Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary tangles.Th...Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary tangles.The etiology of Alzheimer’s disease remains elusive.There is a growing body of evidence for an infectious trigger of Alzheimer’s disease,and,in particular,the focus has been on the oral pathogen Porphyromonas gingivalis(P.gingivalis).Reports of the expression of a misfolded form of p53 in non-neuronal cells(fibroblasts,peripheral blood mononuclear cells,and B cells)and serum,which appears several years before clinical symptoms manifest,may provide further support for the role of bacteria in general,and P.gingivalis in particular,in the initiation of the disease.This review presents a model of the pathway from initial oral infection with P.gingivalis to amyloid plaque formation and neuronal degeneration,via the steps of chronic periodontitis;secretion of the inflammagens lipopolysaccharide and gingipains into the bloodstream;induction of an inflammatory response in both peripheral cells and tissues;disruption of the blood-brain barrier,and entry into the central nervous system of the inflammagens and the P.gingivalis bacteria themselves.In this model,the misfolded p53(or“unfolded p53”;up53)is induced in non-neuronal cells and upregulated in serum as a result of oxidative stress due to lipopolysaccharide from P.gingivalis.up53 is therefore a potential biomarker for early diagnosis of the presence of a causative agent of Alzheimer’s disease.Fastidious dental hygiene and aggressive antibiotic treatment may prevent the patient progressing to clinical Alzheimer’s disease if serum up53 is detected at this pre-symptomatic stage.展开更多
BACKGROUND： Porphyromonas gingivalis is a periodontal pathogen, which is considered to be a keystone pathogen for periodontitis. A diverse conglomerate of P. gingivalis virulence factors including lipopolysaccharide,...BACKGROUND： Porphyromonas gingivalis is a periodontal pathogen, which is considered to be a keystone pathogen for periodontitis. A diverse conglomerate of P. gingivalis virulence factors including lipopolysaccharide, fimbriae, capsular polysaccharide, haemagglutinin and cysteine proteases （Arg-gingipains and Lys-gingipain） are considered to be involved in the pathogenesis ofperiodontitis. Leupeptin is a cysteine protease inhibitor which is specific for Arg gingipains. The present review focuses on action of leupeptin on Arg gingipains. METHOD： A search was carried out systematically from the start till September, 2016. The search was made in Medline database via PubMed. The keywords enlisted were ＂leupeptin＂; ＂gingipains＂; ＂periodontitis＂ using Boolean operator ＂and.＂ RESULTS： The result was selection of 58 articles which linked leupeptin to periodontitis and gingipains; pathogenesis of periodontitis, pathogenicity of gingipains and role of leupeptin. CONCLUSION： It was concluded that leupeptin inhibits and attenuates a number of destructive activities of Arg gingipains including inhibition ofplatelet aggregation; inhibit degradation of LL-37, which is an antimicrobial peptide; blocking inhibition ofmonocyte chemoattractant protein; restoring level ofinterleukin-2; inhibiting degradation of collagen type I and IV to name a few.展开更多
文摘Alzheimer’s disease has proven to be largely intractable to treatment,despite years of research,and numerous trials of therapies that target the hallmarks of the disease-amyloid plaques and neurofibrillary tangles.The etiology of Alzheimer’s disease remains elusive.There is a growing body of evidence for an infectious trigger of Alzheimer’s disease,and,in particular,the focus has been on the oral pathogen Porphyromonas gingivalis(P.gingivalis).Reports of the expression of a misfolded form of p53 in non-neuronal cells(fibroblasts,peripheral blood mononuclear cells,and B cells)and serum,which appears several years before clinical symptoms manifest,may provide further support for the role of bacteria in general,and P.gingivalis in particular,in the initiation of the disease.This review presents a model of the pathway from initial oral infection with P.gingivalis to amyloid plaque formation and neuronal degeneration,via the steps of chronic periodontitis;secretion of the inflammagens lipopolysaccharide and gingipains into the bloodstream;induction of an inflammatory response in both peripheral cells and tissues;disruption of the blood-brain barrier,and entry into the central nervous system of the inflammagens and the P.gingivalis bacteria themselves.In this model,the misfolded p53(or“unfolded p53”;up53)is induced in non-neuronal cells and upregulated in serum as a result of oxidative stress due to lipopolysaccharide from P.gingivalis.up53 is therefore a potential biomarker for early diagnosis of the presence of a causative agent of Alzheimer’s disease.Fastidious dental hygiene and aggressive antibiotic treatment may prevent the patient progressing to clinical Alzheimer’s disease if serum up53 is detected at this pre-symptomatic stage.
文摘BACKGROUND： Porphyromonas gingivalis is a periodontal pathogen, which is considered to be a keystone pathogen for periodontitis. A diverse conglomerate of P. gingivalis virulence factors including lipopolysaccharide, fimbriae, capsular polysaccharide, haemagglutinin and cysteine proteases （Arg-gingipains and Lys-gingipain） are considered to be involved in the pathogenesis ofperiodontitis. Leupeptin is a cysteine protease inhibitor which is specific for Arg gingipains. The present review focuses on action of leupeptin on Arg gingipains. METHOD： A search was carried out systematically from the start till September, 2016. The search was made in Medline database via PubMed. The keywords enlisted were ＂leupeptin＂; ＂gingipains＂; ＂periodontitis＂ using Boolean operator ＂and.＂ RESULTS： The result was selection of 58 articles which linked leupeptin to periodontitis and gingipains; pathogenesis of periodontitis, pathogenicity of gingipains and role of leupeptin. CONCLUSION： It was concluded that leupeptin inhibits and attenuates a number of destructive activities of Arg gingipains including inhibition ofplatelet aggregation; inhibit degradation of LL-37, which is an antimicrobial peptide; blocking inhibition ofmonocyte chemoattractant protein; restoring level ofinterleukin-2; inhibiting degradation of collagen type I and IV to name a few.
