Analysis of Mutant Isocitrate Dehydrogenase 1 Immunoexpression, Ki-67 and Programmed Death Ligand 1 in Diffuse Astrocytic Tumours : Study of Single Center in Bandung, Indonesia.

OBJECTIVE: Diffuse astrocytic tumour (DAT) is a diffuse infiltrative astrocytoma tumour accompanied by molecular parameters such as the presence or absence of isocitrate dehydrogenase (IDH) gene mutations. Ki-67 is a marker for DAT proliferation, while programmed death ligand 1 (PD-L1) indicates an immune evasion mechanism. This study aimed to analyze the correlation among mutant IDH1 R132H, Ki-67, and PD-L1 immunoexpression in the DAT. METHODS: A cross-sectional study was carried out on 30 paraffin blocks of DAT cases. Paraffin block samples consist of grade II (n=14), grade III (n=8), and grade IV (n=8). In this study, the immunohistochemistry-staining of mutant IDH1 R132H, Ki-67, and PD-L1 were carried out to determine the frequency of DAT with IDH1 mutations. RESULTS: Our study shown the frequency of IDH1 mutations in grade II 50.0% (7/14), grade III 37.5% (3/8), and grade IV 12.5% (1/8). Our study also showed a difference in Ki-67 and PD-L1 expression between each the degree of DAT histopathology (p=0.0001 and p=0.002, respectively). There was an association between both mutant IDH1 R132H, and Ki-67 with PD-L1 expression in DAT (p=0.0087 and p=0.0049, respectively). CONCLUSION: DAT with the mutant IDH1 is frequently observed in grade II and small number of grade III. The expression of wild type IDH1, Ki-67, and PD-L1 were found to be higher in high grade DAT (grade III and grade IV). There is a correlation between each of mutant IDH1 status and Ki-67 with PD-L1 expression in DAT.

The neurological significance of COVID-19: Lesson learn from the pandemic.

Coronavirus Infectious Disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; previously known as 2019 novel coronavirus) is an emerging and rapidly evolving health issue that has been widespread globally and become a pandemic. The typical symptoms of COVID-19 are: a cough, shortness of breath and a fever; from the initial estimates, about 15% of COVID-19 patients present with severe respiratory symptoms and requires hospitalization and intensive care. Recent accumulated evidences showed that the neurological insults also occurred in patients with COVID-19, ranging from mild headache to severe neurological symptoms. In this review, we summarize the COVID-19 and neurological significance of COVID-19.

Identification of Periostin as a Potential Biomarker in Gliomas by Database Mining.

BACKGROUND: Bioinformatics analysis integrating microenvironmental factors and single cell analysis segregated the glioblastoma (GBM) subtype into 3 subtypes: proneural, classic, and mesenchymal. Mesenchymal GBM tends to have the worst survival but benefits from aggressive treatment protocols. Therefore, it is clinically meaningful to identify relevant biomarkers to distinguish the mesenchymal subtype. Moreover, in developing nations with limited resources, rigorous examinations are costly and inefficient for patient care. METHODS: In this study, we analyzed The Cancer Genome Atlas (TCGA)-Glioblastoma and TCGA-Low-Grade Glioma RNA sequencing (RNAseq) cohorts and confirmed that the mesenchymal subtype was associated with the worst prognosis. RESULTS: We identified periostin (POSTN) as a mesenchymal subtype biomarker with prognostic value across histologic grades and confirmed the reliability of POSTN by gene expression meta-analysis combining TCGA, Chinese Glioma Genome Atlas (CGGA) and REMBRANDT (Repository for Molecular Brain Neoplasia Data) GBM cohorts (hazard ratio, 1.71 [range, 1.47-2.07], n = 693) and LGG cohorts (hazard ratio, 2.55 [range, 1.61-4.05], n = 1226). CONCLUSIONS: By using available online glioma databases, our study provided an insight into the expression of POSTN as an independent predictor for patients with glioma (GBM and LGG) and could be useful for diagnostic simplification to identify high-risk groups.

Xeno-free culture for generation of forebrain oligodendrocyte precursor cells from human pluripotent stem cells.

Oligodendrocytes (OLs) show heterogeneous properties that depend on their location in the central nervous system (CNS). In this regard, the investigation of oligodendrocyte precursor cells (OPCs) derived from human pluripotent stem cells (hPSCs) should be reconsidered, particularly in cases of brain-predominant disorders for which brain-derived OPCs are more appropriate than spinal cord-derived OPCs. Furthermore, animal-derived components are responsible for culture variability in the derivation and complicate clinical translation. In the present study, we established a xeno-free system to induce forebrain OPCs from hPSCs. We induced human forebrain neural stem cells (NSCs) on Laminin 511-E8 and directed the differentiation to the developmental pathway for forebrain OLs with SHH and FGF signaling. OPCs were characterized by the expression of OLIG2, NKX2.2, SOX10, and PDGFRA, and subsequent maturation into O4+ cells. In vitro characterization showed that >85% of the forebrain OPCs (O4+ ) underwent maturation into OLs (MBP+ ) 3 weeks after mitogen removal. Upon intracranial transplantation, the OPCs survived, dispersed in the corpus callosum, and matured into (GSTπ+ ) OLs in the host brains 3 months after transplantation. These findings suggest our xeno-free induction of forebrain OPCs from hPSCs could accelerate clinical translation for brain-specific disorders.

Transplantation of feeder-free human induced pluripotent stem cell-derived cortical neuron progenitors in adult male Wistar rats with focal brain ischemia.

The use of human induced pluripotent stem cells (hiPSCs) eliminates the ethical issues associated with fetal or embryonic materials, thus allowing progress in cell therapy research for ischemic stroke. Strict regulation of cell therapy development requires the xeno-free condition to eliminate clinical complications. Maintenance of hiPSCs with feeder-free condition presents a higher degree of spontaneous differentiation in comparison with conventional cultures. Therefore, feeder-free derivation might be not ideal for developing transplantable hiPSC derivatives. We developed the feeder-free condition for differentiation of cortical neurons from hiPSCs. Then, we evaluated the cells' characteristics upon transplantation into the sham and focal brain ischemia on adult male Wistar rats. Grafts in lesioned brains demonstrated polarized reactivity toward the ischemic border, indicated by directional preferences in axonal outgrowth and cellular migration, with no influence on graft survival. Following the transplantation, forelimb asymmetry was better restored compared with controls. Herein, we provide evidence to support the use of the xeno-free condition for the development of cell therapy for ischemic stroke.

Histopathological Features of Brain Arteriovenous Malformations in Japanese Patients.

Clinical features of high risk brain arteriovenous malformations (BAVMs) are well characterized. However, pathological evidences about the differences that are possessed by high risk patients are still lacking. We reviewed archived routine hematoxylin-eosin specimens from a total of 54 surgical treated BAVMs. The histopathological features in nidus were semi-quantitatively analyzed. We obtained the pathological differences of BAVMs nidus between several clinical features. Among the analyzed pathological features, the significant differences were observed in degree of venous enlargement and intimal hyperplasia. Juvenile, female, diffuse nidus, high Spetzler-Martin grade, and low flow patients had a lesser degree of those parameters compared to adult, male, compact nidus, low Spetzler-Martin grade and high flow patients. High risk profiles of BAVMs patients were well-reflected in the nidus pathology. Therefore, juvenile, female, diffuse nidus, and low flow in Japanese BAVMs patients might have different vascular remodeling process that predispose to higher tendency of hemorrhage.

Histopathological Characteristics of Distal Middle Cerebral Artery in Adult and Pediatric Patients with Moyamoya Disease.

Moyamoya disease (MMD) is a unique progressive steno-occlusive disease of the distal ends of bilateral internal arteries and their proximal branches. The difference in clinical symptoms between adult and children MMD patients has been well recognized. In this study, we sought to investigate the phenomenon through histopathological study. Fifty-one patients underwent surgical procedures for treatment of standard indications of MMD at Kyoto University Hospital. Fifty-nine specimens of MCA were obtained from MMD patients during the surgical procedures. Five MCA samples were also obtained in the same way from control patients. The samples were analyzed by histopathological methods. In this study, MCA specimens from MMD patients had significantly thinner media and thicker intima than control specimens. In subsequent analysis, adult (≥ 20 years) patients had thicker intima of MCA compared to pediatric (< 20 years) patients. There is no difference in internal elastic lamina pathology between adult and pediatric patients. Our results indicated that the pathological feature of MMD in tunica media occurs in both adult and pediatric patients. However, the MMD feature in tunica intima of MCA is more prominent in adult patients. Further analysis from MCA specimens and other researches are necessary to elucidate the pathophysiology of MMD.

Immunohistochemical Analysis of Sox17 Associated Pathway in Brain Arteriovenous Malformations.

BACKGROUND: Sox17 has emerged as an important factor in vascular remodeling because of the potential linkage with Wnt/ß-catenin, Notch, and the inflammatory pathway. Brain arteriovenous malformation (BAVM), as an angiogenic and inflammatory disorder, might possess an aberrant regulation of the Sox17 associated pathway. We sought to investigate the expression of the Sox17 associated pathway in BAVMs. METHODS: Using immunohistochemical methods, 16 paraffin specimens of BAVM nidus were analyzed. Specimens were obtained from patients during surgical procedures. RESULTS: Expression of Sox17, Hey1, and ß-catenin was observed in all specimens. Large veins possessed a distinct pattern of expression; thick-walled veins had a stronger intensity, whereas thin-walled veins had a weaker intensity, of Sox17, Hey1, and ß-catenin (P < 0.001). Thick-walled veins also had a higher expression of Sox17, Hey1, and ß-catenin compared with large arteries (P < 0.05). Hey1 and ß-catenin expression was also higher in thick-walled veins compared with brain microvessels (P < 0.01). In addition, the difference in expression of the Sox17 associated pathway (Hey1 and ß-catenin) was observed in medium and small arteries compared with large arteries in BAVM nidus and brain microvessels (P < 0.01). CONCLUSIONS: The Sox17 associated pathway was activated in the BAVM nidus. Our results indicate that arterial identity is gained in thick-walled veins; this might reflect the process of arterialization of the veins as a result of hemodynamic stress. In addition, high expression of the Sox17 associated pathway in medium and small arteries indicates that BAVM vessels are intrinsically active.