Search tips
Search criteria

Results 1-25 (33)

Clipboard (0)

Select a Filter Below

Year of Publication
1.  The Anti-apoptotic Effect of Ghrelin on Restraint Stress-Induced Thymus Atrophy in Mice 
Immune Network  2016;16(4):242-248.
Thymic atrophy is a complication that results from exposure to many environmental stressors, disease treatments, and microbial challenges. Such acute stress-associated thymic loss can have a dramatic impact on the host's ability to replenish the necessary naïve T cell output to reconstitute the peripheral T cell numbers and repertoire to respond to new antigenic challenges. We have previously reported that treatment with the orexigenic hormone ghrelin results in an increase in the number and proliferation of thymocytes after dexamethasone challenge, suggesting a role for ghrelin in restraint stress-induced thymic involution and cell apoptosis and its potential use as a thymostimulatory agent. In an effort to understand how ghrelin suppresses thymic T cell apoptosis, we have examined the various signaling pathways induced by receptor-specific ghrelin stimulation using a restraint stress mouse model. In this model, stress-induced apoptosis in thymocytes was effectively blocked by ghrelin. Western blot analysis demonstrated that ghrelin prevents the cleavage of pro-apoptotic proteins such as Bim, Caspase-3, and PARP. In addition, ghrelin stimulation activates the Akt and Mitogen-activated protein kinases (MAPK) signaling pathways in a time/dose-dependent manner. Moreover, we also revealed the involvement of the FoxO3a pathway in the phosphorylation of Akt and ERK1/2. Together, these findings suggest that ghrelin inhibits apoptosis by modulating the stress-induced apoptotic signal pathway in the restraint-induced thymic apoptosis.
PMCID: PMC5002450  PMID: 27574503
Ghrelin; Apoptosis; Restraint stress; Thymic atrophy
2.  CD160 is essential for NK-mediated IFN-γ production 
Tu et al. generated a novel CD160-deficient mouse and showed impaired NK cell–mediated tumor elimination and IFN-γ production. CD160+ NK cells are functionally distinct in secretion of IFN-γ from their CD160− NK cell counterparts.
NK-derived cytokines play important roles for natural killer (NK) function, but how the cytokines are regulated is poorly understood. CD160 is expressed on activated NK or T cells in humans but its function is unknown. We generated CD160-deficient mice to probe its function. Although CD160−/− mice showed no abnormalities in lymphocyte development, the control of NK-sensitive tumors was severely compromised in CD160−/− mice. Surprisingly, the cytotoxicity of NK cells was not impaired, but interferon-γ (IFN-γ) secretion by NK cells was markedly reduced in CD160−/− mice. Functionally targeting CD160 signaling with a soluble CD160-Ig also impaired tumor control and IFN-γ production, suggesting an active role of CD160 signaling. Using reciprocal bone marrow transfer and cell culture, we have identified the intrinsic role of CD160 on NK cells, as well as its receptor on non-NK cells, for regulating cytokine production. To demonstrate sufficiency of the CD160+ NK cell subset in controlling NK-dependent tumor growth, intratumoral transfer of the CD160+ NK fraction led to tumor regression in CD160−/− tumor-bearing mice, indicating demonstrable therapeutic potential for controlling early tumors. Therefore, CD160 is not only an important biomarker but also functionally controls cytokine production by NK cells.
PMCID: PMC4354368  PMID: 25711213
3.  Biological lipid membranes for on-demand, wireless drug delivery from thin, bioresorbable electronic implants 
NPG Asia materials  2015;7:e227.
On-demand, localized release of drugs in precisely controlled, patient-specific time sequences represents an ideal scenario for pharmacological treatment of various forms of hormone imbalances, malignant cancers, osteoporosis, diabetic conditions and others. We present a wirelessly operated, implantable drug delivery system that offers such capabilities in a form that undergoes complete bioresorption after an engineered functional period, thereby obviating the need for surgical extraction. The device architecture combines thermally actuated lipid membranes embedded with multiple types of drugs, configured in spatial arrays and co-located with individually addressable, wireless elements for Joule heating. The result provides the ability for externally triggered, precision dosage of drugs with high levels of control and negligible unwanted leakage, all without the need for surgical removal. In vitro and in vivo investigations reveal all of the underlying operational and materials aspects, as well as the basic efficacy and biocompatibility of these systems.
PMCID: PMC4861403  PMID: 27175221
4.  API5 confers tumoral immune escape through FGF2-dependent cell survival pathway 
Cancer research  2014;74(13):3556-3566.
Identifying immune escape mechanisms used by tumors may define strategies to sensitize them to immunotherapies to which they are otherwise resistant. In this study, we show that the anti-apoptotic gene API5 acts as an immune escape gene in tumors by rendering them resistant to apoptosis triggered by tumor antigen-specific T cells. Its RNAi-mediated silencing in tumor cells expressing high levels of API5 restored antigen-specific immune sensitivity. Conversely, introducing API5 into API5low cells conferred immune resistance. Mechanistic investigations revealed that API5 mediated resistance by upregulating FGF2 signaling through a FGFR1/PKCδ/ERK effector pathway that triggered degradation of the pro-apoptotic molecule BIM. Blockade of FGF2, PKCδ or ERK phenocopied the effect of API5 silencing in tumor cells expressing high levels of API5, to either murine or human antigen-specific T cells. Our results identify a novel mechanism of immune escape that can be inhibited to potentiate the efficacy of targeted active immunotherapies.
PMCID: PMC4394897  PMID: 24769442
5.  Innate lymphoid cells facilitate NK cell development through a lymphotoxin-mediated stromal microenvironment 
The Journal of Experimental Medicine  2014;211(7):1421-1431.
Lymphotoxin expressed by RORγt+ innate lymphoid cells is critical for natural killer cell development.
Natural killer (NK) cell development relies on signals provided from the bone marrow (BM) microenvironment. It is thought that lymphotoxin (LT) α1β2 expressed by the NK cell lineage interacts with BM stromal cells to promote NK cell development. However, we now report that a small number of RORγt+ innate lymphoid cells (ILCs), and not CD3−NK1.1+ cells, express LT to drive NK development. Similar to LT−/− or RORγt−/− mice, the mice conditionally lacking LTα1β2 on RORγt+ ILCs experience a developmental arrest at the immature NK stages, between stages of NK development to the mature NK cell stage. This developmental block results in a functional deficiency in the clearance of NK-sensitive tumor cells. Reconstitution of Thy1+ ILCs from BM or purified RORγt+ ILCs from lamina propria lymphocytes into LT-deficient RORγt+ BM cultures rescues NK cell development. These data highlight a previously undiscovered role of RORγt+ ILCs for NK cell development and define LT from ILCs as an essential molecule for the stromal microenvironment supporting NK cell development.
PMCID: PMC4076579  PMID: 24913234
6.  Kaempferol inhibits UVB-induced COX-2 expression by suppressing Src kinase activity 
Biochemical pharmacology  2010;80(12):2042-2049.
Ultraviolet (UV) radiation is the primary environmental risk factor in the development of nonmelanoma skin cancer, and UVB in particular promotes tumor growth through various signaling pathways. Kaempferol, a flavonoid with anti-inflammatory and anti-oxidative properties, has been studied as a chemopreventive agent; however, little is known regarding its effects on UVB-induced photo-carcinogenesis. Here, we examined the effect of kaempferol on UVB-induced skin inflammation. We found that kaempferol suppressed UVB-induced cyclooxygenase-2 (COX-2) protein expression in mouse skin epidermal JB6 P+ cells and attenuated the UVB-induced transcriptional activities of cox-2 and activator protein-1 (AP-1). Kaempferol attenuated the UVB-induced phosphorylation of several mitogen-activated protein kinases (MAPKs), including ERKs, p38, and JNKs, but had no effect on the phosphorylation of the upstream MAPK regulator Src. However, in vitro and ex vivo kinase assays demonstrated that kaempferol suppressed Src kinase activity. Furthermore, in vivo data from mouse skin support the idea that kaempferol suppresses UVB-induced COX-2 expression by blocking Src kinase activity. A pull-down assay revealed that kaempferol competes with ATP for direct binding to Src. Docking data suggest that kaempferol docks easily into the ATP-binding site of Src, which is located between the N and C lobes of the kinase domain. Taken together, these results suggest that kaempferol is a potent chemopreventive agent against skin cancer through its inhibitory interaction with Src.
PMCID: PMC2974004  PMID: 20599768
flavonoid; photo-carcinogenesis; skin cancer
7.  Gain of HIF-1α under normoxia in cancer mediates immune adaptation through the AKT/ERK and VEGFA axes 
Adaptation to host immune surveillance is now recognized as a hallmark of cancer onset and progression, and represents an early, indispensable event in cancer evolution. This process of evolution is first instigated by an immune selection pressure imposed by natural host surveillance mechanisms and may then be propagated by vaccination or other types of immunotherapy.
Experimental Design
We developed a system to simulate cancer evolution in a live host and to dissect the mechanisms responsible for adaptation to immune selection. Here we show that the oxygen-sensitive α subunit of hypoxia-inducible factor 1 (HIF-1α) plays a central role in cancer immune adaptation under conditions of normal oxygen tension.
We found that tumor cells gain HIF-1α in the course of immune selection under normoxia and that HIF-1α renders tumor cells resistant to lysis by tumor-specific cytotoxic T lymphocytes (CTLs) in culture and in mice. The effects of HIF-1α on immune adaptation were mediated through VEGFA-dependent activation of the AKT and ERK signaling pathways, which induced an anti-apoptotic gene expression network in tumor cells.
Our study therefore establishes a link between immune selection, overexpression of HIF-1α, and cancer immune adaptation under normoxia, providing new opportunities for molecular intervention in cancer patients.
PMCID: PMC4359944  PMID: 25589622
8.  Tpl2 is a key mediator of arsenite-induced signal transduction 
Cancer research  2009;69(20):8043-8049.
Arsenite is a well-known human carcinogen that especially targets skin. The tumor progression locus 2 (Tpl2) gene encodes a serine/threonine protein kinase that is overexpressed in various cancer cells. However, the relevance of Tpl2 in arsenite-induced carcinogenesis and the underlying mechanisms remain to be explored. We demonstrate that arsenite increased Tpl2 kinase activity and its phosphorylation in mouse epidermal JB6 P+ cells in a dose- and time-dependent manner. Exposure to arsenite resulted in a marked induction of cyclooxygenase (COX)-2 and prostaglandin (PG)E2, important mediators of inflammation and tumor promotion. Treatment with a Tpl2 kinase inhibitor (TKI) or Tpl2 short hairpin RNA (shRNA) suppressed COX-2 expression and PGE2 production induced by arsenite treatment, suggesting that Tpl2 is critical in arsenite-induced carcinogenesis. We also found that arsenite-induced phosphorylation of extracellular signal-regulated kinases (ERKs) or c-Jun NH2-terminal kinases (JNKs) was markedly suppressed by TKI or Tpl2 shRNA. Inhibition of arsenite-induced ERKs or JNKs signaling using a pharmacological inhibitor of ERKs or JNKs substantially blocked COX-2 expression. Furthermore, inhibition of Tpl2 reduced the arsenite-induced promoter activity of nuclear factor kappa B (NF-κB) and activator protein-1 (AP-1), indicating that NF-κB and AP-1 are downstream transducers of arsenite-triggered Tpl2. Our results demonstrated that Tpl2 plays a key role in arsenite-induced COX-2 expression and PGE2 production and further elucidated the role of Tpl2 in arsenite signals that activate ERKs/JNKs and NF-κB/AP-1 in JB6 P+ cells.
PMCID: PMC2830613  PMID: 19808956
tumor progression locus 2 (Tpl2); arsenite; cyclooxygenase (COX)-2; prostaglandin (PG)E2
9.  Primary Nasopharyngeal Tuberculosis Combined with Tuberculous Otomastoiditis and Facial Nerve Palsy 
Iranian Journal of Radiology  2016;13(1):e30941.
Primary nasopharyngeal tuberculosis (TB) without pulmonary involvement is rare, even in endemic areas. Herein, we present a rare complication of primary nasopharyngeal TB accompanied with tuberculous otomastoiditis (TOM) and ipsilateral facial nerve palsy, in a 24-year-old female patient, with computed tomography and magnetic resonance imagery findings.
PMCID: PMC4841938  PMID: 27127580
Facial Nerve; Mastoiditis; Nasopharyngeal Diseases; Paralysis; Tuberculosis
10.  2B4 Acts As a Non–Major Histocompatibility Complex Binding Inhibitory Receptor on Mouse Natural Killer Cells 
The Journal of Experimental Medicine  2004;199(9):1245-1254.
Natural killer (NK) cells are critical in the immune response to tumor cells, virally infected cells, and bone marrow allografts. 2B4 (CD244) is expressed on all NK cells and the ligand for 2B4, CD48, is expressed on hematopoietic cells. Cross-linking 2B4 on NK cells with anti-2B4 monoclonal antibody leads to NK cell activation in vitro. Therefore, 2B4 is considered to be an activating receptor. Surprisingly, we have found, using antibody-blocking and 2B4-deficient NK cells, that NK lysis of CD48+ tumor and allogeneic targets is inhibited by 2B4 ligation. Interferon γ production by NK cells is also inhibited. Using a peritoneal tumor clearance assay, it was found that 2B4−/− mice have increased clearance of CD48+ tumor cells in vivo. Retroviral transduction of 2B4 was sufficient to restore inhibition in 2B4−/− primary NK cells. It was found that although mature NK cells express SH2D1A, in vitro–derived NK cells do not. However, both populations are inhibited by 2B4 ligation. This indicates that 2B4 inhibitory signaling occurs regardless of the presence of SH2D1A. These findings reveal a novel role for 2B4 as a non–major histocompatibility complex binding negative regulator of NK cells.
PMCID: PMC2211902  PMID: 15123744
CD48; CD150; tumor; IFN-γ; innate immunity
11.  Clinical Implications of Sulcal Enhancement on Postcontrast Fluid Attenuated Inversion Recovery Images in Patients with Acute Stroke Symptoms 
Korean Journal of Radiology  2015;16(4):906-913.
Hyperintense acute reperfusion marker (HARM) without diffusion abnormalities is occasionally found in patients with an acute stroke. This study was to determine the prevalence and clinical implications of HARM without diffusion abnormalities.
Materials and Methods
There was a retrospective review of magnetic resonance images 578 patients with acute strokes and identified those who did not have acute infarction lesions, as mapped by diffusion-weighted imaging (DWI). These patients were classified into an imaging-negative stroke and HARM without diffusion abnormalities groups, based on the DWI findings and postcontrast fluid attenuated inversion recovery images. The National Institutes of Health Stroke Scale (NIHSS) scores at admission, 1 day, and 7 days after the event, as well as clinical data and risk factors, were compared between the imaging-negative stroke and HARM without diffusion abnormalities groups.
Seventy-seven acute stroke patients without any DWI abnormalities were found. There were 63 patients with an imaging-negative stroke (accounting for 10.9% of 578) and 13 patients with HARM without diffusion abnormalities (accounting for 2.4% of 578). The NIHSS scores at admission were higher in HARM without diffusion abnormalities group than in the imaging-negative stroke group (median, 4.5 vs. 1.0; p < 0.001), but the scores at 7 days after the event were not significantly different between the two groups (median, 0 vs. 0; p = 1). The patients with HARM without diffusion abnormalities were significantly older, compared with patients with an imaging-negative stroke (mean, 73.1 years vs. 55.9 years; p < 0.001).
Patients with HARM without diffusion abnormalities are older and have similarly favorable short-term neurological outcomes, compared with the patients with imaging-negative stroke.
PMCID: PMC4499557  PMID: 26175592
Hyperintense acute reperfusion marker; HARM without diffusion abnormalities; Postcontrast FLAIR imaging; Acute stroke
12.  Effect of Donor Age on the Proportion of Mesenchymal Stem Cells Derived from Anterior Cruciate Ligaments 
PLoS ONE  2015;10(3):e0117224.
The characteristics of anterior cruciate ligament (ACL)-derived mesenchymal stem cells (MSCs), such as proportion and multilineage potential, can be affected by donor age. However, the qualitative and quantitative features of ACL MSCs isolated from younger and older individuals have not yet been compared directly. This study assessed the phenotypic and functional differences in ACL-MSCs isolated from younger and older donors and evaluated the correlation between ACL-MSC proportion and donor age. Torn ACL remnants were harvested from 36 patients undergoing ACL reconstruction (young: 29.67 ± 10.92 years) and 33 undergoing TKA (old: 67.96 ± 5.22 years) and the proportion of their MSCs were measured. The mean proportion of MSCs was slightly higher in older ACL samples of the TKA group than of the younger ACL reconstruction group (19.69 ± 8.57% vs. 15.33 ± 7.49%, p = 0.024), but the proportions of MSCs at passages 1 and 2 were similar. MSCs from both groups possessed comparable multilineage potentiality, as they could be differentiated into adipocytes, osteocytes, and chondrocytes at similar level. No significant correlations were observed between patient age and MSC proportions at passages 0–2 or between age and MSC proportion in both the ACL reconstruction and TKA groups. Multiple linear regression analysis found no significant predictor of MSC proportion including donor age for each passage. Microarray analysis identified several genes that were differentially regulated in ACL-MSCs from old TKA patients compared to young ACL reconstruction patients. Genes of interest encode components of the extracellular matrix (ECM) and may thus play a crucial role in modulating tissue homeostasis, remodeling, and repair in response to damage or disease. In conclusion, the proportion of freshly isolated ACL-MSC was higher in elderly TKA patients than in younger patients with ACL tears, but their phenotypic and multilineage potential were comparable.
PMCID: PMC4346262  PMID: 25729860
13.  Homotypic NK cell-to-cell communication controls cytokine responsiveness of innate immune NK cells 
Scientific Reports  2014;4:7157.
While stationary organ cells are in continuous contact with neighboring cells, immune cells circulate throughout the body without an apparent requirement for cell-cell contact to persist in vivo. This study challenges current convention by demonstrating, both in vitro and in vivo, that innate immune NK cells can engage in homotypic NK-to-NK cell interactions for optimal survival, activation, and proliferation. Using a specialized cell-laden microwell approach, we discover that NK cells experiencing constant NK-to-NK contact exhibit a synergistic increase in activation status, cell proliferation, and anti-tumor function in response to IL-2 or IL-15. This effect is dependent on 2B4/CD48 ligation and an active cytoskeleton, resulting in amplification of IL-2 receptor signaling, enhanced CD122/CD132 colocalization, CD25 upregulation, and Stat3 activation. Conversely, ‘orphan' NK cells demonstrate no such synergy and fail to persist. Therefore, our data uncover the existence of homotypic cell-to-cell communication among mobile innate lymphocytes, which promotes functional synergy within the cytokine-rich microenvironment.
PMCID: PMC4256668  PMID: 25475707
14.  GM-CSF-loaded chitosan hydrogel as an immunoadjuvant enhances antigen-specific immune responses with reduced toxicity 
BMC Immunology  2014;15:48.
The application of vaccine adjuvants has been vigorously studied for a diverse range of diseases in order to improve immune responses and reduce toxicity. However, most adjuvants have limited uses in clinical practice due to their toxicity.
Therefore, to reduce health risks associated with the use of such adjuvants, we developed an advanced non-toxic adjuvant utilizing biodegradable chitosan hydrogel (CH-HG) containing ovalbumin (OVA) and granulocyte-macrophage colony-stimulating factor (GM-CSF) as a local antigen delivery system.
After subcutaneous injection into mice, OVA/GM-CSF-loaded CH-HG demonstrated improved safety and enhanced OVA-specific antibody production compared to oil-based adjuvants such as Complete Freund’s adjuvant (CFA) or Incomplete Freund’s adjuvant (IFA). Moreover, CH-HG system-mediated immune responses was characterized by increased number of OVA-specific CD4+ and CD8+ INF-γ+ T cells, leading to enhanced humoral and cellular immunity.
In this study, the improved safety and enhanced immune response characteristics of our novel adjuvant system suggest the possibility of the extended use of adjuvants in clinical practice with reduced apprehension about toxic side effects.
Electronic supplementary material
The online version of this article (doi:10.1186/s12865-014-0048-x) contains supplementary material, which is available to authorized users.
PMCID: PMC4201920  PMID: 25323934
Adjuvant; Chitosan; Hydrogel; Immune response
15.  Value of Perfusion Weighted Magnetic Resonance Imaging in the Diagnosis of Supratentorial Anaplastic Astrocytoma 
We report perfusion weighted imaging (PWI) findings of nonenhanced anaplastic astrocytoma in a 30-year-old woman. Brain magnetic resonance imaging showed a nonenhanced brain tumor with mild peritumoral edema on the right medial frontal lobe and right genu of corpus callosum, suggesting a low-grade glioma. However, PWI showed increased relative cerebral blood volume, relative cerebral blood flow, and permeability of nonenhanced brain tumor compared with contralateral normal brain parenchyma, suggesting a high-grade glioma. After surgery, final histopathological analysis revealed World Health Organization grade III anaplastic astrocytoma. This case demonstrates the importance of PWI for preoperative evaluation of nonenhanced brain tumors.
PMCID: PMC4217066  PMID: 25368772
Anaplastic astrocytoma; MRI; Perfusion weighted MRI
16.  A Comparison of Transcriptional Patterns and Mycological Phenotypes following Infection of Fusarium graminearum by Four Mycoviruses 
PLoS ONE  2014;9(6):e100989.
Many fungi-infecting viruses, which are termed mycoviruses, have been identified, and most do not cause any visible symptoms. Some mycoviruses, however, can attenuate the virulence of the infected fungi, a phenomenon referred to as hypovirulence. To study fungus responses to virus infection, we established a model system composed of Fusarium graminearum and four mycoviruses including FgV1 (Fusarium graminearum virus 1), FgV2, FgV3, and FgV4. FgV1 and FgV2 infections caused several phenotypic alterations in F. graminearum including abnormal colony morphology, defects in perithecium development, and reductions in growth rate, conidiation, and virulence. In contrast, FgV3 and FgV4 infections did not cause any phenotypic change. An RNA-Seq-based analysis of the host transcriptome identified four unique Fusarium transcriptomes, one for each of the four mycoviruses. Unexpectedly, the fungal host transcriptome was more affected by FgV1 and FgV4 infections than by FgV2 and FgV3 infections. Gene ontology (GO) enrichment analysis revealed that FgV1 and FgV3 infections resulted in down-regulation of host genes required for cellular transport systems. FgV4 infection reduced the expression of genes involved in RNA processing and ribosome assembly. We also found 12 genes that were differentially expressed in response to all four mycovirus infections. Unfortunately, functions of most of these genes are still unknown. Taken together, our analysis provides further detailed insights into the interactions between mycoviruses and F. graminearum.
PMCID: PMC4071046  PMID: 24964178
17.  Applications and Implications of Heparin and Protamine in Tissue Engineering and Regenerative Medicine 
BioMed Research International  2014;2014:936196.
Drug repositioning is one of the most rapidly emerging fields of study. This concept is anchored on the principle that diseases have similar damaged or affected signaling pathways. Recently, drugs have been repositioned not only for their alternative therapeutic uses but also for their applications as biomaterials in various fields. However, medical drugs as biomaterials are rarely focused on in reviews. Fragmin and protamine have been recently the sources of increasing attention in the field of tissue engineering and regenerative medicine. Fragmin and protamine have been manufactured primarily as a safe antidote for the circulating heparin. Lately, these drugs have been utilized as either micro- or nanoparticle biomaterials. In this paper, we will briefly describe the concept of drug repositioning and some of the medical drugs that have been repurposed for their alternative therapeutic uses. Also, this will feature the historical background of the studies focused on fragmin/protamine micro/nanoparticles (F/P M/NPs) and their applications as biomaterials in tissue engineering, stem cell therapy, and regenerative medicine.
PMCID: PMC4065694  PMID: 24995338
18.  The HEX1 Gene of Fusarium graminearum Is Required for Fungal Asexual Reproduction and Pathogenesis and for Efficient Viral RNA Accumulation of Fusarium graminearum Virus 1 
Journal of Virology  2013;87(18):10356-10367.
The accumulation of viral RNA depends on many host cellular factors. The hexagonal peroxisome (Hex1) protein is a fungal protein that is highly expressed when the DK21 strain of Fusarium graminearum virus 1 (FgV1) infects its host, and Hex1 affects the accumulation of FgV1 RNA. The Hex1 protein is the major constituent of the Woronin body (WB), which is a peroxisome-derived electron-dense core organelle that seals the septal pore in response to hyphal wounding. To clarify the role of Hex1 and the WB in the relationship between FgV1 and Fusarium graminearum, we generated targeted gene deletion and overexpression mutants. Although neither HEX1 gene deletion nor overexpression substantially affected vegetative growth, both changes reduced the production of asexual spores and reduced virulence on wheat spikelets in the absence of FgV1 infection. However, the vegetative growth of deletion and overexpression mutants was increased and decreased, respectively, upon FgV1 infection compared to that of an FgV1-infected wild-type isolate. Viral RNA accumulation was significantly decreased in deletion mutants but was significantly increased in overexpression mutants compared to the viral RNA accumulation in the virus-infected wild-type control. Overall, these data indicate that the HEX1 gene plays a direct role in the asexual reproduction and virulence of F. graminearum and facilitates viral RNA accumulation in the FgV1-infected host fungus.
PMCID: PMC3754002  PMID: 23864619
19.  The Effect of Radiation on the Immune Response to Cancers 
In cancer patients undergoing radiation therapy, the beneficial effects of radiation can extend beyond direct cytotoxicity to tumor cells. Delivery of localized radiation to tumors often leads to systemic responses at distant sites, a phenomenon known as the abscopal effect which has been attributed to the induction and enhancement of the endogenous anti-tumor innate and adaptive immune response. The mechanisms surrounding the abscopal effect are diverse and include trafficking of lymphocytes into the tumor microenvironment, enhanced tumor recognition and killing via up-regulation of tumor antigens and antigen presenting machinery and, induction of positive immunomodulatory pathways. Here, we discuss potential mechanisms of radiation-induced enhancement of the anti-tumor response through its effect on the host immune system and explore potential combinational immune-based strategies such as adoptive cellular therapy using ex vivo expanded NK and T cells as a means of delivering a potent effector population in the context of radiation-enhanced anti-tumor immune environment.
PMCID: PMC3907847  PMID: 24434638
radiation; abscopal effect; cell therapy; trafficking; recognition
20.  Differential expression of thymic DNA repair genes in low-dose-rate irradiated AKR/J mice 
Journal of Veterinary Science  2013;14(3):271-279.
We previously determined that AKR/J mice housed in a low-dose-rate (LDR) (137Cs, 0.7 mGy/h, 2.1 Gy) γ-irradiation facility developed less spontaneous thymic lymphoma and survived longer than those receiving sham or high-dose-rate (HDR) (137Cs, 0.8 Gy/min, 4.5 Gy) radiation. Interestingly, histopathological analysis showed a mild lymphomagenesis in the thymus of LDR-irradiated mice. Therefore, in this study, we investigated whether LDR irradiation could trigger the expression of thymic genes involved in the DNA repair process of AKR/J mice. The enrichment analysis of Gene Ontology terms and Kyoto Encyclopedia of Genes and Genomes pathways showed immune response, nucleosome organization, and the peroxisome proliferator-activated receptors signaling pathway in LDR-irradiated mice. Our microarray analysis and quantitative polymerase chain reaction data demonstrated that mRNA levels of Lig4 and RRM2 were specifically elevated in AKR/J mice at 130 days after the start of LDR irradiation. Furthermore, transcriptional levels of H2AX and ATM, proteins known to recruit DNA repair factors, were also shown to be upregulated. These data suggest that LDR irradiation could trigger specific induction of DNA repair-associated genes in an attempt to repair damaged DNA during tumor progression, which in turn contributed to the decreased incidence of lymphoma and increased survival. Overall, we identified specific DNA repair genes in LDR-irradiated AKR/J mice.
PMCID: PMC3788152  PMID: 23820165
AKR/J mice; DNA repair genes; low-dose-rate radiation; thymic lymphoma
21.  The proto-oncoprotein FBI-1 interacts with MBD3 to recruit the Mi-2/NuRD-HDAC complex and BCoR and to silence p21WAF/CDKN1A by DNA methylation 
Nucleic Acids Research  2013;41(13):6403-6420.
The tumour-suppressor gene CDKN1A (encoding p21Waf/Cip1) is thought to be epigenetically repressed in cancer cells. FBI-1 (ZBTB7A) is a proto-oncogenic transcription factor repressing the alternative reading frame and p21WAF/CDKN1A genes of the p53 pathway. FBI-1 interacts directly with MBD3 (methyl-CpG–binding domain protein 3) in the nucleus. We demonstrated that FBI-1 binds both non-methylated and methylated DNA and that MBD3 is recruited to the CDKN1A promoter through its interaction with FBI-1, where it enhances transcriptional repression by FBI-1. FBI-1 also interacts with the co-repressors nuclear receptor corepressor (NCoR), silencing mediator for retinoid and thyroid receptors (SMRT) and BCL-6 corepressor (BCoR) to repress transcription. MBD3 regulates a molecular interaction between the co-repressor and FBI-1. MBD3 decreases the interaction between FBI-1 and NCoR/SMRT but increases the interaction between FBI-1 and BCoR. Because MBD3 is a subunit of the Mi-2 autoantigen (Mi-2)/nucleosome remodelling and histone deacetylase (NuRD)-HDAC complex, FBI-1 recruits the Mi-2/NuRD-HDAC complex via MBD3. BCoR interacts with the Mi-2/NuRD-HDAC complex, DNMTs and HP1. MBD3 and BCoR play a significant role in the recruitment of the Mi-2/NuRD-HDAC complex– and the NuRD complex–associated proteins, DNMTs and HP. By recruiting DNMTs and HP1, Mi-2/NuRD-HDAC complex appears to play key roles in epigenetic repression of CDKN1A by DNA methylation.
PMCID: PMC3711425  PMID: 23658227
22.  Pituitary Stalk Hemangioblastoma in a von Hippel-Lindau Patient : Clinical Course Follow-Up Over a 20-Year Period 
Supratentorial hemangioblastomas (HBs) are rare, and pituitary stalk HBs are extremely uncommon; therefore, pituitary stalk evaluation is often overlooked. Herein, we report the development of pituitary stalk HB over a 20-year period and the importance of regular long-term follow up for patients with HBs.
PMCID: PMC3730032  PMID: 23908704
Cerebellar hemangioblastoma; von Hippel-Lindau disease; Pituitary stalk dissemination; Natural course
23.  Dynamic correlations between heart and brain rhythm during Autogenic meditation 
This study is aimed to determine significant physiological parameters of brain and heart under meditative state, both in each activities and their dynamic correlations. Electrophysiological changes in response to meditation were explored in 12 healthy volunteers who completed 8 weeks of a basic training course in autogenic meditation. Heart coherence, representing the degree of ordering in oscillation of heart rhythm intervals, increased significantly during meditation. Relative EEG alpha power and alpha lagged coherence also increased. A significant slowing of parietal peak alpha frequency was observed. Parietal peak alpha power increased with increasing heart coherence during meditation, but no such relationship was observed during baseline. Average alpha lagged coherence also increased with increasing heart coherence during meditation, but weak opposite relationship was observed at baseline. Relative alpha power increased with increasing heart coherence during both meditation and baseline periods. Heart coherence can be a cardiac marker for the meditative state and also may be a general marker for the meditative state since heart coherence is strongly correlated with EEG alpha activities. It is expected that increasing heart coherence and the accompanying EEG alpha activations, heart brain synchronicity, would help recover physiological synchrony following a period of homeostatic depletion.
PMCID: PMC3728977  PMID: 23914165
EEG; HRV; heart coherence; meditation; lagged coherence; heart brain synchronicity
24.  Augmentation of natural cytotoxicity by chronic low-dose ionizing radiation in murine natural killer cells primed by IL-2 
Journal of Radiation Research  2012;53(6):823-829.
The possible beneficial effects of chronic low-dose irradiation (LDR) and its mechanism of action in a variety of pathophysiological processes such as cancer are a subject of intense investigation. While animal studies involving long-term exposure to LDR have yielded encouraging results, the influence of LDR at the cellular level has been less well defined. We reasoned that since natural killer (NK) cells constitute an early responder to exogenous stress, NK cells may reveal sentinel alterations in function upon exposure to LDR. When purified NK cells received LDR at 4.2 mGy/h for a total of 0.2 Gy in vitro, no significant difference in cell viability was observed. Likewise, no functional changes were detected in LDR-exposed NK cells, demonstrating that LDR alone was insufficient to generate changes at the cellular level. Nonetheless, significant augmentation of cytotoxic, but not proliferative, function was detected when NK cells were stimulated with low-dose IL-2 prior to irradiation. This enhancement of NK cytotoxicity was not due to alterations in NK-activating receptors, NK1.1, NKG2D, CD69 and 2B4, or changes in the rate of early or late apoptosis. Therefore, LDR, in the presence of suboptimal cytokine levels, can facilitate anti-tumor cytotoxicity of NK cells without influencing cellular proliferation or apoptosis. Whether these results translate to in vivo consequences remains to be seen; however, our data provide initial evidence that exposure to LDR can lead to subtle immune-enhancing effects on NK cells and may explain, in part, the functional basis underlying, diverse beneficial effects seen in the animals chronically exposed to LDR.
PMCID: PMC3483842  PMID: 22915781
Low-dose radiation; natural killer cells; natural cytotoxicity; innate immunity
25.  Effect of Workplace-Visiting Nutrition Education on Anthropometric and Clinical Measures in Male Workers 
Clinical Nutrition Research  2012;1(1):49-57.
The purpose of this study was to investigate effect of nutrition education at worksite program in male workers. The subjects were 75 male workers who had received nutrition education by a clinical dietitian for 4 months. The anthropometric data, blood pressure and biochemical blood indices were measured before and after nutrition education. Dietary habits and lifestyle were investigated by self-administered questionnaires. Nutrients intake was determined by 24-hour dietary recall method. The results showed significant decreases in body mass index (p < 0.05), fasting blood sugar (p < 0.01), total cholesterol (p < 0.05), and LDL-cholesterol (p < 0.05) after nutrition education. The correlation analyses among anthropometric and clinical parameters after nutrition education indicated that there was a significantly positive correlations between blood pressure and weight, r-GTP. A significantly positive correlations was observed between fasting blood sugar and triglycerides. A significantly positive correlations was observed between triglycerides and body mass index, r-GTP, SGPT. A significantly positive correlations was observed between SGPT and weight, body mass index. A significantly negative correlations was observed between HDL-cholesterol and weight. It could be concluded that nutrition education might be effective tool to improve anthropometric measures and clinical parameters in male workers. Continuing and systematic nutritional management programs should be developed and implemented for male workers at the worksites to maintain optimal health status.
PMCID: PMC3572802  PMID: 23430239
Body mass index; Blood lipids; Blood pressure; Blood glucose; Liver function tests; Nutrition eduction

Results 1-25 (33)