👤 Shinji Kanda

Dementia, marked by a decline in mental abilities like memory that interferes with daily life, is primarily caused by Alzheimer's Disease (AD). Symplocos racemosa, rich in acetyl oleanolic acid, serves as a neuroprotective agent by lowering amyloid β levels in the brain. This study aims to develop a nanoemulsion for the targeted delivery of S. racemosa phytoconstituents to enhance therapeutic efficacy against dementia. The study also aims to find out the mechanism of the responsible molecules via molecular docking studies. S. racemosa bark was ultrasonically extracted with methanol and ethyl acetate, yielding six phytoconstituents: ellagic acid, betulinic acid, acetyl oleanolic acid, salireposide (from methanol), oleanolic acid, symlocoside (from ethyl acetate), isolated by column chromatography. Molecular docking against AChE and BACE-1 was conducted using CB Dock-2. A chitosan- based nanoemulsion containing all six compounds was prepared to enhance brain delivery and was physically characterized. All isolated phytoconstituents and nanoemulsions were evaluated for their in vitro enzyme inhibition (AChE and BACE-1) potential. Its anti-dementia efficacy was evaluated in scopolamine-induced rodent models using Hebb-Williams and Elevated Plus Maze tests, complemented by histopathological analysis of the brain cortex to assess therapeutic effects. Docking studies showed acetyl oleanolic acid had stronger binding to BACE-1 and AChE than donepezil. This was further supported by an in vitro enzyme inhibition assay. Nanoemulsion at 200 and 400 mg/kg significantly reduced the time taken by memory-impaired mice to complete the Hebb-Williams Maze and transfer latency in the Elevated Plus Maze. Histopathological analysis showed a significant recovery of cortical damage. This indicates that the nanoemulsion has strong potential for the treatment of Alzheimer 's-related neurodegeneration. The neuroprotective action of S. racemosa nanoemulsion (SRMN) is attributed to the large-scale presence of its phytoconstituents, which reportedly exhibit a better binding affinity and inhibitory action against AChE and BACE-1 than donepezil. Additionally, the nanoemulsion enhanced bioavailability, stability, and blood-brain barrier penetration, which in turn improved therapeutic outcomes. From behavioral and histological studies, we observed that SRMN performed well in terms of memory improvement and cortical protection, suggesting that it is a very good multi-target approach for dementia. The prepared nanoemulsion from S. racemosa's isolated phytoconstituents is reported to exhibit synergistic action, thereby effectively managing dementia through BACE-1 and AChE inhibition. Show less

A 79-year-old female presented with progressive dyspnea. A bone marrow biopsy revealed hypoplastic marrow with abnormal lymphoid cells. A genetic analysis revealed a MYD88 p.V204F mutation, supporting the diagnosis of lymphoplasmacytic lymphoma/Waldenström's macroglobulinemia (LPL/WM). Additional evaluations established a concomitant diagnosis of aplastic anemia (AA). Treatment prioritized AA with cyclosporine and eltrombopag. Subsequently, the LPL/WM was treated with rituximab monotherapy. This sequential treatment resulted in a symptomatic improvement. Although AA is a diagnosis of exclusion, its coexistence with lymphoma is rare. This case highlights the diagnostic and therapeutic complexity of AA and LPL/WM overlap and suggests that prioritizing the treatment of AA may lead to better outcomes. Show less

Neuroblastoma (NB), a common childhood solid tumor, is the leading cause of childhood cancer deaths. Transgelin (TAGLN) is an actin-binding protein of the calponin family, and it is involved in cell motility and migration. The TAGLN gene expression was induced in NB cell lines, such as GOTO, SK-N-SH, and TGW, by gene overexpression using a retroviral Tet-On inducible expression system, and was repressed by RNA interference (RNAi) treatment. TAGLN overexpression repressed cell growth and migration and induced cell arrest and differentiation. On the other hand, RNAi-mediated TAGLN repression activated cell growth. Cells overexpressing TAGLN showed decreased levels of undifferentiated cell markers, such as SOX2, OCT4, KLF4, and ID2. Single-cell analysis after TAGLN overexpression revealed a distinguishable cluster characterized by expression of POSTM, APOE, PDGFRA, IGFBP3, SMAD5, and IGFBP7. In TH-MYCN mice, which have a high frequency of NB development, Tagln overexpression by induction of the murine Tagln gene significantly reduced tumor formation and prolonged survival. In conclusion, these in vitro and in vivo analyses suggest that TAGLN is a candidate tumor suppressor gene in NB. Show less

Ablation of short single cones (SSCs) expressing short-wavelength-sensitive opsin (SWS1) is well analyzed in the field of regenerative retinal cells. In contrast with ablation studies, the phenomena caused by the complete deletion of SWS1 are less well-understood. To assess the effects of SWS1 deficiency on retinal structure, we established and analyzed sws1-mutant medaka. To visualize SWS1, a monoclonal anti-SWS1 antibody and transgenic reporter fish (Tg(sws1:mem-egfp)) were generated. We also developed a CRISPR/Cas-driven sws1-mutant line. Retinal structure of sws1 mutant was visualized using anti-SWS1, 1D4, and ZPR1 antibodies and coumarin derivatives and compared with wild type, Tg(sws1:mem-egfp), and another opsin (lws) mutant. Our rat monoclonal antibody specifically recognized medaka SWS1. Sws1 mutant retained regularly arranged cone mosaic as lws mutant and its SSCs had neither SWS1 nor long wavelength sensitive opsin. Depletion of sws1 did not affect the expression of long wavelength sensitive opsin, and vice versa. ZPR1 antibody recognized arrestin spread throughout double cones and long single cones in wild-type, transgenic, and sws1-mutant lines. Comparative observation of sws1-mutant and wild-type retinas revealed that ZPR1 negativity is not a marker for SSCs with SWS1, but SSCs themselves. Loss of functional sws1 did not cause retinal degeneration, indicating that sws1 is not essential for cone mosaic development in medaka. Our two fish lines, one with visualized SWS1 and the other lacking functional SWS1, offer an opportunity to study neural network synapsing with SSCs and to clarify the role of SWS1 in vision. Show less

Dual-specificity phosphatase 6 (DUSP6) is a key negative feedback regulator of the member of the RAS-ERK MAPK signaling pathway that is associated with cellular proliferation and differentiation. Deterioration of DUSP6 expression could therefore result in deregulated growth activity. We have previously discovered ACA-28, a novel anticancer compound with a unique property to stimulate ERK phosphorylation and induce apoptosis in ERK-active melanoma cells. However, the mechanism of cancer cell-specific-apoptosis by ACA-28 remains obscure. Here, we investigated the involvement of DUSP6 in the mechanisms of the ACA-28-mediated apoptosis by using the NIH/3T3 cells overexpressing HER2/ErbB2 (A4-15 cells), as A4-15 exhibited higher ERK phosphorylation and are more susceptible to ACA-28 than NIH/3T3. We showed that A4-15 exhibited high DUSP6 protein levels, which require ERK activation. Notably, the silencing of the DUDSP6 gene by siRNA inhibited proliferation and induced apoptosis in A4-15, but not in NIH/3T3, indicating that A4-15 requires high DUSP6 expression for growth. Importantly, ACA-28 preferentially down-regulated the DUSP6 protein and proliferation in A4-15 via the proteasome, while it stimulated ERK phosphorylation. Collectively, the up-regulation of DUSP6 may exert a growth-promoting role in cancer cells overexpressing HER2. DUSP6 down-regulation in ERK-active cancer cells might have the potential as a novel cancer measure. Show less

ApoA5 has a critical role in the regulation of plasma TG concentrations. In order to determine whether ApoA5 also impacts ectopic lipid deposition in liver and skeletal muscle, as well as tissue insulin sensitivity, we treated mice with an antisense oligonucleotide (ASO) to decrease hepatic expression of ApoA5. ASO treatment reduced ApoA5 protein expression in liver by 60-70%. ApoA5 ASO-treated mice displayed approximately 3-fold higher plasma TG concentrations, which were associated with decreased plasma TG clearance. Furthermore, ApoA5 ASO-treated mice fed a high-fat diet (HFD) exhibited reduced liver and skeletal muscle TG uptake and reduced liver and muscle TG and diacylglycerol (DAG) content. HFD-fed ApoA5 ASO-treated mice were protected from HFD-induced insulin resistance, as assessed by hyperinsulinemic-euglycemic clamps. This protection could be attributed to increases in both hepatic and peripheral insulin responsiveness associated with decreased DAG activation of protein kinase C (PKC)-ε and PKCθ in liver and muscle, respectively, and increased insulin-stimulated AKT2 pho-sphory-lation in these tissues. In summary, these studies demonstrate a novel role for ApoA5 as a modulator of susceptibility to diet-induced liver and muscle insulin resistance through regulation of ectopic lipid accumulation in liver and skeletal muscle. Show less

Nonalcoholic fatty liver disease (NAFLD) and insulin resistance have recently been found to be associated with increased plasma concentrations of apolipoprotein CIII (APOC3) in humans carrying single nucleotide polymorphisms within the insulin response element of the APOC3 gene. To examine whether increased expression of APOC3 would predispose mice to NAFLD and hepatic insulin resistance, human APOC3 overexpressing (ApoC3Tg) mice were metabolically phenotyped following either a regular chow or high-fat diet (HFD). After HFD feeding, ApoC3Tg mice had increased hepatic triglyceride accumulation, which was associated with cellular ballooning and inflammatory changes. ApoC3Tg mice also manifested severe hepatic insulin resistance assessed by a hyperinsulinemic-euglycemic clamp, which could mostly be attributed to increased hepatic diacylglycerol content, protein kinase C-ϵ activation, and decreased insulin-stimulated Akt2 activity. Increased hepatic triglyceride content in the HFD-fed ApoC3Tg mice could be attributed to a ≈ 70% increase in hepatic triglyceride uptake and ≈ 50% reduction hepatic triglyceride secretion. These data demonstrate that increase plasma APOC3 concentrations predispose mice to diet-induced NAFLD and hepatic insulin resistance. Show less