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On page 1 showing 1 ~ 20 papers out of 24 papers

Effects of Tai Chi Exercise on Reducing Falls and Improving Balance Performance in Parkinson's Disease: A Meta-Analysis.

  • Hsin-Hsuan Liu‎ et al.
  • Parkinson's disease‎
  • 2019‎

Parkinson's disease (PD) is a common neurodegenerative disorder that may increase the risk of falls, functional limitation, and balance deficits. Tai Chi was used as an option for improving balance in people with PD. The aim of this meta-analysis was to evaluate the effects of Tai Chi on falls, balance, and functional mobility in individuals with PD.


Predicting Cognitive Decline in Parkinson's Disease with Mild Cognitive Impairment: A One-Year Observational Study.

  • Pei-Hao Chen‎ et al.
  • Parkinson's disease‎
  • 2020‎

We conducted an observational study to investigate clinical predictors of cognitive decline in patients with mild cognitive impairment (MCI), with a focus on patients with Parkinson's disease (PD) and Alzheimer's disease (AD). The study was performed with detailed neuropsychological testing, a portable device for gait analysis, and a comprehensive geriatric assessment for patients with MCI. Cognitive decline was defined as subjective cognitive impairment with an objective decline in the Mini-Mental State Examination (MMSE) ≥2 points at the one-year follow-up. Participants (n = 74) had a median age of 70 (interquartile range 60-79) years, and 45.9% of them were women. At the end of the study, 17.6% of the patients with MCI had a cognitive decline. Although no differences were observed between groups at the baseline cognitive study, patients with PD-MCI demonstrated more cognitive decline than patients with AD-MCI (28.6% vs. 7.7% p = 0.03). Patients with PD-MCI had more physical disabilities, including scores of instrumental activities of daily living (IADL), Tinetti balance, and gait scores, and some Timed Up and Go components. Initial Clinical Dementia Rating-Sum of Boxes score was a better predictor of future cognitive decline than MMSE in PD-MCI. For predicting the occurrence of cognitive decline in PD-MCI, the prediction accuracy increased from the reduced model (AUC = 0.822, p < 0.001) to the full model (a total of five independent variables, AUC = 0.974, p < 0.001). Given the potentially modifiable predictor, our findings also highlight the importance of identifying sleep quality and the ability to perform IADL.


Mitochondrial oxidative stress by Lon-PYCR1 maintains an immunosuppressive tumor microenvironment that promotes cancer progression and metastasis.

  • Cheng-Liang Kuo‎ et al.
  • Cancer letters‎
  • 2020‎

Mitochondrial Lon is a chaperone protein whose upregulation increases the production of mitochondrial reactive oxygen species (ROS). However, there is a lack of information in detail on how mitochondrial Lon regulates cancer metastasis through ROS production in the tumor microenvironment (TME). Our results show that elevated Lon promotes epithelial-mesenchymal transition (EMT) via ROS-dependent p38 and NF-κB-signaling. We further identified pyrroline-5-carboxylate reductase 1 (PYCR1) as a client of chaperone Lon, which induces mitochondrial ROS and EMT by Lon. Mitochondrial Lon induces ROS-dependent production of inflammatory cytokines, such as TGF-β, IL-6, IL-13, and VEGF-A, which consequently activates EMT, angiogenesis, and M2 macrophage polarization. In addition, Lon expression is induced upon the activation and M2 polarization of macrophages, which further promotes M2 macrophages to enhance the immunosuppressive microenvironment and metastatic behaviors in the TME. This raises the possibility that manipulation of the mitochondrial redox balance in the TME may serve as a therapeutic strategy to improve T cell function in cancer immunotherapy.


Lysyl oxidase-like 2 promotes stemness and enhances antitumor effects of gefitinib in head and neck cancer via IFIT1 and IFIT3.

  • Yi-Jie Lu‎ et al.
  • Cancer science‎
  • 2023‎

Lysyl oxidase-like 2 (LOXL2) is a matrix-remodeling enzyme that has recently been identified as an important regulator of tumor progression and metastasis. This study discovered that LOXL2 expression in oral squamous cell carcinoma (OSCC) tissues was significantly associated with tumor clinical stage, lymph node metastasis and patients' overall survival time. LOXL2-overexpressing human buccal SCC TW2.6 (TW2.6/LOXL2) and hypopharyngeal SCC FaDu (FaDu/LOXL2) cells exhibited enhanced migration, invasion, epithelial-mesenchymal transition (EMT), and cancer stem cell (CSC) phenotypes, independently of its enzymatic activity. Moreover, TW2.6/LOXL2 significantly increased tumor-initiating frequency in SCID mice. We further demonstrated that LOXL2 increased the levels of interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) and IFIT3 in TW2.6/LOXL2 and FaDu/LOXL2 cells. We also identified IFIT1 and IFIT3 as key downstream components of LOXL2 action in migration, invasion, EMT, and CSC phenotypes in TW2.6 and FaDu cells. Furthermore, a significant positive correlation between LOXL2 expression and IFIT1 and IFIT3 overexpression in human OSCC tissues was observed. In addition, TW2.6/LOXL2 and FaDu/LOXL2 cells were 3.3- to 3.6-fold more susceptible to the epidermal growth factor receptor (EGFR) inhibitor gefitinib than were their respective control cells. The antitumor effect of gefitinib on orthotopic TW2.6/LOXL2 xenograft tumor was fourfold higher than that on controls. Our results indicate that LOXL2 expression is a strong prognostic factor for OSCC and may be used as a marker to identify patients most likely to respond to EGFR-targeted therapy.


Effects of exercise intensity on spatial memory performance and hippocampal synaptic plasticity in transient brain ischemic rats.

  • Pei-Cheng Shih‎ et al.
  • PloS one‎
  • 2013‎

Memory impairment is commonly noted in stroke survivors, and can lead to delay of functional recovery. Exercise has been proved to improve memory in adult healthy subjects. Such beneficial effects are often suggested to relate to hippocampal synaptic plasticity, which is important for memory processing. Previous evidence showed that in normal rats, low intensity exercise can improve synaptic plasticity better than high intensity exercise. However, the effects of exercise intensities on hippocampal synaptic plasticity and spatial memory after brain ischemia remain unclear. In this study, we investigated such effects in brain ischemic rats. The middle cerebral artery occlusion (MCAO) procedure was used to induce brain ischemia. After the MCAO procedure, rats were randomly assigned to sedentary (Sed), low-intensity exercise (Low-Ex), or high-intensity exercise (High-Ex) group. Treadmill training began from the second day post MCAO procedure, 30 min/day for 14 consecutive days for the exercise groups. The Low-Ex group was trained at the speed of 8 m/min, while the High-Ex group at the speed of 20 m/min. The spatial memory, hippocampal brain-derived neurotrophic factor (BDNF), synapsin-I, postsynaptic density protein 95 (PSD-95), and dendritic structures were examined to document the effects. Serum corticosterone level was also quantified as stress marker. Our results showed the Low-Ex group, but not the High-Ex group, demonstrated better spatial memory performance than the Sed group. Dendritic complexity and the levels of BDNF and PSD-95 increased significantly only in the Low-Ex group as compared with the Sed group in bilateral hippocampus. Notably, increased level of corticosterone was found in the High-Ex group, implicating higher stress response. In conclusion, after brain ischemia, low intensity exercise may result in better synaptic plasticity and spatial memory performance than high intensity exercise; therefore, the intensity is suggested to be considered during exercise training.


Identification of Novel Cdc7 Kinase Inhibitors as Anti-Cancer Agents that Target the Interaction with Dbf4 by the Fragment Complementation and Drug Repositioning Approach.

  • An Ning Cheng‎ et al.
  • EBioMedicine‎
  • 2018‎

Cdc7-Dbf4 is a conserved serine/threonine kinase that plays an important role in initiation of DNA replication and DNA damage tolerance in eukaryotic cells. Cdc7 has been found overexpressed in human cancer cell lines and tumor tissues, and the knockdown of Cdc7 expression causes an p53-independent apoptosis, suggesting that Cdc7 is a target for cancer therapy. Only a handful Cdc7 kinase inhibitors have been reported. All Cdc7 kinase inhibitors, including PHA-767491, were identified and characterized as ATP-competitive inhibitors. Unfortunately, these ATP-competitive Cdc7 inhibitors have no good effect on clinical trial.


Fractional anisotropy in corpus callosum is associated with facilitation of motor representation during ipsilateral hand movements.

  • Shin-Yi Chiou‎ et al.
  • PloS one‎
  • 2014‎

Coactivation of primary motor cortex ipsilateral to a unilateral movement (M1(ipsilateral)) has been observed, and the magnitude of activation is influenced by the contracting muscles. It has been suggested that the microstructural integrity of the callosal motor fibers (CMFs) connecting M1 regions may reflect the observed response. However, the association between the structural connectivity of CMFs and functional changes in M1(ipsilateral) remains unclear. The purpose of this study was to investigate the relationship between functional changes within M1(ipsilateral) during unilateral arm or leg movements and the microstructure of the CMFs connecting both homotopic representations (arm or leg).


The effects of Ai Chi for balance in individuals with chronic stroke: a randomized controlled trial.

  • Pei-Hsin Ku‎ et al.
  • Scientific reports‎
  • 2020‎

This study investigated the effectiveness of Ai Chi compared to conventional water-based exercise on balance performance in individuals with chronic stroke. A total of 20 individuals with chronic stroke were randomly allocated to receive either Ai Chi or conventional water-based exercise for 60 min/time, 3 times/week, and a total of 6 weeks. Balance performance assessed by limit of stability (LOS) test and Berg balance scale (BBS). Fugl-Meyer assessment (FMA) and gait performance were documented for lower extremity movement control and walking ability, respectively. Excursion and movement velocity in LOS test was significantly increased in anteroposterior axis after receiving Ai Chi (p = 0.005 for excursion, p = 0.013 for velocity) but not conventional water-based exercise. In particular, the improvement of endpoint excursion in the Ai Chi group has significant inter-group difference (p = 0.001). Both groups showed significant improvement in BBS and FMA yet the Ai Chi group demonstrated significantly better results than control group (p = 0.025). Ai Chi is feasible for balance training in stroke, and is able to improve weight shifting in anteroposterior axis, functional balance, and lower extremity control as compared to conventional water-based exercise.


Maintaining Gait Performance by Cortical Activation during Dual-Task Interference: A Functional Near-Infrared Spectroscopy Study.

  • Chia-Feng Lu‎ et al.
  • PloS one‎
  • 2015‎

In daily life, mobility requires walking while performing a cognitive or upper-extremity motor task. Although previous studies have evaluated the effects of dual tasks on gait performance, few studies have evaluated cortical activation and its association with gait disturbance during dual tasks. In this study, we simultaneously assessed gait performance and cerebral oxygenation in the bilateral prefrontal cortices (PFC), premotor cortices (PMC), and supplemental motor areas (SMA), using functional near-infrared spectroscopy, in 17 young adults performing dual tasks. Each participant was evaluated while performing normal-pace walking (NW), walking while performing a cognitive task (WCT), and walking while performing a motor task (WMT). Our results indicated that the left PFC exhibited the strongest and most sustained activation during WCT, and that NW and WMT were associated with minor increases in oxygenation levels during their initial phases. We observed increased activation in channels in the SMA and PMC during WCT and WMT. Gait data indicated that WCT and WMT both caused reductions in walking speed, but these reductions resulted from differing alterations in gait properties. WCT was associated with significant changes in cadence, stride time, and stride length, whereas WMT was associated with reductions in stride length only. During dual-task activities, increased activation of the PMC and SMA correlated with declines in gait performance, indicating a control mechanism for maintaining gait performance during dual tasks. Thus, the regulatory effects of cortical activation on gait behavior enable a second task to be performed while walking.


Positive Effects of Specific Exercise and Novel Turning-based Treadmill Training on Turning Performance in Individuals with Parkinson's disease: A Randomized Controlled Trial.

  • Fang-Yu Cheng‎ et al.
  • Scientific reports‎
  • 2016‎

Two different training strategies to improve turning performance in individuals with Parkinson's disease (PD) were designed and investigated in this study. Subjects were randomly assigned to a specific exercise group, turning-based training group, or control group to receive training that emphasized balance and strengthening, turning-based treadmill training, and general exercise training, respectively. A total of 12 30-min training sessions followed by 10 min of turning training on a level surface were administered over 4 to 6 weeks. The results (n = 12 for each group) showed that both the specific exercise and turning-based training group experienced improved turning performance, the primary outcome, compared with the control group (specific exercise, 33% change, p = 0.016; turning-based training, 35% change, p = 0.021). For the secondary outcomes, the specific exercise group performed better than the control group on the Tinetti balance scale, limit of stability test and lower extremity extensor and abductor strength. The turning-based training groups performed better than the control group in sensory organization and ankle plantar flexor strength. In summary, specific exercise training and turning-based treadmill training were both effective in improving turning performance in participants with PD. However, the improvements in turning performance of these two groups resulted from improving different aspects of impairment in individuals with PD.


Intermittent hypoxia after transient focal ischemia induces hippocampal neurogenesis and c-Fos expression and reverses spatial memory deficits in rats.

  • Yi-Wei Tsai‎ et al.
  • PloS one‎
  • 2011‎

Memory impairment is a frequent complication of brain ischemia. Neurogenesis is implicated in learning and memory and is regulated by the transcription factor c-Fos. Preconditioning intermittent hypoxia (IH) attenuates ischemia-related memory impairments, but it is not known whether post-ischemia IH intervention has a similar effect. We investigated the effects of post-ischemia IH on hippocampal neurogenesis and c-Fos expression as well as spatial learning and memory in rats.


Effects of Transcranial Direct Current Stimulation Followed by Treadmill Training on Dual-Task Walking and Cortical Activity in Chronic Stroke: A Double-Blinded Randomized Controlled Trial.

  • Pei-Ling Wong‎ et al.
  • Journal of rehabilitation medicine‎
  • 2023‎

To explore the effects of transcranial direct current stimulation followed by treadmill training on dual-task gait performance and contralesional cortical activity in chronic stroke patients.


The SDF1-CXCR4 Axis Is Involved in the Hyperbaric Oxygen Therapy-Mediated Neuronal Cells Migration in Transient Brain Ischemic Rats.

  • Ray-Yau Wang‎ et al.
  • International journal of molecular sciences‎
  • 2022‎

Neurogenesis is a physiological response after cerebral ischemic injury to possibly repair the damaged neural network. Therefore, promoting neurogenesis is very important for functional recovery after cerebral ischemic injury. Our previous research indicated that hyperbaric oxygen therapy (HBOT) exerted neuroprotective effects, such as reducing cerebral infarction volume. The purposes of this study were to further explore the effects of HBOT on the neurogenesis and the expressions of cell migration factors, including the stromal cell-derived factor 1 (SDF1) and its target receptor, the CXC chemokine receptor 4 (CXCR4). Thirty-two Sprague-Dawley rats were divided into the control or HBO group after receiving transient middle cerebral artery occlusion (MCAO). HBOT began to intervene 24 h after MCAO under the pressure of 3 atmospheres for one hour per day for 21 days. Rats in the control group were placed in the same acrylic box without HBOT during the experiment. After the final intervention, half of the rats in each group were cardio-perfused with ice-cold saline followed by 4% paraformaldehyde under anesthesia. The brains were removed, dehydrated and cut into serial 20μm coronal sections for immunofluorescence staining to detect the markers of newborn cell (BrdU+), mature neuron cell (NeuN+), SDF1, and CXCR4. The affected motor cortex of the other half rats in each group was separated under anesthesia and used to detect the expressions of brain-derived neurotrophic factor (BDNF), SDF1, and CXCR4. Motor function was tested by a ladder-climbing test before and after the experiment. HBOT significantly enhanced neurogenesis in the penumbra area and promoted the expressions of SDF1 and CXCR4. The numbers of BrdU+/SDF1+, BrdU+/CXCR4+, and BrdU+/NeuN+ cells and BDNF concentrations in the penumbra were all significantly increased in the HBO group when compared with the control group. The motor functions were improved in both groups, but there was a significant difference between groups in the post-test. Our results indicated that HBOT for 21 days enhanced neurogenesis and promoted cell migration toward the penumbra area in transient brain ischemic rats. HBOT also increased BDNF expression, which might further promote the reconstructions of the impaired neural networks and restore motor function.


HMGCS2 enhances invasion and metastasis via direct interaction with PPARα to activate Src signaling in colorectal cancer and oral cancer.

  • Shih-Wen Chen‎ et al.
  • Oncotarget‎
  • 2017‎

Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS2) is the rate-limiting enzyme of ketogenesis. Growing evidence indicates that HMGCS2 may be involved in cancer progression, but its exact role is largely unknown. In this study, we demonstrate that HMGCS2 mRNA expression is associated with poor clinical prognosis and outcomes in patients with colorectal cancer (CRC) and oral squamous cell carcinoma (OSCC). In vitro, ectopic expression of HMGCS2 enhanced cancer cell motility in a ketogenesis-independent manner. Moreover, HMGCS2 promoted Src activity by directly binding to peroxisome proliferator-activated receptor alpha (PPARα), a transcriptional activator of Src. Taken together, these results suggest that HMGCS2 may serve as a useful prognostic marker and vital target for future therapeutic strategies against advanced cancer.


Cognitive and motor dual task gait training improve dual task gait performance after stroke - A randomized controlled pilot trial.

  • Yan-Ci Liu‎ et al.
  • Scientific reports‎
  • 2017‎

This study investigated effects of cognitive and motor dual task gait training on dual task gait performance in stroke. Participants (n = 28) were randomly assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or conventional physical therapy (CPT) group. Participants in CDTT or MDTT group practiced the cognitive or motor tasks respectively during walking. Participants in CPT group received strengthening, balance, and gait training. The intervention was 30 min/session, 3 sessions/week for 4 weeks. Three test conditions to evaluate the training effects were single walking, walking while performing cognitive task (serial subtraction), and walking while performing motor task (tray-carrying). Parameters included gait speed, dual task cost of gait speed (DTC-speed), cadence, stride time, and stride length. After CDTT, cognitive-motor dual task gait performance (stride length and DTC-speed) was improved (p = 0.021; p = 0.015). After MDTT, motor dual task gait performance (gait speed, stride length, and DTC-speed) was improved (p = 0.008; p = 0.008; p = 0.008 respectively). It seems that CDTT improved cognitive dual task gait performance and MDTT improved motor dual task gait performance although such improvements did not reach significant group difference. Therefore, different types of dual task gait training can be adopted to enhance different dual task gait performance in stroke.


Mitochondrial Lon sequesters and stabilizes p53 in the matrix to restrain apoptosis under oxidative stress via its chaperone activity.

  • Ya-Ju Sung‎ et al.
  • Cell death & disease‎
  • 2018‎

Mitochondrial Lon is a multi-function matrix protease with chaperone activity. However, little literature has been undertaken into detailed investigations on how Lon regulates apoptosis through its chaperone activity. Accumulating evidences indicate that various stresses induce transportation of p53 to mitochondria and activate apoptosis in a transcription-independent manner. Here we found that increased Lon interacts with p53 in mitochondrial matrix and restrains the apoptosis induced by p53 under oxidative stress by rescuing the loss of mitochondrial membrane potential (Δψm) and the release of cytochrome C and SMAC/Diablo. Increased chaperone Lon hampers the transcription-dependent apoptotic function of p53 by reducing the mRNA expression of p53 target genes. The ATPase mutant (K529R) of chaperone Lon decreases the interaction with p53 and fails to inhibit apoptosis. Furthermore, the chaperone activity of Lon is important for mitochondrial p53 accumulation in an mtHsp70-dependent manner, which is also important to prevent the cytosolic distribution of p53 from proteasome-dependent degradation. These results indicate that the chaperone activity of Lon is important to bind with mitochondrial p53 by which increased Lon suppresses the apoptotic function of p53 under oxidative stress. Furthermore, mitochondrial Lon-mtHsp70 increases the stability/level of p53 through trafficking and retaining p53 in mitochondrial matrix and preventing the pool of cytosolic p53 from proteasome-dependent degradation in vitro and in clinic.


Do cognitive performance and physical function differ between individuals with motoric cognitive risk syndrome and those with mild cognitive impairment?

  • Fang-Yu Cheng‎ et al.
  • BMC geriatrics‎
  • 2021‎

Motoric cognitive risk syndrome (MCR) is defined by slow gait speed combined with subjective cognitive complaint. MCR is a predementia syndrome, similar to mild cognitive impairment (MCI). However, there is currently no study comparing the differences in cognitive performance and physical function between these two types of cognitive impairment. Thus, the aim of this study is to compare cognitive performance and physical function in individuals with MCR versus MCI.


Cognitive and motor dual task gait training exerted specific training effects on dual task gait performance in individuals with Parkinson's disease: A randomized controlled pilot study.

  • Yea-Ru Yang‎ et al.
  • PloS one‎
  • 2019‎

Gait impairments in Parkinson's disease (PD) are aggravated under dual task conditions. Providing effective training to enhance different dual task gait performance is important for PD rehabilitation. This pilot study aimed to investigate the effects of cognitive and motor dual task gait training on dual task gait performance in PD. Eighteen PD participants (n = 6 per training group) were assigned to cognitive dual task gait training (CDTT), motor dual task gait training (MDTT), or general gait training (control) group randomly. The training was 30 min each session, 3 sessions per week for 4 weeks. Primary outcomes including gait performance during cognitive dual task, motor dual task, and single walking were assessed at pre- and post-training. The results showed decreased double support time during cognitive dual task walking after CDTT (-17.1±10.3%) was significantly more than MDTT (6.3±25.6%, p = .006) and control training (-5.6±7.8%, p = .041). Stride time variability during motor dual task walking decreased more after MDTT (-16.3±32.3%) than CDTT (38.6±24.0%, p = .015) and control training (36.8±36.4%, p = .041). CDTT also improved motor dual task walking performance especially on gait speed (13.8±10.71%, p = .046) stride length (10.5±6.6%, p = .046), and double support time (-8.0±2.0%, p = .028). CDTT improved single walking performance as well on gait speed (11.4±5.5%, p = .046), stride length (9.2±4.6%, p = .028), and double support time (-8.1±3.0%, p = .028). In summary, our preliminary data showed 12-session of CDTT decreased double support time during cognitive dual task walking, and MDTT reduced gait variability during motor dual task walking. Different training strategy can be adopted for possibly different training effects in people with PD.


Genetic and Biochemical Characterization of Halogenation and Drug Transportation Genes Encoded in the Albofungin Biosynthetic Gene Cluster.

  • Zhe-Chong Wang‎ et al.
  • Applied and environmental microbiology‎
  • 2022‎

Albofungin, a hexacyclic aromatic natural product, exhibits broad-spectrum antimicrobial activity. Its biosynthesis, regulation, and resistance remain elusive. Here, we report the albofungin (abf) biosynthetic gene cluster (BGC) from its producing strain Streptomyces tumemacerans JCM5050. The nascent abf BGC encodes 70 putative genes, including regulators, transporters, type II polyketide synthases (PKSs), oxidoreductase, and tailoring enzymes. To validate the intactness and functionality of the BGC, we developed an Escherichia coli-Streptomyces shuttle bacterial artificial chromosome system, whereby the abf BGC was integrated into the genome of a nonproducing host via heterologous conjugation, wherefrom albofungin can be produced, confirming that the BGC is in effect. We then delimited the boundaries of the BGC by means of in vitro CRISPR-Cas9 DNA editing, concluding a minimal but essential 60-kb abf BGC ranging from orfL to abf58. The orfA gene encoding a reduced flavin adenine dinucleotide (FADH2)-dependent halogenase was examined and is capable of transforming albofungin to halogen-substituted congeners in vivo and in vitro. The orfL gene encoding a transporter was examined in vivo. The presence/absence of orfA or orfL demonstrated that the MIC of albofungin is subject to alteration when an extracellular polysaccharide intercellular adhesin was formed. Despite that halogenation of albofungin somewhat increases binding affinity to transglycosylase (TGase), albofungin with/without a halogen substituent manifests similar in vitro antimicrobial activity. Halogenation, however, limits overall dissemination and effectiveness given a high secretion rate, weak membrane permeability, and high hydrophobicity of the resulting products, whereby the functions of orfA and orfL are correlated with drug detoxification/resistance for the first time. IMPORTANCE Albofungin, a natural product produced from Streptomycetes, exhibits bioactivities against bacteria, fungi, and tumor cells. The biosynthetic logic, regulations, and resistance of albofungin remain yet to be addressed. Herein, the minimal albofungin (abf) biosynthetic gene cluster (BGC) from the producing strain Streptomyces tumemacerans JCM5050 was precisely delimited using the Escherichia coli-Streptomyces shuttle bacterial artificial chromosome system, of which the gene essentiality was established in vivo and in vitro. Next, we characterized two genes orfA and orfL encoded in the abf BGC, which act as a reduced flavin adenine dinucleotide (FADH2)-dependent halogenase and an albofungin-congeners transporter, respectively. While each testing microorganism exhibited different sensitivities to albofungins, the MIC values of albofungins against testing strains with/without orfA and/or orfL were subject to considerable changes. Halogen-substituted albofungins mediated by OrfA manifested overall compromised dissemination and effectiveness, revealing for the first time that two functionally distinct proteins OrfA and OrfL are associated together, exerting a novel "belt and braces" mechanism in antimicrobial detoxification/resistance.


Metastasis and immunosuppression promoted by mtDNA and PD-L1 in extracellular vesicles are reversed by WGP β-glucan in oral squamous cell carcinoma.

  • Hui-Hsin Ko‎ et al.
  • Cancer science‎
  • 2023‎

The suppressive regulatory T cells (Treg) are frequently upregulated in cancer patients. This study aims to demonstrate the hypothesis that arecoline could induce the secretion of mitochondrial (mt) DNA D-loop and programmed cell death-ligand 1 (PD-L1) in extracellular vesicles (EVs), and attenuate T-cell immunity by upregulated Treg cell numbers. However, the immunosuppression could be reversed by whole glucan particle (WGP) β-glucan in oral squamous cell (OSCC) patients. Arecoline-induced reactive oxygen specimen (ROS) production and cytosolic mtDNA D-loop were analyzed in OSCC cell lines. mtDNA D-loop, PD-L1, IFN-γ, and Treg cells were also identified for the surgical specimens and sera of 60 OSCC patients. We demonstrated that higher mtDNA D-loop, PD-L1, and Treg cell numbers were significantly correlated with larger tumor size, nodal metastasis, advanced clinical stage, and areca quid chewing. Furthermore, multivariate analysis confirmed that higher mtDNA D-loop levels and Treg cell numbers were unfavorable independent factors for survival. Arecoline significantly induced cytosolic mtDNA D-loop leakage and PD-L1 expression, which were packaged by EVs to promote immunosuppressive Treg cell numbers. However, WGP β-glucan could elevate CD4+ and CD8+ T-cell numbers, mitigate Treg cell numbers, and promote oral cancer cell apoptosis. To sum up, arecoline induces EV production carrying mtDNA D-loop and PD-L1, and in turn elicits immune suppression. However, WGP β-glucan potentially enhances dual effects on T-cell immunity and cell apoptosis and we highly recommend its integration with targeted and immune therapies against OSCC.


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