Decreased circulating branched-chain amino acids are associated with development of Alzheimer's disease in elderly individuals with mild cognitive impairment.

Background: Nutritional epidemiology has shown that inadequate dietary protein intake is associated with poor brain function in the elderly population. The plasma free amino acid (PFAA) profile reflects nutritional status and may have the potential to predict future changes in cognitive function. Here, we report the results of a 2-year interim analysis of a 3-year longitudinal study following mild cognitive impairment (MCI) participants. Method: In a multicenter prospective cohort design, MCI participants were recruited, and fasting plasma samples were collected. Based on clinical assessment of cognitive function up to 2 years after blood collection, MCI participants were divided into two groups: remained with MCI or reverted to cognitively normal ("MCI-stable," N = 87) and converted to Alzheimer's disease (AD) ("AD-convert," N = 68). The baseline PFAA profile was compared between the two groups. Stratified analysis based on apolipoprotein E ε4 (APOE ε4) allele possession was also conducted. Results: Plasma concentrations of all nine essential amino acids (EAAs) were lower in the AD-convert group. Among EAAs, three branched-chain amino acids (BCAAs), valine, leucine and isoleucine, and histidine (His) exhibited significant differences even in the logistic regression model adjusted for potential confounding factors such as age, sex, body mass index (BMI), and APOE ε4 possession (p < 0.05). In the stratified analysis, differences in plasma concentrations of these four EAAs were more pronounced in the APOE ε4-negative group. Conclusion: The PFAA profile, especially decreases in BCAAs and His, is associated with development of AD in MCI participants, and the difference was larger in the APOE ε4-negative population, suggesting that the PFAA profile is an independent risk indicator for AD development. Measuring the PFAA profile may have importance in assessing the risk of AD conversion in the MCI population, possibly reflecting nutritional status. Clinical trial registration: [https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000025322], identifier [UMIN000021965].

Osteomyelitis of the Pubis Treated by Masquelet Technique in a Football Player: A Case Report.

Introduction: Osteomyelitis pubis is a rare disease that presents with fever, pubic or hip pain, pain during hip movement, and claudication to avoid pain. It most frequently affects young athletes involved in sports that require twisting and cutting, but its exact cause is unknown and no definite treatment has been established. We report a case of pubic osteomyelitis in a young football player who was treated using the Masquelet technique and antibiotics with a good clinical course. Case Reports: A 22-year-old male football player in a national-level university club team visited a nearby clinic complaining of high fever and mild pain in his bilateral hip joints. As a result of examination, we diagnosed osteomyelitis pubis and reconstructed the pubic symphysis by the Masquelet technique. In this case, the joint-like structure of the pubic symphysis was successfully reconstructed, and the patient was able to continue playing the sport. Three years and 3 months after surgery, he had no limitation of bilateral hip joint range of motion and did not display any symptoms while playing football. Conclusion: Masquelet technique could be a novel surgical method for managing osteomyelitis pubis, even in athletes.

A variant of death-receptor 3 associated with rheumatoid arthritis interferes with apoptosis-induction of T cell.

Rheumatoid arthritis (RA) is a chronic polyarthritis of unknown etiology. To unravel the molecular mechanisms in RA, we performed targeted DNA sequencing analysis of patients with RA. This analysis identified a variant of the death receptor 3 (DR3) gene, a member of the family of apoptosis-inducing Fas genes, which contains four single-nucleotide polymorphisms (SNPs) and a 14-nucleotide deletion within exon 5 and intron 5. We found that the deletion causes the binding of splicing regulatory proteins to DR3 pre-mRNA intron 5, resulting in a portion of intron 5 becoming part of the coding sequence, thereby generating a premature stop codon. We also found that this truncated DR3 protein product lacks the death domain and forms a heterotrimer complex with wildtype DR3 that dominant-negatively inhibits ligand-induced apoptosis in lymphocytes. Myelocytes from transgenic mice expressing the human DR3 variant produced soluble truncated DR3, forming a complex with TNF-like ligand 1A (TL1A), which inhibited apoptosis induction. In summary, our results reveal that a DR3 splice variant that interferes with ligand-induced T cell responses and apoptosis may contribute to RA pathogenesis.

A new class of aggregation inhibitor of amyloid-ß peptide based on an O-acyl isopeptide.

Inhibition of amyloid ß peptide (Aß) aggregation is a potential therapeutic approach to treat Alzheimer's disease. We report that an O-acyl isopeptide of Aß1-42 (1) containing an ester bond at the Gly(25)-Ser(26) moiety inhibits Aß1-42 fibril formation at equimolar ratio. Inhibitory activity was retained by an N-Me-ß-Ala(26) derivative (2), in which the ester of 1 was replaced with N-methyl amide to improve chemical stability at physiological pH. Inhibition was verified by fluorescence anisotropy, Western blot, and atomic force microscopy. This report suggests a new class of Aß aggregation inhibitor based on modification of Aß1-42 at Gly(25)-Ser(26).

Tetrapeptides, as small-sized peptidic inhibitors; synthesis and their inhibitory activity against BACE1.

Beta-site amyloid precursor protein cleaving enzyme 1 (BACE1) is known to be involved in the production of amyloid beta-peptide in Alzheimer's disease and is a major target for current drug design. We previously reported substrate-based peptidomimetics, KMI-compounds as potent BACE1 inhibitors. In this study, we designed and synthesized tetrapeptides as low molecular-sized inhibitors. These exhibited high potency against recombinant BACE1, with the highest IC(50) value of 34.6 nM from KMI-927.

Heat shock protein 90 is required for increased DNA binding activity of activator protein-1, a heterodimer of Fos/JunD, in rheumatoid synovial cells under inflammatory stimuli.

We have studied the DNA binding profiles of activator protein-1 (AP-1) involved in synovial overgrowth and osteoporosis in rheumatoid arthritis (RA) in relation to the molecular chaperon heat shock protein 90 (HSP90). The AP-1 binding activity of the nuclear extracts of rheumatoid synovial cells was basically increased as compared with osteoarthritic synovial cells. Upon stimulation with inflammatory cytokines IL-1beta or TNFalpha, the AP-1 binding activity was further increased in rheumatoid synovial cells, and increased AP-1 protein was composed as heterodimers of Fos and JunD which was not known before as a major component of AP-1 in rheumatoid synovial cells. The increase of AP-1 binding activity as induced by inflammatory cytokines was specifically inhibited by geldanamycin, radicicol or herbimycin A, specific inhibitors of HSP90, while AP-1 protein was not decreased by geldanamycin. Further, HSP90 protein was not decreased by the inhibitors. The findings indicate that HSP90 is required for increased AP-1 binding activity of rheumatoid synovial cells under inflammatory stimuli and that AP-1 binding activity is inhibited by functionally inactivating HSP90 with the inhibitors.