Jan Näslund

ARREST OF BETA -AMYLOID FIBRIL FORMATION BY A PENTAPEPTIDE LIGAND

Polymerization of amyloid β-peptide (Aβ) into amyloid fibrils is a critical step in the pathogenesis of Alzheimers disease. Here, we show that peptides incorporating a short Aβ fragment (KLVFF; Aβ) can bind full-length Aβ and prevent its assembly into amyloid fibrils. Through alanine substitution, it was demonstrated that amino acids Lys, Leu, and Phe are critical for binding to Aβ and inhibition of Aβ fibril formation. A mutant Aβ molecule, in which these residues had been substituted, had a markedly reduced capability of forming amyloid fibrils. The present data suggest that residues Aβ serve as a binding sequence during Aβ polymerization and fibril formation. Moreover, the present KLVFF peptide may serve as a lead compound for the development of peptide and non-peptide agents aimed at inhibiting Aβ amyloidogenesis in vivo.

Characterization of stable complexes involving apolipoprotein E and the amyloid β peptide in Alzheimer's disease brain

Genetic evidence suggests a role for apolipoprotein E (apoE) in Alzheimers disease (AD) amyloidogenesis. Here, amyloid-associated apoE from 32 AD patients was purified and characterized. We found that brain amyloid-associated apoE apparently exists not as free molecules but as complexes with polymers of the amyloid beta peptide (A beta). Brain A beta-apoE complexes were detected irrespective of the apoE genotype, and similar complexes could be mimicked in vitro. The fine structure of purified A beta-apoE complexes was fibrillar, and immunogold labeling revealed apoE immunoreactivity along the fibrils. Thus, we conclude that A beta-apoE complexes are principal components of AD-associated brain amyloid and that the data presented here support a role for apoE in the pathogenesis of AD.

Amyloid fibril formation by pulmonary surfactant protein C.

Lung surfactant protein C (SP‐C) is a lipopeptide that contains two fatty acyl (palmitoyl) chains bound via intrinsically labile thioester bonds. SP‐C can transform from a monomeric α‐helix into β‐sheet aggregates, reminiscent of structural changes that are supposed to occur in amyloid fibril formation. SP‐C is here shown to form amyloid upon incubation in solution. Furthermore, one patient with pulmonary alveolar proteinosis (PAP, a rare disease where lung surfactant proteins and lipids accumulate in the airspaces) and six healthy controls have been studied regarding presence and composition of amyloid fibrils in the cell‐free fraction of bronchoalveolar lavage (BAL) fluid. Abundant amyloid fibrils were found in BAL fluid from the patient with PAP and, in low amounts, in three of the six healthy controls. SDS‐insoluble fibrillar material associated with PAP mainly consists of SP‐C, in contrast to the fibrils found in controls. Fibrillated SP‐C has to a significant extent lost the palmitoyl groups, and removal of the palmitoyl groups in vitro increases the rate of fibril formation.

Clinical and Neuropathological Features of the Arctic APP Gene Mutation Causing Early-Onset Alzheimer Disease

BACKGROUND A majority of mutations within the beta-amyloid region of the amyloid precursor protein (APP) gene cause inherited forms of intracerebral hemorrhage. Most of these mutations may also cause cognitive impairment, but the Arctic APP mutation is the only known intra-beta-amyloid mutation to date causing the more typical clinical picture of Alzheimer disease. OBJECTIVE To describe features of 1 Swedish and 1 American family with the previously reported Arctic APP mutation. DESIGN, SETTING, AND PARTICIPANTS Affected and nonaffected carriers of the Arctic APP mutation from the Swedish and American families were investigated clinically. In addition, 1 brain from each family was investigated neuropathologically. RESULTS The clinical picture, with age at disease onset in the sixth to seventh decade of life and dysfunction in multiple cognitive areas, is indicative of Alzheimer disease and similar to the phenotype for other Alzheimer disease APP mutations. Several affected mutation carriers displayed general brain atrophy and reduced blood flow of the parietal lobe as demonstrated by magnetic resonance imaging and single-photon emission computed tomography. One Swedish case and 1 American case with the Arctic APP mutation came to autopsy, and both showed no signs of hemorrhage but revealed severe congophilic angiopathy, region-specific neurofibrillary tangle pathological findings, and abundant amyloid plaques. Intriguingly, most plaques from both of these cases had a characteristic ringlike character. CONCLUSIONS Overall, our findings corroborate that the Arctic APP mutation causes a clinical and neuropathological picture compatible with Alzheimer disease.

Is Placebo Acupuncture What It is Intended to Be

Randomized, placebo-controlled clinical trials are recommended for evaluation of a treatments efficacy with the goal of separating the specific effects (verum) from the non-specific ones (placebo). In order to be able to carry out placebo-controlled acupuncture trials, minimal/sham acupuncture procedures and a sham acupuncture needle has been used with the intention of being inert. However, clinical and experimental results suggest that sham/minimal acupuncture is not inert since it is reported that both verum acupuncture and sham/minimal acupuncture induce a significant alleviation of pain. This alleviation is as pronounced as the alleviation obtained with standard treatment and more obvious than the one obtained with placebo medication or by the use of waiting list controls. These results also suggest that sham acupuncture needles evoke a physiological response. In healthy individuals sham acupuncture results in activation of limbic structures, whereas a deactivation is seen in patients with pain, i.e. results from healthy individuals do not reflect what is seen in clinical conditions. Also, depending on the etiology of pain (or any under clinical condition under investigation), the response to sham acupuncture is varying. The acupuncture ritual may also be seen as an emotional focused therapy allowing for psychological re-orientation. Sham needling in such context may be as powerful as verum acupuncture. We recommend that the evaluated effects of acupuncture could be compared with those of standard treatment, also taking the individual response into consideration, before its use or non-use is established.

The Emperors sham – wrong assumption that sham needling is sham

During the last five years a large number of randomised controlled clinical trials (RCTs) have been published on the efficacy of acupuncture in different conditions. In most of these studies verum is compared with sham acupuncture. In general both verum and sham have been found to be effective, and often with little reported difference in outcome. This has repeatedly led to the conclusion that acupuncture is no more effective than placebo treatment. However, this conclusion is based on the assumption that sham acupuncture is inert. Since sham acupuncture evidently is merely another form of acupuncture from the physiological perspective, the assumption that sham is sham is incorrect and conclusions based on this assumption are therefore invalid. Clinical guidelines based on such conclusions may therefore exclude suffering patients from valuable treatments.

The Arctic mutation interferes with processing of the amyloid precursor protein.

The Arctic amyloid precursor protein (APP) Alzheimer mutation, is located inside the &bgr;-amyloid (A&bgr;) domain. Here, hybrid APP mutants containing both the Swedish and the Arctic APP mutations were investigated. ELISA measurements of cell media showed decreased levels of both A&bgr;40 and A&bgr;42. Similar results were obtained for the Dutch and Italian mutations, whereas the Flemish mutation displayed increased amounts of A&bgr;40 and A&bgr;42. Immunoprecipitation studies revealed increased A&bgr;40/p340 and A&bgr;42/p342 ratios for the Arctic mutation. These results were further verified by quantification revealing decreased levels of &agr;APPs accompanied by increased &bgr;APPs levels in the media. Thus, the pathogenic effects of the Arctic mutation may not only be due to the changed properties of the peptide but also altered processing of Arctic APP.

SENSORY STIMULATION (ACUPUNCTURE) FOR THE TREATMENT OF IDIOPATHIC ANTERIOR KNEE PAIN

A randomized controlled study was conducted to evaluate the effect of acupuncture treatment in idiopathic anterior knee pain, a pain syndrome without known aetiology. Fifty-eight patients, clinically and radiologically examined, were randomly assigned to either deep or minimal superficial acupuncture treatment. The patients were treated twice weekly for a total of 15 treatments. The main outcome measurements were one leg vertical jump, functional score, daily VAS recording and skin temperature. Fifty-seven patients completed the study. Pain measurements on VAS decreased significantly within both groups; in the deep acupuncture group from 25 before treatments to 10 afterwards, and in the superficial (placebo) acupuncture group from 30 to 10. There was no significant difference between the groups. The improvement on the VAS recordings remained significant even after 3 and 6 months. Even though the pain decreased after sensory stimulation, neither the ability to jump on one leg, the functional score nor the skin temperature changed. This study shows that patients with idiopathic anterior knee pain benefit from both electroacupuncture treatment and subcutaneous needling. The pain-relieving effect remains for at least 6 months. Central pain inhibition, caused by either afferent stimulation or by non-specific therapeutic (placebo) effects, is a plausible explanation behind the treatment effects.

Comparison of symptoms and clinical findings in subgroups of individuals with patellofemoral pain

Patellofemoral pain syndrome (PFPS) is one of the most common musculoskeletal disorders. However, no consensus on the definition, classification, assessment, diagnosis, or management has been reached. We evaluated symptoms and clinical findings in subgroups of individuals with PFPS, classified on the basis of the findings in radiological examinations and compared the findings with knee-healthy subjects. An orthopedic surgeon and a physical therapist consecutively examined 80 patients clinically diagnosed as having PFPS and referred for physical therapy. The examination consisted of taking a case history and clinical tests. Radiography revealed pathology in 15 patients, and scintigraphic examination revealed focal uptake in 2 patients indicating pathology (group C). Diffusely increased uptake was present in 29 patients (group B). In the remaining 29 patients radiographic and scintigraphic examinations were normal (group A). Knee-healthy controls (group D) reported no clinical symptoms. No symptom could be statistically demonstrated to differ between the three patient groups. Knee-healthy subjects differed significantly from the three patient groups in all clinical tests measuring pain in response to the provocations; compression test, medial and lateral tenderness, passive gliding of the patella, but they also differed in Q angle. Differences in clinical tests between the patient groups were nonsignificant. The main finding in our study on patients clinically diagnosed with PFPS is that possible pathologies cannot be detected from the patients history or from commonly used clinical tests.

Presenilin-1 Mutation L271V Results in Altered Exon 8 Splicing and Alzheimer's Disease with Non-cored Plaques and No Neuritic Dystrophy

The mutation L271V in exon 8 of the presenilin-1 (PS-1) gene was detected in an Alzheimers disease pedigree. Neuropathological examination of affected individuals identified variant, large, non-cored plaques without neuritic dystrophy, reminiscent of cotton wool plaques. Biochemical analysis of L271V mutation showed that it increased secretion of the 42-amino acid amyloid-β peptide, suggesting a pathogenic mutation. Analysis of PS-1 transcripts from the brains of two mutation carriers revealed a 17–50% increase in PS-1 transcripts with deletion of exon 8 (PS-1Δexon8) compared with unrelated Alzheimers disease brains. Exon trapping analysis confirmed that L271V mutation enhanced the deletion of exon 8. Western blots of brain lysates indicated that PS-1Δexon8 was overexpressed in an affected individual. Biochemical analysis of PS-1Δexon8 in COS and BD8 cells indicate the splice isoform is not intrinsically active but interacts with wild-type PS-1 to generate amyloid-β. Western blots of cell lysates immunoprecipitated with anti-Tau or anti-GSK-3β antibodies indicated that PS-1Δexon8, unlike wild-type PS-1, does not interact directly with Tau or GSK-3β, potential modifiers of neuritic dystrophy. We postulate that variant plaques observed in this family are due in part to the effects of PS-1Δexon8 and that interaction between PS-1 and various protein complexes are necessary for neuritic plaque formation.