Class-switch recombination (CSR), induced by activation-induced cytidine deaminase (AID), can be divided into two phases: DNA cleavage of the switch (S) regions and the joining of the cleaved ends of the different S regions. Here, we show that the DSIF complex (Spt4 and Spt5), a transcription elongation factor, is required for CSR in a switch-proficient B cell line CH12F3-2A cells, and Spt4 and Spt5 carry out independent functions in CSR. While neither Spt4 nor Spt5 is required for transcription of S regions and AID, expression array analysis suggests that Spt4 and Spt5 regulate a distinct subset of transcripts in CH12F3-2A cells. Curiously, Spt4 is critically important in suppressing cryptic transcription initiating from the intronic Sμ region. Depletion of Spt5 reduced the H3K4me3 level and DNA cleavage at the Sα region, whereas Spt4 knockdown did not perturb the H3K4me3 status and S region cleavage. H3K4me3 modification level thus correlated well with the DNA breakage efficiency. Therefore we conclude that Spt5 plays a role similar to the histone chaperone FACT complex that regulates H3K4me3 modification and DNA cleavage in CSR. Since Spt4 is not involved in the DNA cleavage step, we suspected that Spt4 might be required for DNA repair in CSR. We examined whether Spt4 or Spt5 is essential in non-homologous end joining (NHEJ) and homologous recombination (HR) as CSR utilizes general repair pathways. Both Spt4 and Spt5 are required for NHEJ and HR as determined by assay systems using synthetic repair substrates that are actively transcribed even in the absence of Spt4 and Spt5. Taken together, Spt4 and Spt5 can function independently in multiple transcription-coupled steps of CSR.

We report a case of longitudinal avulsion of the inferior rectus muscle following orbital floor fracture and describe its clinical presentation, computed tomography (CT) features and management. A 53-year-old man felt vertical diplopia in all gaze immediately after the trauma. Orthoptic assessment showed left over right hypertropia of 20 prism diopters and left exotropia of 10 prism diopters in primary position. The left orbital floor fracture and the prolapse of orbital contents into the maxillary sinus were presented by CT. Exploration of the orbit was performed under general anesthesia. The displaced bone fragment was elevated and repositioned below the slastic implant. Diplopia continued in all directions of gaze, although the impairment of depression was reduced postoperatively. A residual left hypertropia of 10 prism diopters and exotropia of 10 prism diopters was present in primary position 1 month after surgery, though there were no enopthalmos or worsening of hypesthesia. Repeated CT revealed the muscle avulsion of inferior rectus at the lateral portion of the belly. The avulsion of a small segment of the inferior rectus and its herniation into maxillary sinus in more posterior views was detected by review of the preoperative images. Muscle avulsion should be considered in the management of orbital fracture if orbital tissue entrapment and nerve paresis are excluded as causes of reduction in ocular motility. A thorough review of the imaging studies for possible muscle injury is required before surgery in all cases of orbital fracture.

Sox9 plays a critical role in early chondrocyte initiation and promotion as well as repression of later maturation. Fellow Sox family members L-Sox5 and Sox6 also function as regulators of cartilage development by boosting Sox9 activation of chondrocyte-specific genes such as Col2a1 and Agc1; however, the regulatory mechanism and other target genes are largely unknown. MicroRNAs (miRNAs) are a class of short, non-coding RNAs that act as negative regulators of gene expression by promoting target mRNA degradation and/or repressing translation. Analysis of genetically modified mice identified miR-140 as a cartilage-specific miRNA that could be a critical regulator of cartilage development and homeostasis. Recent findings suggest Sox9 promotes miR-140 expression, although the detailed mechanisms are not fully understood. In the present study, we demonstrate that the proximal upstream region of pri-miR-140 has chondrogenic promoter activity in vivo. We found an L-Sox5/Sox6/Sox9 (Sox trio) response element and detailed binding site in the promoter region. Furthermore, detailed analysis suggests the DNA binding and/or transactivation ability of Sox9 as a homodimer is boosted by L-Sox5 and Sox6. These findings provide new insight into cartilage-specific gene regulation by the Sox trio.

We retrospectively reviewed the medical records of 45 patients with relapsed acute leukemia after initial allogeneic hematopoietic stem ell transplantation (allo-HSCT). Among 45 patients, a total of 11 patients eventually underwent second allo-HSCT (HSCT-2). Median survival after relapse was 294 days (range, 135-942 days) for HSCT-2. Multivariate analysis showed significantly better survival for recipients of second allo-HSCT than for other patients (hazard ratio, 4.38; 95 % confidence interval, 1.45-13.2; P = 0.009). Although outcomes for patients with relapsed leukemia were generally poor, our results suggest that second HSCT could offer a survival advantage over other conventional salvage strategies.

Mutations in the fused in sarcoma (FUS) gene are linked to a form of familial amyotrophic lateral sclerosis (ALS), ALS6. The FUS protein is a major component of the ubiquitin-positive neuronal cytoplasmic inclusions in both ALS6 and some rare forms of frontotemporal lobar degeneration (FTLD). The latter are now collectively referred to as FTLD-FUS. In the present study, we investigated the localization of FUS in human and mouse brains. FUS was detected by western blot as an approximately 72 kDa protein in both human and mouse brains. Immunohistochemistry using lightly fixed tissue sections of human and mouse brains revealed FUS-positive granular staining in the neuropil, in addition to nuclear staining. Such granules are abundant in the gray matter of the brainstem and spinal cord. They are not frequent in the telencephalon. At the light microscopic level, FUS-positive granules are often co-localized with synaptophysin and present in association with microtubule-associated protein 2-positive dendrites. In the synaptosomal fraction of mouse brain, FUS is detected mainly in the post-synaptic density fraction. Thus, while FUS is primarily a nuclear protein, it may also play a role in dendrites. In the brains of patients with FTLD with TDP-43 deposition (FTLD-TDP), the number of FUS-positive granules in the cortex is increased compared with control cases. The increase in Alzheimer's disease (AD) is less remarkable but still significant. The dendritic localization of FUS and its increase in FTLD-TDP and AD may have some implication for the pathophysiology of neurodegenerative diseases.

Sugar alcohol derivatives with multi azobenzene arms are photochemically and isothermally liquefied from a powdered solid upon irradiation with ultraviolet light at room temperature, and then solidified on irradiation with visible light, where the transition between solid and liquid are reversible. These compounds possess similar chemical structures to comb-like liquid crystalline oligomers.

Microwrinkle grooves serve as open microchannel capillaries, where the capillary action depends on the wettability of a liquid on the groove surface. Here, we report the photoinduced capillary action of a liquid in such microwrinkle grooves. The wettability is changed through the irradiation of a photoresponsive microwrinkle surface. By utilizing micropattern light-projection apparatus, we prepare liquid filaments that fill only the microgrooves prescribed by the patterned light, with micrometer-scale spatial resolution. This new technology enables the precise spatial control of liquids on a solid surface, and thus, is applicable in the fields of micropatterning and open-channel microfluidics.

We have recently reported that Presenilin 1 (PS1), a causative gene of familial Alzheimer disease (AD), down-regulates the expression level of insulin receptor (IR) as well as its signaling through a γ-secretase-independent pathway. PS1 is phosphorylated by glycogen synthase kinase 3 β (GSK3β) at the serine 353 and 357 residues. The main purpose of the present study was to clarify the effect of PS1 phosphorylation on IR/insulin signaling. Here, we demonstrate that the pseudo-phosphorylation mutant of PS1 inhibited IR transcription and reduced IR expression compared with wild type PS1. Importantly, there was a decrease in expression of IR in the AD brains, and the phosphorylation ratio of PS1 was negatively correlated with IR level in the human brain samples. In the data from mouse models of AD, IR reduction was not observed at the pre-Aβ deposition stage but became apparent in that of post-Aβ deposition. Together with our previous reports, these results suggest that phosphorylated PS1 can promote the down-regulation of insulin signaling, which may be a positive feed-forward mechanism inhibiting insulin signaling. Since insulin resistance is reported to be a risk factor for sporadic AD, this PS1-mediated regulatory mechanism of brain insulin signaling may be causally associated with AD pathology. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

To understand mechanisms underlying acquisition of pluripotency, it is critical to identify cells that can be converted to pluripotent stem cells. For this purpose, we focused on unipotent primordial germ cells (PGCs), which can be reprogrammed into pluripotent embryonic germ (EG) cells under defined conditions. Treatment of PGCs with combinations of signaling inhibitors, including inhibitors of MAP2K (MEK), GSK3B (GSK-3beta), and TGFB (TGF-beta) type-1 receptors, induced cells to enter a pluripotent state at high frequency (12.1%) by Day 10 of culture. When we employed fluorescence-activated cell sorting (FACS) to monitor conversion of candidate cells to a pluripotent state, we observed a cell cycle shift to S-phase, indicating enrichment of pluripotent cells, during the early phase of EG formation. Transcriptome analysis revealed that PGCs retained expression of some pluripotent stem cell-associated genes, such as Pou5f1 and Sox2, during EG cell formation. On the other hand, PGCs lost their germ lineage characteristics and acquired expression of pluripotent stem cell markers such as Klf4 and Eras. The overall gene expression profiles revealed by this system provide novel insight into how pluripotency is acquired in germ-committed cells.

A key component in Lewy body (LB) pathology in LB disorders is α-synuclein phosphorylated at serine 129 (pαsyn). However, it is not known if increase in the level of biochemically-measurable pαsyn precedes the presence of histologically-identified Lewy-type synucleinopathy (LTS). To gain sights into possible temporal sequence, we measured levels of pαsyn in cingulate and temporal cortices that develop LTS pathology at later stages of LB disorders. Brain homogenates from128 autopsy cases including normal controls and subjects classified by Unified LTS histopathology staging system were studied. We found that biochemically-measurable pαsyn levels in cingulate and temporal cortices were significantly increased at Unified stages III and IV. When pαsyn levels were compared between LTS density scores instead of Unified stages, significant increases were detected even as LTS density scores increased from 0 to 1 in olfactory bulb and substantia nigra. Therefore, our findings demonstrated that changes of pαsyn levels in cingulate and temporal cortices coincided with the early appearance of the LTS pathology in olfactory bulb and substantia nigra, even though histologically demonstrable LTS was lacking in the cortical region. Therefore, identifying the underlying mechanisms driving these changes could be crucial to understanding the pathogenesis of LB disorders.