Biomedical Research-tokyo最新文献

Reactive oxygen species (ROS) production in disused skeletal muscle induces capillary regression, which disrupts the balance of pro- and anti-angiogenic factors. We tested whether green coffee bean extract containing rich chlorogenic acid, which has antioxidant properties, can prevent capillary regression caused by muscle atrophy. The study included 24 female Sprague-Dawley rats, randomly assigned to four groups: control (CON), 2-week hindlimb unloading (HU), 2-week hindlimb unloading supplemented with coffee extract rich in chlorogenic acids (HU+50%CGA), and 2-week hindlimb unloading supplemented with trace amounts of chlorogenic acids (HU+5%CGA). Rats in the HU+50%CGA and HU+5%CGA groups received an oral dose of coffee extract at 850 mg/kg per day. The effects of chlorogenic acids in coffee extracts were investigated by comparing these groups. Unloading increased oxidative stress, disrupted mitochondrial oxidative activity, and upregulated TSP-1 expression, triggering endothelial cell apoptosis and leading to capillary regression. In contrast, the supplementation with coffee extract containing rich chlorogenic acids prevented ROS overproduction and improved metabolic activity, promoting angiogenesis by correcting the imbalance of pro- and anti-angiogenic factors, and inhibiting endothelial cell apoptosis. In conclusion, green coffee bean extract rich in chlorogenic acids inhibits ROS production, enhances mitochondrial metabolism, mitigates capillary regression by promoting angiogenesis and preventing apoptosis.

Gastric cancer (GC) has benefited from treatment improvements such as minimally invasive surgery, molecular-targeted drugs, and immune check point inhibitors. However, the prognosis of advanced GC is still unfavorable. Minimally invasive pre-treatment detection of drug sensitivity (MI-PDDS) has increasing importance in view of improved chemotherapy. Gastric biopsy specimens are obtained with relative ease but have not been considered an appropriate source for generating cell lines because of their minute amounts. We therefore materialized the idea of MI-PDDS using biopsy-derived cell lines obtained from endoscopic biopsy specimens. Here, a cell line designated TCC-GC1-C1 was established from a biopsy specimen of a histologically confirmed adenocarcinoma of the stomach. The cell line showed the ability of forming spheroid with deeply stained nuclei and disturbed cellular morphology indicative of malignancy. Single-nucleotide polymorphism (SNP) genotyping of the cell line revealed a duplication of chromosome19q and a deletion of chromosome 8p. A drug screening test with 221 anticancer drugs showed that the cell line had high sensitivity to the proteasome inhibitor (Carfilzomib) and the fibroblast growth factor receptor inhibitor (Erdafitinib), with a low IC50 value of under 0.1 μM. Our MI-PDDS approach holds promise in making a treatment decision for advanced GC.

Following accidental radiation exposure due to a radiological or nuclear emergency, a dose assessment should be performed based on biological samples from exposed individuals. Although previous biological dose assessment approaches have focused on nuclear DNA damage in peripheral lymphocytes, this study investigated the radiation-induced impact on the mitochondrial genome, particularly the chronological changes in the mitochondrial DNA copy number (mtDNAcn) following exposure to radiation. We used B-lymphoblastoid cell lines transformed by Epstein-Barr virus established from 12 healthy individuals in their 20s (six males, six females) with or without a history of smoking. Using real-time quantitative PCR, we determined the mtDNAcn from the B cells cultured for 6, 24, and 96 h and after exposure to 0, 1, 2, and 4 Gy X-rays. We found a significant relationship between the exposed dose and mtDNAcn in the 96-hour post-irradiation cells for non-smoking males, suggesting the possible role of mtDNAcn as a biomarker for dose assessment.

Cleft lip is a birth defect associated with environmental and genetic factors. Recently, microRNAs (miRNAs) have been reported to play a crucial role in lip formation, with the disruption of miRNAs influencing the development of cleft lip. Exposure to medicinal agents in pregnant women is one of the reasons for cleft lip. Although an association between pharmaceuticals-induced cleft lip and miRNAs has been suggested, it remains to be fully elucidated. This study aimed to clarify the molecular mechanism of mycophenolate mofetil (MPM)-induced inhibition of cell proliferation and miRNA expression in human lip fibroblast (KD) cells. Cell viability, apoptosis, and cell cycle-related markers were evaluated after 72 h of MPM treatment. In addition, miRNA levels and the expression of their downstream genes were measured, and a rescue experiment was performed by overexpressing PAX9. We showed that MPM dose-dependently reduced the viability of KD cells. In addition, MPM treatment suppressed cyclin-D1 and cyclin dependent kinase-6 expression in KD cells. Furthermore, MPM upregulated miR-205 expression and downregulated the expression of PAX9 (downstream gene). Moreover, PAX9 overexpression alleviated MPM-induced inhibition of cell proliferation. These results suggest that MPM suppresses cell viability by modulating miR-205-PAX9 expression.

Kidney stone disease is a serious disease due to the severe pain it causes, high morbidity, and high recurrence rate. Notably, calcium oxalate stones are the most common type of kidney stone. Calcium oxalate appears in two forms in kidney stones: the stable phase, monohydrate (COM), and the metastable phase, dihydrate (COD). Particularly, COM stones with concentric structures are hard and difficult to treat. However, the factor determining the growth of either COM or COD crystals in the urine, which is supersaturated for both phases, remains unclear. This study shows that calcium phosphate ingredients preferentially induce COM crystal nucleation and growth, by observing and analyzing kidney stones containing both COM and COD crystals. The forms of calcium phosphate are not limited to Randall's plaques (1-2 mm size aggregates, which contain calcium phosphate nanoparticles and proteins, and form in the renal papilla). For example, aggregates of strip-shaped calcium phosphate crystals and fields of dispersed calcium phosphate microcrystals (nano to micrometer order) also promote the growth of concentric COM structures. This suggests that patients who excrete urine with a higher quantity of calcium phosphate crystals may be more prone to forming hard and troublesome COM stones.

Electromagnetic fields (EMFs) noninvasively promote fracture healing, prevent osteoporosis, promote diaphyseal growth, enhance differentiation, and stimulate cell division. However, no good model systems for analyzing bone regeneration have been reported. In this study, we examined the in vivo regeneration of scales having osteoblasts and osteoclasts using a new magnetic field generator for exposing aquatic animals to EMFs at a sine-wave frequency of 60 Hz. Goldfish scales were put into a fish-breeding space with the developed magnetic field generator and exposed to extremely low-frequency electromagnetic fields (ELF-EMFs) of 60 Hz at an intensity of 1, 3, and 5 mT for 10 days while being regenerated the scales. After exposure, alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) activities in the goldfish scales were measured as markers of osteoblasts and osteoclasts, respectively. As a result, both ALP and TRAP activities in regenerating scales exposed to 3 mT ELF-EMFs were higher than those in regenerating scales exposed to 1 and 5 mT ELF-EMFs. Exposure of scales to 3 mT ELF-EMFs significantly enhanced the scale regeneration rate. Exposure of rat calvaria to 3 mT ELF-EMFs also increased both ALP and TRAP activities like in goldfish scales. Thus, we concluded that 3 mT ELF-EMFs contribute to the medical treatment of bone diseases.

In drug discovery research, it is important to identify target proteins of bioactive small-molecule compounds and analyse their functions. In this study, we examined whether target membrane proteins could be captured by compounds that bind to membrane proteins on the cell surface. For this purpose, we performed affinity purification using the compound-immobilized nanomagnetic beads. Affinity purification with nanomagnetic beads is known to be effective for determining the protein binding partners of small molecules. However, most previous studies have targeted proteins in the cytoplasm. As a model compound, we chose BMS-1166 (a representative small-molecule compound from Bristol Myers Squibb), a PD-1/PD-L1 immune checkpoint inhibitor that binds to PD- L1 and promotes PD-L1 dimerization. BMS-1166-immobilized beads were manufactured and incubated with extracts of cells with high PD-L1 protein expression. The bound protein was confirmed by western blotting and proteomic analysis to be PD-L1. BMS-1166-immobilized nano-magnetic beads were able to specifically bind and capture the membrane protein PD-L1. In addition, high-purity protein could be obtained from cell extracts in a single step. This is the first report of the purification of a membrane protein to high purity with nanobeads. Nanomagnetic beads with immobilized compounds are an effective tool for identifying the protein binding partners of small molecules, especially when the targets are membrane proteins.

Mixed lymphocyte culture under the blockade of CD80/CD86-CD28 co-stimulation induces anergic (completely hyporesponsive) T cells with immune suppressive function (inducible suppressing T cells: iTS cells). Previously, iTS cell therapy has demonstrated outstanding benefits in clinical trials for organ transplantation. Here, we examined whether peptide antigen-specific iTS cells are inducible. DO 11.10 iTS cells were obtained from splenocytes of BALB/c DO 11.10 mice by stimulation with OVA peptide and antagonistic anti-CD80/CD86 mAbs. When DO 11.10 iTS or Foxp3- DO 11.10 iTS cells were stimulated with OVA, these cells produced IL-13, but not IL-4. DO 11.10 iTS cells decreased IL-4 and increased IL-13 production from OVA-stimulated naïve DO 11.10 splenocytes. When Foxp3+ DO 11.10 iTS cells were prepared, these cells significantly inhibited the production of IL-4 and IL-13 compared with freshly isolated Foxp3+ DO 11.10 T cells. Moreover, an increase in the population expressing OX40, ICOS, and 4-1BB suggested activation of Foxp3+ DO 11.10 iTS cells. Thus, blockade of CD80/CD86-CD28 co-stimulation during peptide antigen stimulation augments the inhibitory function of Foxp3+ regulatory T cells, and does not induce anergic Foxp3- conventional T cells. Peptide-specific Foxp3+ regulatory iTS cells could be useful for the treatment of allergic and autoimmune diseases without adverse effects.

Copper (Cu) is known to induce oxidative stress and apoptosis in the liver, kidney, and brain. We previously demonstrated the molecular mechanism underlying the Cu-induced hepatic diurnal variation. However, the cellular molecule(s) involved in Cu-induced renal chronotoxicity remain unknown. In this study, we aimed to elucidate the molecular mechanisms underlying Cu-induced diurnal toxicity in the kidneys. We evaluated cell viability and clock gene expression levels in mouse renal cortex tubular cells (MuRTE61 cells) after Cu treatment. We also examined the Cu homeostasis- and apoptosis-related gene levels after period 1 (Per1) overexpression in MuRTE61 cells. Cu treatment decreased MuRTE61 cell viability in a dose-dependent manner. It increased the Per1 expression levels after 24 h. Notably, Per1 overexpression alleviated the Cu-induced inhibition of MuRTE61 cell viability. Moreover, Per1 overexpression downregulated the cleaved caspase-3 and reduced Cu levels by upregulating the antioxidant 1 copper chaperone (Atox1) levels. These results suggest that Cu-induced renal toxicity is associated with Per1 expression via the regulation of the copper chaperone, Atox1.

Linalool and linalyl acetate are major components of lavender essential oil. These substances possess many biological activities, such as anti-inflammatory activity, analgesic and anxiolytic effects, and anticonvulsant properties, and they also induce modulation of neuronal activity in the autonomic nervous system. However, there are no reports of the direct effects of linalool on respiratory activity. In the present study, we analyzed the effects of linalool and linalyl acetate on central respiratory activity in the brainstem-spinal cord preparation isolated from newborn rats. Linalool dose-dependently decreased the rate of respiratory activity. This effect was reversed by bicuculline, suggesting that linalool enhanced inhibitory synaptic connections via GABAA receptors. In addition, linalool reduced the coefficient of variation of inspiratory burst intervals and thus could work to stabilize the respiratory rhythm. Linalyl acetate did not cause inhibitory effects as observed in linalool treatment. Linalool depressed burst activity of pre-inspiratory neurons in the medullary respiratory networks and increased the amplitude of inspiratory inhibitory postsynaptic potentials of pre-inspiratory neurons. We concluded that linalool caused inhibitory effects on respiratory rhythm generation mainly through activation of presynaptic GABAA receptors of pre-inspiratory neurons.