Transforming growth factor-ß and matrix metalloproteinases as potential biomarkers of fibrotic lesions induced by tuberculosis: a systematic review and meta-analysis.

OBJECTIVES: Very few studies and limited information are available regarding the mechanism of fibrosis in tuberculosis (TB). This study aimed to identify, describe and synthesise potential biomarkers of the development of tissue fibrosis induced by TB through a systematic method and meta-analysis. METHODS: A literature search was performed using keywords according to the topic from electronic databases (ScienceDirect and PubMed) and other methods (websites, organisations and citations). Studies that matched predetermined eligibility criteria were included. The quality assessment tool used was the Quality Assessment of Diagnostic Accuracy Score 2, and the data obtained were processed using Review Manager V.5.3. RESULTS: Of the 305 studies, 7 met the eligibility criteria with a total sample of 365. The results of the meta-analysis showed that the post-TB group of patients with pulmonary parenchymal fibrosis had a higher transforming growth factor (TGF)-ß level (6.09) than the control group (1.82), with a 4.27 (95% CI: 0.92 to 7.61) mean difference. Moreover, patients with residual pleural thickening post-TB had a higher mean of TGF-ß (0.61) than the control group (0.56), with a 0.05 (95% CI: 0.04 to 0.06) mean difference. Besides TGF-ß, our qualitative synthesis also found that matrix metalloproteinase-1 might have a role in forming and developing pulmonary tissue fibrosis, thus, could be used as a predictor marker in the formation of fibrotic lesions in patients with TB. In addition, several other biomarkers were assessed in the included studies, such as tumour necrosis factor-α, interleukin (IL)-4, IL-8, IL-10, plasminogen activator inhibitor-1 and platelet-derived growth factor. However, this study is not intended to examine these biomarkers. CONCLUSIONS: There were differences in the results of TGF-ß levels in patients with fibrotic lesions compared with controls. TGF-ß might be a biomarker of fibrotic tissue formation or increased pulmonary tissue fibrosis in post-TB patients. However, further studies are needed on a larger scale.

Bioconversion of biowaste by black soldier fly larvae ( Hermetia illucens L.) for dried larvae production: A life cycle assessment and environmental impact analysis.

Background: Hermetia illucens L. have gained popularity in recent years as an environmentally friendly response to both the present and potential future food/feed crisis. The larvae of H. illucens L., or black soldier fly larvae (BSFL), is an alternative solution to tackle the issue of organic waste bioconversion. However, understanding the environmental loads associated with biowaste bioconversion using BSFL to produce dried BSFL is a pivotal point to keep the environment sustainable. This study reported a life cycle assessment (LCA) of the biowaste bioconversion process of BSFL and determined the environment impact analysis to make recommendations for modifications to lessen environmental consequences. Methods: The methodology used is life cycle assessment (LCA), which includes: (a) system boundary determination (gate-to-gate), starting from biowaste production, biowaste bioconversion, prepupae and BSFL frass production. The system boundary of the dried BSFL production is designed for both the processing and production of one cycle of BSFL; (b) life cycle inventory activities carried out at PT Biomagg Sinergi Internasional, Depok, West Java, Indonesia; (c) conducting life cycle impact assessment on five environmental impact categories namely global warming potential (GWP), acidification (AC), terrestrial eutrophication (TE), fossil fuel depletion (FFE), eco-toxicity (ET); and (d) interpretation of the assessment result. The LCA is conducted using openLCA 1.11 software and TRACI 2.1 impact assessment method. Results: The impact values of GWP, AC, TE, FFE, and ET, per 100 kg of BSFL dried production was 6.687 kg CO 2 eq; 0.029 kg SO 2-eq; 0.092 kg N-eq; 16.732 MJ surplus; 121.231 CTUe. Production of prepupa had the highest hotspots in these emissions, followed dried BSFL production. Conclusions: Efforts to reduce environmental impacts that can be done are by implementing an integrated rearing system using substrate from a single type of known substrate for BSFL and using alternative drying methods for BSFL dried production.

Decreasing mRNA HMGB1 expression in Klebsiella pneumoniae infection treated by Miana (Coleus scutellarioides (L.) Benth): a cohort experimental study.

Pneumonia is one of the most common infections caused by the bacterium Klebsiella pneumoniae. During the initiation of an infection, the immune system recognizes the pathogen through the release of high mobility group box 1 (HMGB1), thereby triggering the inflammation process. Miana has demonstrated potent inhibitory effects on the inflammatory process during infection in animal models. The aim of this study was to determine the effect of Miana leaf extract on mRNA HMGB1 expression in Balb/c mice infected with K. pneumoniae. Methods: This study comprised a cohort experiment using 20 Balb/c mice divided into four groups. Balb/c mice in each group were intraperitoneally injected with K. pneumoniae. Group 1 was given a placebo; Group 2 was given Miana; Group 3 was given levofloxacin; and Group 4 was given both levofloxacin and Miana. The levels of mRNA HMGB1 expression were measured using real-time PCR before, during, and after the infection as well as after the treatments. Results: The initial examination results showed that the average level of mRNA HMGB1 expression was 5.51 fc. The mRNA HMGB1 expression in mice after being challenged with K. pneumoniae was 9.64 fc. Group 1 that was given a placebo had a mean mRNA HMGB1 expression level of 14.99 fc. Group 2 that was given Miana had a mean mRNA HMGB1 expression level of 13.95 fc. Group 3 that was given levofloxacin had an average mRNA HMGB1 expression level of 6.45 fc, and Group 4 that was given levofloxacin and Miana together had an average mRNA HMGB1 expression level of 5.59 fc. Conclusion: Miana (Coleus scutellarioides (L.) Benth) increased mRNA HMGB1 expression at the initial administration via regulation of the immune system. Administration of Miana following K. pneumoniae infection inhibited the increase in mRNA HMGB1 expression. Treatment with levofloxacin reduced the level of mRNA HMGB1 expression, and the effect was optimized by the administration of Miana leaf extract as a supplement.

Correlation expression Toll-like receptor 4 with multidrugs resistant tuberculosis in diabetes mellitus condition.

BACKGROUND: Toll-like receptor (TLR) are ligand homologous protein in the APC cell membrane that has functions as a receptor to triger leukocytes and innate immune responses. When there is a Microbacterium tuberculosis (MTB) infection enters from droplets to the lungs, the alveolar macrophages perform a phagocytic function. The interaction between M. tuberculosis and the TLR macrophage receptors produces chemokines which induce migration of monocytes and dendrite cells for destruction. Diabetes militus (DM) has become risk factor for developing tuberculosis. DM condition will reduce immunity and the ability of immune cell phagocytes bactery and triger severe infections. The consequences of more severe infection and metabolic disorders that occur make a person more likely to experience Multidrugs resistant MTB. Not much data that reports on the expression of TLR4 as a ligand that triggers an immune response in conditions of MDR and DM. We try to find out correlation between TLR-4 in MDR MTB, diabetes and level of MTB bacteria in experimental animals. METHODS: We conducted an experimental study on 30 experimental mice weighing 25 grams consisting of negative control grub, infected with MTB, infected with MDR MTB, negative control diabetes, MTB DM, MDR MTB DM. DM animals were induced by streptozosin to experience DM, then in the treatment of infection, intraperitoneal MTB and MDR MTB bacterial injections were given. Termination was carried out on day 14. We count number of bacteria level in the lungs and perform evaluation TLR4 from blood sampel. RESULTS: The negative control group had mean TLR value of 1.47 (± 0.46) while the MTB group showed an increase in TLR 9.22 (± 0.39) followed by MDR MTB 9.50 (± 0.29), DM negative control 9, 21 (± 0.24) and more increasing in conditions of DM MTB 13.36 (± 0.32) and DM MDR MTB 13.35 (± 0.34). ANOVA analysis showed a significant difference (P = 0.00). pearson correlation analysis find strong correlation TLR4 in MTB and MDR MTB with diabetes. CONCLUSION: there were a significant difference level TLR4 between MTB and MDR TB infection with diabetes. higher TLR4 level higher in DM MTB, DM MDR MTB. TLR 4 strong correlates with an increase in the number of MTB bacteria.

Expression of miRNA-29a-3p and IFN-γ as biomarkers in active and latent pulmonary tuberculosis.

Background: Diagnosis and management of latent tuberculosis (TB) infections are one of the challenges of eradicating pulmonary TB. A critical aspect of controlling pulmonary TB spread is early diagnosis. One TB biological marker type under evaluation is microRNAs (miRNAs). Mycobacterium tuberculosis infection causes epigenetic changes. The upregulation of miRNA-29a-3p suppresses the immune response by post-transcriptionally inhibiting interferon (INF)-γ expression in T cells, increasing susceptibility to pulmonary TB. This study aimed to assess miRNA-29a-3p expression as a biomarker of active and latent pulmonary TB infection. Methods: This case-control study included 50 individuals with active TB, 33 household contacts with a positive IFN-γ release assay (IGRA), and 30 healthy controls. An enzyme-linked immunosorbent assay-based IGRA was used to determine latent pulmonary TB infection in household contacts. Quantitative real-time PCR was used to quantify miRNA-29a-3p expression. Data analysis used analyses of variance and receiver operating characteristic (ROC) curves. Results: miRNA-29a-3p expression differed significantly between active TB, latent TB, and healthy participants (controls; p = <0.001. ROC curve analysis showed that miRNA-29a-3p expression had 86% sensitivity and 73% specificity with an area under the ROC curve (AUC) of 0.763 (95% confidence interval [CI]: 0.668-0.858). The miRNA-29a-3p ROC curve had 84.8% sensitivity and 70% specificity with an AUC of 0.808 (95% CI: 0.698-0.919) for latent TB. Additionally, miRNA-29a-3p expression was significantly correlated with active (p < 0.0001) and latent (p < 0.0001) pulmonary TB. However, miRNA-29a-3p expression was not significantly correlated with INF-γ levels in patients with active (R = 0.005; p = 0.62) and latent (R = 0.010; p = 0.38) pulmonary TB or healthy controls (R = 0.060; p = 0.19). Conclusion: miRNA-29a-3p expression was increased in patients with active and latent pulmonary TB. Therefore, miRNA-29a-3p represents a potential biomarker for latent and active pulmonary TB. However, IFN-γ levels were not correlated with miR-29a-3p expression.

In vivo and in vitro inhibition effect of propolis on Klebsiella pneumoniae: A review.

For centuries, propolis has been used to treat various diseases in traditional medicine due to its biological and pharmacological activities. It remains popular because of its potentially beneficial role in human health due to its well-known broad multispectrum properties, including antiviral, anti-inflammatory, antibacterial, anesthetic, antioxidant, anticancer, antifungal, antiprotozoal, antihepatotoxic, antimutagenic, and antiseptic activity. Numerous studies have examined the antibacterial activity of propolis and its derivatives, which include many natural antimicrobial compounds with broad spectrum activity against different bacterial types. In vitro studies have shown propolis's antibacterial activity against Gram-positive and Gram-negative bacteria. Many studies have examined propolis's effect on inhibiting bacterial growth. Several studies examining propolis's inhibition of Gram-positive and Gram-negative bacteria have shown it to be an effective antimicrobial agent. Klebsiella pneumoniae is a Gram-negative bacterium commonly associated with respiratory infections, particularly in hospital settings. Inappropriate antibiotic use may contribute to the increasing number of bacterial strains resistant to available drugs. This review summarizes the findings of previous studies on propolis and its potential mechanisms in inhibiting K. pneumoniae growth in animals.

Correlation between innate and adaptive immunity response in TB children post BCG vaccination. Is it effective or not?: Cross-sectional study.

Background: How far the role of innate immunity and adaptive immunity do in children who have been BCG vaccinated in controlling the course and the severity of the TB disease has not been completely known. Mycobacterium tuberculosis entry to the body will be recognized by Toll-like receptors found on macrophages, neutrophils, and dendritic cells as part of the innate immune response, after which the dendritic cells will then present the antigen to lymphocyte T0 cells and initiate the adaptive immune response (of which CD4 T cells have an important role in). Was one or were both of these immune responses function well or not in a BCG Vaccinated Children with TB? Objective: This study aim to find a better understanding of the role of innate immune response assessed by TLR2/TLR4 mRNA gene expression and serum TLR2/TLR4 levels, while the role of adaptive immune response is assessed by analyzing serum CD4 level in children with TB who have had BCG vaccination. Methods: This cross-sectional study was conducted among children with TB at the outpatient and inpatient wards at Bhakti Medicare and Jakarta Islamic Hospital. Expression of mRNA gene was measured using the Boom method and protein serum levels were measured using the ELISA method. The results were analyzed by using the SPSS v.23 program. Results: Sixty-nine children were recruited as subjects. In this study, 68.1% of whom had BCG scars. TLR4 mRNA gene expression was found to be higher than TLR2 mRNA gene expression. Serum CD4 level was found to be highest out of TLR2 and TLR4 level, but serum TLR2 level was higher than TLR4 level. TLR2/TLR4 mRNA gene expression, serum TLR2/TLR4 levels, and CD4 levels in subjects with BCG scar were also found to be significantly higher than in subjects without BCG scar (p < 0.001). There was a significant positive correlation between TLR2/TLR4 mRNA gene expression and serum TLR2/TLR4 levels (r = 0.860; r = 0.864; p < 0.001) and between serum levels TLR2/TLR4 with serum CD4 levels (r = 0.822; r = 0.832 p < 0.001). Conclusion: As early as possible, BCG vaccine administration is needed in endemic countries, but it must be ensured that scars can be formed. It is also important to control Latent TB Infection (LTBI) to prevent transmission and relapse of disease.

The strong correlation between ADAM33 expression and airway inflammation in chronic obstructive pulmonary disease and candidate for biomarker and treatment of COPD.

Airway inflammation in patients with chronic obstructive pulmonary disease (COPD) is an amplified response of the normal immune system that occurs as a result of chronic irritation by toxic substances, such as cigarette smoke. This leads to the characteristic pathological changes in the inflammatory cells of COPD patients. ADAM33 has been reported to be involved in the pathogenesis of COPD in East Asia by affecting airway inflammation and other immune responses. The aim of this study was to determine the potential role of ADAM33 (mRNA and soluble levels) as a biomarker of inflammation in COPD patients. This is a case control study using consecutive sampling. The COPD case and control (non-COPD) groups comprised 37 and 29 patients, respectively. We used univariate analysis to assess differences in the parameters between the groups and bivariate analysis to non-parametrically compare these parameters between the two groups. We observed significantly higher mRNA levels of ADAM33 in the COPD patients (10.39 ± 1.76) as compared to that in the non-COPD individuals (6.93 ± 0.39; P < 0.001). The levels of soluble ADAM33 were also significantly higher in the COPD patients (2.188 ± 1.142 ng/ml) compared to the non-COPD individuals (0.487 ± 0.105 ng/ml; P < 0.001). The mRNA and soluble ADAM33 levels were significantly higher in COPD patients compared to those in the parameter-matched non-COPD individuals. Thus, ADAM33 is a potential biomarker and treatment for inflammation in COPD patients.

Comparison TLR2 and TLR4 serum levels in children with pulmonary and extrapulmonary tuberculosis with and without a Bacillus Calmette-Guérin (BCG) scar.

The formation of a scar after Mycobacterium bovis Bacillus Calmette-Guérin (BCG) vaccination influences the effectiveness of protection against Mycobacterium tuberculosis (MTB) infection. The innate immunity plays a critical role both in the pathophysiology of tuberculosis (TB) and BCG vaccination protection mechanism. Parts of innate immunity: macrophages, dendritic cells, and neutrophils, have microbial recognition surface receptors called Toll-like receptors (TLR) 2 and 4. The objective of this study is to compare the serum levels of TLR2 and TLR4 in BCG-vaccinated pediatric patients with pulmonary and extrapulmonary TB. This cross-sectional study included children aged less than 18 years old with contracted TB disease and had received BCG vaccination. The subjects were recruited by convenience sampling from both outpatient and inpatient care at Bhakti Medicare and Jakarta Islamic Hospital, from November 2018 to December 2019. Serum TLR2 and TLR4 levels measured using ELISA of the two groups of subjects: children with pulmonary TB (PTB) and extrapulmonary TB (EPTB), were then compared. The presence of BCG scars was included in the analysis. Independent T-test, ANOVA test, and Kolmogorov-Smirnov normality tests on the SPSS program were used to statistically analyze the results. Serum TLR2 and TLR4 levels were higher in EPTB group, but the difference was not significant (TLR2 p = 0.758 and TLR4 p = 0.646, respectively). Subjects with BCG scars in both groups have significantly higher serum TLR2 and TLR4 levels than those without BCG scars in the EPTB group (EPTB p = 0.001 and p = 0.004, respectively); (PTB p < 0.001 and p < 0.001, respectively). BCG vaccination and MTB infection stimulate better innate immune response in EPTB than in PTB and serum TLR2 and TLR4 levels in those with BCG scars were higher when compared to those without BCG scars.

Analysis of CD4 and CD8 expression in multidrug-resistant tuberculosis infection with diabetes mellitus: An experimental study in mice.

BACKGROUND: Tuberculosis (TB) remains a major global health problem, in the top 10 causes of death. As a regulator of the immune response, T-helper (Th) cells activate other lymphocytes from the immune system, such as B cells, to destroy the TB pathogen by releasing CD4 and CD8 Th cells. Diabetes mellitus (DM) is a known cause of developing active pulmonary TB. Few studies have examined the biomolecular expression affecting Mycobacterium tuberculosis (MTB) and multidrug-resistant (MDR) MTB, which are associated with low immunity represented by TB in diabetes and CD4 and CD8 levels. MATERIALS AND METHODS: This animal study used a post-test control group design. We performed an experimental study using 30 BALB/c mice, each weighing 25 g. It included six experimental animal groups, of which three had a diabetes condition induced using intraperitoneal streptozotocin, and all were infected with MTB or MDR TB. We evaluated the CD4 and CD8 levels in each group and analyzed the differences. RESULTS: We found a significant difference in CD4 and CD8 levels in MTB and MDR TB conditions. CONCLUSION: This study shows that acute infection in experimental mice with MTB and MDR TB with or without diabetes had the highest levels of both CD4 and CD8 cells, which can be a sign of increased cellular immunity in a mice model.

Increasing Natural Resistance Associated Macrophage Protein 1 serum level after Miana treatment in BALB/c induced Klebsiella pneumoniae experimental research.

BACKGROUND: Miana (Coleus Scutellariodes [L] Benth) inhibits growth of bacterial pathogen inside macrophage. OBJECTIVE: The aim of this study is to determine the protein level of Natural Resistance Associated Macrophage Protein 1 (NRAMP1), after administration of Miana extracts in BALB/c mice induced Klebsiella pneumoniae. METHODS: This is an experimental study using animal model with post test-only controlled group design. Twenty healthy adult male BALB/c mice were randomly divided into four groups, negative control group (distilled water), Levofloxacin 100 mg/kg, injection intraperitoneal, first treatment group (Miana leaves extract/MLE 510 mg/kg) and second treatment group (Miana + levofloxacin). MLE were administered via gastric gavage for ten consecutive days. The blood was drawn from each mice on the first day, on the eight day of experiment (2 h after treatment), and at 10 days. The blood sample was examined by ELISA to determine the NRAMP1 protein level. Analysis of the number of lung tissue bacteria used Plate count agar to see the growth of Klebsiella pneumonia. RESULTS: NRAMP1 protein level in BALB/c mice after administration of Miana extract was increased significantly in after 10 days treatment (p < 0.0001). The highest increasing in protein levels was found in treatment group (Miana + levofloxacin) with an increase before treatment 3036,07 to 10010,30 pg/ml after treatment p < 0,0001. CONCLUSION: NRAMP1 protein level in BALB/c mice were highest increasing in protein levels after administration of Miana extract and Levofloxacin compared Miana or Levofloxacin only and clinical impact proved a comparable effect on suppressing Klebsiella pneumoniae growth.The institutional protocol number of this study is 1010/UN4.6.4.5.31/PP36/2019.

Depression among Patients with Pulmonary Tuberculosis at the State Hospital of Makassar.

BACKGROUND: Comorbidity of tuberculosis (TB) and depression is common. It is associated with the decrease in function, increasing rate of medical cost, nonadherence to long-term medication and self-care, and upward trend of mortality. This study aims to determine the prevalence and distribution of depression in pulmonary TB patients by age, sex, and marital status. METHODS: This study is a descriptive research conducted at the Pulmonary Clinic of the State Hospital of Makassar (RSUD Kota Makassar). Ninety-two of 820 patients were selected using the Slovin sample size formula. The patients of the study were collected from the population of patients with TB using consecutive sampling through an interview. The depression rate was examined using the Beck Depression Inventory-II (BDI-II) questionnaire. Interpretation of the BDI-II was determined by a score of ≤16 indicating no depression and >16 for depression. RESULTS: The study indicates that the percentage of patients with depression constituted 31.5%. The number of female patients with depression was higher than that in males with 38.2% and 27.6%, respectively. The biggest proportion of patients with depression was in senior patients (>45 years old) with 37.5%. The fraction of unmarried/divorced respondents was bigger than coupled respondents, with a percentage of 43.5 and 27.5, respectively. CONCLUSION: The prevalence of depression in pulmonary TB patients who visited the Pulmonary Clinic of the State Hospital of Makassar reached over one-third of the total patients. Depression was more prevalent among female patients, patients within the age of >45 years, and unmarried/divorced patients, respectively.

OX40 ligand newly expressed on bronchiolar progenitors mediates influenza infection and further exacerbates pneumonia.

Influenza virus epidemics potentially cause pneumonia, which is responsible for much of the mortality due to the excessive immune responses. The role of costimulatory OX40-OX40 ligand (OX40L) interactions has been explored in the non-infectious pathology of influenza pneumonia. Here, we describe a critical contribution of OX40L to infectious pathology, with OX40L deficiency, but not OX40 deficiency, resulting in decreased susceptibility to influenza viral infection. Upon infection, bronchiolar progenitors increase in number for repairing the influenza-damaged epithelia. The OX40L expression is induced on the progenitors for the antiviral immunity during the infectious process. However, these defense-like host responses lead to more extensive infection owing to the induced OX40L with α-2,6 sialic acid modification, which augments the interaction with the viral hemagglutinin. In fact, the specific antibody against the sialylated site of OX40L exhibited therapeutic potency in mitigating the OX40L-mediated susceptibility to influenza. Our data illustrate that the influenza-induced expression of OX40L on bronchiolar progenitors has pathogenic value to develop a novel therapeutic approach against influenza.

Syndecan 4 Mediates Nrf2-dependent Expansion of Bronchiolar Progenitors That Protect Against Lung Inflammation.

The use of lung progenitors for regenerative medicine appears promising, but their biology is not fully understood. Here, we found anti-inflammatory attributes in bronchiolar progenitors that were sorted as a multipotent subset of mouse club cells and found to express secretory leukocyte protease inhibitor (SLPI). Notably, the impaired expression of SLPI in mice increased the number of bronchiolar progenitors and decreased the lung inflammation. We determined a transcriptional profile for the bronchiolar progenitors of Slpi-deficient mice and identified syndecan 4, whose expression was markedly elevated as compared to that of wild-type mice. Systemic administration of recombinant syndecan 4 protein caused a substantial increase in the number of bronchiolar progenitors with concomitant attenuation of both airway and alveolar inflammation. The syndecan 4 administration also resulted in activation of the Keap1-Nrf2 antioxidant pathway in lung cells, which is critically involved in the therapeutic responses to the syndecan 4 treatment. Moreover, in 3D culture, the presence of syndecan 4 induced differentiated club cells to undergo Nrf2-dependent transition into bronchiolar progenitors. Our observations reveal that differentiative switches between bronchiolar progenitors and club cells are under the Nrf2-mediated control of SLPI and syndecan 4, suggesting the possibility of new therapeutic approaches in inflammatory lung diseases.

Human marrow stromal cells downsize the stem cell fraction of lung cancers by fibroblast growth factor 10.

The functional interplay between cancer cells and marrow stromal cells (MSCs) has attracted a great deal of interest due to the MSC tropism for tumors but remains to be fully elucidated. In this study, we investigated human MSC-secreted paracrine factors that appear to have critical functions in cancer stem cell subpopulations. We show that MSC-conditioned medium reduced the cancer stem cell-enriched subpopulation, which was detected as a side population and quiescent (G0) cell cycle fraction in human lung cancer cells by virtue of fibroblast growth factor 10 (FGF10). This reduction of the stem cell-enriched fraction was also observed in lung cancer cells supplemented with recombinant human FGF10 protein. Moreover, supplementary FGF10 attenuated the expression of stemness genes encoding transcription factors, such as OCT3/4 and SOX2, and crippled the self-renewal capacity of lung cancer cells, as evidenced by the impaired formation of floating spheres in the suspension culture. We finally confirmed the therapeutic potential of the FGF10 treatment, which rendered lung cancer cells prone to a chemotherapeutic agent, probably due to the reduced cancer stem cell subpopulation. Collectively, these results add further clarification to the molecular mechanisms underlying MSC-mediated cancer cell kinetics, facilitating the development of future therapies.

Targeting lysophosphatidic acid signaling retards culture-associated senescence of human marrow stromal cells.

Marrow stromal cells (MSCs) isolated from mesenchymal tissues can propagate in vitro to some extent and differentiate into various tissue lineages to be used for cell-based therapies. Cellular senescence, which occurs readily in continual MSC culture, leads to loss of these characteristic properties, representing one of the major limitations to achieving the potential of MSCs. In this study, we investigated the effect of lysophosphatidic acid (LPA), a ubiquitous metabolite in membrane phospholipid synthesis, on the senescence program of human MSCs. We show that MSCs preferentially express the LPA receptor subtype 1, and an abrogation of the receptor engagement with the antagonistic compound Ki16425 attenuates senescence induction in continually propagated human MSCs. This anti-aging effect of Ki16425 results in extended rounds of cellular proliferation, increased clonogenic potential, and retained plasticity for osteogenic and adipogenic differentiation. Expressions of p16(Ink4a), Rb, p53, and p21(Cip1), which have been associated with cellular senescence, were all reduced in human MSCs by the pharmacological inhibition of LPA signaling. Disruption of this signaling pathway was accompanied by morphological changes such as cell thinning and elongation as well as actin filament deformation through decreased phosphorylation of focal adhesion kinase. Prevention of LPA receptor engagement also promoted ubiquitination-mediated c-Myc elimination in MSCs, and consequently the entry into a quiescent state, G(0) phase, of the cell cycle. Collectively, these results highlight the potential of pharmacological intervention against LPA signaling for blunting senescence-associated loss of function characteristic of human MSCs.