OLIG2 is an in vivo bookmarking transcription factor in the developing neural tube in mouse.

Cells possess intrinsic features that are inheritable via epigenetic regulation, such as DNA methylation and histone modification. These inheritable features maintain a unique gene expression pattern, underlying cellular memory. Because of the degradation or displacement of mitotic chromosomes, most transcription factors do not contribute to cellular memory. However, accumulating in vitro evidence indicates that some transcription factors can be retained in mitotic chromosomes called as bookmarking. Such transcription factors may contribute to a novel third mechanism of cellular memory. Since most findings of transcription factor bookmarking have been reported in vitro, little is currently known in vivo. In the neural tube of mouse embryos, we discovered that OLIG2, a basic helix loop helix (bHLH) transcription factor that regulates proliferation of neural progenitors and the cell fate of motoneurons and oligodendrocytes, binds to chromatin through every cell cycle including M-phase. OLIG2 chromosomal localization coincides with mitotic cell features such as the phosphorylation of histone H3, KI67, and nuclear membrane breakdown. Chromosomal localization of OLIG2 is regulated by an N-terminus triple serine motif. Photobleaching analysis revealed slow OLIG2 mobility, suggesting a high affinity of OLIG2 to DNA. In Olig2 N-terminal deletion mutant mice, motoneurons and oligodendrocyte progenitor numbers are reduced in the neural tube, suggesting that the bookmarking regulatory domain is important for OLIG2 function. We conclude that OLIG2 is a de novo in vivo bookmarking transcription factor. Our results demonstrate the presence of in vivo bookmarking in a living organism and illustrate a novel function of transcription factors.

Establishment of neural stem cell culture from the central nervous system of the Iberian ribbed newt Pleurodeles waltl.

Urodele amphibians have exceptional regeneration ability in various organs. Among these, the Iberian ribbed newt (Pleurodeles waltl) has emerged as a useful model organism for investigating the mechanisms underlying regeneration. Neural stem cells (NSCs) are an important source of regeneration in the central nervous system (CNS) and their culture method in vitro has been well established. NSCs form spherical cell aggregates called neurospheres and their formation has been demonstrated in various vertebrates, including some urodele species, but not in P. waltl. In this study, we reported neurosphere formation in brain- and spinal cord-derived cells of post-metamorphic P. waltl. These neurospheres showed proliferative activity and similar expression of marker proteins. However, the surface morphology was found to vary according to their origin, implying that the characteristics of the neurospheres generated from the brain and spinal cord could be similar but not identical. Subsequent in vitro differentiation analysis demonstrated that spinal cord-derived neurospheres gave rise to neurons and glial cells. We also found that cells in neurospheres from P. waltl differentiated to oligodendrocytes, whereas those from axolotls were reported not to differentiate to this cell type under standard culture conditions. Based on our findings, implantation of genetically modified neurospheres together with associated technical advantages in P. waltl could reveal pivotal gene(s) and/or signaling pathway(s) essential for the complete spinal cord regeneration ability in the future.

Cytoplasmic Polyadenylation Element-Binding Protein 1 Post-transcriptionally Regulates Fragile X Mental Retardation 1 Expression Through 3' Untranslated Region in Central Nervous System Neurons.

Fragile X syndrome (FXS) is an inherited intellectual disability caused by a deficiency in Fragile X mental retardation 1 (Fmr1) gene expression. Recent studies have proposed the importance of cytoplasmic polyadenylation element-binding protein 1 (CPEB1) in FXS pathology; however, the molecular interaction between Fmr1 mRNA and CPEB1 has not been fully investigated. Here, we revealed that CPEB1 co-localized and interacted with Fmr1 mRNA in hippocampal and cerebellar neurons and culture cells. Furthermore, CPEB1 knockdown upregulated Fmr1 mRNA and protein levels and caused aberrant localization of Fragile X mental retardation protein in neurons. In an FXS cell model, CPEB1 knockdown upregulated the mRNA levels of several mitochondria-related genes and rescued the intracellular heat shock protein family A member 9 distribution. These findings suggest that CPEB1 post-transcriptionally regulated Fmr1 expression through the 3' untranslated region, and that CPEB1 knockdown might affect mitochondrial function.

Sulfatide with ceramide composed of phytosphingosine (t18:0) and 2-hydroxy FAs in renal intercalated cells.

Diverse molecular species of sulfatide with differences in FA lengths, unsaturation degrees, and hydroxylation statuses are expressed in the kidneys. However, the physiological functions of specific sulfatide species in the kidneys are unclear. Here, we evaluated the distribution of specific sulfatide species in the kidneys and their physiological functions. Electron microscopic analysis of kidneys of Cst-deficient mice lacking sulfatide showed vacuolar accumulation in the cytoplasm of intercalated cells in the collecting duct, whereas the proximal and distal tubules were unchanged. Immunohistochemical analysis revealed that vacuolar H+-ATPase-positive vesicles were accumulated in intercalated cells in sulfatide-deficient kidneys. Seventeen sulfatide species were detected in the murine kidney by iMScope MALDI-MS analysis. The distribution of the specific sulfatide species was classified into four patterns. Although most sulfatide species were highly expressed in the outer medullary layer, two unique sulfatide species of m/z 896.6 (predicted ceramide structure: t18:0-C22:0h) and m/z 924.6 (predicted ceramide structure: t18:0-C24:0h) were dispersed along the collecting duct, implying expression in intercalated cells. In addition, the intercalated cell-enriched fraction was purified by fluorescence-activated cell sorting using the anti-vacuolar H+-ATPase subunit 6V0A4, which predominantly contained sulfatide species (m/z 896.6 and 924.6). The Degs2 and Fa2h genes, which are responsible for ceramide hydroxylation, were expressed in the purified intercalated cells. These results suggested that sulfatide molecular species with ceramide composed of phytosphingosine (t18:0) and 2-hydroxy FAs, which were characteristically expressed in intercalated cells, were involved in the excretion of NH3 and protons into the urine.

Cpeb1 expression is post-transcriptionally regulated by AUF1, CPEB1, and microRNAs.

Cytoplasmic polyadenylation element binding protein 1 (CPEB1) regulates the translation of numerous mRNAs. We previously showed that AU-rich binding factor 1 (AUF1) regulates Cpeb1 expression through the 3' untranslated region (3'UTR). To investigate the molecular basis of the regulatory potential of the Cpeb1 3'UTR, here we performed reporter analyses that examined expression levels of Gfp reporter mRNA containing the Cpeb1 3'UTR. Our findings indicate that CPEB1 represses the translation of Cpeb1 mRNA and that miR-145a-5p and let-7b-5p are involved in the reduction in Cpeb1 expression in the absence of AUF1. These results suggest that Cpeb1 expression is post-transcriptionally regulated by AUF1, CPEB1, and microRNAs.

[A Case of Long-Term Survival after Administration of Regorafenib for Stage â £ Colorectal Cancer].

The patient was a 65-year-old man for whom a right hemicolectomy was performed for transverse colon cancer and multiple lymph node metastases. Peritoneal dissemination was observed throughout the abdominal cavity, and curative resection was not possible. Postoperative diagnosis: pT4bN2M1c(P3), Stage Ⅳc, and mutant RAS status. Therapy consisting of mFOLFOX6 plus bevacizumab was started 1 month after surgery, and up to 25 courses were completed. FOLFIRI plus bevacizumab therapy was performed up to 13 courses as the second-line therapy. Regorafenib 80 mg/day was started as the third-line therapy and the dose was gradually increased. It was performed up to 14 courses for about 13 months, without major adverse events, to keep the disease stable or slow its progression. Although up to 5 courses of FTD/TPI plus bevacizumab therapy were delivered as the fourth-line therapy, he died of disease progression. Regorafenib, which has been approved as a salvage line for metastatic colorectal cancer, features many adverse events, and there are few cases in which the approved dose can be administered. In our case, starting at a low dose resulted in fewer adverse events, adequate disease control, and long-term administration.

Distribution, fine structure, and three-dimensional innervation of lamellar corpuscles in rat plantar skin.

Lamellar corpuscles function as mechanoreceptors in the skin, composed of axon terminals and lamellae constructed by terminal Schwann cells. They are classified into Pacinian, Meissner, and simple corpuscles based on histological criteria. Lamellar corpuscles in rat dermal papilla cells have been reported; however, the morphological aspects have yet to be thoroughly investigated. In the present study, we analyzed the enzyme activity, distribution, fine structure, and three-dimensional innervation of lamellar corpuscles in rat plantar skin. The lamellar corpuscles exhibiting non-specific cholinesterase were densely distributed in rat footpads, evident as notable skin elevations, especially at the apex, the highest portion of the ridges in each footpad. In contrast, only a few lamellar corpuscles were found in other plantar skin areas. Lamellar corpuscle was considered composed of a flat axon terminal Schwann cell lamellae, which were roughly concentrically arranged in the dermal papilla. These histological characteristics correspond to those of the simple corpuscle. Moreover, the axon tracing method revealed that one trunk axon innervated several simple corpuscles. The territory of the trunk axons overlapped with each other. Finally, the animals' footprints were analyzed. During the pausing and walking phases, footpads are often in contact with the floor. These results demonstrate that the type of lamellar corpuscles in the dermal papillae of rat plantar skin is a simple corpuscle and implies that their distribution pattern in the plantar skin is convenient for efficient sensing and transmission of mechanical stimuli from the ground.

AUF1, an mRNA decay factor, has a discordant role in Cpeb1 expression.

Cytoplasmic polyadenylation element binding protein 1 (CPEB1) regulates polyadenylation and subsequent translation of CPE-containing mRNAs involved in various physiological and pathological phenomena. Although the significance of CPEB1-mediated translational regulation has recently been reported, the detailed regulatory mechanism of Cpeb1 expression remains unclear. To elucidate the post-transcriptional regulatory mechanisms of Cpeb1 expression, we constructed reporter plasmids containing various deletions or mutations in the Cpeb1 mRNA 3' untranslated region (3'UTR). We investigated their expression levels in Neuro2a neuroblastoma cells. We found that Cpeb1 expression is regulated through an AU-rich element in its 3'UTR. Furthermore, the mRNA decay factor AU-rich binding factor 1 (AUF1) regulates Cpeb1 expression, and knockdown of AUF1 upregulates Cpeb1 mRNA expression but results in a decrease in CPEB1 protein levels. These findings indicate that AUF1 has a discordant role in the expression of Cpeb1.

Change in phospholipid species of retinal layer in traumatic optic neuropathy model.

Injured optic nerves induce death in almost all retinal ganglion cells (RGC) and cause a loss of axons. To date, we have studied injured RGC axon regeneration by using a traumatic optic nerve injury (TONI) rodent model, and we revealed that axonal regeneration is induced by the graft of an autologous peripheral nerve. The efficient approach to the regeneration of axons thus needs an environmental adjustment of RGC. However, the RGC environment induced by TONI remains unknown. Here, we analyzed female and male C57BL/6 mouse retinal tissue alterations in detail after TONI and focused on the major phospholipid species that are enriched in the whole retina. Reactive astrocyte accumulation, glia scar formation, and demyelination were observed in the injured optic nerve area, while RGC cell death, astrocyte accumulation, and Glial fibrillary acidic protein (GFAP) positive Müller cell increases were detected in the retinal layer. Furthermore, phosphatidylinositol (PI) 18:0/20:4 was localized to three nuclear layer structures: the ganglion cell layer (GCL), the inner nuclear layer (INL), and the outer nuclear layer (ONL) in control retina; however, the localization of 18:0/20:4 PI in TONI was disturbed. Meanwhile, phosphatidylserine (PS) 18:0/22:6 showed that the expression was specifically in the inner plexiform layer (IPL) with similar signal intensity in both cases. Other PS species and phosphatidylethanolamine (PE) were differentially localized in the retinal layer; however, the expressions of PE including docosahexaenoic acid (DHA) were affected by TONI. These results suggest that not only GCL but also other retinal layers were influenced by TONI.

[A Case of Lung Metastases from Rectal Cancer Treated for Quite Long with FOLFIRI plus Ramucirumab as a Late Line of Therapy].

We herein report a case of lung metastases from rectal cancer treated with FOLFIRI plus ramucirumab(Ram)therapy after salvage for a long time. A 44-year-old woman underwent low anterior resection for rectal cancer. Fifteen months after the surgery, mFOLFOX6 plus bevacizumab(BV)therapy was initiated for left obturator lymph node metastases. Although the target lesion shrunk, left lung metastasis was found 36 months after the surgery. Partial resection of the lung metastasis was performed, and carbon-ion radiotherapy for pelvic recurrence was administered. Following these treatments, mFOLFOX6 plus BV therapy was administered again for multiple lung metastases 42 months after the surgery. FOLFIRI plus BV therapy, TAS- 102 plus BV therapy, and regorafenib were then administered because of the disease progression. Although the best supportive care was provided after disease progression, FOLFIRI plus Ram therapy was initiated owing to the patient's wish. Although Grade 3 hematological toxicity was observed, severe digestive symptoms were not noted. Long-term administration(approximately 1 year, 21 courses)of the drugs was possible with withdrawal. The patient died due to disease progression 66 months after recurrence. We experienced a case in which FOLFIRI plus Ram therapy after salvage line could be administered for a quite long time. It has been suggested that anti-VEGF drugs with different targets may improve the prognosis even as a late line of therapy if it is tolerable.

[Efficacy of Negative Pressure Wound Therapy for Post-Operative Wound Dehiscence after Resection of a Metastatic AbdominalWal lTumor from Cecal Cancer during Chemotherapy with Bevacizumab].

A 74-year-old man with recurrence of cecal cancer received systemic chemotherapy(CapeOX plus bevacizumab). After the administration of 9 courses, he reported sudden appearance of bloody bowel discharge. Endoscopic examination could not locate the bleeding point. A CT scan indicated that the small intestine was affected by the recurrence of cancer. Therefore, resection of the small intestine was performed after 6 weeks of drug withdrawal. Although direct closure with fascia incision was performed for the repair of wound dehiscence after surgery, re-dehiscence occurred because of paralytic ileus. Wound lavage and nutritional intervention were performed, followed by negative pressure wound therapy. Excellent wound healing was achieved by this therapeutic approach for 3 months.

Acupuncture Point "Hegu" (LI4) Is Close to the Vascular Branch from the Superficial Branch of the Radial Nerve.

The acupuncture point "Hegu" (LI4) has been used for treating peripheral circulatory failure, which is located in the area covered by the superficial branch of the radial nerve (SBRN). SBRN has branches reaching arteries, so-called vascular branches (VBs), which are thought to be involved in the arterial constriction. The distribution areas of the VBs from the SBRN have been reported, but the positional relationship between these distribution areas and the acupuncture points are not known. To examine the positional relationship between LI4 and VBs from the SBRN, forty hands were examined to assess the positional relationship between the acupuncture points "Erjian" (LI2), "Sanjian" (LI3), LI4, and "Yangxi" (LI5) in the Yangming Large Intestine Meridian of Hand, which are located in the area covered by SBRN, and the VBs from the SBRN. After the VBs were identified, the distances from the acupuncture points (LI2, LI3, LI4, and LI5) to the point where the VBs reached the radial artery or the first dorsal metacarpal artery were measured. VBs reaching the radial arteries were observed in all specimens. The mean distances from LI2, LI3, LI4, and LI5 to the point where the VBs reached the radial artery were 64.2 ± 8.2 mm, 42.0 ± 7.5 mm, 4.3 ± 4.3 mm, and 33.0 ± 4.8 mm, respectively. LI4 was significantly closer than the other acupuncture points (P<0.01). The nerve fibers of the VBs adjacent to the radial artery were confirmed using hematoxylin and eosin staining. Our findings provide anatomical evidence that stimulation at LI4 is used for treating peripheral circulatory failure such as Raynaud's disease. LI4 is significant because it is located at a source point, making it clinically important.

Involvement of PLAGL1/ZAC1 in hypocretin/orexin transcription.

The hypocretin/orexin neuropeptide system coordinates the regulation of various physiological processes. Our previous study reported that a reduction in the expression of pleomorphic adenoma gene­like 1 (Plagl1), which encodes a C2H2 zinc­finger transcription factor, occurs in hypocretin neuron­ablated transgenic mice, suggesting that PLAGL1 is co­expressed in hypocretin neurons and regulates hypocretin transcription. The present study examined whether canonical prepro­hypocretin transcription is functionally modulated by PLAGL1. Double immunostaining indicated that the majority of hypocretin neurons were positive for PLAGL1 immunoreactivity in the nucleus. Notably, PLAGL1 immunoreactivity in hypocretin neurons was altered in response to several conditions affecting hypocretin function. An uneven localization of PLAGL1 was detected in the nuclei of hypocretin neurons following sleep deprivation. Chromatin immunoprecipitation revealed that endogenous PLAGL1 may bind to a putative PLAGL1­binding site in the proximal region of the hypocretin gene, in the murine hypothalamus. In addition, electroporation of the PLAGL1 expression vector into the fetal hypothalamus promoted hypothalamic hypocretin transcription. These results suggested that PLAGL1 may regulate hypothalamic hypocretin transcription.

Morphological characteristics of p75 neurotrophin receptor-positive cells define a new type of glial cell in the rat dorsal root ganglia.

In the dorsal root ganglia (DRG), two types of glial cells (Schwann cells and satellite glial cells) have been identified based on cell morphology and expression of specific markers. In the present study, we observed unknown glial cells that were positive for p75 neurotrophin receptor (p75NTR), and therefore were immunohistochemically and ultrastructurally characterized for the first time. These cells exhibited stronger immunoreactivity against an anti-p75NTR antibody than the DRG neurons (hereafter referred to as p75NTR++ cells). Moreover, these cells covered the glial cells surrounding proximal process of the large-diameter DRG neurons. The proximal process is called "dendro-axon." The p75NTR++ cells were predominantly distributed where the first myelinating Schwann cells appear. The p75NTR++ cells were also positive for the pan-glial cell markers S100, nestin, and Sox10, but negative for fibroblast and macrophage markers. Moreover, they were negative for a satellite glial cell marker, inwardly rectifying potassium channel Kir4.1, as well as a nonmyelinating Schwann cell marker, glial fibrillary acidic protein. In addition, their morphological features were distinct from those of the myelinating Schwann cells. To investigate the three-dimensional ultrastructure of the p75NTR++ cells, we used array tomography combined with correlative light and electron microscopic observation. Three-dimensional ultrastructural observation revealed that the p75NTR++ cells loosely covered glial cells around the dendro-axons with highly ramified processes. Glial cells with these morphological features have not been reported before, indicating that the p75NTR++ glial cells are a new glial cell type in the DRG. Our results will give new insights into cell-cell relationships.

[Efficacy of Laparoscopic Surgery for Elderly Patients with Colorectal Cancer Over 80 Years Old].

The efficacy of laparoscopic surgery for elderly patients aged over 80 years who have colorectal cancer was investigated concerning complications. Sixty-five patients over 80 years old who underwent colorectal cancer resection until January 2018 were enrolled. Factors that led to complication were analyzed retrospectively. Thirty-three men and 32 women were included, with a median age of 83 years. Forty-eight cases were located at the colon; and 17, at the rectum. The median operating time was 164 minutes, including 39 cases treated with the laparoscopic approach. Postoperative complications were observed in 28 cases(43.1%), of which 15(23.1%)had a Clavien-Dindo(CD)classification of Grade BⅡ. These cases had significantly prolonged postoperative hospital stay. Complications included 10 cases of incisional surgical site infection(SSI), 9 cases of ileus, 6 cases of melena, 2 cases of urinary infection, 2 cases of urinary disorder, and 1 case of postoperative death. Open surgery was the only significant factor associated with the incidence of CD classification of BⅡ(p=0.0330). Among the complications, the incisional SSI was reduced by laparoscopic surgery(p=0.0050). The number of laparoscopic surgeries reduced the incidence of CD classification BⅡ of complications in elderly patients aged over 80 years who had with colorectal cancer resection. The use of incisional SSI also decreased with the use of laparoscopic surgery. Laparoscopic surgery for colorectal cancer in elderly patients may lead to reduced complication rates.

Methods for array tomography with correlative light and electron microscopy.

The three-dimensional ultra-structure is the comprehensive structure that cannot be observed from a two-dimensional electron micrograph. Array tomography is one method for three-dimensional electron microscopy. In this method, to obtain consecutive cross sections of tissue, connected consecutive sections of a resin block are mounted on a flat substrate, and these are observed with scanning electron microscopy. Although array tomography requires some bothersome manual procedures to prepare specimens, a recent study has introduced some techniques to ease specimen preparation. In addition, array tomography has some advantages compared with other three-dimensional electron microscopy techniques. For example, sections on the substrate are stored semi-eternally, so they can be observed at different magnifications. Furthermore, various staining methods, including post-embedding immunocytochemistry, can be adopted. In the present review, the preparation of specimens for array tomography, including ribbon collection and the staining method, and the adaptability for correlative light and electron microscopy are discussed.

Differential expression of nuclear lamin subtypes in the neural cells of the adult rat cerebral cortex.

Lamins are type V intermediate filament proteins that are located beneath the inner nuclear membrane. In mammalian somatic cells, LMNB1 and LMNB2 encode somatic lamins B1 and B2, respectively, and the LMNA gene is alternatively spliced to generate somatic lamins A and C. Mutations in lamin genes have been linked to many human hereditary diseases, including neurodegenerative disorders. Knowledge about lamins in the nervous system has been accumulated recently, but a precise analysis of lamin subtypes in glial cells has not yet been reported. In this study we investigated the composition of lamin subtypes in neurons, astrocytes, oligodendrocyte-lineage cells, and microglia in the adult rat cerebral cortex using an immunohistochemical staining method. Lamin A was not observed in neurons and glial cells. Lamin C was observed in astrocytes, mature oligodendrocytes and neurons, but not observed in oligodendrocyte progenitor cells. Microglia also did not stain positive for lamin C which differed from macrophages, with lamin C positive. Lamin B1 and B2 were observed in all glial cells and neurons. Lamin B1 was intensely positive in oligodendrocyte progenitor cells compared with other glial cells and neurons. Lamin B2 was weakly positive in all glial cells compared to neurons. Our current study might provide useful information to reveal how the onset mechanisms of human neurodegenerative diseases are associated with mutations in genes for nuclear lamin proteins.

[A Case of Neuroendocrine Carcinoma of the Ascending Colon That Responded Completely to Chemotherapy].

We report a case of effective treatment comprising mFOLFOX6 plus bevacizumab for neuroendocrine carcinoma of the ascending colon. A 60-year-old woman was admitted for diarrhea and abdominal pain. Colonoscopy showed a Type 2 tumor in the ascending colon. She was diagnosed with neuroendocrine cell carcinoma based on biopsy and immunostaining. CT and MRI showed liver metastasis and lymph node #12a metastasis. Right hemi-colectomy, lymphadenectomy, and partial hepatectomy were performed(T4a, N2, M1b, Stage IV). Neuroendocrine cell carcinoma(small-cell type)was finally diagnosed based on a histological examination because the nuclear fission image was 30(/10HPF)and the Ki-67 index was 42%. Three months after the surgery, multiple lymph node metastases were found using CT and MRI. mFOLFOX6 plus bevacizumab was initiated. After 4 courses of the chemotherapy, the metastases responded completely. A total of 10 courses of chemotherapy were administered. About 2 years and 6 months after the surgery, no recurrence is allowed.

[Analyses of Relapsed Cases after Oxaliplatin-Based Adjuvant Chemotherapy for Colorectal Cancer with Cur A Resection].

INTRODUCTION: There are few reports on the outcome of relapsed cases after curative resection for colorectal cancer(CRC) with adjuvant oxaliplatin-based chemotherapy. Thus, we analyzed such cases. PATIENTS AND METHOD: In total, 48 patients with CRC who received oxaliplatin-based postoperative adjuvant chemotherapy from 2012 were analyzed. The clinical course was examined in 9 cases ofrecurrence. RESULTS: Stages II, III a, and III b(1, 3, and 5 cases, respectively)were judged as recurrence in 9 cases. Metastatic sites were the lungs, local sites, liver, and peritoneum(3, 3, 3, and 1 case[s], respectively). The median time to relapse was 390 days. There were 2 cases ofwild -type RAS and 7 cases ofmutant RAS. Although R0 resection was performed in 1 case, re-relapse was recognized. Another 8 cases involved induced chemotherapy. An oxaliplatin-based regimen was administered as first-line treatment in 4 of8 cases. At present, 5 patients died, and 3 of8 cases could not progress to second-line treatment. The overall survival(OS)after relapse was 475 days, and survival more than 3 years was not observed. CONCLUSION: Recurrent cases after Cur A resection for CRC with oxaliplatin-based adjuvant chemotherapy were examined. Although the 3-year RFS and 5-year OS were relatively good, the prognosis after relapse was quite poor.