Lactic acidosis caused by repressed lactate dehydrogenase subunit B expression down-regulates mitochondrial oxidative phosphorylation via the pyruvate dehydrogenase (PDH)-PDH kinase axis.

Aerobic glycolysis and mitochondrial dysfunction are key metabolic features of cancer cells, but their interplay during cancer development remains unclear. We previously reported that human hepatoma cells with mitochondrial defects exhibit down-regulated lactate dehydrogenase subunit B (LDHB) expression. Here, using several molecular and biochemical assays and informatics analyses, we investigated how LDHB suppression regulates mitochondrial respiratory activity and contributes to liver cancer progression. We found that transcriptional LDHB down-regulation is an upstream event during suppressed oxidative phosphorylation. We also observed that LDHB knockdown increases inhibitory phosphorylation of pyruvate dehydrogenase (PDH) via lactate-mediated PDH kinase (PDK) activation and thereby attenuates oxidative phosphorylation activity. Interestingly, monocarboxylate transporter 1 was the major lactate transporter in hepatoma cells, and its expression was essential for PDH phosphorylation by modulating intracellular lactate levels. Finally, bioinformatics analysis of the hepatocellular carcinoma cohort from The Cancer Genome Atlas revealed that a low LDHB/LDHA ratio is statistically significantly associated with poor prognostic outcomes. A low ratio was also associated with a significant enrichment in glycolysis genes and negatively correlated with PDK1 and 2 expression, supporting a close link between LDHB suppression and the PDK-PDH axis. These results suggest that LDHB suppression is a key mechanism that enhances glycolysis and is critically involved in the maintenance and propagation of mitochondrial dysfunction via lactate release in liver cancer progression.

Lactate-mediated mitoribosomal defects impair mitochondrial oxidative phosphorylation and promote hepatoma cell invasiveness.

Impaired mitochondrial oxidative phosphorylation (OXPHOS) capacity, accompanied by enhanced glycolysis, is a key metabolic feature of cancer cells, but its underlying mechanism remains unclear. Previously, we reported that human hepatoma cells that harbor OXPHOS defects exhibit high tumor cell invasiveness via elevated claudin-1 (CLN1). In the present study, we show that OXPHOS-defective hepatoma cells (SNU354 and SNU423 cell lines) exhibit reduced expression of mitochondrial ribosomal protein L13 (MRPL13), a mitochondrial ribosome (mitoribosome) subunit, suggesting a ribosomal defect. Specific inhibition of mitoribosomal translation by doxycycline, chloramphenicol, or siRNA-mediated MRPL13 knockdown decreased mitochondrial protein expression, reduced oxygen consumption rate, and increased CLN1-mediated tumor cell invasiveness in SNU387 cells, which have active mitochondria. Interestingly, we also found that exogenous lactate treatment suppressed MRPL13 expression and oxygen consumption rate and induced CLN1 expression. A bioinformatic analysis of the open RNA-Seq database from The Cancer Genome Atlas (TCGA) liver hepatocellular carcinoma (LIHC) cohort revealed a significant negative correlation between MRPL13 and CLN1 expression. Moreover, in patients with low MRPL13 expression, two oxidative metabolic indicators, pyruvate dehydrogenase B expression and the ratio of lactate dehydrogenase type B to type A, significantly and negatively correlated with CLN1 expression, indicating that the combination of elevated glycolysis and deficient MRPL13 activity was closely linked to CLN1-mediated tumor activity in LIHC. These results suggest that OXPHOS defects may be initiated and propagated by lactate-mediated mitoribosomal deficiencies and that these deficiencies are critically involved in LIHC development.

The Ubiquitin-like with PHD and Ring Finger Domains 1 (UHRF1)/DNA Methyltransferase 1 (DNMT1) Axis Is a Primary Regulator of Cell Senescence.

As senescence develops, cells sequentially acquire diverse senescent phenotypes along with simultaneous multistage gene reprogramming. It remains unclear what acts as the key regulator of the collective changes in gene expression at initiation of senescent reprogramming. Here we analyzed time series gene expression profiles obtained in two different senescence models in human diploid fibroblasts: replicative senescence and H2O2-induced senescence. Our results demonstrate that suppression of DNA methyltransferase 1 (DNMT1)-mediated DNA methylation activity was an initial event prior to the display of senescent phenotypes. We identified seven DNMT1-interacting proteins, ubiquitin-like with PHD and ring finger domains 1 (UHRF1), EZH2, CHEK1, SUV39H1, CBX5, PARP1, and HELLS (also known as LSH (lymphoid-specific helicase) 1), as being commonly down-regulated at the same time point as DNMT1 in both senescence models. Knockdown experiments revealed that, among the DNMT1-interacting proteins, only UHRF1 knockdown suppressed DNMT1 transcription. However, UHRF1 overexpression alone did not induce DNMT1 expression, indicating that UHRF1 was essential but not sufficient for DNMT1 transcription. Although UHRF1 knockdown effectively induced senescence, this was significantly attenuated by DNMT1 overexpression, clearly implicating the UHRF1/DNMT1 axis in senescence. Bioinformatics analysis further identified WNT5A as a downstream effector of UHRF1/DNMT1-mediated senescence. Senescence-associated hypomethylation was found at base pairs -1569 to -1363 from the transcription start site of the WNT5A gene in senescent human diploid fibroblasts. As expected, WNT5A overexpression induced senescent phenotypes. Overall, our results indicate that decreased UHRF1 expression is a key initial event in the suppression of DNMT1-mediated DNA methylation and in the consequent induction of senescence via increasing WNT5A expression.

Mitochondrial Respiratory Dysfunction Induces Claudin-1 Expression via Reactive Oxygen Species-mediated Heat Shock Factor 1 Activation, Leading to Hepatoma Cell Invasiveness.

Although mitochondrial dysfunction has been implicated in tumor metastasis, it is unclear how it regulates tumor cell aggressiveness. We have reported previously that human hepatoma cells harboring mitochondrial defects have high tumor cell invasion activity via increased claudin-1 (Cln-1) expression. In this study, we demonstrated that mitochondrial respiratory defects induced Cln-1 transcription via reactive oxygen species (ROS)-mediated heat shock factor 1 (HSF1) activation, which contributed to hepatoma invasiveness. We first confirmed the inverse relationship between mitochondrial defects and Cln-1 induction in SNU hepatoma cells and hepatocellular carcinoma tissues. We then examined five different respiratory complex inhibitors, and complex I inhibition by rotenone most effectively induced Cln-1 at the transcriptional level. Rotenone increased both mitochondrial and cytosolic ROS. In addition, rotenone-induced Cln-1 expression was attenuated by N-acetylcysteine, an antioxidant, and exogenous H2O2 treatment was enough to increase Cln-1 transcription, implying the involvement of ROS. Next we found that ROS-mediated HSF1 activation via hyperphosphorylation was the key event for Cln-1 transcription. Moreover, the Cln-1 promoter region (from -529 to +53) possesses several HSF1 binding elements, and this region showed increased promoter activity and HSF1 binding affinity in response to rotenone treatment. Finally, we demonstrated that the invasion activity of SNU449 cells, which harbor mitochondrial defects, was blocked by siRNA-mediated HSF1 knockdown. Taken together, these results indicate that mitochondrial respiratory defects enhance Cln-1-mediated hepatoma cell invasiveness via mitochondrial ROS-mediated HSF1 activation, presenting a potential role for HSF1 as a novel mitochondrial retrograde signal-responsive transcription factor to control hepatoma cell invasiveness.

Identification of a mitochondrial defect gene signature reveals NUPR1 as a key regulator of liver cancer progression.

UNLABELLED: Many cancer cells require more glycolytic adenosine triphosphate production due to a mitochondrial respiratory defect. However, the roles of mitochondrial defects in cancer development and progression remain unclear. To address the role of transcriptomic regulation by mitochondrial defects in liver cancer cells, we performed gene expression profiling for three different cell models of mitochondrial defects: cells with chemical respiratory inhibition (rotenone, thenoyltrifluoroacetone, antimycin A, and oligomycin), cells with mitochondrial DNA depletion (Rho0), and liver cancer cells harboring mitochondrial defects (SNU354 and SNU423). By comparing gene expression in the three models, we identified 10 common mitochondrial defect-related genes that may be responsible for retrograde signaling from cancer cell mitochondria to the intracellular transcriptome. The concomitant expression of the 10 common mitochondrial defect genes is significantly associated with poor prognostic outcomes in liver cancers, suggesting their functional and clinical relevance. Among the common mitochondrial defect genes, we found that nuclear protein 1 (NUPR1) is one of the key transcription regulators. Knockdown of NUPR1 suppressed liver cancer cell invasion, which was mediated in a Ca(2+) signaling-dependent manner. In addition, by performing an NUPR1-centric network analysis and promoter binding assay, granulin was identified as a key downstream effector of NUPR1. We also report association of the NUPR1-granulin pathway with mitochondrial defect-derived glycolytic activation in human liver cancer. CONCLUSION: Mitochondrial respiratory defects and subsequent retrograde signaling, particularly the NUPR1-granulin pathway, play pivotal roles in liver cancer progression.

Anti-tuberculosis effect of microbiome therapeutic PMC205 in extensively drug-resistant pulmonary tuberculosis in vivo.

BACKGROUND: Tuberculosis is a highly contagious disease caused by Mycobacterium tuberculosis, and the increase in antibiotic resistance threatens humankind. Therefore, there is an urgent need to develop new anti-tuberculosis drugs that can overcome the limitations of existing drugs. Here, we report the anti-tuberculosis effect of microbiome therapeutic PMC205, a strain of Bacillus subtilis. METHODS: The anti-tuberculosis activity of probiotics was evaluated in mouse models of lethal and latent pulmonary tuberculosis induced by high or low-dose infection of the extensively drug-resistant (XDR) strain. Probiotics were administered by inhalation, and the burden of M. tuberculosis in the lungs, along with mortality and clinical observations, were monitored for 12 weeks and 8 months, respectively. For an in-depth understanding, analysis of the microbiome and inflammatory profile of the lung microenvironment and induction of autophagy in vitro were explored. RESULTS: After inhalation administration of PMC205 for 3 months, the survival rate was 100%, unlike all deaths in the saline-treated group, and the burden of M. tuberculosis in the lungs was reduced by log 1.3 in the 8-month latent tuberculosis model. Moreover, PMC205 induced recovery of disrupted lung microflora, increased butyric acid, and suppressed excessive inflammation. It also promoted autophagy. CONCLUSIONS: These results confirm PMC205's anti-tuberculosis effect, suggesting that it can be developed as an adjuvant to current antibiotic therapy to solve the drug-resistant tuberculosis problem.

Cellular senescence is associated with the spatial evolution toward a higher metastatic phenotype in colorectal cancer.

In this study, we explore the dynamic process of colorectal cancer progression, emphasizing the evolution toward a more metastatic phenotype. The term "evolution" as used in this study specifically denotes the phenotypic transition toward a higher metastatic potency from well-formed glandular structures to collective invasion, ultimately resulting in the development of cancer cell buddings at the invasive front. Our findings highlight the spatial correlation of this evolution with tumor cell senescence, revealing distinct types of senescent tumor cells (types I and II) that play different roles in the overall cancer progression. Type I senescent tumor cells (p16INK4A+/CXCL12+/LAMC2-/MMP7-) are identified in the collective invasion region, whereas type II senescent tumor cells (p16INK4A+/CXCL12+/LAMC2+/MMP7+), representing the final evolved form, are prominently located in the partial-EMT region. Importantly, type II senescent tumor cells associate with local invasion and lymph node metastasis in colorectal cancer, potentially affecting patient prognosis.

Clinical effect of Pediococcus acidilactici PMC48 on hyperpigmented skin.

BACKGROUND: The excessive production and accumulation of melanin in the epidermal skin layer can result in skin hyperpigmentation and darkening. Current technologies for regulating melanin are based on inhibiting melanin biosynthesis. They have low effectiveness and safety issues. AIMS: This study aimed to evaluate the potential role of Pediococcus acidilactici PMC48 as a probiotic strain in medicines and cosmetics for skin treatment. MATERIALS AND METHODS: Meanwhile, our research team has reported that P. acidilactici PMC48 strain isolated from sesame leaf kimchi can directly decompose the already synthesized melanin. It can also inhibit melanin biosynthesis. In the present study, we investigated the skin-whitening effect of this strain by arranging an 8-week clinical trial with 22 participants. PMC48 was applied to each participant's artificially UV-induced tanned skin in the clinical trial. Its whitening effect was investigated based on visual evaluation, skin brightness, and melanin index. RESULTS: PMC48 showed a significant effect on the artificially induced pigmented skin. The color intensity of the tanned skin was decreased by 47.647%, and skin brightness was increased by 8.098% after the treatment period. PMC48 also significantly decreased the melanin index by 11.818%, indicating its tyrosinase inhibition capacity. Also, PMC48 improved skin moisture content level by 20.943%. Additionally, 16S rRNA-based amplicon sequencing analysis showed a distinct increase in Lactobacillaceae in the skin by up to 11.2% at the family level without affecting other skin microbiota. Furthermore, it showed no toxicity in in vitro or in vivo analyses. DISCUSSION: These results indicate that P. acidilactici PMC48 is a promising probiotic strain that can be used to develop medicines and cosmetic products to solve skin-related problems. CONCLUSIONS: These results demonstrate that P. acidilactici PMC48 can be a potential probiotic for the cosmetic industry against different skin disorders.

GSK3 inactivation is involved in mitochondrial complex IV defect in transforming growth factor (TGF) ß1-induced senescence.

Transforming growth factor ß1 (TGF ß1) induces Mv1Lu cell senescence by persistently producing mitochondrial reactive oxygen species (ROS) through decreased complex IV activity. Here, we investigated the molecular mechanism underlying the effect of TGF ß1 on mitochondrial complex IV activity. TGF ß1 progressively phosphorylated the negative regulatory sites of both glycogen synthase kinase 3 (GSK3) α and ß, corresponding well to the intracellular ROS generation profile. Pre-treatment of N-acetyl cysteine, an antioxidant, did not alter this GSK3 phosphorylation (inactivation), whereas pharmacological inhibition of GSK3 by SB415286 significantly increased mitochondrial ROS, implying that GSK3 phosphorylation is an upstream event of the ROS generation. GSK3 inhibition by SB415286 decreased complex IV activity and cellular O(2) consumption rate and eventually induced senescence of Mv1Lu cell. Similar results were obtained with siRNA-mediated knockdown of GSK3. Moreover, we found that GSK3 not only exists in cytosol but also in mitochondria of Mv1Lu cell and the mitochondrial GSK3 binds complex IV subunit 6b which has no electron carrier and is topologically located in the mitochondrial intermembrane space. Involvement of subunit 6b in controlling complex IV activity and overall respiration rate was proved with siRNA-mediated knockdown of subunit 6b. Finally, TGF ß1 treatment decreased the binding of the subunit 6b to GSK3 and subunit 6b phosphorylation. Taken together, our results suggest that GSK3 inactivation is importantly involved in TGF ß1-induced complex IV defects through decreasing phosphorylation of the subunit 6b, thereby contributing to senescence-associated mitochondrial ROS generation.

p15INK4B is an alternative marker of senescent tumor cells in colorectal cancer.

Senescent tumor cells are nonproliferating tumor cells which are closely related to cancer progression by secreting senescence-related molecules, called senescence-associated secreting phenotypes. Therefore, the presence of senescent tumor cells is considered a prognostic factor in various cancer types. Although senescence-associated ß-galactosidase staining is considered the best marker for detection of senescent tumor cells, it can only be performed in fresh-frozen tissues. p16INK4A, a cyclin-dependent inhibitor, has been used as an alternative marker to detect senescent tumor cells in formalin-fixed paraffin-embedded tissues. However, other reliable markers to detect senescent tumor cells is still lacking. In the present study, using public single-cell RNA-sequencing data, we found that p15INK4B, a cyclin-dependent kinase inhibitor, is a novel marker for detection of senescent tumor cells. Moreover, p15INK4B expression was positively correlated with that of p16INK4A in colorectal cancer tissues. In in vitro studies, mRNA expression of p15INK4B was increased together with that of p16INK4A in H2O2- and therapy-induced cancer senescence models. However, the mRNA level of p15INK4B did not increase in the oncogene-induced senescence model in primary colonic epithelial cells. In conclusion, p15INK4B is a potential alternative marker for detection of senescent tumor cells together with conventional markers in advanced stages of colorectal cancer.

Mid-old cells are a potential target for anti-aging interventions in the elderly.

The biological process of aging is thought to result in part from accumulation of senescent cells in organs. However, the present study identified a subset of fibroblasts and smooth muscle cells which are the major constituents of organ stroma neither proliferative nor senescent in tissues of the elderly, which we termed "mid-old status" cells. Upregulation of pro-inflammatory genes (IL1B and SAA1) and downregulation of anti-inflammatory genes (SLIT2 and CXCL12) were detected in mid-old cells. In the stroma, SAA1 promotes development of the inflammatory microenvironment via upregulation of MMP9, which decreases the stability of epithelial cells present on the basement membrane, decreasing epithelial cell function. Remarkably, the microenvironmental change and the functional decline of mid-old cells could be reversed by a young cell-originated protein, SLIT2. Our data identify functional reversion of mid-old cells as a potential method to prevent or ameliorate aspects of aging-related tissue dysfunction.

Decreased lactate dehydrogenase B expression enhances claudin 1-mediated hepatoma cell invasiveness via mitochondrial defects.

Aerobic lactate production of which the final step is executed by lactate dehydrogenase (LDH) is one of the typical phenotypes in invasive tumor development. However, detailed mechanism of how LDH links to cancer cell invasiveness remains unclear. This study shows that suppressed LDHB expression plays a critical role in hepatoma cell invasiveness by inducing claudin-1 (Cln-1), a tight junction protein, via mitochondrial respiratory defects. First, we found that all the SNU human hepatoma cells with increased glycolytic lactate production have the defective mitochondrial respiratory activity and the Cln-1-mediated high invasive activity. Similar results were also obtained with human hepatocellular carcinoma tissues. Unexpectedly, the increased lactate production was due to LDH isozyme shifts to LDH5 by LDHB down-expression rather than LDHA induction, implying the importance of LDHB modulation. Second, LDHB knockdown did not only trigger Cln-1 induction at the transcriptional level, but also induced respiratory impairment. Interestingly, most respiratory inhibitors except KCN induced Cln-1 expression although complex I inhibition by rotenone was most effective on Cln-1 induction. Respiratory defect-mediated Cln-1 induction was further confirmed by knockdown of NDUFA9, one of complex I subunits. Finally, ectopic expression of LDHB attenuated the invasiveness of both SNU 354 and 449 cells whereas LDHB knockdown significantly augmented the invasiveness of Chang cells with Cln-1induction. The increased invasive activity by LDHB modulation was clearly reversed by knocking-down Cln-1. Taken together, our results suggest that LDHB suppression plays an important role in triggering or maintaining the mitochondrial defects and then contributes to cancer cell invasiveness by inducing Cln-1 protein.

In Vivo Efficacy of Bacillus velezensis Isolated from Korean Gochang Bokbunja Vinegar against Carbapenem-Resistant Klebsiella pneumoniae Infections.

Outbreaks of carbapenem-resistant Enterobacteriaceae (CRE), especially Klebsiella pneumoniae (CRKP), are commonly reported as severe infections in hospitals and long-term care settings, and their occurrence is increasing globally. Conventional antibiotics used for treating CRE have become ineffective due to resistance development. Furthermore, their safety issues restrict their availability and use for CRE treatment. Therefore, developing new drugs different from existing drugs to combat this deadly menace is urgently needed. Probiotics can be a potential option in this context, as probiotics' efficacy against a variety of infectious illnesses has already been well established. Here, we report the effect of the Bacillus velezensis strain isolated from Gochang Bokbunja vinegar in Korea on CRE infection using two mouse models. Data showed that pretreatment with B. velezensis significantly reduced body weight loss and mortality of CRKP-infected mice in the preventive model. The oral administration of B. velezensis in a therapeutic model also decreased the mortality and illness severity in CRKP-infected mice. Moreover, a two-week oral acute toxicity assay in guinea pigs did not reveal any aberrant clinical signs. Our findings demonstrate the potential effectiveness of our candidate probiotic strain, B. velezensis, against CRKP, suggesting that it could be used as an antimicrobial agent for treating CRKP-related infections.

Characterization of Fecal Microbiomes of Osteoporotic Patients in Korea.

An imbalanced gut microbiome has been linked to a higher risk of many bone-related diseases. The objective of this study was to discover biomarkers of osteoporosis (OP). So, we collected 76 stool samples (60 human controls and 16 OP patients), extracted DNA, and performed 16S ribosomal ribonucleic acid (rRNA) gene-based amplicon sequencing. Among the taxa with an average taxonomic composition greater than 1%, only the Lachnospira genus showed a significant difference between the two groups. The Linear Discriminant Effect Size analysis and qPCR experiments indicated the Lachnospira genus as a potential biomarker of OP. Moreover, a total of 11 metabolic pathways varied between the two groups. Our study concludes that the genus Lachnospira is potentially crucial for diagnosing and treating osteoporosis. The findings of this study might help researchers better understand OP from a microbiome perspective. This research might develop more effective diagnostic and treatment methods for OP in the future.

In vitro anti-tuberculosis effect of probiotic Lacticaseibacillus rhamnosus PMC203 isolated from vaginal microbiota.

Mycobacterium tuberculosis (M. tb), the etiological agent of tuberculosis (TB), poses a severe challenge for public health and remains the number one cause of death as a single infectious agent. There are 10 million active cases of TB per year with 1.5 million deaths, and 2-3 billion people are estimated to harbor latent M. tb infection. Moreover, the emergence of multi-drug-resistant (MDR), extremely-drug-resistant (XDR), and the recent totally drug-resistant (TDR) M. tb is becoming a global issue that has fueled the need to find new drugs different from existing regimens. In these circumstances, probiotics can be a potential choice, so we focused on developing them as an anti-tuberculosis drug candidate. Here, we report the anti-tubercular activities of Lacticaseibacillus rhamnosus PMC203 isolated from the vaginal microbiota of healthy women. PMC203 exhibited a promising intracellular killing effect against both drug-sensitive and resistant M. tb infected murine macrophage cell line RAW 264.7 without showing any cytotoxicity. Additionally, it also inhibited the growth of M. tb under broth culture medium. PMC203 did not cause weight change or specific clinical symptoms in a 2-week repeated oral administration toxicity test in a guinea pig model. Here, we also found that PMC203 induces autophagy in a dose dependent manner by increasing the signal of well-known autophagy gene markers, suggesting a possible intracellular killing mechanism.

Mitoribosomal Deregulation Drives Senescence via TPP1-Mediated Telomere Deprotection.

While mitochondrial bioenergetic deregulation has long been implicated in cellular senescence, its mechanistic involvement remains unclear. By leveraging diverse mitochondria-related gene expression profiles derived from two different cellular senescence models of human diploid fibroblasts, we found that the expression of mitoribosomal proteins (MRPs) was generally decreased during the early-to-middle transition prior to the exhibition of noticeable SA-ß-gal activity. Suppressed expression patterns of the identified senescence-associated MRP signatures (SA-MRPs) were validated in aged human cells and rat and mouse skin tissues and in aging mouse fibroblasts at single-cell resolution. TIN2- and POT1-interaction protein (TPP1) was concurrently suppressed, which induced senescence, accompanied by telomere DNA damage. Lastly, we show that SA-MRP deregulation could be a potential upstream regulator of TPP1 suppression. Our results indicate that mitoribosomal deregulation could represent an early event initiating mitochondrial dysfunction and serve as a primary driver of cellular senescence and an upstream regulator of shelterin-mediated telomere deprotection.

Increased Susceptibility of Mycobacterium tuberculosis to Ethionamide by Expressing PPs-Induced Rv0560c.

Tuberculosis, an infectious disease, is one of the leading causes of death worldwide. Drug-resistant tuberculosis exacerbates its threat. Despite long-term and costly treatment with second-line drugs, treatment failure rates and mortality remain high. Therefore, new strategies for developing new drugs and improving the efficiency of existing drug treatments are urgently needed. Our research team reported that PPs, a new class of potential anti-tuberculosis drug candidates, can inhibit the growth of drug-resistant Mycobacterium tuberculosis. Here, we report a synergistic effect of PPs with ethionamide (ETH), one of the second-line drugs, as a result of further research on PPs. While investigating gene expression changes based on microarray and 2DE (two-dimensional gel electrophoresis), it was found that PPs induced the greatest overexpression of Rv0560c in M. tuberculosis. Based on this result, a protein microarray using Rv0560c protein was performed, and it was confirmed that Rv0560c had the highest interaction with EthR, a repressor for EthA involved in activating ETH. Accordingly, a synergistic experiment was conducted under the hypothesis of increased susceptibility of ETH to M. tuberculosis by PPs. As a result, in the presence of 0.5× MIC PPs, ETH showed a growth inhibitory effect on drug-sensitive and -resistant M. tuberculosis even at a much lower concentration of about 10-fold than the original MIC of ETH. It is also suggested that the effect was due to the interaction between PPs and Rv2887, the repressor of Rv0560c. This effect was also confirmed in a mouse model of pulmonary tuberculosis, confirming the potential of PPs as a booster to enhance the susceptibility of M. tuberculosis to ETH in treating drug-resistant tuberculosis. However, more in-depth mechanistic studies and extensive animal and clinical trials are needed in the future.

Characteristics and Microbiome Profiling of Korean Gochang Bokbunja Vinegar by the Fermentation Process.

As NGS (next-generation sequencing) technology develops, metagenomics-based microbial ecology, that is, microbiome research, has recently led to the science of fermented food. Based on the above technology, a study was conducted to understand the characteristics of vinegar made from bokbunja, a local crop in Gochang-gun, Korea. Physicochemical characteristics of vinegar, organic acid analysis, microbial community analysis, and electronic tongue analysis were explored while fermenting the vinegar for 70 days under eight fermentation conditions according to the concentration of bokbunja liquid (100% or 50%), type of fermenter (porcelain jar or stainless container), and fermentation environment (natural outdoor conditions or temperature/oxygen controlled). As a result, distinct microbial community patterns were found in the stage of acetic acid fermentation and, accordingly, this fermentation of Gochang vinegar is classified into three categories. Vinegar prepared by the traditional method of outdoor fermentation using jars showed characteristics of "Acetobacter (42.1%)/Lactobacillus (56.9%) fusion fermentation". Under conditions where oxygen and temperature were controlled indoors using jars, characteristics of "Komagataeibacter (90.2%) fermentation" were found. "Lactobacillus (92.2%) fermentation" characteristics were discovered under natural outdoor conditions using stainless steel containers. These fermentation pattern differences were related to taxonomic phylogenetic diversity, which was also considered involved in determining organic acid production and taste. These results will be helpful as a scientific basis for understanding the fermentation characteristics of Gochang vinegar and developing high-value-added traditional vinegar products.

Anti-Tuberculosis Activity of Pediococcus acidilactici Isolated from Young Radish Kimchi against Mycobacterium tuberculosis.

Tuberculosis is a highly contagious disease caused by Mycobacterium tuberculosis. It affects about 10 million people each year and is still one of the leading causes of death worldwide. About 2 to 3 billion people (equivalent to 1 in 3 people in the world) are infected with latent tuberculosis. Moreover, as the number of multidrug-resistant, extensively drug-resistant, and totally drug-resistant strains of M. tuberculosis continues to increase, there is an urgent need to develop new anti-tuberculosis drugs that are different from existing drugs to combat antibiotic-resistant M. tuberculosis. Against this background, we aimed to develop new anti-tuberculosis drugs using probiotics. Here, we report the anti-tuberculosis effect of Pediococcus acidilactici PMC202 isolated from young radish kimchi, a traditional Korean fermented food. Under coculture conditions, PMC202 inhibited the growth of M. tuberculosis. In addition, PMC202 inhibited the growth of drug-sensitive and -resistant M. tuberculosis- infected macrophages at a concentration that did not show cytotoxicity and showed a synergistic effect with isoniazid. In a 2-week, repeated oral administration toxicity study using mice, PMC202 did not cause weight change or specific clinical symptoms. Furthermore, the results of 16S rRNA-based metagenomics analysis confirmed that dysbiosis was not induced in bronchoalveolar lavage fluid after oral administration of PMC202. The anti-tuberculosis effect of PMC202 was found to be related to the reduction of nitric oxide. Our findings indicate that PMC202 could be used as an anti-tuberculosis drug candidate with the potential to replace current chemicalbased drugs. However, more extensive toxicity, mechanism of action, and animal efficacy studies with clinical trials are needed.

Activity of Lactobacillus crispatus isolated from vaginal microbiota against Mycobacterium tuberculosis.

Tuberculosis, an infectious disease, is caused by Mycobacterium tuberculosis. It remains a significant public health issue around the globe, causing about 1.8 million deaths every year. Drug-resistant M. tuberculosis, including multi-drug-resistant (MDR), extremely-drug-resistant (XDR), and totally drug-resistant (TDR) M. tuberculosis, continues to be a threat to public health. In the case of antibiotic-resistant tuberculosis, the treatment effect of conventional antibiotics is low. Side effects caused by high doses over a long period are causing severe problems. To overcome these problems, there is an urgent need to develop a new anti-tuberculosis drug that is different from the existing compound-based antibiotics. Probiotics are defined as live microorganisms conferring health benefits. They can be potential therapeutic agents in this context as the effectiveness of probiotics against different infectious diseases has been well established. Here, we report that Lactobacillus crispatus PMC201 shows a promising effect on tuberculosis isolated from vaginal fluids of healthy Korean women. Lactobacillus crispatus PMC201 reduced M. tuberculosis H37Rv under co-culture conditions in broth and reduced M. tuberculosis H37Rv and XDR M. tuberculosis in macrophages. Lactobacillus crispatus PMC201 was not toxic to a guinea pig model and did not induce dysbiosis in a human intestinal microbial ecosystem simulator. Taken together, these results indicate that L. crispatus PMC201 can be a promising alternative drug candidate in the current tuberculosis drug regime. Further study is warranted to assess the in vivo efficacy and confirm the mode of action of L. crispatus PMC201.