Partial suppression of M1 microglia by Janus kinase 2 inhibitor does not protect against neurodegeneration in animal models of amyotrophic lateral sclerosis

BACKGROUND: Accumulating evidence has shown that the inflammatory process participates in the pathogenesis of amyotrophic lateral sclerosis (ALS), suggesting a therapeutic potential of anti-inflammatory agents. Janus kinase 2 (JAK2), one of the key molecules in inflammation, transduces signals downstream of various inflammatory cytokines, and some Janus kinase inhibitors have already been clinically applied to the treatment of inflammatory diseases. However, the efficacy of JAK2 inhibitors in treatment of ALS remains to be demonstrated. In this study, we examined the role of JAK2 in ALS by administering a selective JAK2 inhibitor, R723, to an animal model of ALS (mSOD1(G93A) mice). FINDINGS: Orally administered R723 had sufficient access to spinal cord tissue of mSOD1(G93A) mice and significantly reduced the number of Ly6c positive blood monocytes, as well as the expression levels of IFN-γ and nitric oxide synthase 2, inducible (iNOS) in the spinal cord tissue. R723 treatment did not alter the expression levels of Il-1β, Il-6, TNF, and NADPH oxidase 2 (NOX2), and suppressed the expression of Retnla, which is one of the markers of neuroprotective M2 microglia. As a result, R723 did not alter disease progression or survival of mSOD1(G93A) mice. CONCLUSIONS: JAK2 inhibitor was not effective against ALS symptoms in mSOD1(G93A) mice, irrespective of suppression in several inflammatory molecules. Simultaneous suppression of anti-inflammatory microglia with a failure to inhibit critical other inflammatory molecules might explain this result. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12974-014-0179-2) contains supplementary material, which is available to authorized users

Stable and efficient collection of single photons emitted from a semiconductor quantum dot into a single-mode optical fiber

We study stable and efficient coupling of single photons generated from a quantum dot (QD) into a single-mode fiber (SMF) prepared in a fiber couple module (FCM). We propose a method to focus the objective lens to a sample surface without imaging with the help of laser reflection. By assembling all the constituents, i.e., a pair of lenses, the SMF, and the optical alignment to the QD source, we demonstrate stable single-photon count rate and a high collection efficiency of 43.5% of the photons emitted in air from the QD into the collection lens in the FCM

Deleterious effects of lymphocytes at the early stage of neurodegeneration in an animal model of amyotrophic lateral sclerosis

<p>Abstract</p> <p>Background</p> <p>Non-neuronal cells, such as microglia and lymphocytes, are thought to be involved in the pathogenesis of amyotrophic lateral sclerosis (ALS). Previous studies have demonstrated neuroprotective effects of lymphocytes at the end stage of ALS, partly through induction of alternatively activated microglia (M2 microglia), which are neuroprotective. In this study, we investigated the role of lymphocytes in the early stage of the disease using an animal model of inherited ALS.</p> <p>Methods</p> <p>We established a transgenic mouse line overexpressing the familial ALS-associated G93A-SOD1 mutation (harboring a single amino acid substitution of glycine to alanine at codon 93) with depletion of the Rag2 gene (mSOD1/RAG2-/- mice), an animal model of inherited ALS lacking mature lymphocytes. Body weights, clinical scores and motor performance (hanging wire test) of mSOD1/RAG2-/- mice were compared to those of mutant human SOD1 transgenic mice (mSOD1/RAG2+/+ mice). Activation of glial cells in the spinal cords of these mice was determined immunohistochemically, and the expression of mRNA for various inflammatory and anti-inflammatory molecules was evaluated.</p> <p>Results</p> <p>Clinical onset in mSOD1/RAG2-/- mice was significantly delayed, and the number of lectin-positive cells in spinal cord was increased at the early stage of disease when compared to mSOD1/RAG2+/+ mice. Quantitative RT-PCR confirmed that mRNA for Ym1, an M2 microglial-related molecule, was significantly increased in mSOD1/RAG2-/- mouse spinal cords at the early disease stage.</p> <p>Conclusions</p> <p>Compared with mSOD1/RAG2+/+ mice, mSOD1/RAG2-/- mice displayed delayed onset and increased M2 microglial activation at the early stage of disease. Thus, lymphocytes at the early pathological phase of ALS display a deleterious effect via inhibition of M2 microglial activation.</p

BAFF Controls Neural Cell Survival through BAFF Receptor

<div><p>Various neuroprotective factors have been shown to help prevention of neuronal cell death, which is responsible for the progression of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS). However, most of these therapeutic potentials have been tested by administration of recombinant proteins, transgenic expression or virus vector-mediated gene transfer. Therefore, it remains to be clarified whether any endogenous factors has advantage for neuroprotection in a pathological nervous system. Here we show the role of BAFF-R signaling pathway in the control of neural cell survival. Both B cell–activating factor (BAFF) and its receptor (BAFF-R) are expressed in mouse neurons and BAFF-R deficiency reduces the survival of primary cultured neurons. Although many studies have so far addressed the functional role of BAFF-R on the differentiation of B cells, impaired BAFF-R signaling resulted in accelerated disease progression in an animal model of inherited ALS. We further demonstrate that BAFF-R deficient bone marrow cells or genetic depletion of B cells does not affect the disease progression, indicating that BAFF-mediated signals on neurons, not on B cells, support neural cell survival. These findings suggest opportunities to improve therapeutic outcome for patients with neurodegenerative diseases by synthesized BAFF treatment.</p></div

Neither B lymphocytes nor bone marrow-derived cells affect disease progression or the survival of mSOD1 mice.

<p>(A–C) The absence of B lymphocytes does not affect body weight (A), motor performance (B), or the survival (C) of mSOD1 mice (log rank test for survival, p = 0.051). In panels A and B, n = 15 for mSOD1/μMT mice and n = 19 for control mSOD1 mice. In panel C, n = 20 for mSOD1/μMT mice and n = 35 for control mSOD1 mice. (D–F) BAFF-R–deficient bone marrow cells do not affect body weight (D), motor performance (E), or the survival (F) of mSOD1 mice. (log rank test for survival, p = 0.284) (n = 7 per group) Data are expressed as the mean ± SEM. *:p<0.05, #:p<0.01.</p

BAFF expression in mouse primary cultured neurons and on mouse spinal cord neurons.

<p>(A–D) Primary cultured mouse neurons (A and B) and sections of a mouse spinal cord (C and D) were co-stained with Cy5-conjugated anti-BAFF antibodies (A and C) or control antibodies (B and D) and an Alexa488-conjugated anti-Map2 antibody (A and B) or anti-SMI-32 antibody (C and D). DAPI was also used to stain nuclei. Scale bars represent 20 μm (calculated for each panel). (E) BAFF mRNA expression in 6–3 microglia cells and primary cultured neurons was examined by quantitative RT-PCR. The data are presented as the mean ± s.d. of samples examined in triplicate.</p