS and GS. A total of 876 proteins were identified, which were subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. The results showed that carbohydrate metabolic processes, responses to stress and ribosome biogenesis were the main biological processes. The changes in protein accumulation were validated by qRT-PCR. The results showed that starch, sucrose, pyruvate and fatty acid metabolism played significant roles and that the contents of stored substances were gradually degraded during stratification. This study provides a theoretical basis in terms of proteomics for exploring the post-ripening and germination of H. moellendorffii seeds.

Mitofusin 2-Deficiency Suppresses Mycobacterium tuberculosis Survival in Macrophages

Apoptosis is an important host defense mechanism against mycobacterial infection. However, the molecular mechanisms regulating apoptosis during mycobacterial infection are not well known. Recent reports suggest that bacterial infection regulates mitochondrial fusion and fission in various ways. Here, we investigated the role of mitochondria in Mycobacterium tuberculosis (Mtb)-infected macrophages. Mtb H37Rv (Rv) infection induced mitofusin 2 (MFN2) degradation, leading to mitochondrial fission. Interestingly, Mtb H37Ra (Ra) infection induced significantly greater mitochondrial fragmentation than Rv infection. Mtb-mediated Parkin, an E3 ubiquitin ligase, contributed to the degradation of MFN2. To evaluate the role of endoplasmic reticulum stress in the production of Parkin during Mtb infection, we analyzed Parkin production in 4-phenylbutyric acid (4-PBA)-pretreated macrophages. Pretreatment with 4-PBA reduced Parkin production in Mtb-infected macrophages. In contrast, the level of MFN2 production recovered to a level similar to that of the unstimulated control. In addition, Ra-infected macrophages had reduced mitochondrial membrane potential (MMP) compared to those infected with Rv. Interestingly, intracellular survival of mycobacteria was decreased in siMFN2-transfected macrophages; in contrast, overexpression of MFN2 in macrophages increased Mtb growth compared with the control.

Reactive oxygen species-mediated endoplasmic reticulum stress response induces apoptosis of Mycobacterium avium-infected macrophages by activating regulated IRE1-dependent decay pathway

Mycobacterium avium, a slow‐growing nontuberculous mycobacterium, causes fever, diarrhoea, loss of appetite, and weight loss in immunocompromised people. We have proposed that endoplasmic reticulum (ER) stress‐mediated apoptosis plays a critical role in removing intracellular mycobacteria. In the present study, we investigated the role of the regulated IRE1‐dependent decay (RIDD) pathway in macrophages during M. avium infection based on its role in the regulation of gene expression. The inositol‐requiring enzyme 1 (IRE1)/apoptosis signal‐regulating kinase 1 (ASK1)/c‐Jun N‐terminal kinase (JNK) signalling pathway was activated in macrophages after infection with M. avium. The expression of RIDD‐associated genes, such as Bloc1s1 and St3gal5, was decreased in M. avium‐infected macrophages. Interestingly, M. avium‐induced apoptosis was significantly suppressed by pretreatment with irestatin (inhibitor of IRE1α) and 4μ8c (RIDD blocker). Macrophages pretreated with N‐acetyl cysteine (NAC) showed decreased levels of reactive oxygen species (ROS), IRE1α, and apoptosis after M. avium infection. The expression of Bloc1s1 and St3gal5 was increased in NAC‐pretreated macrophages following infection with M. avium. Growth of M. avium was significantly increased in irestatin‐, 4μ8c‐, and NAC‐treated macrophages compared with the control. The data indicate that the ROS‐mediated ER stress response induces apoptosis of M. avium‐infected macrophages by activating IRE1α‐RIDD. Thus, activation of IRE1α suppresses the intracellular survival of M. avium in macrophages.

Phagocytosis influences the intracellular survival of Mycobacterium smegmatis via the endoplasmic reticulum stress response

Background

Mycobacterium smegmatis, a rapidly growing non-tuberculosis mycobacterium, is a good model for studying the pathogenesis of tuberculosis because of its genetic similarity to Mycobacterium tuberculosis (Mtb). Macrophages remove mycobacteria during an infection. Macrophage apoptosis is a host defense mechanism against intracellular bacteria. We have reported that endoplasmic reticulum (ER) stress is an important host defense mechanism against Mtb infection.

Results

In this study, we found that M. smegmatis induced strong ER stress. M. smegmatis-induced reactive oxygen species (ROS) play a critical role in the induction of ER stress-mediated apoptosis. Pretreatment with an ROS scavenger suppressed M. smegmatis-induced ER stress. Elimination of ROS decreased the ER stress response and significantly increased the intracellular survival of M. smegmatis. Interestingly, inhibition of phagocytosis significantly decreased ROS synthesis, ER stress response induction, and cytokine production.

Conclusions

Phagocytosis of M. smegmatis induces ROS production, leading to production of proinflammatory cytokines. Phagocytosis-induced ROS is associated with the M. smegmatis-mediated ER stress response in macrophages. Therefore, phagocytosis plays a critical role in the induction of ER stress-mediated apoptosis during mycobacterial infection.

Observations of foetal heart veins draining directly into the left and right atria

Evaluation of semiserial sections of 14 normal hearts from human foetuses of gestational age 25-33 weeks showed that all of these hearts contained thin veins draining directly into the atria (maximum, 10 veins per heart). Of the 75 veins in these 14 hearts, 55 emptied into the right atrium and 20 into the left atrium. These veins were not accompanied by nerves, in contrast to tributaries of the great cardiac vein, and were negative for both smooth muscle actin (SMA) and CD34. However, the epithelium and venous wall of the anterior cardiac vein, the thickest of the direct draining veins, were strongly positive for SMA and CD34, respectively. In general, developing fibres in the vascular wall were positive for CD34, while the endothelium of the arteries and veins was strongly positive for the present DAKO antibody of SMA. The small cardiac vein, a thin but permanent tributary of the terminal portion of the great cardiac vein, was also positive for SMA and CD34. A few S100 protein-positive nerves were observed along both the anterior and small cardiac veins, but no nerves accompanied the direct dra- inage veins. These findings suggested that the latter did not develop from the early epicardiac vascular plexus but from a gulfing of the intratrabecular space or sinus of the atria. However, the immunoreactivity of the anterior cardiac vein suggests that it originated from the vascular plexus, similar to tributaries of the great cardiac vein.

TNF-α-mediated ER stress causes elimination of Mycobacterium fortuitum reservoirs by macrophage apoptosis

Mycobacterium fortuitum (MF), a rapidly growing nontuberculosis mycobacterium, is recognized as an important human pathogen. We investigated whether the endoplasmic reticulum (ER) stress response is associated with the apoptosis of MF-infected macrophages. The expression of ER molecular chaperones was significantly induced by MF infection. We found that MF-induced reactive oxygen species (ROS) generation plays a critical role in the induction of ER stress-mediated apoptosis. Excess TNF-α in the ER led to ER stress-mediated apoptosis during MF infection. The intracellular survival of MF was significantly increased by TNF-α knockdown compared with the control. This is the first report of MF-induced TNF-α as a cause of ER stress in macrophages. Furthermore, we found that TLR2-mediated ER stress response contributed to the elimination of intracellular MF in vivo. These results suggest that TNF-α-mediated ER stress during MF infection contributes to the suppression of intracellular survival of MF in macrophages. Our findings provide new insight into the importance of ER stress in mycobacterial infection.-Oh, S.-M., Lim, Y.-J., Choi, J.-A., Lee, J., Cho, S.-N., Go, D., Kim, S.-H., Song, C.-H. TNF-α-mediated ER stress causes elimination of Mycobacterium fortuitum reservoirs by macrophage apoptosis.

Enhancement of the antimycobacterial activity of macrophages by ajoene

Ajoene, a garlic-derived sulfur-containing compound, has broad-spectrum antimicrobial activity. To assess the potential of ajoene for treating tuberculosis (TB), we determined whether it induces the stress response of the endoplasmic reticulum (ER), which plays an important role in TB. We showed that ajoene stimulation induced the production of ER stress sensor molecules and reactive oxygen species (ROS) levels. Ajoene-induced ROS production was dependent on c-Jun N-terminal kinase (JNK) activation. Interestingly, the inhibition of JNK activity and suppression of ROS production reduced ajoene-induced CHOP production in macrophages. Because ER stress activates autophagy, the activation of which suppresses the growth of mycobacteria, we investigated the ajoene-induced production of autophagy-related factors, including LC3-II, P62 and Beclin-1. As expected, ajoene treatment increased the levels of these factors in RAW 264.7 cells. Remarkably, the total amount of Mycobacterium tuberculosis (Mtb) H37Rv was significantly reduced in ajoene-treated RAW 264.7 cells. The treatment of macrophages with ajoene resulted in the activation of JNK, induction of ROS synthesis and accumulation of ROS, possibly leading to the activation of ER stress and autophagy. These results reveal the mechanism of the antimycobacterial effects of ajoene against Mtb H37Rv. Our findings might facilitate the development of novel therapies for patients with TB.

Calreticulin modulates the intracellular survival of mycobacteria by regulating ER-stress-mediated apoptosis

Endoplasmic reticulum (ER)-stress-mediated apoptosis is a host defense mechanism against Mycobacterium tuberculosis (Mtb) infection. Calreticulin (CRT) is the major calcium-binding chaperone protein. Previous reports have suggested a close relationship between the cell-surface expression of CRT and apoptosis. In this study, the role of CRT during Mtb infection was examined. The results showed that Mtb infection induces CRT production by macrophages and that CRT levels are correlated with the degree of apoptotic cell death. The enhanced production of CRT was associated with the ER stress induced by Mtb infection. A significant increase in CRT translocation from the cytosol to the plasma membrane after 24 h of infection suggested the importance of CRT localization in the induction of apoptosis during Mtb infection. An investigation of the factors associated with CRT translocation and the ability of ectopically expressed CRT to induce apoptosis showed that pretreatment with a reactive oxygen species scavenger decreased Mtb-induced CRT expression, leading to the reduction of CHOP and caspase-3 activation. The intracellular survival of Mtb was significantly higher in macrophages transfected with a CRT-specific small interfering RNA than in control cells. The key role of CRT in inducing apoptosis included its interaction with CXCR1 and TNFR1 in Mtb-infected macrophages. The CRT/CXCR1/TNFR1 complex was shown to induce the extrinsic apoptotic pathway during Mtb infection. Together, these results demonstrate that CRT is critical for the intracellular survival of Mtb, via ER-stress-induced apoptosis, as well as the importance of ER stress-mediated CRT localization in the pathogenesis of tuberculosis.

The Role of Prostate Apoptosis Response-4 (Par-4) in Mycobacterium tuberculosis Infected Macrophages

Prostate apoptosis response-4 (Par-4) is a tumor suppressor protein that forms a complex with glucose-regulated protein 78 (GRP78) to induce apoptosis. Previously, we reported that ER stress-induced apoptosis is a critical host defense mechanism against Mycobacterium tuberculosis (Mtb). We sought to understand the role of Par-4 during ER stress-induced apoptosis in response to mycobacterial infection. Par-4 and GRP78 protein levels increased in response Mtb (strain: H37Ra) infection. Furthermore, Par-4 and GRP78 translocate to the surface of Mtb H37Ra-infected macrophages and induce apoptosis via caspase activation. NF-κB activation, Mtb-mediated ER stress, and Par-4 production were significantly diminished in macrophages with inhibited ROS production. To test Par-4 function during mycobacterial infection, we analyzed intracellular survival of Mtb H37Ra in macrophages with Par-4 overexpression or knockdown. Mtb H37Ra growth was significantly reduced in Par-4 overexpressing macrophages and increased in knockdown macrophages. We also observed increased Par-4, GRP78, and caspases activation in Bacillus Calmette-Guérin (BCG)-infected prostate cancer cells. Our data demonstrate that Par-4 is associated with ER stress-induced apoptosis resulting in reduced intracellular survival of mycobacteria. BCG treatment increases Par-4-dependent caspase activation in prostate cancer cells. These results suggest ER stress-induced Par-4 acts as an important defense mechanism against mycobacterial infection and regulates cancer.

Lithium inhibits growth of intracellular Mycobacterium kansasii through enhancement of macrophage apoptosis

Mycobacterium kansasii (Mk) is an emerging pathogen that causes a pulmonary disease similar to tuberculosis. Macrophage apoptosis contributes to innate host defense against mycobacterial infection. Recent studies have suggested that lithium significantly enhances the cytotoxic activity of death stimuli in many cell types. We examined the effect of lithium on the viability of host cells and intracellular Mk in infected macrophages. Lithium treatment resulted in a substantial reduction in the viability of intracellular Mk in macrophages. Macrophage cell death was significantly enhanced after adding lithium to Mk-infected cells but not after adding to uninfected macrophages. Lithium-enhanced cell death was due to an apoptotic response, as evidenced by augmented DNA fragmentation and caspase activation. Reactive oxygen species were essential for lithium-induced apoptosis. Intracellular scavenging by N-acetylcysteine abrogated the lithium-mediated decrease in intracellular Mk growth as well as apoptosis. These data suggest that lithium is associated with control of intracellular Mk growth through modulation of the apoptotic response in infected macrophages.

Evaluation of female hormone-related symptoms in women undergoing carpal tunnel release

As carpal tunnel syndrome is more common in women, particularly around the menopause, female-related risk factors are suspected to play a role in its pathogenesis. We have assessed whether female hormone-related symptoms are associated with upper extremity disabilities in women undergoing carpal tunnel release. A total of 92 women with a mean age of 53 years scheduled for surgery for carpal tunnel syndrome were assessed preoperatively for female hormone-related symptoms using the menopausal rating scale and other female-related factors such as menopausal status, pregnancy number and serum female hormone levels. Upper extremity disability was evaluated using the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. DASH scores had a moderate correlation with total menopausal rating scale scores, but not with other female-related factors assessed. This study suggests that female hormone-related symptoms are associated with subjective upper extremity disabilities in women with carpal tunnel syndrome. This information may be helpful in addressing patients' complex symptoms or interpretation of outcomes in women with carpal tunnel syndrome.

Role of Staphylococcal Enterotoxin B on the Differentiation of Regulatory T Cells in Nasal Polyposis

Background

The pathogenesis of nasal polyposis has not been fully understood. Recent studies indicate that there is a subset of CD4+CD25high FoxP3+T cells (regulatory T cells [Tregs]) that express retinoic acid receptor related orphan receptor C (RORC) or IL-17, and these cells might be new proinflammatory cells because of the expression of IL-17 with loss of their suppressive function. The goals of this study were to localize Th17-like Tregs (Th17-like Tregs or RORC+Tregs) in nasal polyps and to investigate the role of staphylococcal enterotoxin B (SEB) on the differentiation of Tregs to RORC+Tregs in vitro.

Methods

A total of 60 patients were enrolled in this study. Of the 60 patients, 40 had chronic rhinosinusitis with nasal polyps (CRSwNPs), and 20 subjects who were undergoing septoplasty were enrolled as control subjects. The nasal polyps of CRSwNP patients were subclassified as either eosinophilic polyp (EP) and noneosinophilic polyp (NEP) according to the result of hematoxylin and eosin stain. Tissues and whole blood were collected from all subjects. Double immunofluorescent staining and reverse-transcription polymerase chain reaction for RORC and FOXP3 were conducted on the tissues. RORC expressions of Tregs were measured in the tissue using flow cytometry. The proportions of RORC+Tregs subsets and cytokines profiles from the supernatant were measured using flow cytometry after stimulation with SEB.

Results

The cells that express both RORC and FOXP3 and RORC+Tregs were significantly higher in the nasal polyps, especially in EPs compared with NEPs, and control mucosa. RORC+Tregs in peripheral blood mononuclear cells significantly increase in patients with EPs 24 hours after SEB stimulation in vitro.

Conclusion

The results indicate that SEB may be involved in the differentiation of Tregs to RORC+Tregs, and these cells may be involved in the pathogenesis of eosinophilic nasal polyposis.

Staphylococcus aureus enterotoxin B-induced endoplasmic reticulum stress response is associated with chronic rhinosinusitis with nasal polyposis

OBJECTIVE

Staphylococcus aureus enterotoxin B (SEB) might participate in the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). However, the exact mechanism of polyp formation in CRSwNP remains unclear. Since the endoplasmic reticulum (ER) stress response is closely associated with chronic inflammation, we investigated the association between ER stress and SEB in the pathogenesis of CRSwNP.

DESIGN AND METHODS

Twenty-three CRSwNP patients with eosinophilic polyps (EP) or non-eosinophilic polyps (NEP) and 10 healthy subjects who were undergoing septoplasty were enrolled in this study. ER stress response was investigated using immunohistochemical staining and Western blotting.

RESULTS

We show in this study that there are significantly more SEB-positive cells and higher production of reactive oxygen species (ROS) in the epithelial layer of EP than NEP or control tissue. Both SEB and protein A were detected strongly in tissues from patients with CRSwNP. We observed SEB induced the ER stress response in RPMI 2650 cells. GRP78 elevation by SEB was reduced by ROS scavenger pretreatment. In addition, the induction of GRP78 and p47 phox was increased significantly in EP compared with NEP or control mucosa.

CONCLUSIONS

SEB may induce ER stress via ROS production in CRSwNP. Therefore, we suggest that SEB-induced ER stress may play important roles in the pathogenesis of nasal polyposis.

Uncertainty in biogenic isoprene emissions and its impacts on tropospheric chemistry in East Asia

In this study, the accuracy of biogenic isoprene emission fluxes over East Asia during two summer months (July and August) was examined by comparing two tropospheric HCHO columns (ΩHCHO) obtained from the SCIAMACHY sensor and the Community Multi-scale Air Quality (CMAQ v4.7.1) model simulations, using three available biogenic isoprene emission inventories over East Asia: i) GEIA, ii) MEGAN and iii) MOHYCAN. From this comparative analysis, the tropospheric HCHO columns from the CMAQ model simulations, using the MEGAN and MOHYCAN emission inventories (Ω(CMAQ, MEGAN) and Ω(CMAQ, MOHYCAN)), were found to agree well with the tropospheric HCHO columns from the SCIAMACHY observations (Ω(SCIA)). Secondly, the propagation of such uncertainties in the biogenic isoprene emission fluxes to the levels of atmospheric oxidants (e.g., OH and HO2) and other atmospheric gaseous/particulate species over East Asia during the two summer months was also investigated. As the biogenic isoprene emission fluxes decreased from the GEIA to the MEGAN emission inventories, the levels of OH radicals increased by factors of 1.39 and 1.75 over Central East China (CEC) and South China, respectively. Such increases in the OH radical mixing ratios subsequently influence the partitioning of HO(y) species. For example, the HO2/OH ratios from the CMAQ model simulations with GEIA isoprene emissions were 2.7 times larger than those from the CMAQ model simulations based on MEGAN isoprene emissions. The large HO2/OH ratios from the CMAQ model simulations with the GEIA biogenic emission were possibly due to the overestimation of GEIA biogenic isoprene emissions over East Asia. It was also shown that such large changes in HO(x) radicals created large differences on other tropospheric compounds (e.g., NO(y) chemistry) over East Asia during the summer months.

Transcription factor zinc finger and BTB domain 1 is essential for lymphocyte development

Absent T lymphocytes were unexpectedly found in homozygotes of a transgenic mouse from an unrelated project. T cell development did not progress beyond double-negative stage 1 thymocytes, resulting in a hypocellular, vestigial thymus. B cells were present, but NK cell number and B cell isotype switching were reduced. Transplantation of wild-type hematopoietic cells corrected the defect, which was traced to a deletion involving five contiguous genes at the transgene insertion site on chromosome 12C3. Complementation using bacterial artificial chromosome transgenesis implicated zinc finger BTB-POZ domain protein 1 (Zbtb1) in the immunodeficiency, confirming its role in T cell development and suggesting involvement in B and NK cell differentiation. Targeted disruption of Zbtb1 recapitulated the T(-)B(+)NK(-) SCID phenotype of the original transgenic animal. Knockouts for Zbtb1 had expanded populations of bone marrow hematopoietic stem cells and also multipotent and early lymphoid lineages, suggesting a differentiation bottleneck for common lymphoid progenitors. Expression of mRNA encoding Zbtb1, a predicted transcription repressor, was greatest in hematopoietic stem cells, thymocytes, and pre-B cells, highlighting its essential role in lymphoid development.

Mycobacterium tuberculosis Rv0652 stimulates production of tumour necrosis factor and monocytes chemoattractant protein-1 in macrophages through the Toll-like receptor 4 pathway

Mycobacterial proteins interact with host macrophages and modulate their functions and cytokine gene expression profile. The protein Rv0652 is abundant in culture filtrates of Mycobacterium tuberculosis K-strain, which belongs to the Beijing family, compared with levels in the H37Rv and CDC1551 strains. Rv0652 induces strong antibody responses in patients with active tuberculosis. We investigated pro-inflammatory cytokine production induced by Rv0652 in murine macrophages and the roles of signalling pathways. In RAW264.7 cells and bone marrow-derived macrophages, recombinant Rv0652 induced predominantly tumour necrosis factor (TNF) and monocyte chemoattractant protein (MCP)-1 production, which was dependent on mitogen-activated protein kinases and nuclear factor-κB. Specific signalling pathway inhibitors revealed that the extracellular signal-regulated kinase 1/2 (ERK1/2), p38 and phosphatidylinositol 3-kinase (PI3K) pathways were essential for Rv0652-induced TNF production, whereas the ERK1/2 and PI3K pathways, but not the p38 pathway, were critical for MCP-1 production in macrophages. Rv0652-stimulated TNF and MCP-1 secretion by macrophages occurred in a Toll-like receptor 4-dependent and MyD88-dependent manner. In addition, Rv0652 significantly up-regulated the expression of the mannose receptor, CD80, CD86 and MHC class II molecules. These results suggest that Rv0652 can induce a protective immunity against M. tuberculosis through the macrophage activation.

Comparison of peripheral nerve damages according to glucose control timing in experimental diabetes

OBJECTIVE

In addition to tight glucose control, early intensive therapy has been reported to be more important for the prevention of diabetic micro- and macro-vascular complications. What is not known exactly is the quantitative difference according to timing delay in glucose control and whether early period control is really better than late control in terms of diabetic peripheral neuropathy. In this study, we investigated the effect of timing differences in glucose control on the peripheral nerves in an experimental diabetic model.

METHODS

5 groups (6-8 rats in each group) were comprised of normal glucose rats (designated control), rats with hyperglycemia (designated DM), rats with glucose control for the entire 28-week study period (designated DM + INS [W0-28]), rats with glucose control for the early 14-week period followed by hyperglycemia for the late 14-week period (designated DM + INS [W0-14]), and rats with hyperglycemia for the early 14-week period followed by glucose control in the late 14-week period (designated DM + INS [W15-28]).

RESULTS

We found that the current perception threshold (CPT) was lower in the DM + INS (W0-28) and DM + INS (W15-28) groups than in the DM + INS (W0-14) or DM groups (P<0.05). The mean myelinated fiber area of the sciatic nerve was significantly greater in the DM + INS (W0-28) and DM + INS (W15-28) groups (63.5±2.32 and 60.1±2.14 um, respectively) than in the DM + INS (W0-14) or DM groups (55.5±2.81 or 51.5±2.64 um, respectively) (P<0.05), and the intraepidermal nerve fiber (IENF) density was significantly higher in the DM + INS (W0-28) and DM + INS (W15-28) groups (6.9±0.46 and 6.8±0.11, respectively) than in the DM + INS (W0-14) or DM groups (59.5±0.32 and 5.3±0.39/mm, respectively) (P<0.05).

CONCLUSION

Our results indicate that continuous glucose control is necessary to alleviate peripheral nerve damage and that glycemic control during the later period may be more important than early period management. The importance of continuous glucose control, including the later period of diabetes, should therefore be emphasized in diabetic peripheral neuropathy.

Endoplasmic reticulum stress pathway-mediated apoptosis in macrophages contributes to the survival of Mycobacterium tuberculosis

BACKGROUND

Apoptosis is thought to play a role in host defenses against intracellular pathogens, including Mycobacterium tuberculosis (Mtb), by preventing the release of intracellular components and the spread of mycobacterial infection. This study aims to investigate the role of endoplasmic reticulum (ER) stress mediated apoptosis in mycobacteria infected macrophages.

METHODOLOGY/PRINCIPAL FINDINGS

Here, we demonstrate that ER stress-induced apoptosis is associated with Mtb H37Rv-induced cell death of Raw264.7 murine macrophages. We have shown that Mtb H37Rv induced apoptosis are involved in activation of caspase-12, which resides on the cytoplasmic district of the ER. Mtb infection increase levels of other ER stress indicators in a time-dependent manner. Phosphorylation of eIF2α was decreased gradually after Mtb H37Rv infection signifying that Mtb H37Rv infection may affect eIF2α phosphorylation in an attempt to survive within macrophages. Interestingly, the survival of mycobacteria in macrophages was enhanced by silencing CHOP expression. In contrast, survival rate of mycobacteria was reduced by phosphorylation of the eIF2α. Futhermore, the levels of ROS, NO or CHOP expression were significantly increased by live Mtb H37Rv compared to heat-killed Mtb H37Rv indicating that live Mtb H37Rv could induce ER stress response.

CONCLUSION/SIGNIFICANCE

These findings indicate that eIF2α/CHOP pathway may influence intracellular survival of Mtb H37Rv in macrophages and only live Mtb H37Rv can induce ER stress response. The data support the ER stress pathway plays an important role in the pathogenesis and persistence of mycobacteria.

Ministry of Health clinical practice guidelines: bipolar disorder

The Ministry of Health (MOH) has published clinical practice guidelines on Bipolar Disorder to provide doctors and patients in Singapore with evidence-based guidance on the management of bipolar disorders. This article reproduces the introduction and executive summary (with recommendations from the guidelines) from the MOH clinical practice guidelines on Bipolar Disorder, for the information of readers of the Singapore Medical Journal. Chapters and page numbers mentioned in the reproduced extract refer to the full text of the guidelines, which are available from the Ministry of Health website: http: //www.moh.gov.sg/content/moh_web/home/Publications/guidelines/clinical_practiceguidelines/2011/bipolar_disorder.html. The recommendations should be used with reference to the full text of the guidelines. Following this article are multiple choice questions based on the full text of the guidelines.

Mycobacterial cell-wall skeleton as a universal vaccine vehicle for antigen conjugation

Mycobacterial cell-wall skeleton (CWS) is an immunoactive and biodegradable particulate adjuvant and has been used for immunotherapy in patients with cancer. The CWS of Mycobacterium bovis bacillus Calmette-Guérin (BCG-CWS) was studied as a universal vaccine vehicle for antigen conjugation, to develop potentially effective and safe vaccines. Here, we describe experiments in which protein antigens, such as keyhole limpet haemocyanin (KLH), ovalbumin (OVA) and bovine serum albumin (BSA) were highly efficiently coupled to 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and N-hydroxysuccinimide (EDC/NHS)-activated carboxyl groups of BCG-CWS, and tested the immunogenicity of OVA-conjugated BCG-CWS vaccine. We found that a strong immune response was induced in mice immunised with OVA-conjugated BCG-CWS, which was similar to the enhancement of the immune responses in mice immunised with OVA and complete Freund's adjuvant. Covalent conjugation of OVA to BCG-CWS was essential for Th1-skewed immune responses, with prominent expression of IFN-γ. Furthermore, antigen-conjugated BCG-CWS vaccine is simple to manufacture, safe, and easy to use. Our results suggest that mycobacterial CWS as a universal vaccine vehicle for conjugation of a wide variety of antigens constitutes a breakthrough for development of the most promising vaccines for infections, allergic diseases, and cancer.

Endoplasmic reticulum stress response is involved in Mycobacterium tuberculosis protein ESAT-6-mediated apoptosis

Mycobacterium tuberculosis (Mtb) infection leads to the induction of the apoptotic response, which is associated with bacilli killing. The early secreted mycobacterial antigen ESAT-6 of Mtb has been shown to induce apoptosis in human macrophages and epithelial cells. In the present study, we demonstrate that the stimulation of human epithelial A549 cells by ESAT-6 induces the endoplasmic reticulum (ER) stress response. We observed that ESAT-6 treatment increases intracellular Ca(2+) concentration, which results in ROS accumulation, and therefore induces the onset of ER stress-induced apoptosis. Our results uncover a novel apoptotic mechanism of ESAT-6 through ER stress responses in pathologic conditions such as tuberculosis.

Phenotypic and genotypic correction of WASP gene mutation in Wiskott-Aldrich syndrome by unrelated cord blood stem cell transplantation

We present two cases of Wiskott-Aldrich syndrome (WAS), in which nonsense mutations in the WASP gene were corrected phenotypically as well as genotypically by unrelated cord blood stem cell transplantation (CBSCT). Two male patients were diagnosed with WAS at the age of 5-month and 3-month and each received unrelated CBSCT at 16-month and 20-month of age, respectively. The infused cord blood (CB) units had 4/6 and 5/6 HLA matches and the infusion doses of total nucleated cells (TNC) and CD34+ cells were 6.24x10(7)/kg and 5.08x10(7)/kg for TNC and 1.33x10(5)/kg and 4.8x10(5)/kg for CD34+ cells, for UPN1 and UPN2, respectively. Complete donor cell chimerism was documented by variable number tandem repeat (VNTR) with neutrophil engraftment on days 31 and 13 and platelets on days 58 and 50, respectively. Immunologic reconstitution demonstrated that CBSCT resulted in consistent and stable T-, B-, and NK-cell development. Flow cytometric analysis for immunologic markers and sequence analysis of the WASP gene mutation revealed a normal pattern after CBSCT. These cases demonstrate that CBs can be an important source of stem cells for the phenotypical and genotypical correction of genetic diseases such as WAS.

Transcriptional regulatory defects in the first intron of Bruton's tyrosine kinase

BACKGROUND

X-linked agammaglobulinemia (XLA), characterized by the early onset of recurrent bacterial infections, profound hypogammaglobulinemia, and a markedly diminished number of peripheral B lymphocytes, is caused by mutations in the Bruton's tyrosine kinase (BTK) gene. The >600 unique mutations identified to date include single base pair substitutions, small insertions or deletions, and gross deletions. A few cases, however, have been found to have no mutations in the coding region even with reduced BTK mRNA or protein expression. Mutations in intron 1 positions +5 (G-->A) and +6 (T-->G) of the BTK gene have been identified, and these changes were associated with reduced transcriptional activity.

METHODS

In the present study a novel mutation in intron 1 position +5 (G-->T) was identified in a Japanese patient with XLA. The reporter constructs containing these mutations were made, and the reporter activities were measured using a luciferase assay.

RESULTS

All the mutant constructs were demonstrated to have reduced transcriptional activity.

CONCLUSIONS

Positions +5 and +6 in intron 1 of the BTK gene are critical for transcriptional activity, and defects in these regions cause XLA.

Degradation of naturally contaminated polycyclic aromatic hydrocarbons in municipal sewage sludge by electron beam irradiation

This study was to evaluate the degradation efficiency of naturally contaminated polycyclic aromatic hydrocarbons in sewage sludge by using electron beam irradiation as a function of the absorbed dose. Degradation efficiency of PAHs was near to 90% at the absorbed doses 5 kGy. The degradation of PAHs was "first order" reaction rates with respect to absorbed dose. The electron beam irradiation was found effective in means of removing PAHs in domestic wastewater.

Differential cytokine levels and immunoreactivities against Mycobacterium tuberculosis antigens between tuberculous and malignant effusions

Much effort has been devoted to the identification of immunologically important factors in tuberculous pleurisy (TBP) and malignant pleurisy (MP) to improve the differential diagnosis of the two major causes of lymphocyte-dominant pleurisy. This study evaluated the immunoreactivity and potential diagnostic utility of both host (cytokines and chemokines) and pathogen (mycobacterial proteins) factors in pleural effusions. Effusion samples were collected from 41 patients with MP caused by lung cancer and from 81 patients with TBP. The concentrations of nine cytokines and chemokines (interleukin (IL)-12 p40, interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, IL-6, IL-10, CXCL8/IL-8, CXCL10/IP-10, CCL3/MIP-1alpha, and CCL4/MIP-1beta) and antibody responses (IgG, IgM, and IgA) against five Mycobacterium tuberculosis antigens (early secreted antigenic target (ESAT)-6, 30-kDa, MTB12, 38-kDa, and a heparin-binding hemagglutinin (HBHA)) were determined in pleural fluids using enzyme-linked immunosorbent assays (ELISA). In the logistic regression, IFN-gamma (odds ratio, 7.178; 95% confidence interval (CI), 2.258-22.817; p=0.001), IL-12 p40 (odds ratio, 11.037; 95% CI, 3.38-36.037; p<0.001), and IL-6 (odds ratio, 3.295; 95% CI, 1.147-9.463; p=0.027) were found to be statistically significant cytokines predicting tuberculous from malignant effusions. Although IgG responses to all of the M. tuberculosis antigens tested were significantly higher in effusions from TBP (p<0.001) compared with those from MP, the logistic regression showed IgG levels for ESAT-6 and MTB12 to be statistically significant for differentiation of TBP from MP. HBHA showed the highest sensitivity of IgM antibody responses in TBP in comparison with other antigens. These data indicate that selected mycobacterial antigens (ESAT-6 and MTB12) and cytokine markers (IFN-gamma, IL-12p40, and IL-6) provide useful information for differentiating tuberculous and malignant effusions in clinical practice.

Polymorphisms of interleukin-10 and tumour necrosis factor-? genes are associated with newly diagnosed and recurrent pulmonary tuberculosis

BACKGROUND AND OBJECTIVES

The genetic determinants for developing TB or having recurrent TB are unknown. The present study investigated the relationship between susceptibility to tuberculosis and human tumour necrosis factor-alpha (TNF-alpha) and interleukin-10 genes (IL-10).

METHODS

A case-control study was conducted using two groups of cases--newly diagnosed TB (N-TB) and recurrent TB (R-TB)--and a control group.

RESULTS

One hundred and seventeen healthy controls, 80 newly diagnosed TB patients and 65 patients with recurrent TB were enrolled. There was no significant difference in the TNF-alpha-308 G/A genotype between the TB patient groups and the controls. The IL-10 -1082A alleles were markedly over-represented among the TB patient groups compared with the control subjects, however, there was no significant difference in the IL-10 genotype frequency between the N-TB and R-TB patient groups.

CONCLUSION

The -1082A allele of the IL-10 gene may be important in determining susceptibility to TB, however, the -308 allele of the TNF-alpha gene does not affect differential TB susceptibility.

Expression, production and release of the Eis protein by Mycobacterium tuberculosis during infection of macrophages and its effect on cytokine secretion

The eis gene of Mycobacterium tuberculosis has been shown to play a role in the survival of the avirulent Mycobacterium smegmatis within the macrophage. In vitro and in vivo analysis of Deltaeis deletion mutants and complemented strains showed no effect on survival of M. tuberculosis in U-937 macrophages or in a mouse aerosol infection model, respectively. Further studies were done in an attempt to determine the role of eis in M. tuberculosis intracellular survival and to define a phenotypic difference between wild-type and the Deltaeis deletion mutant. Bioinformatic analysis indicated that Eis is an acetyltransferase of the GCN5-related family of N-acetyltransferases. Immunofluorescence microscopy and Western blot analysis studies demonstrated that Eis is released into the cytoplasm of M. tuberculosis-infected U-937 macrophages. Eis was also found in the extravesicular fraction and culture supernatant of M. tuberculosis-infected macrophages. The effect of Eis on human macrophage cytokine secretion was also examined. Eis modulated the secretion of IL-10 and TNF-alpha by primary human monocytes in response both to infection with M. tuberculosis and to stimulation with recombinant Eis protein. These results suggest that Eis is a mycobacterial effector that is released into the host cell to modulate inflammatory responses, possibly via transcriptional or post-translational means.

Roles of peroxiredoxin II in the regulation of proinflammatory responses to LPS and protection against endotoxin-induced lethal shock

Mammalian 2-Cys peroxiredoxin II (Prx II) is a cellular peroxidase that eliminates endogenous H₂O₂. The involvement of Prx II in the regulation of lipopolysaccharide (LPS) signaling is poorly understood. In this report, we show that LPS induces substantially enhanced inflammatory events, which include the signaling molecules nuclear factor κB and mitogen-activated protein kinase (MAPK), in Prx II–deficient macrophages. This effect of LPS was mediated by the robust up-regulation of the reactive oxygen species (ROS)–generating nicotinamide adenine dinucleotide phosphate (NADPH) oxidases and the phosphorylation of p47^phox. Furthermore, challenge with LPS induced greater sensitivity to LPS-induced lethal shock in Prx II–deficient mice than in wild-type mice. Intravenous injection of Prx II–deficient mice with the adenovirus-encoding Prx II gene significantly rescued mice from LPS-induced lethal shock as compared with the injection of a control virus. The administration of catalase mimicked the reversal effects of Prx II on LPS-induced inflammatory responses in Prx II–deficient cells, which suggests that intracellular H₂O₂ is attributable, at least in part, to the enhanced sensitivity to LPS. These results indicate that Prx II is an essential negative regulator of LPS-induced inflammatory signaling through modulation of ROS synthesis via NADPH oxidase activities and, therefore, is crucial for the prevention of excessive host responses to microbial products.

Diacyltrehalose ofMycobacterium tuberculosisinhibits lipopolysaccharide- and mycobacteria-induced proinflammatory cytokine production in human monocytic cells

The lipids located in the outer layer of Mycobacterium tuberculosis, which include sulfolipid, phthiocerol dimycocerosate (PDIM), diacyltrehalose, and polyacyltrehalose, may play a role in host-pathogen interactions. These lipids were purified using thin-layer chromatography, and their ability to induce proinflammatory cytokines in human monocytes and in a human acute monocytic leukemia cell line (THP-1) was examined. None of the lipids tested induced significant interleukin (IL)-12p40 or tumor necrosis factor (TNF)-alpha production in monocytic cells. Diacyltrehalose significantly inhibited lipopolysaccharide- and M. tuberculosis-induced IL-12p40, TNF-alpha, and IL-6 productions in human monocytes, whereas other lipids had no effect. However, diacyltrehalose was unable to inhibit peptidoglycan-induced IL-12p40 production. These results suggest that diacyltrehalose is a mycobacterial factor capable of modulating host immune responses.

Mycobacterium tuberculosis HBHA protein reacts strongly with the serum immunoglobulin M of tuberculosis patients

Identification and characterization of serologically active mycobacterial antigens are prerequisites for the development of diagnostic reagents. We examined the humoral immune responses of active tuberculosis (TB) patients against Triton-soluble proteins extracted from Mycobacterium tuberculosis by immunoblotting. A 29-kDa protein reacted with immunoglobulin M (IgM) in the pooled sera of the patients, and its N-terminal amino acid sequence matched that of the heparin-binding hemagglutinin (HBHA). Recombinant full-length HBHA was expressed in Escherichia coli (rEC-HBHA) and M. smegmatis (rMS-HBHA). In immunoblot analysis, the IgM antibodies of the TB patients reacted strongly with rMS-HBHA but not with rEC-HBHA, whereas the IgG antibodies of these patients reacted weakly with both recombinant HBHA proteins. In enzyme-linked immunosorbent assay analysis using rMS-HBHA and 85B as antigens, the mean levels and sensitivities of the anti-HBHA IgM antibodies of the TB patients were significantly higher than those of the anti-antigen 85B IgM antibodies, while the IgG antibodies showed the opposite results. Of interest in this respect, the pooled sera from the TB patients that contained anti-HBHA IgM antibodies neutralized the entry of M. tuberculosis into epithelial cells. These findings suggest that IgM antibody to HBHA may play a role in protection against extrapulmonary dissemination.

Associations of serum minerals with body mass index in adult women

OBJECTIVE

This cross-sectional study evaluated the association between serum minerals and body mass index in adult women.

METHODS

One hundred and eighteen adult women were recruited by written advertisement from outpatient clinics or a health promotion center at a university hospital. Serum calcium, magnesium, copper and zinc were measured by an automatic analytical instrument and body mass index was calculated from height and weight.

RESULTS

Serum magnesium was inversely associated with body mass index (beta=-0.283, P=0.001) whereas serum copper had a positive association with body mass index (beta=0.197, P=0.025) after adjusting for age, physical activity, energy intake, dietary fat, alcohol consumption, supplements and menopause status. No associations were found with serum calcium and zinc.

CONCLUSION

Serum magnesium and copper may be involved in the regulation of body size in adult women.

Protein kinase C zeta plays an essential role for Mycobacterium tuberculosis-induced extracellular signal-regulated kinase 1/2 activation in monocytes/macrophages via Toll-like receptor 2

This study characterized the upstream signalling molecules involved in extracellular signal-regulated kinase (ERK) 1/2 activation and determined their effects on differential tumour necrosis factor (TNF)-alpha expression by monocytes/macrophages infected with virulent or avirulent mycobacteria. The avirulent Mycobacterium tuberculosis (MTB) strain H37Ra (MTBRa) induced higher levels of activation of ERK 1/2 and the upstream MAPK kinase (MEK)1 and, subsequently, higher levels of TNF-alpha expression in human primary monocytes and monocyte-derived macrophages, as compared with MTB strain H37Rv (MTBRv). The MTB-induced activation of ERK 1/2 was not dependent on Ras or Raf. However, inhibition of the activity of atypical protein kinase C (PKC) zeta decreased the in vitro phosphorylation of MEK, ERK 1/2 activation and subsequent TNF-alpha induction caused by MTBRv or MTBRa. Toll-like receptor (TLR) 2 was found to play a major role in MTB-induced TNF-alpha expression and PKCzeta phosphorylation. Co-immunoprecipitation experiments showed that PKCzeta interacts physically with TLR2 after MTB stimulation. Moreover, PKCzeta phosphorylation was increased more in macrophages following MTBRa, versus MTBRv, infection. This is the first demonstration that PKCzeta interacts with TLR2 to play an essential role in MTB-induced ERK 1/2 activation and subsequent TNF-alpha expression in monocytes/macrophages.

Role of the phosphatidylinositol 3-kinase and mitogen-activated protein kinase pathways in the secretion of tumor necrosis factor-alpha and interleukin-10 by the PPD antigen of Mycobacterium tuberculosis

Here we investigated the role of the phosphatidylinositol 3-kinase (PI 3-K) and mitogen-activated protein kinase (MAPK) pathways in the secretion of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 in human primary monocytes after stimulation with the PPD antigen of Mycobacterium tuberculosis. MAPK [extracellular signal-regulated kinase (ERK) 1/2 and p38] and Akt are rapidly phosphorylated in human monocytes stimulated with PPD. We found that the PI 3-K-Akt pathway stimulated by PPD is essential for both IL-10 and TNF-alpha production, although the inhibition of IL-10 production was more pronounced. The analysis of cytokine production using specific inhibitors of the MAPK pathway revealed that both p38 and ERK activation are essential for PPD-induced TNF-alpha production, whereas p38, but not ERK, activation is essential for IL-10 secretion. The inhibition of PI 3-K did not significantly activate p38 MAPK or ERK 1/2 in PPD-stimulated human monocytes. Further, the Src inhibitor PP2 inhibited the release of TNF-alpha but enhanced IL-10 release, suggesting the differential regulation of Src kinase in upstream signaling. Collectively, these data suggest that the PI 3-K and MAPK pathways play a central role in the regulation of both pro- and anti-inflammatory cytokines by the PPD antigen of M. tuberculosis.

Intracellular network of phosphatidylinositol 3-kinase, mammalian target of the rapamycin/70 kDa ribosomal S6 kinase 1, and mitogen-activated protein kinases pathways for regulating mycobacteria-induced IL-23 expression in human macrophages

We previously demonstrated that Mycobacterium tuberculosis (M. tbc)-induced interleukin (IL)-12 expression is negatively regulated by the phosphatidylinositol 3-kinase (PI3K) and extracellular signal-regulated kinase (ERK) 1/2 pathways in human monocyte-derived macrophages (MDMs). To extend these studies, we examined the nature of the involvement of toll-like receptors (TLRs) and intracellular signalling pathways downstream from PI3K in M. tbc-induced IL-23 expression in human MDMs. M. tbc-induced Akt activation and IL-23 expression were essentially dependent on TLR2. Blockade of the mammalian targets of rapamycin (mTOR)/70 kDa ribosomal S6 kinase 1 (S6K1) pathway by the specific inhibitor rapamycin greatly enhanced M. tbc-induced IL-12/IL-23 p40 (p40) and IL-23 p19 (p19) mRNA and IL-23 protein expression. In sharp contrast, p38 mitogen-activated protein kinase (MAPK) inhibition abrogated the p40 and p19 mRNA and IL-23 protein expression induced by M. tbc. Furthermore, the inhibition of PI3K-Akt, but not ERK 1/2 pathway, attenuated M. tbc-induced S6K1 phosphorylation, whereas PI3K inhibition enhanced p38 phosphorylation and apoptosis signal-regulating kinase 1 activity during exposure to M. tbc. Although the negative or positive regulation of IL-23 was not reversed by neutralization of IL-10, it was significantly modulated by blocking TLR2. Collectively, these findings provide new insight into the homeostatic mechanism controlling type 1 immune responses during mycobacterial infection involving the intracellular network of PI3K, S6K1, ERK 1/2 and p38 MAPK pathways in a TLR2-dependent manner.