T-helper 17 and interleukin-17-producing lymphoid tissue inducer-like cells make different contributions to colitis in mice

BACKGROUND & AIMS

T helper (Th) 17 cells that express the retinoid-related orphan receptor (ROR) γt contribute to the development of colitis in mice, yet are found in normal and inflamed intestine. We investigated their development and functions in intestines of mice.

METHODS

We analyzed intestinal Th17 cells in healthy and inflamed intestinal tissues of mice. We analyzed expression of lymphotoxin (LT)α by Th17 cells and lymphoid tissue inducer-like cells.

RESULTS

LTα(-/-) and RORγt(-/-) mice had significantly lower percentages of naturally occurring Th17 cells in the small intestine than wild-type mice. Numbers of CD3(-)CD4(+/-)interleukin-7Rα(+)c-kit(+)CCR6(+)NKp46(-) lymphoid tissue inducer-like cells that produce interleukin-17A were increased in LTα(-/-) and LTα(-/-) × recombination activating gene (RAG)-2(-/-) mice, compared with wild-type mice, but were absent from RORγt(-/-) mice. Parabiosis of wild-type and LTα(-/-) mice and bone marrow transplant experiments revealed that LTα-dependent gut-associated lymphoid tissue structures are required for generation of naturally occurring Th17 cells. However, when wild-type or LTα(-/-) CD4(+)CD45RB(high) T cells were transferred to RAG-2(-/-) or LTα(-/-)×RAG-2(-/-) mice, all groups, irrespective of the presence or absence of LTα on the donor or recipient cells, developed colitis and generated Th1, Th17, and Th17/Th1 cells. RAG-2(-/-) mice that received a second round of transplantation, with colitogenic but not naturally occurring Th17 cells, developed intestinal inflammation. The presence of naturally occurring Th17 cells in the colons of mice inhibited development of colitis after transfer of CD4(+)CD45RB(high) T cells and increased the numbers of Foxp3(+) cells derived from CD4(+)CD45RB(high) T cells.

CONCLUSIONS

Gut-associated lymphoid tissue structures are required to generate naturally occurring Th17 cells that have regulatory activities in normal intestines of mice, but not for colitogenic Th17 and Th17/Th1 cells during inflammation.

[Case report of anesthesia with veno-veno extracorporeal membrane oxygenation (V-V ECMO) during one-lung ventilation for acute respiratory distress syndrome (ARDS) complicated with severe sepsis due to spontaneous esophageal rupture]

A 55-year-old man was transferred to our hospital with spontaneous esophageal rupture. An emergency operation of mediastinum drainage by thoracotomy was performed. On postoperative day 8, he had new abcesses located at the upper mediastinum around the esophagus, and required another operation. But one-lung ventilation for the operation was difficult, because of profound hypoxia caused by the acute respiratory distress syndrome (ARDS) with severe sepsis. Therefore we introduced V-V ECMO for the treatment of severe hypoxia and could anesthetize him safely during surgical operation. Intraoperative and post-operative hemodynamics was stable. His respiratory condition improved, and he was weaned from V-V ECMO. Unfortunately, postoperative day 11, he died because of sudden intrathoracic bleeding from the thoracic aorta which might have been infected by the severe mediastinitis.

IgA plasma cells express the negative regulatory co-stimulatory molecule programmed cell death 1 ligand and have a potential tolerogenic role in the intestine

To maintain immune homeostasis in the intestine, the intestinal immune system has evolved several tolerogenic mechanisms toward intestinal microflora and food antigens. Although programmed cell death-1 (PD-1) protein has been implicated in immunological tolerance in the intestine and gut-associated lymphoid tissues (GALTs), distribution of its ligands PD-L1 and PD-L2 in the small intestine lamina propria (LP) are unknown. We investigated PD-L1 expression in intestinal LP and found that IgA plasma cells (PCs) were major PD-L1 expressing cells. PD-L1 expression levels on IgA PCs were higher than that on IgG PCs in peripheral lymphoid tissues. IgA PCs expressed antigen-presenting molecule MHC class II and co-stimulatory molecules CD80, CD86, and PD-L2. IgA PCs isolated from intestinal LP exhibited antigen presentation activity, and in the presence of TGF-β induced FoxP3(+) regulatory T cells, but not IFN-γ(+) Th1 cells, from naïve T cells. Thus, IgA PCs in the intestine may be involved in an immune regulatory role in the intestinal immune system.

Development of multi-channel Doppler spectroscopic measurement system using 8 × 8 multianode photomultiplier tube assembly

Using an 8 × 8 channel photomultiplier tube assembly and a single Czerny-Turner monochromator, we have developed a novel Doppler spectroscopic system which can measure the time evolutions of spectral distribution of plasma emission from eight different lines of sight simultaneously. An optical lens system is employed to couple the output of the monochromator with the detector assembly, resulting in small cross-talks less than 5% in spatial distribution together with large magnification of up to 50 in wavelength direction. The suggested system yields cost-effective polychromatic measurements of eight spatial channels with uniform optical and electrical characteristics.

Amadori-glycated phosphatidylethanolamine up-regulates telomerase activity in PANC-1 human pancreatic carcinoma cells

Several lines of experimental data have highlighted a key role of Amadori-glycated phosphatidylethanolamine (Amadori-PE) in the development of diabetic complications. Recent epidemiological studies suggest that diabetes mellitus could be a risk factor for some cancers. A characteristic of cancer cells is their immortal phenotype, and the enzyme telomerase contributes to the infinite replicative potential of cancer cells. The purpose of this study was to obtain new information about the effect of Amadori-PE on the regulation of telomerase in PANC-1 human pancreatic carcinoma cells. Amadori-PE enhanced cellular telomerase in a time- and dose-dependent manner by up-regulating hTERT expression through induction of c-myc. These results provide experimental evidence for a novel role of Amadori-PE in linking diabetes and cancer.

Phf14, a novel regulator of mesenchyme growth via platelet-derived growth factor (PDGF) receptor-α

The regulation of mesenchymal cell growth by signaling molecules plays an important role in maintaining tissue functions. Aberrant mesenchymal cell proliferation caused by disruption of this regulatory process leads to pathogenetic events such as fibrosis. In the current study we have identified a novel nuclear factor, Phf14, which controls the proliferation of mesenchymal cells by regulating PDGFRα expression. Phf14-null mice died just after birth due to respiratory failure. Histological analyses of the lungs of these mice showed interstitial hyperplasia with an increased number of PDGFRα(+) mesenchymal cells. PDGFRα expression was elevated in Phf14-null mesenchymal fibroblasts, resulting in increased proliferation. We demonstrated that Phf14 acts as a transcription factor that directly represses PDGFRα expression. Based on these results, we used an antibody against PDGFRα to successfully treat mouse lung fibrosis. This study shows that Phf14 acts as a negative regulator of PDGFRα expression in mesenchymal cells undergoing normal and abnormal proliferation, and is a potential target for new treatments of lung fibrosis.

Expression of Bcl-2, Bcl-x, and Bax proteins in astrocytomas in relation to patient survival

The Bcl-2 family is composed of a group of related proteins that either prevent or promote apoptosis. This study was undertaken to assess the prognostic value of Bcl-2, Bcl-x, and Bax in patients with astrocytomas. Tissue samples from 104 astrocytomas (WHO grade 2, 21 cases: grade 3, 49 cases; grade 4, 34 cases), including 68 primary and 36 recurrent tumors, were examined immunohistochemically for Bcl-2, Bcl-x, and Bax expression. Patient charts were reviewed for clinical presentation, and survival was followed. The mean values of the Bcl-2, Bcl-x, and Bax labeling indexes (LI) were 15.9 +/- 13.1%, 53.2 +/- 35.3%, and 25.9 +/- 23.2%, respectively. Statistical analysis showed that the Bcl-x LI of high-grade (grade 3 or 4) astrocytomas was higher than that of low-grade (grade 2) tumors (P = 0.0064). There were no significant differences in patient survival between the high- and low-LI groups of Bcl-2, Bcl-x, and Bax. Since the mechanism and regulation of apoptosis are still unclear, it seems difficult to use the Bcl-2 family as a biological marker in predicting the prognosis of patients with astrocytomas.

Donor-based single electron pumps with tunable donor binding energy

We report on single electron pumping via a tunable number of individual donors. We use a device that essentially consists of a silicon nanowire with local arsenic implantation between a set of fine gates. A temperature-dependent characterization of the pumped current allows us to extract the ionization energy of a single arsenic donor. We observe the ionization energy to be tunable by the gate electric field over a large range of energies.

CCR9+ macrophages are required for acute liver inflammation in mouse models of hepatitis

BACKGROUND & AIMS

Antigen-presenting cells (APCs) are involved in the induction of liver inflammation. We investigated the roles of specific APCs in the pathogenesis of acute liver injury in mice.

METHODS

We used concanavalin A (con A) or carbon tetrachloride to induce acute liver inflammation in mice and studied the roles of macrophages that express CCR9.

RESULTS

After injection of con A, we detected CCR9(+)CD11b(+)CD11c(-) macrophages that express tumor necrosis factor (TNF)-α in livers of mice, whereas CCR9(+)Siglec-H(+)CD11b(-)CD11c(low) plasmacytoid DCs (pDCs), which are abundant in normal livers, disappeared. The CCR9(+) macrophages were also detected in the livers of RAG-2(-/-) mice, which lack lymphocytes and natural killer T cells, after injection of con A. Under inflammatory conditions, CCR9(+) macrophages induced naive CD4(+) T cells to become interferon gamma-producing Th1 cells in vivo and in vitro. CCR9(-/-) mice injected with con A did not develop hepatitis unless they also received CCR9(+) macrophages from mice that received con A; more CCR9(+) macrophages accumulated in their inflamed livers than CCR9(+) pDCs, CCR9(-) pDCs, or CCR9(-) macrophages isolated from mice that had received injections of con A. Levels of CCL25 messenger RNA increased in livers after injection of con A; neutralizing antibodies against CCL25 reduced the induction of hepatitis by con A by blocking the migration of CCR9(+) macrophages and their production of TNF-α. Peripheral blood samples from patients with acute hepatitis had greater numbers of TNF-α-producing CCR9(+)CD14(+)CD16(high) monocytes than controls.

CONCLUSIONS

CCR9(+) macrophages contribute to the induction of acute liver inflammation in mouse models of hepatitis.

Surgery for aortic regurgitation due to dehiscence of aortic valve commissure

A 74-year-old man underwent aortic valve replacement due to aortic regurgitation after two months of medication for congestive heart failure. At surgery, the cause of the aortic regurgitation appeared to be dehiscence of an aortic valve commissure. Dehiscence was closed with mattress sutures from outside of the sinus. Dehiscence of an aortic valve commissure is rare and difficult to be diagnosed preoperatively, and we carefully repaired it, and the patient had a good recovery.

Ion and electron heating characteristics of magnetic reconnection in a two flux loop merging experiment

Characteristics of the high-power reconnection heating were measured for the first time directly by two-dimensional measurements of ion and electron temperatures. While electrons are heated mainly inside the current sheet by the Ohmic heating power, ions are heated mainly by fast shock or viscosity damping of the reconnection outflow in the two downstream areas. The magnetic reconnection converts the energy of reconnecting magnetic field B(p) mostly to the ion thermal energy, indicating that the reconnection heating energy is proportional to B(p)(2).

Endovascular Treatment of Basilar Trunk Saccular Aneurysms

Basilar artery (BA) trunk aneurysms are rare and still remain a formidable surgical challenge. The purpose of this retrospective study was to report the clinical entities and results of endovascular surgery of BA trunk saccular aneurysms. Between 1995 and 2009, 14 patients with 14 BA trunk saccular aneurysms underwent endovascular surgery. Six patients presented subarachnoid hemorrhage (SAH), three patients had another associated aneurysm which developed SAH, one patient presented with mass effect to the brain stem, and four patients were incidentally discovered. Five ruptured and seven unruptured aneurysms were successfully treated by endovascular surgery. Another one incompletely embolized aneurysm had grown to huge size five years later and the patient underwent a Hunterian ligation with a radial artery graft between the extracranial vertebral artery and the posterior cerebral artery. In one ruptured case, we attempted neck clipping, but this was abandoned because of concern for neck tearing by clipping. The aneurysm was embolized using detachable coils later. BA trunk aneurysms showed characteristic features such as so-called lateral aneurysm (43%), multiple aneurysms (43%) and four BA fenestrations (36%). The unusual high incidence of associated various vascular anomalies suggests that focal wall weakness must be based on the mechanism of aneurysm initiation on the BA trunk. Most patients presented with SAH. Pre-treatment neurological state was predictive for clinical outcome. Endovascular surgery is an effective therapeutic alternative that is associated with low morbidity and mortality rates, and should be considered the first choice treatment.

Regulatory T cells suppress development of colitis, blocking differentiation of T-helper 17 into alternative T-helper 1 cells

BACKGROUND & AIMS

Although T-helper (Th) 17 and Th1 cells are involved in pathogenesis of intestinal inflammation, their developmental pathways and sufficiency to promote disease are not known; nor are the roles of CD4⁺CD25⁺ regulatory T (T(R)) cells in their development.

METHODS

We performed adoptive transfer experiments to investigate the induction and suppression of colitis using naïve CD4⁺CD45RB(high) T cells and/or CD4⁺CD25⁺ T(R) cells that were obtained from retinoid-related orphan receptor gamma t (RORγt) gfp/⁺ or Ly5.1/Ly5.2 congenic mice.

RESULTS

We observed 3 types of colitogenic CD4⁺ Th1 cells (interleukin [IL]-17A⁻interferon [IFN]-γ⁺): RORγt⁻ classical Th1 cells that differentiated directly from naïve T cells; RORγt⁺ Th1-like cells; and RORγt⁻ alternative Th1 cells that were terminally differentiated from RORγt⁺ cells via Th17 (IL-17A⁺IFN-γ⁻), Th17/Th1 (IL-17A⁺IFN-γ⁺), or Th1-like (IL-17A⁻IFN-γ⁺) cells. In this pathway, CD4⁺CD25⁺ T(R) cells suppress the development of not only classical Th1 cells, but also alternative Th1 cells at the transition of Th17/Th1 into alternative Th1 cells, resulting in accumulation of Th17 and Th17/Th1 cells in mice in which the development of colitis was suppressed. Furthermore, T(R) cells regulated the established balance of Th17 and Th1 cells under colitic conditions to yield a high ratio of Th17 and Th17/Th1 cells to Th1 cells in noncolitic conditions.

CONCLUSIONS

Th17 and Th17/Th1 cells become colitogenic alternative Th1 cells via Th17, Th17/Th1, and Th1-like cells, independently of classical Th1 cells. T(R) cells suppress this pathway, resulting in accumulation of Th17 and Th17/Th1 cells.

Atomic Layer Chemical Vapor Deposition of Hafnium Oxide Using Anhydrous Hafnium Nitrate Precursor

HfO2 films have been deposited using anhydrous hafnium nitrate (Hf(NO3)4) as a precursor for atomic layer chemical vapor deposition (ALCVD). These films have been characterized using x-ray diffraction, x-ray reflectivity, atomic force microscopy, current vs. voltage, and capacitance vs. voltage measurements. An advantage of this precursor is that it produces smooth and uniform initiation of film deposition on H-terminated silicon surfaces. As deposited films remained amorphous at temperatures below ∼700°C. The effective dielectric constant of the film (neglecting quantum effects) for films less than ∼15 nm thick, was in the range of kfilm ∼ 10-11, while the HfO2 layer value was estimated to be kHfO2 ∼ 12-14. The lower than expected dielectric constant of the film stack is due in part to the presence of an interfacial layer such as HfSiOx. Excess oxygen may play a role in the lower than expected dielectric constant of the HfO2 layer. Breakdown of HfO2 films occurred at ∼5-7 MV/cm. Leakage current was lower than that of SiO2 films of comparable equivalent thickness.

Development of effective power supply using electric double layer capacitor for static magnetic field coils in fusion plasma experiments

A cost-effective power supply for static magnetic field coils used in fusion plasma experiments has been developed by application of an electric double layer capacitor (EDLC). A prototype EDLC power supply system was constructed in the form of a series LCR circuit. Coil current of 100 A with flat-top longer than 1 s was successfully supplied to an equilibrium field coil of a fusion plasma experimental apparatus by a single EDLC module with capacitance of 30 F. The present EDLC power supply has revealed sufficient performance for plasma confinement experiments whose discharge duration times are an order of several seconds.

Identification of genes expressed during hair follicle induction

The hair follicle is one of the skin appendages that develops through reciprocal epithelial-mesenchymal interactions. Although a large number of studies have been made on the mechanisms of hair follicle development, the whole molecular mechanism that governs hair follicle development remains poorly defined. To further understand the molecular basis of hair follicle development, it is necessary to identify genes that drive hair morphogenesis. As an initial approach, we attempted to identify gene products associated with mouse hair follicle development. Genes upregulated in the vibrissal hair placodes were screened by polymerase chain reaction (PCR)-based cDNA subtraction. The genes thus isolated were evaluated for their hair development-associated induction and spatiotemporal expression by quantitative reverse-transcription-PCR analysis and whole-mount in situ hybridization, respectively. Finally, we identified four genes whose upregulation and spatiotemporal expression in developing hair follicles were confirmed. Successful identification of novel hair development-associated genes will be informative as clues for further characterization of hair follicle development at the molecular level.

Migration, early axonogenesis, and Reelin-dependent layer-forming behavior of early/posterior-born Purkinje cells in the developing mouse lateral cerebellum

Background

Cerebellar corticogenesis begins with the assembly of Purkinje cells into the Purkinje plate (PP) by embryonic day 14.5 (E14.5) in mice. Although the dependence of PP formation on the secreted protein Reelin is well known and a prevailing model suggests that Purkinje cells migrate along the 'radial glial' fibers connecting the ventricular and pial surfaces, it is not clear how Purkinje cells behave in response to Reelin to initiate the PP. Furthermore, it is not known what nascent Purkinje cells look like in vivo. When and how Purkinje cells start axonogenesis must also be elucidated.

Results

We show that Purkinje cells generated on E10.5 in the posterior periventricular region of the lateral cerebellum migrate tangentially, after only transiently migrating radially, towards the anterior, exhibiting an elongated morphology consistent with axonogenesis at E12.5. After their somata reach the outer/dorsal region by E13.5, they change 'posture' by E14.5 through remodeling of non-axon (dendrite-like) processes and a switchback-like mode of somal movement towards a superficial Reelin-rich zone, while their axon-like fibers remain relatively deep, which demarcates the somata-packed portion as a plate. In reeler cerebella, the early born posterior lateral Purkinje cells are initially normal during migration with anteriorly extended axon-like fibers until E13.5, but then fail to form the PP due to lack of the posture-change step.

Conclusions

Previously unknown behaviors are revealed for a subset of Purkinje cells born early in the posteior lateral cerebellum: tangential migration; early axonogenesis; and Reelin-dependent reorientation initiating PP formation. This study provides a solid basis for further elucidation of Reelin's function and the mechanisms underlying the cerebellar corticogenesis, and will contribute to the understanding of how polarization of individual cells drives overall brain morphogenesis.

MyD88-dependent pathway accelerates the liver damage of Concanavalin A-induced hepatitis

We have explored the pathological role of the MyD88 signaling pathway via Toll-like receptors (TLRs) that mediate the recognition of pathogen-associated molecular patterns (PAMPs) in a murine model of autoimmune hepatitis induced by administering Concanavalin A (ConA). We first found that various TLRs and MyD88 molecules were expressed in liver of Con A-treated and untreated wild-type (WT) mice including liver macrophages. Flowcytometric analysis revealed that liver CD11b(+)CD11c(-) and CD11b(+)CD11c(+) antigen-presenting cells express TLR2, although NK and NKT cells did not. When WT and MyD88(-/-) mice were intravenously administered with Con A, the severity of hepatitis was significantly lower in Con A-injected MyD88(-/-) mice than in WT mice in terms of the histopathology, the levels of serum transaminase and pro-inflammatory cytokines (TNF-alpha, IFN-gamma, and IL-6), and upregulation of CD80/CD86 and TNF-alpha on/in liver macrophages. The results provide evidence of a possible contribution of the TLRs-MyD88 signaling pathway in activating TLR-expressing liver macrophages in the autoimmune hepatitis model, and thus indicate that the strategy of blockade of pathological pathogens via the intestinal lumen may be feasible for the treatment of the disease.

BMP signalling permits population expansion by preventing premature myogenic differentiation in muscle satellite cells

Satellite cells are the resident stem cells of adult skeletal muscle, supplying myonuclei for homoeostasis, hypertrophy and repair. In this study, we have examined the role of bone morphogenetic protein (BMP) signalling in regulating satellite cell function. Activated satellite cells expressed BMP receptor type 1A (BMPR-1A/Alk-3) and contained phosphorylated Smad proteins, indicating that BMP signalling is operating during proliferation. Indeed, exogenous BMP4 stimulated satellite cell division and inhibited myogenic differentiation. Conversely, interfering with the interactions between BMPs and their receptors by the addition of either the BMP antagonist Noggin or soluble BMPR-1A fragments, induced precocious differentiation. Similarly, blockade of BMP signalling by siRNA-mediated knockdown of BMPR-1A, disruption of the intracellular pathway by either Smad5 or Smad4 knockdown or inhibition of Smad1/5/8 phosphorylation with Dorsomorphin, also caused premature myogenic differentiation. BMP signalling acted to inhibit the upregulation of genes associated with differentiation, in part, through regulating Id1. As satellite cells differentiated, Noggin levels increased to antagonise BMP signalling, since Noggin knockdown enhanced proliferation and impeded myoblast fusion into large multinucleated myotubes. Finally, interference of normal BMP signalling after muscle damage in vivo perturbed the regenerative process, and resulted in smaller regenerated myofibres. In conclusion, BMP signalling operates during routine satellite cell function to help coordinate the balance between proliferation and differentiation, before Noggin is activated to antagonise BMPs and facilitate terminal differentiation.

The basic helix-loop-helix transcription factor Nato3 controls neurogenic activity in mesencephalic floor plate cells

Floor plate (FP) cells, the ventral midline cells of the developing neural tube, have long been thought to be non-neurogenic organizer cells that control neuronal patterning and axonal guidance. Recent studies have revealed that mesencephalic FP (mesFP) cells have neurogenic activity and generate dopaminergic neurons. However, the mechanisms underlying the control of neurogenic potential in FP cells are not yet fully understood. Here we identified the bHLH factor Nato3 as an FP-specific transcription factor. In Nato3-null mutant mice, FP cells in the spinal cord were correctly specified, but could not properly mature. By contrast, in the developing mesencephalon, loss of Nato3 did not affect FP differentiation, but led to loss of neurogenic activity in the medial subpopulation of mesFP cells by suppressing proneural gene expression and inducing cell cycle arrest. As a consequence, the number of midbrain dopaminergic neurons generated was decreased in mutants. We also found that Hes1, which is known to be required for non-dividing organizer cell development in the neural tube, was aberrantly upregulated in the mesFP cells of Nato3 mutants. Consistently, forced expression of Nato3 repressed Hes1 expression and consequently induced premature neurogenesis. Finally, we showed that forced expression of Hes1 in mesFP cells induced cell cycle arrest and downregulation of proneural factors. Taken together, these results suggest that Nato3 confers neurogenic potential on mesFP cells by suppressing classical non-neurogenic FP cell differentiation, at least in part, through repressing Hes1.