Idiopathic pulmonary fibrosis (IPF) is a chronic and fatal lung disease, and fibroblasts derived from patients with IPF are resistant to type I collagen matrix-induced cell death. The alteration of ...the PTEN-Akt axis permits IPF fibroblasts to maintain a pathological phenotype on collagen by suppressing autophagy. However, the precise underlying mechanism by which the Akt downstream molecule suppresses autophagic activity remains elusive. FoxO3a is a direct target of Akt and is implicated with the transcriptional activation of autophagy. Therefore, we investigated whether reduced FoxO3a expression causes abnormally low autophagy in IPF fibroblasts on collagen. We found that FoxO3a mRNA and protein levels are low in IPF fibroblasts, which subsequently suppresses the autophagosomal marker LC3B expression on collagen matrix. In contrast, the majority of control fibroblasts showed an increase in FoxO3a and LC3B expression at both the mRNA and protein levels. The luciferase assay confirmed that FoxO3a binds to the promoter region of LC3B and transcriptionally activates LC3B. The overexpression of wild-type FoxO3a increased LC3B mRNA and protein expression in IPF fibroblasts, whereas the dominant negative FoxO3a decreased the LC3B level in control fibroblasts. The inhibition of autophagic activity sensitized control fibroblasts to collagen matrix-induced cell death. In contrast, enhanced viability was found when autophagic function was inhibited in IPF fibroblasts. Our study showed that aberrantly low FoxO3a expression participates in reducing autophagic activity via transcriptional suppression of LC3B in IPF fibroblasts on collagen. This suggests that low autophagic activity by the alteration of FoxO3a may contribute to IPF progression.
AbstractDuring the last decade, many ophthalmic therapeutic drugs have been clinically approved, and intraocular injection has been a common surgical intervention. Injecting drugs directly into the ...subretinal space is crucial to treat retinal complications effectively. Here, we report a handheld microinjector with two fiber-optic distance sensors and time-delay control (TDC) to mitigate nonlinear disturbances during the injection task. The conventional method exhibited a cosine error of approximately 77 μm at an angle of 45°, whereas our proposed needle reduced measurement errors to ∼6 μm. Also, TDC-based position regulation is designed to adaptively apply motor inputs by estimating disturbances during the handheld task and achieving fast system responses with minor control errors. Phantom studies show a maximum reduction of 26.5% in root-mean-square error (RMSE) compared to the existing approach. Moreover, ex-vivo experiments demonstrated superior and robust injection performance, resulting in an injection RMSE of 10.3 μm.
Virtual reality (VR) technology plays a significant role in many biomedical applications. These VR scenarios increase the valuable experience of tasks requiring great accuracy with human subjects. ...Unfortunately, commercial VR controllers have large positioning errors in a micro-manipulation task. Here, we propose a VR-based framework along with a sensor fusion algorithm to improve the microposition tracking performance of a microsurgical tool. To the best of our knowledge, this is the first application of Kalman filter in a millimeter scale VR environment, by using the position data between the VR controller and an inertial measuring device. This study builds and tests two cases: (1) without sensor fusion tracking and (2) location tracking with active sensor fusion. The static and dynamic experiments demonstrate that the Kalman filter can provide greater precision during micro-manipulation in small scale VR scenarios.
Chronic lung diseases include a variety of obstinate and fatal diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), idiopathic pulmonary fibrosis (IPF), and ...lung cancers. Pharmacotherapy is important for the treatment of chronic lung diseases, and current progress in nanoparticles offers great potential as an advanced strategy for drug delivery. Based on their biophysical properties, nanoparticles have shown improved pharmacokinetics of therapeutics and controlled drug delivery, gaining great attention. Herein, we will review the nanoparticle-based drug delivery system for the treatment of chronic lung diseases. Various types of nanoparticles will be introduced, and recent innovative efforts to utilize the nanoparticles as novel drug carriers for the effective treatment of chronic lung diseases will also be discussed.
Radiation therapy is critical for the control of many tumors and lung is an important dose-limiting organ that impacts radiation dose prescribed to avoid irreversible pulmonary fibrosis in cancer ...survivors. Idiopathic pulmonary fibrosis (IPF) is a chronic, irreversible lung disease caused by aberrantly activated lung (myo)fibroblasts. The presence of pro-fibrotic, apoptosis-resistant fibroblasts in IPF promotes progressive fibrosis and may have a role in other diseases, if these resistant cells are selected for as a consequence of treatment. However, the pathological response of IPF fibroblasts to radiation compared to non-IPF lung fibroblasts is not known. To address this, we examined fibroblast viability following radiation in lung fibroblasts from IPF and non-IPF patients and the underlying mechanism that protects IPF fibroblasts from radiation-induced death. IPF fibroblasts are significantly more resistant to apoptosis compared to non-IPF lung fibroblasts, suggesting that resistance to radiation-induced cell death is a predominant mechanism leading to lung fibrosis. Analysis of γH2AX induction demonstrated that radiation-induced DNA damage is reduced in IPF fibroblasts and correlates to the activation of the transcription factor forkhead box M1 (FoxM1) and subsequent upregulation of DNA repair proteins RAD51 and BRCA2. FoxM1 activation occurs secondary to FoxO3a suppression in IPF fibroblasts while restoration of FoxO3a function sensitizes IPF fibroblasts to radiation-induced cell death and downregulates FoxM1, RAD51, and BRCA2. Our findings support that increased FoxO3a/FoxM1-dependent DNA repair may be integral to the preservation of death-resistant fibrotic fibroblasts after radiation and that selective targeting of radioresistant fibroblasts may mitigate fibrosis.
is a Gram-positive, facultative anaerobic bacterium frequently found in the gastrointestinal tract, oral cavity, and periodontal tissue. Although it is considered a commensal, it can cause ...bacteremia, endocarditis, endodontic infections, and urinary tract infections. Because antibiotics are cytotoxic not only to pathogens, but also to health-beneficial commensals, phage therapy has emerged as an alternative strategy to specifically control pathogenic bacteria with minimal damage to the normal flora. In this study, we isolated a novel phage,
phage vB_EfaS_HEf13 (phage HEf13), with broad lytic activity against 12 strains of
among the three laboratory strains and 14 clinical isolates of
evaluated. Transmission electron microscopy showed that phage HEf13 has morphological characteristics of the family
. Phage HEf13 was stable at a wide range of temperature (4-60°C) and showed tolerance to acid or alkaline (pH 3-12) growth conditions. Phage HEf13 had a short latent period (25 min) with a large burst size (approximately 352 virions per infected cell). The lytic activity of phage HEf13 at various multiplicities of infection consistently inhibited the growth of diverse clinical isolates of
without any lysogenic process. Moreover, phage HEf13 showed an effective lytic activity against
on human dentin
infection model. Whole genome analysis demonstrated that the phage HEf13 genome contains 57,811 bp of double-stranded DNA with a GC content of 40.1% and 95 predicted open reading frames (ORFs). Annotated functional ORFs were mainly classified into four groups: DNA replication/packaging/regulation, phage structure, host cell lysis, and additional functions such as RNA transcription. Comparative genomic analysis demonstrated that phage HEf13 is a novel phage that belongs to the
lineage. Furthermore, the results of multiple sequence alignment showed that polymorphism of phage infection protein of
(PIP
) contributes to determine the host specificity of phage HEf13 against various
strains. Collectively, these results suggest that phage HEf13 has characteristics of a lytic phage, and is a potential therapeutic agent for treatment or prevention of
-associated infectious diseases.
Although members of the hyaluronan (HA)‐CD44/HA‐mediated motility receptor (RHAMM) signaling pathway have been shown to be overexpressed in lung cancer, their role in lung tumorigenesis is unclear. ...In the present study, we first determined levels of HA and its receptors CD44 and RHAMM in human non‐small cell lung cancer (NSCLC) cells and stromal cells as well as mouse lung tumors. Subsequently, we examined the role of HA‐CD44/RHAMM signaling pathway in mediating the proliferation and survival of NSCLC cells and the cross‐talk between NSCLC cells and normal human lung fibroblasts (NHLFs)/lung cancer‐associated fibroblasts (LCAFs). The highest levels of HA and CD44 were observed in NHLFs/LCAFs followed by NSCLC cells, whereas THP‐1 monocytes/macrophages showed negligible levels of both HA and CD44. Simultaneous silencing of HA synthase 2 (HAS2) and HAS3 or CD44 and RHAMM suppressed cell proliferation and survival as well as the EGFR/AKT/ERK signaling pathway. Exogenous HA partially rescued the defect in cell proliferation and survival. Moreover, conditioned media (CM) generated by NHLFs/LCAFs enhanced the proliferation of NSCLC cells in a HA‐dependent manner as treatment of NHLFs and LCAFs with HAS2 siRNA, 4‐methylumbelliferone, an inhibitor of HASs, LY2228820, an inhibitor of p38MAPK, or treatment of A549 cells with CD44 blocking antibody suppressed the effects of the CM. Upon incubation in CM generated by A549 cells or THP‐1 macrophages, NHLFs/LCAFs secreted higher concentrations of HA. Overall, our findings indicate that targeting the HA‐CD44/RHAMM signaling pathway could be a promising approach for the prevention and therapy of lung cancer.
Idiopathic pulmonary fibrosis (IPF) is a lethal and progressive lung disease characterized by persistent (myo)fibroblasts and the relentless accumulation of collagen matrix. Unlike normal lung ...fibroblasts, IPF lung fibroblasts have suppressed forkhead box O3a (FoxO3a) activity, which allows them to expand in this diseased environment. microRNA-96 (miR-96) has recently been found to directly bind to the 3'-untranslated region of FoxO3a mRNA, which subsequently inhibits its function. We examined whether aberrantly low FoxO3a expression is in part due to increased miR-96 levels in IPF fibroblasts on polymerized collagen, thereby causing IPF fibroblasts to maintain their pathological properties. miR-96 expression was upregulated in IPF fibroblasts compared with control fibroblasts when cultured on collagen. In contrast, FoxO3a mRNA levels were reduced in most IPF fibroblasts. However, when miR-96 function was inhibited, FoxO3a mRNA and protein expression were increased, suppressing IPF fibroblast proliferation and promoting their cell death in a dose-dependent fashion. Likewise, FoxO3a and its target proteins p21, p27, and Bim expression was also increased in the presence of a miR-96 inhibitor in IPF fibroblasts. However, when control fibroblasts were treated with miR-96 mimic, FoxO3a, p27, p21, and Bim mRNA and protein levels were decreased. In situ hybridization analysis further revealed the presence of enhanced miR-96 expression in cells within the fibroblastic foci of IPF lung tissue. Our results suggest that when IPF fibroblasts interact with collagen-rich matrix, pathologically altered miR-96 expression inhibits FoxO3a function, causing IPF fibroblasts to maintain their pathological phenotype, which may contribute to the progression of IPF.
, an opportunistic Gram-positive bacterium, causes an infective endocarditis that could be fatal to human health. Dendritic cells (DCs) are known to be involved in disease progression and immune ...responses in
infection. Since lipoteichoic acid (LTA) is a representative virulence factor of
, we here investigated its role in the activation of human DCs stimulated with LTA-deficient (Δ
)
or
LTA. DCs were differentiated from human blood-derived monocytes in the presence of GM-CSF and IL-4 for 6 days. DCs treated with heat-killed Δ
(Δ
HKSG) showed relatively higher binding and phagocytic activities than those treated with heat-killed wild-type
(wild-type HKSG). Furthermore, Δ
HKSG was superior to wild-type HKSG in inducing phenotypic maturation markers including CD80, CD83, CD86, PD-L1, and PD-L2, antigen-presenting molecule MHC class II, and proinflammatory cytokines such as TNF-α and IL-6. Concomitantly, DCs treated with the Δ
HKSG induced better T cell activities, including proliferation and activation marker (CD25) expression, than those treated with the wild-type. LTA, but not lipoproteins, isolated from
weakly activated TLR2 and barely affected the expression of phenotypic maturation markers or cytokines in DCs. Collectively, these results demonstrated that LTA is not a major immuno-stimulating agent of
but rather it interferes with bacteria-induced DC maturation, suggesting its potential role in immune evasion.
Bacterial biofilm residing in the oral cavity is closely related to the initiation and persistence of various dental diseases. Previously, we reported the anti-biofilm activity of
Lactobacillus ...plantarum
lipoteichoic acid (Lp.LTA) on a representative dental cariogenic pathogen,
Streptococcus mutans
. Since LTA structure varies in a bacterial strain-specific manner, LTAs from various
L. plantarum
strains may have differential anti-biofilm activity due to their distinct molecular structures. In the present study, we isolated Lp.LTAs from four different strains of
L. plantarum
(LRCC 5193, 5194, 5195, and 5310) and compared their anti-biofilm effects on the dental pathogens, including
S. mutans
,
Enterococcus faecalis
, and
Streptococcus gordonii
. All Lp.LTAs similarly inhibited
E. faecalis
biofilm formation in a dose-dependent manner. However, their effects on
S. gordonii
and
S. mutans
biofilm formation were different: LRCC 5310 Lp.LTA most effectively suppressed the biofilm formation of all strains of dental pathogens, while Lp.LTAs from LRCC 5193 and 5194 hardly inhibited or even enhanced the biofilm formation. Furthermore, LRCC 5310 Lp.LTA dramatically reduced the biofilm formation of the dental pathogens on the human dentin slice infection model. Collectively, these results suggest that Lp.LTAs have strain-specific regulatory effects on biofilm formation of dental pathogens and LRCC 5310 Lp.LTA can be used as an effective anti-biofilm agent for the prevention of dental infectious diseases.
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