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1.
mBio ; 14(5): e0153523, 2023 Oct 31.
Article En | MEDLINE | ID: mdl-37800958

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.


Mycobacterium tuberculosis , Reactive Oxygen Species , Macrophages , Endoplasmic Reticulum Stress , Autophagy
2.
Cell Biosci ; 13(1): 158, 2023 Aug 30.
Article En | MEDLINE | ID: mdl-37649112

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.

3.
Healthcare (Basel) ; 10(11)2022 Nov 20.
Article En | MEDLINE | ID: mdl-36421648

This study aimed to determine the association between symptoms of depression and sleep duration in a representative sample of the Korean population. Using national cross-sectional data from the seventh Korea National Health and Nutrition Examination Surveys (KNHANES-VII), 5461 adults aged 18−49 years were analyzed using logistic regression models. The proportions of participants with total daily sleep durations (24 h) of <6 h, 6−8 h, and ≥9 h were 26.2%, 60.6%, and 13.3%, respectively. The proportions of individuals with symptoms of depression in the <6 h, 6−8 h, and ≥9 h sleep duration groups were 37.4%, 46.3%, and 16.3%, respectively. The odds ratios (ORs) were significantly higher in the <6 h and ≥9 h sleep groups than in the 6−8 h sleep group. There was a significant association between short (<6 h/day) and long (≥9 h/day) sleep duration and symptoms of depression among the general Korean population. In particular, our findings suggest that short sleep (<6 h/day) is more associated with symptoms of depression than long sleep (≥9 h/day).

5.
Sci Rep ; 12(1): 12891, 2022 07 28.
Article En | MEDLINE | ID: mdl-35902681

Angle measurement methods for measuring pes planus may lose consistency by errors between observers. If the feature points for angle measurement can be provided in advance with the algorithm developed through the deep learning method, it is thought that the error between the observers can be reduced. A total of 300 weightbearing lateral radiographs were used for the development of the deep learning-based algorithm, and a total of 95 radiographs were collected for the clinical validation test set. Meary angle (MA) and calcaneal pitch (CP) were selected as measurement methods and measured twice by three less-experienced physicians with the algorithm-based tool and twice without. The intra- and inter-observer agreements of MA and CP measures were assessed via intra-class correlation coefficient. In addition, verification of the improvement of measurement performance by the algorithm was performed. Interobserver agreements for MA and CP measurements with algorithm were more improved than without algorithm. As for agreement with reference standard, combining the results of all readers, both MA and CP with algorithm were greater than those without algorithm. The deep learning algorithm tool is expected to improve the reproducibility of radiographic measurements for pes planus, especially by improving inter-observer agreement.


Deep Learning , Flatfoot , Humans , Observer Variation , Radiography , Reproducibility of Results , Weight-Bearing
6.
Cell Biosci ; 11(1): 175, 2021 Sep 25.
Article En | MEDLINE | ID: mdl-34563261

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.

7.
Cells ; 10(9)2021 09 19.
Article En | MEDLINE | ID: mdl-34572127

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.


Angiotensin II/toxicity , Apoptosis , Hypertension/pathology , Lung/pathology , Macrophages/pathology , Mycobacterium tuberculosis/physiology , Tuberculosis/pathology , Animals , Hypertension/chemically induced , Lung/microbiology , Macrophages/microbiology , Male , Mice , Mice, Inbred C57BL , Necrosis , Tuberculosis/microbiology , Vasoconstrictor Agents/toxicity
8.
J Altern Complement Med ; 27(10): 813-823, 2021 Oct.
Article En | MEDLINE | ID: mdl-34242093

Background: Aromatherapy is widely used in women's health as a complementary therapy. Objective: This review aimed to critically evaluate clinical evidence of the effectiveness of aromatherapy in managing menopausal symptoms. Design: A systematic review and meta-analysis. Methods: A total of 11 electronic databases were searched up to November 5, 2020. Randomized controlled trials (RCTs) evaluating any type of aromatherapy against placebo in menopausal individuals were eligible. Two authors independently assessed the study eligibility and risk of bias as well as extracted the data for each study. Cochrane risk of bias tool was used to evaluate the methodological quality of each included studies. No ethical approval was required for this manuscript as this study did not involve human subjects or laboratory animals. Results: Seven RCTs met our inclusion criteria and were analyzed. Most of the included RCTs had low risk of bias in most domains except for blinding. Four studies tested the efficacy of aromatherapy for menopausal symptoms. The results showed that aromatherapy (lavender or low dose of neroli) inhalation had superior effects on reducing the total menopausal symptom score compared with the placebo. One study presented that aromatherapy massage with mixed oils reduced menopausal symptoms. Three studies investigated the effects of aromatherapy inhalation on sexual desire, and all of the studies showed that aromatherapy inhalation (lavender or low dose of neroli or mixed oils) had superior effects compared with the placebo. Conclusion: This review indicates limited evidence of the benefit of aromatherapy (lavender or low dose of neroli) in improving total menopausal symptoms and sexual desire. Further studies are highly warranted to validate the findings.


Aromatherapy , Lavandula , Humans , Massage , Menopause , Plant Oils , Randomized Controlled Trials as Topic
9.
Integr Med Res ; 10(3): 100706, 2021 Sep.
Article En | MEDLINE | ID: mdl-33665094

BACKGROUND: This study aimed to obtain the symptom, prescription and therapeutic patterns for the treatment of patients with menopausal syndrome in major Korean medicine (KM) hospitals. METHODS: We used a retrospective chart review of climacteric disorder and postmenopausal syndrome patients by examining medical records (ICD-10, menopausal and female climacteric states: N95.1, Menopausal and perimenopausal disorder, unspecified: N95.9) from eight university KM hospitals in South Korea. RESULTS: The main symptoms of 1,682 patients with menopausal disorders visiting eight college-affiliated oriental medicine hospitals were hot flush, hyperhidrosis, fatigue, insomnia, and chest tightness. Guipi decoction, Si-wu guipi decoction, Qing-xin lianzi-yin, Jiawei xiao-yao-san and Guipi wen-dan decoction were the most commonly prescribed treatments for menopausal disorders. Patients were most often treated with a combination of herbal medicine and acupuncture. CONCLUSION: Our study shows that the current prescribed herbal medicines were used for treating menopausal disorders in Korean medicine hospitals. However, the objectivity of the efficacy assessment should be studied further.

10.
Complement Ther Clin Pract ; 40: 101175, 2020 Aug.
Article En | MEDLINE | ID: mdl-32347211

BACKGROUND: This survey aimed to investigate clinicians' perceptions and current practice patterns of Korean medicine (KM) treatment for female infertility. METHODS: A questionnaire on clinical practice patterns of KM treatment for female infertility was constructed and distributed to 703 KM doctors (KMDs). RESULTS: A total of 20.5% of physicians (n = 144/703) completed the survey and delivered integrative care for female infertility patients. Integrative care mainly consisted of acupuncture, herbal medicine, and moxibustion. The participants largely relied on radiological findings on ultrasonography and hormone tests for diagnosis. The most frequently prescribed herbal medication was Jogyeongjongok-tang (Tiaojing Zhongyu decoction), and the most frequently applied acupoints were SP6, CV4 and ST36. CONCLUSIONS: This study provides expert opinions and information on actual clinical practice patterns of KM for treating female infertility. However, we cannot completely discount the possibility that biased selection of subjects and the low response rate limit the interpretations of the study results.


Acupuncture Therapy , Infertility, Female/therapy , Phytotherapy/statistics & numerical data , Practice Patterns, Physicians'/statistics & numerical data , Acupuncture Points , Adult , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Physicians/statistics & numerical data , Republic of Korea , Surveys and Questionnaires , Young Adult
11.
Complement Ther Clin Pract ; 38: 101073, 2020 Feb.
Article En | MEDLINE | ID: mdl-31765985

BACKGROUND: The aim of this study was to investigate the clinical practice of Korean medicine doctors (KMDs) for managing menopausal disorders. METHODS: We conducted a web-based questionnaire for KMDs to respond to recommendations across the three main KM domains: major symptoms of menopausal disorders, herbal prescriptions, and pattern identification. RESULTS: We received responses from 227 doctors who have treated menopausal disorders. The major pattern identifications recommended by the doctors for the pre-, peri-, and postmenopausal phases, respectively, were depression of liver energy (59.5%), kidney yin deficiency (49.8%), and kidney yin deficiency (50.7%). The most frequent herbal remedies prescribed for the pre-, peri-, and postmenopausal phases were Jiawei shaoyao-san (58.1%), Jiawei shaoyao-san (48.5%), and Jiawei guipi-decoction (37.9%), respectively. CONCLUSION: The results of our clinical practice survey provide information on KMDs' clinical experiences of using herbal medicines and their use of pattern identification to manage menopausal disorders.


Menopause , Physicians/statistics & numerical data , Plant Preparations/therapeutic use , Practice Patterns, Physicians'/statistics & numerical data , Adult , Female , Humans , Male , Middle Aged , Phytotherapy/statistics & numerical data , Republic of Korea , Surveys and Questionnaires , Young Adult
12.
Apoptosis ; 25(1-2): 42-55, 2020 02.
Article En | MEDLINE | ID: mdl-31691131

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.


Macrophages/metabolism , Mycobacterium tuberculosis/growth & development , Tuberculosis/metabolism , Tumor Suppressor Protein p53/metabolism , Adult , Aged , Animals , Apoptosis , Female , Host-Pathogen Interactions , Humans , Male , Mice , Mice, Inbred C57BL , Microbial Viability , Middle Aged , Mycobacterium tuberculosis/physiology , Tuberculosis/genetics , Tuberculosis/microbiology , Tuberculosis/physiopathology , Tumor Suppressor Protein p53/genetics
13.
Apoptosis ; 25(1-2): 56, 2020 Feb.
Article En | MEDLINE | ID: mdl-31776833

The original version of this article unfortunately contains an error in the acknowledgement section. The text "Brain Korea 21 PLUS Project for Medical Science, Chungnam National University" was omitted by mistake. The correct and complete acknowledgment is given below: Acknowledgments This work was supported by the research fund of Chungnam National University and the Brain Korea 21 PLUS Project for Medical Science, Chungnam National University. The funders had no role in study design, data collection and analysis decision to publish, or preparation of the manuscript.

14.
Cells ; 8(11)2019 10 30.
Article En | MEDLINE | ID: mdl-31671648

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.


Apoptosis , Endoplasmic Reticulum Stress , GTP Phosphohydrolases/deficiency , Macrophages/microbiology , Macrophages/pathology , Mycobacterium tuberculosis/growth & development , Tuberculosis/prevention & control , Animals , Cells, Cultured , Macrophages/metabolism , Mice , Mice, Inbred C57BL , Mitochondria/metabolism , Mitochondria/microbiology , Mitochondria/pathology , Oxygen Consumption , Tuberculosis/microbiology , Tuberculosis/pathology
15.
Integr Med Res ; 8(4): 229-233, 2019 Dec.
Article En | MEDLINE | ID: mdl-31646139

BACKGROUND: Most women experiencing menopause have sought out traditional treatment options to relieve their symptoms. The aim of this study, which used a web-based survey, was to investigate perceptions of Korean medicine doctors (KMDs) on managing menopausal symptoms with herbal medicines. METHODS: We developed and then sent a questionnaire via email to a total 497 KMDs in obstetrics and gynecology affiliated with the Society of Korean Medicine. The questionnaire consisted of three categories and a total of 26 items focusing on major menopausal symptoms, prescriptions, pattern identification, and background characteristics. RESULTS: Out of the 497 KMDs, we received responses from 48 doctors, a response rate of 9.7%. The most common symptoms of menopausal disorder perceived by responded KMDs were hot flashes (22.9%), sleep disorders (18.2%), systemic fatigue (12.5%), and sweating (12.0%). The herbal medicines reported to be the most effective when treating patients with menopausal disorders were Jiawei shaoyao-san (12.5%), Jiawei guipi-decoction (11.8%). The responding KMDs recommended one to two months of treatment for female menopausal disorder, using two to three doses of herbal medicine per day in combination with traditional Korean medicine (KM) therapies such as acupuncture, moxibustion, cupping, and pharmacopuncture. CONCLUSION: The results of this survey may provide information about doctor's perceptions on using herbal medicines to manage patient's menopausal symptoms. Future studies should be done with a larger sample size to overcome the limitation of this study and to examine how KM is used for treating menopausal symptoms in clinical practice.

16.
Cell Microbiol ; 21(12): e13094, 2019 12.
Article En | MEDLINE | ID: mdl-31386788

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.


Apoptosis/physiology , Endoplasmic Reticulum Stress/physiology , Macrophages/metabolism , Macrophages/microbiology , Membrane Proteins/metabolism , Protein Serine-Threonine Kinases/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction/physiology , Animals , Cell Line , Mice , Mycobacterium avium/pathogenicity , RAW 264.7 Cells , Tuberculosis, Avian/metabolism , Tuberculosis, Avian/microbiology
17.
Article En | MEDLINE | ID: mdl-31360206

Blood stasis syndrome (BSS) is an important pathological condition in traditional East Asian medicine and is associated with ischemic heart disease, cerebral vascular accident, diabetes mellitus, chronic renal failure, severe traumatic injury, and dysmenorrhea. However, previous studies have been unable to reveal the clinical and biological characteristics or biological markers of BSS. We hypothesized that the heterogeneity among the manifestations of BSS or non-BSS could interfere with an analysis to describe the characteristics of BSS. In this study, male participants based on the severity of BSS-associated symptoms and signs were clustered and classified into four subgroups: BSS subgroups (1), (2), (3), and (4). Non-BSS core subgroup was redefined using manifestation cluster analysis. Biological characteristics of subgroups BSS(1) and BSS(2) belong to the range of the non-BSS core subgroup (1), whereas that of subgroups BSS(3) and BSS(4) are characterized by different biological parameters such as systemic inflammatory conditions and elevated D-dimer level. Our results suggested that patients in subgroups of BSS(3) and BSS(4) are more likely to be exposed in an inflammatory state than other BSS subgroups. We found the heterogeneity among the manifestations which could mask the characteristics of BSS and identified the clinical and biological profiles of the four BSS subgroups through comparisons of the redefined non-BSS and BSS subgroups. This finding could provide accurate diagnostic criteria and new approaches for BSS treatments in different subgroups.

18.
Sci Rep ; 9(1): 4027, 2019 03 11.
Article En | MEDLINE | ID: mdl-30858471

Tuberculosis (TB) remains a global healthcare issue. Understanding the host-pathogen interactions in TB is vital to develop strategies and therapeutic tools for the control of Mycobacterium tuberculosis (Mtb). In this study, transcriptome analyses of macrophages infected with either the virulent Mtb strain H37Rv (Rv) or the avirulent Mtb strain H37Ra (Ra) were carried out and 750 differentially expressed genes (DEGs) were identified. As expected, the DEGs were mainly involved in the induction of innate immune responses against mycobacterial infections. Among the DEGs, solute carrier family 7 member 2 (Slc7a2) was more strongly expressed in Ra-infected macrophages. Induction of SLC7A2 was important for macrophages to control the intracellular survival of Mtb. Our results imply that SLC7A2 plays an important role in macrophages during Mtb infection. Our findings could prove useful for the development of new therapeutic strategies to control TB infection.


Amino Acid Transport Systems, Basic/physiology , Macrophages/metabolism , Macrophages/microbiology , Mycobacterium tuberculosis , Tuberculosis , Animals , Cells, Cultured , Host-Pathogen Interactions , Macrophages/pathology , Mice, Inbred C57BL , Mycobacterium tuberculosis/pathogenicity , Mycobacterium tuberculosis/physiology , RNA-Seq/methods , Tuberculosis/immunology , Tuberculosis/microbiology , Virulence
19.
Front Immunol ; 10: 3147, 2019.
Article En | MEDLINE | ID: mdl-32082307

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.


Endoplasmic Reticulum Stress/immunology , Immunity, Innate/immunology , Infections/immunology , Unfolded Protein Response/immunology , Animals , Humans
20.
Cell Biosci ; 8: 52, 2018.
Article En | MEDLINE | ID: mdl-30288253

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.

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