Amine Pharma (Japan)

Dementia, including Alzheimer's disease (AD), is one of the serious diseases at advanced age, and its early detection is important for maintaining quality of life (QOL). In this study, we sought novel biomarkers for dementia in urine. Samples of urine were collected from 57 control subjects without dementia, 62 mild cognitive impairment (MCI) patients, and 42 AD patients. Mini-Mental State Examination (MMSE) was evaluated when subjects were examined by medical doctors. Urinary amino acid (lysine)-conjugated acrolein (AC-Acro) was measured using N ɛ-(3-formyl-3, 4-dehydropiperidine) lysine (FDP-Lys) ELISA kit, and taurine content was measured using a taurine assay kit. Values were normalized by creatinine content which was measured with the colorimetric assay kit. We found that urinary amino acid (lysine)-conjugated acrolein (AC-Acro) and taurine negatively correlated with MMSE score and are significantly lower in dementia patients compared to the normal subjects. When AC-Acro and taurine were evaluated together with age using an artificial neural network model, median relative risk values for subjects with AD, subjects with mild cognitive impairment, and control subjects were 0.96, 0.53, and 0.06, respectively. Since urine is relatively easy to collect, our findings provide a novel biomarker for dementia without invasiveness.

Abstract Brain stroke is a major cause of being bedridden for elderly people, and preventing stroke is important for maintaining quality of life (QOL). Acrolein is a highly reactive aldehyde and causes tissue damage during stroke. Decreasing acrolein toxicity ameliorates tissue injury during brain stroke. In this study, we tried to identify food components which decrease acrolein toxicity. We found that 2-furanmethanethiol, cysteine methyl and ethyl esters, alliin, lysine and taurine decreased acrolein toxicity. These compounds neutralized acrolein by direct interaction. However, the interaction between acrolein and taurine was not so strong. Approximately 30 mM taurine was necessary to interact with 10 µM acrolein, and 2 g/kg taurine was necessary to decrease the size of mouse brain infarction. Taurine also slightly increased polyamine contents, which are involved in decrease in the acrolein toxicity. Mitochondrial potential damage by acrolein was also protected by taurine. Our results indicate that daily intake of foods containing 2-furanmethanethiol, cysteine methyl and ethylesters, alliin, lysine and taurine may prevent severe injury in brain stroke and improve the quality of life for elderly people.

An extreme thermophile, Thermus thermophilus grows at an optimum temperature of around 70°C and produces 16 different polyamines including long-chain and branched-chain polyamines. We found that the composition of polyamines in the thermophile cells changes with culture temperature. Long-chain and branched-chain polyamines (unusual polyamines) were increased in the cells grown at high temperature such as 80°C, but they were minor components in the cells grown at relatively lower temperature such as 60°C. The effects of polyamines on cell growth were studied using T. thermophilus HB8 ΔspeA deficient in arginine decarboxylase. Cell growth of this mutant strain was significantly decreased at 70°C. This mutant strain cannot produce polyamines and grows poorly at 75°C. It was also determined whether polyamines are directly involved in protecting DNA from DNA double-strand breaks (DSBs) induced by heat. Polyamines protected DNA against double-strand breaks. Therefore, polyamines play essential roles in cell growth at extremely high temperature through maintaining a functional conformation of DNA against DSBs and depurination.

Infiltration of peripheral immune cells after blood-brain barrier dysfunction causes severe inflammation after a stroke. Although the endothelial glycocalyx, a network of membrane-bound glycoproteins and proteoglycans that covers the lumen of endothelial cells, functions as a barrier to circulating cells, the relationship between stroke severity and glycocalyx dysfunction remains unclear. In this study, glycosaminoglycans, a component of the endothelial glycocalyx, were studied in the context of ischemic stroke using a photochemically induced thrombosis mouse model. Decreased levels of heparan sulfate and chondroitin sulfate and increased activity of hyaluronidase 1 and heparanase (HPSE) were observed in ischemic brain tissues. HPSE expression in cerebral vessels increased after stroke onset and infarct volume greatly decreased after co-administration of N-acetylcysteine + glycosaminoglycan oligosaccharides as compared with N-acetylcysteine administration alone. These results suggest that the endothelial glycocalyx was injured after the onset of stroke. Interestingly, scission activity of proHPSE produced by immortalized endothelial cells and HEK293 cells transfected with hHPSE1 cDNA were activated by acrolein (ACR) exposure. We identified the ACR-modified amino acid residues of proHPSE using nano LC–MS/MS, suggesting that ACR modification of Lys139 (6-kDa linker), Lys107, and Lys161, located in the immediate vicinity of the 6-kDa linker, at least in part is attributed to the activation of proHPSE. Because proHPSE, but not HPSE, localizes outside cells by binding with heparan sulfate proteoglycans, ACR-modified proHPSE represents a promising target to protect the endothelial glycocalyx.

It is well known that schizophrenic patients have high incidence of metabolic syndrome and life-style related diseases. There are reports that the rates of these diseases are increased more in outpatients than inpatients, but are also reports that the rates are not different between both patient groups. These differences might be related to the length of hospitalization. Hospitalization of Japanese psychiatric patients is about 300 days, much longer than western countries (below 50 days). Therefore, we investigated lipid and glucose metabolism of schizophrenic patients transferred from hospitalization to outpatients at Kohnodai hospital with a mean of 80 days hospitalization period to clarify metabolic characteristics in Japanese patients. Study participants were 144 schizophrenia inpatients and 109 outpatients at Kohnodai Hospital. These 109 outpatients were followed for approximately 2 years, without changes of administrated drugs, and from 144 inpatients. Data from outpatients were obtained at 6 months, 1 year and 2 years after their discharge. Outpatients 2 years after discharge had significantly higher levels of total cholesterol, triglyceride and non-high density lipoprotein (non-HDL) cholesterol than inpatients, accompanied with an increase of body weight. Serum HDL-cholesterol (HDL-C), low density lipoprotein-cholesterol (LDL-C), fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) levels had no significant difference between both groups. These lipids and glucose levels also showed the same tendency in outpatients 0.5 year and 1 year after discharge as those after 2 years. We found that schizophrenic patients in our study appeared to have changes of lipid metabolism 2 years after their discharge, but no significant changes of glucose metabolism, such as FPG and HbA1c.

Mast cells have secretory granules containing chemical mediators such as histamine and play important roles in the immune system. Polyamines are essential factors for cellular processes such as gene expression and translation. It has been reported that secretory granules contain both histamine and polyamines, which have similar chemical structures and are produced from the metabolism of cationic amino acids. We investigated the effect of polyamine depletion on mast cells using bone marrow-derived mast cells (BMMCs). Polyamine depletion was induced using α-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase. DFMO treatment resulted in a significant reduction of cell number and abnormal secretory granules in BMMCs. Moreover, the cells showed a 2.3-fold increase in intracellular histamine and up-regulation of histidine decarboxylase (HDC) at the transcriptional level during BMMC differentiation. Levels of the transcription factor kruppel-like factor 4 (KLF4) greatly decreased upon DFMO treatment; however, Klf4 mRNA was expressed at levels similar to controls. We determined the translational regulation of KLF4 using reporter genes encoding Klf4-luc2 fusion mRNA, for transfecting NIH3T3 cells, and performed in vitro translation. We found that the efficiency of KLF4 synthesis in response to DFMO treatment was enhanced by the existence of a GC-rich 5'-untranslated region (5'-UTR) on Klf4 mRNA, regardless of the recognition of the initiation codon. Taken together, these results indicate that the enhancement of histamine synthesis by DFMO depends on the up-regulation of Hdc expression, achieved by removal of transcriptional suppression of KLF4, during differentiation.

The polyamines (PA) putrescine, spermidine, and spermine have numerous roles in the growth of both prokaryotic and eukaryotic cells. For example, it is well known that putrescine and spermidine are strongly involved in proliferation and viability of Escherichia coli cells. Studies of polyamine functions and distributions in E. coli cells have revealed that polyamines mainly exist as an RNA-polyamine complex. Polyamines stimulate the assembly of 30S ribosomal subunits and thereby increase general protein synthesis 1.5- to 2.0-fold. Moreover, these studies have shown that polyamines stimulate synthesis of 20 different proteins at the level of translation, which are strongly involved in cell growth and viability. The genes encoding these 20 different proteins were termed as the "polyamine modulon." We here review the mechanism of activation of 30S ribosomal subunits and stimulation of specific proteins. Other functions of polyamines in E. coli are also described.

Polyamines exist mainly as RNA-polyamine complexes in cells. Thus, we looked for proteins whose synthesis is enhanced by polyamines at the level of translation in mammalian cells. Here, we describe how synthesis of Cct2 (T-complex protein 1, β-subunit, a chaperonin assisting in the folding actin, tubulin, and several other proteins) and eEF1A (one of the elongation factors of protein synthesis) is stimulated by polyamines at the level of translation. Polyamines stimulated Cct2 synthesis through the stimulation of ribosome shunting during 5'-processive scanning of 40S ribosomal subunits from the m7G-cap to the initiation codon AUG, and eEF1A synthesis through the structural change of the unusual position of a complementary sequence to 18S rRNA in eEF1A mRNA.