Dorfin localizes to Lewy bodies and ubiquitylates synphilin-1

Parkinson's disease (PD) is a neurodegenerative disease characterized by loss of nigra dopaminergic neurons. Lewy bodies (LBs) are a characteristic neuronal inclusion in PD brains. In this study, we report that Dorfin, a RING finger-type ubiquityl ligase for mutant superoxide dismutase-1, was localized with ubiquitin in LBs. Recently, synphilin-1 was identified to associate with alpha-synuclein and to be a major component of LBs. We found that overexpression of synphilin-1 in cultured cells led to the formation of large juxtanuclear inclusions, but showed no cytotoxicity. Dorfin colocalized in these large inclusions with ubiquitin and proteasomal components. In contrast to full-length synphilin-1, overexpression of the central portion of synphilin-1, including ankyrin-like repeats, a coiled-coil domain, and an ATP/GTP-binding domain, predominantly led to the formation of small punctate aggregates scattered throughout the cytoplasm and showed cytotoxic effects. Dorfin and ubiquitin did not localize in these small aggregates. Overexpression of the N or C terminus of synphilin-1 did not lead to the formation of any aggregates. Dorfin physically bound and ubiquitylated synphilin-1 through its central portion, but did not ubiquitylate wild-type or mutant alpha-synuclein. These results suggest that the central domain of synphilin-1 has an important role in the formation of aggregates and cytotoxicity and that Dorfin may be involved in the pathogenic process of PD and LB formation by ubiquitylation of synphilin-1.

Cross-correlation suppressed T1 and NOE experiments for protein side-chain 13CH2 groups

Relaxation measurements of side-chain 13CH2-groups of uniformly 13C labeled human ubiquitin were performed at 600 MHz and 800 MHz magnetic field strength at 30 degrees C. Dipole-dipole cross-correlated relaxation effects in T1 experiments were suppressed by the combination of radio-frequency pulses and pulsed field gradients during the relaxation delay leading to monoexponential relaxation decays that allow a more accurate extraction of the 13C T1 relaxation times. Heteronuclear [1H]-13C NOEs obtained by using different proton saturation schemes indicate that the influence of cross-correlation is small. The experimental T1 and NOE data were interpreted in a model-free way in terms of a generalized order parameter and an internal correlation time.

Corticospinal tract degeneration in the progressive muscular atrophy variant of ALS

OBJECTIVE

Examining the unresolved relationship between the lower motor neuron disorder progressive muscular atrophy (PMA) and ALS is important in clinical practice because of emerging therapies.

METHODS

Spinal and brainstem tissues donated from patients with ALS/motor neuron disorder (n = 81) were examined. Using retrospective case note review, the authors assigned patients into three categories: PMA (12), PMA progressing to ALS (6), and ALS ab initio (63). Conventional stains for long tract degeneration and immunocytochemistry for ubiquitin and the macrophage marker CD68 were examined.

RESULTS

Rapid progression and typical ubiquitinated inclusions in lower motor neurons were present in 77 (95%) of the cases. Immunocytochemistry for CD68 was a more sensitive marker of long tract pathology in comparison with conventional stains. Half of the cases with PMA showed corticospinal tract degeneration by CD68.

CONCLUSION

Patients with PMA frequently have undetected long tract pathology and most have ubiquitinated inclusions typical of ALS. A patient presenting with PMA with rapid clinical evolution likely has the pathology and pathophysiology of ALS whether or not upper motor neuron signs evolve.

Immunohistochemical study of neuronal intranuclear and cytoplasmic inclusions in Machado-Joseph disease

Machado-Joseph disease (MJD) is a dominantly inherited spinocerebellar disorder, and expansions of trinucleotide (CAG) at chromosome 14 have been shown to be the locus of this disorder. Polyglutamine CAG stretches in the neuronal cytoplasms and nuclei were studied with immunolabeling using 1C2, a monoclonal antibody recognizing polyglutamine stretches, and polyclonal antiubiquitin antibody in six genetically verified cases of MJD. 1C2 clearly labeled two types of neuronal intranuclear inclusions (NII) and neuronal cytoplasmic inclusions (NCI) in the substantia nigra, pontine nucleus, dentate nucleus and spinal anterior horn where NII and NCI were also positive for ubiquitin, as were extracellular dot-like structures and oligodendroglial inclusions. 1C2-positive NII and NCI had a lesion-specific distribution. While the spinal motoneurons contained only 1C2-positive NCI and lacked 1C2-positive NII, the ventral pontine nucleus neurons had many 1C2-positive NII and few 1C2-positive NCI. Semi-quantitative examination of NII and NCI positive for 1C2 or ubiquitin demonstrated that there were more 1C2-positive NII and NCI than ubiquitin-positive ones. It is noteworthy that the nuclei of the spinal motoneurons lacked 1C2-positive immunoreactivity, so that ubiquitination of 1C2-positive structures is presumed to occur late in the course of the disease.

Clinicopathological study of two subtypes of Pick's disease in Japan

We examined the clinical and neuropathological findings in 3 cases of Pick's disease with Pick bodies (PiD) and 7 cases of atypical Pick's disease without Pick bodies (aPiD). PiD and aPiD cases corresponded clinically to frontotemporal dementia and semantic dementia, respectively, based on the clinical diagnostic criteria of frontotemporal lobar degeneration. Brain CT showed that cerebral atrophy was accentuated at an early stage of the illness in the anterior portion of the frontal lobes in PiD cases and in the anterior portion of the temporal lobes in aPiD cases. Neuropathologically, PiD cases showed more circumscribed lobar atrophy than aPiD cases. Both PiD and aPiD cases revealed moderate to severe degeneration with neuronal loss and gliosis in the affected cerebral cortex and subcortical nuclei, but only aPiD cases had pyramidal tract degeneration. Immunohistochemical analyses demonstrated that tauopathy with phosphorylated tau accumulation in the Pick bodies in PiD cases, while aPiD cases showed ubiquitinopathy with ubiquitin accumulation in the intraneuronal and dendritic inclusions. These findings suggested that two subtypes of Pick's disease in Japan can be distinguished not only neuropathologically but also clinically based on differences in pathogenesis.

Extending the range of amide proton relaxation dispersion experiments in proteins using a constant-time relaxation-compensated CPMG approach

Relaxation compensated constant-time Carr-Purcell-Meiboom-Gill relaxation dispersion experiments for amide protons are presented that detect mus-ms time-scale dynamics of protein backbone amide sites. Because of their ten-fold larger magnetogyric ratio, much shorter 180 degrees pulses can be applied to (1)H than to (15)N spins; therefore, off-resonance effects are reduced and a wider range of effective rf fields can often be used in the case of (1)H experiments. Applications to [(1)H-(15)N]-ubiquitin and [(1)H-(15)N]-perdeuterated HIV-1 protease are discussed. In the case of ubiquitin, we present a pulse sequence that reduces artifacts that arise from homonuclear (3)J(H(N)-H(alpha)) coupling. In the case of the protease, we show that relaxation dispersion of both (1)H and (15)N spins provides a more comprehensive picture of slow backbone dynamics than does the relaxation dispersion of either spin alone. We also compare the relative merits of (1)H versus (15)N transverse relaxation measurements and note the benefits of using a perdeuterated protein to measure the relaxation dispersion of both spin types.

blue cheese mutations define a novel, conserved gene involved in progressive neural degeneration

A common feature of many human neurodegenerative diseases is the accumulation of insoluble ubiquitin-containing protein aggregates in the CNS. Although Drosophila has been helpful in understanding several human neurodegenerative disorders, a loss-of-function mutation has not been identified that leads to insoluble CNS protein aggregates. The study of Drosophila mutations may identify unique components that are associated with human degenerative diseases. The Drosophila blue cheese (bchs) gene defines such a novel degenerative pathway. bchs mutants have a reduced adult life span with the age-dependent formation of protein aggregates throughout the neuropil of the CNS. These inclusions contain insoluble ubiquitinated proteins and amyloid precursor-like protein. Progressive loss of CNS size and morphology along with extensive neuronal apoptosis occurs in aged bchs mutants. BCHS protein is widely expressed in the cytoplasm of CNS neurons and is present over the entire length of axonal projections. BCHS is nearly 3500 amino acids in size, with the last 1000 amino acids consisting of three functional protein motifs implicated in vesicle transport and protein processing. This region along with previously unidentified proteins encoded in the human, mouse, and nematode genomes shows striking homology along the full length of the BCHS protein. The high degree of conservation between Drosophila and human bchs suggests that study of the functional pathway of BCHS and associated mutant phenotype may provide useful insights into human neurodegenerative disorders.

Antimicrobial polypeptides of human vernix caseosa and amniotic fluid: implications for newborn innate defense

Antimicrobial peptides/proteins are widespread in nature and play a critical role in host defense. To investigate whether these components contribute to surface protection of newborns at birth, we have characterized antimicrobial polypeptides in vernix caseosa (vernix) and amniotic fluid (AF). Concentrated peptide/protein extracts were obtained from 11 samples of vernix and six samples of AF and analyzed for antimicrobial activity using an inhibition zone assay. Proteins/peptides in all vernix extracts exhibited strong antibacterial activity against Bacillus megaterium (strain Bm11), in addition to antifungal activity against Candida albicans, whereas AF-derived proteins/peptides showed only the former activity. Fractions obtained after separation by reverse-phase HPLC exhibited antibacterial activity, with the most pronounced activity in a fraction containing alpha-defensins (HNP1-3). The presence of HNP1-3 was proved by dot blot analysis and confirmed by mass spectrometry. Lysozyme and ubiquitin were identified by sequence analysis in two fractions with antibacterial activity. Fractions of vernix and AF were also positive for LL-37 with dot blot and Western blot analyses, and one fraction apparently contained an extended form of LL-37. Interestingly, psoriasin, a calcium-binding protein that is up-regulated in psoriatic skin and was found recently to exhibit antimicrobial activity, was characterized in the vernix extract. The presence of all of these antimicrobial polypeptides in vernix suggests that they are important for surface defense and may have an active biologic role against microbial invasion at birth.

Age-related histological changes in the canine substantia nigra

Age-related changes in the canine substantia nigra, were examined using immunostaining for tyrosine hydroxylase (TH), glial fibrillary acidic protein (GFAP), neurofilament (NF), ubiquitin, single stranded DNA (ssDNA), and alpha-synuclein (alphaSN). Brain sections from 34 necropsied dogs, ranging from 2 months to 18 years old, were used for this study. On general histological examinations, several age-related changes, including lipofuscin deposition, polyglucosan bodies, amorphous basophilic inclusions and eosinophilic crystal inclusions, were found in the aged dogs. Immunohistochemically, TH-positive neurons were located only in the substantia nigra. The number of TH-positive neurons was well preserved in all dogs examined, however, the ratio of TH-positive neurons to GFAP-positive glial cells tended to show slight decrease in aged dogs. By ssDNA immunostaining for apoptotic cells, there were no significant results in the number of ssDNA-positive neurons. The number of ubiquitin- and NF-positive swollen neurites was increased markedly in aged dogs. Ubiquitin immunostaining revealed a small number of basophilic and eosinophilic inclusions, although both types of inclusions were negative for NF. By alphaSN immunostaining, no neurons were immunoreactive and no basophilic or eosinophilic intracytoplasmic inclusions were revealed. These results indicate that in the substantia nigra of aged dogs the dopaminergic neurons are well preserved, but intracytoplasmic inclusions and ubiquitin-positive degenerative neurites are commonly found.

[Lewy bodies, a misleading marker for Parkinson's disease?]

The Lewy body, an eosinophilic inclusion around 10 microns in diameter, is localised in the neuronal perikaryon. Its dense core is surrounded by a clear halo, which is lacking in the so-called "cortical Lewy bodies". Numerous proteins have been identified in Lewy bodies, among which the three neurofilament isoforms, ubiquitin and proteasome subunits. More recently, alpha-synuclein--a pre-synaptic protein--has been found to be the essential constituent of the Lewy body. Alpha-synuclein antibody has greatly increased the sensitivity of the neuropathological examination: it has emphasized the frequency of "Lewy neurites" (accumulation of alpha--synuclein in neuronal processes) and has shown the importance of extra-nigral pathology. Lewy bodies and neurites are indeed to be found in many areas of the central and peripheral nervous system: stellate ganglia, cardiac and enteric plexus, pigmented nuclei of the brainstem, basal nucleus of Meynert, amygdala, limbic nuclei of the thalamus, parahippocampal and cingulate gyri, insula and isocortex. Lewy body diseases include at least three clinical syndromes: 1) idiopathic Parkinson disease in which the brainstem bears the brunt of the pathology 2) Parkinson disease dementia in which Lewy lesions are found in the brainstem and are also abundant in the isocortex. A large number of senile plaques is frequently associated. 3) In dementia with Lewy bodies, the same lesions are observed but the cognitive deficit occurs first or shortly (less than one year) after the motor symptoms.

Selective neurodegeneration in murine mucopolysaccharidosis VII is progressive and reversible

The mucopolysaccharidoses are caused by inherited deficiencies of lysosomal enzymes involved in the degradative pathway of glycosaminoglycans. Lysosomal storage leads to cellular and organ dysfunction, including mental retardation. Storage lesions are found throughout the diseased brain, but little is known about the cellular and molecular mechanisms that underlie brain dysfunction. In the mouse model of mucopolysaccharidosis VII, we found that specific regions of the brain are vulnerable to neurodegeneration, characterized by the presence of ubiquitin inclusions, neurofilament inclusions, and reactive astrogliosis. The pathological lesions were found predominantly in the hippocampus and cerebral cortex, and they increased progressively with age. Treatment with a recombinant viral vector to correct the enzymatic defect quantitatively reversed the neurodegenerative lesions in targeted regions to normal levels.

Selective colocalization of transglutaminase-like activity in ubiquitinated intranuclear inclusions of hereditary dentatorubral-pallidoluysian atrophy

To investigate the role of transglutaminase (TG) in the pathophysiology of dentatorubral-pallidoluysian atrophy (DRPLA), the distributions of ubiquitin-positive neuronal intranuclear inclusions (Ub-NII) and TG activity were studied in three patients with DRPLA and four disease controls. In the cerebellar granule cells of DRPLA, 2.5-4.9% of neurons had Ub-NII, and 7.5-9.8% of them were TG positive. In the frontal cortex; however, the ratio of neurons with Ub-NII was relatively low compared with those in the cerebellar cortex, and no Ub-NII was TG positive. There was no distinct difference in the ratio of neurons with Ub-NII and their TG positivity between the cases with homozygous or heterozygous DRPLA patients. The selective and good colocalization of Ub-NII and TG in the cerebellar granule cells may reveal a role of TG in the neurodegenerative process in DRPLA.

The importance of preferential solvation of the CN ligands in electron- and proton-transfers observed for cis-[Ru(CN)2(bpy)2] under ion bombardment

Liquid secondary ion mass spectrometry (LSIMS) mass spectra of cis-[Ru(CN)2(bpy)2] with a strong hydrogen-bonding-induced solvatochromism were measured using 3-nitrobenzyl alcohol (NBA) (oxidizing agent) and glycerol (reducing agent), and mixtures of these solvents. The formation of M+ (oxidized molecule) correlated closely to the extent of preferential solvation by NBA (preferential solvation-shell) around the cyanide ligands as observed from changes in the energy of the maximum metal-to-ligand charge transfer absorption. (M + H)+ is caused mainly by the preferential orientation of OH groups with protons in the NBA molecules toward the cyanide ligands in the disrupted region of the solvent structure as observed from the variation in the peak position of the stretching vibration of (OH) in the solvents. Large decreases in (M + 2H)+ and (M + 3H)+ (reduced molecules) resulted from the large decrease in the interaction between the cyanide ligands and glycerol owing to the preferential solvation by NBA. The LSIMS mass spectra clearly showed the electron- and proton-transfer processes along with the change in the hydrogen-bonding interaction between the acceptor (NBA and glycerol) and donor (the cyanide ligands), and in the solvent structure of the preferential solvation-shell. These results indicate that the composition of solvent molecules around the cyanide ligands at the surface of the solvents in LSIMS still holds the composition in the preferential solvation around the ligands in the primary solvation-shell.

Ubiquitin is a possible new predictive marker for the recurrence of human hepatocellular carcinoma

BACKGROUND/AIM

Ubiquitin (Ub)-dependent degradation of regulatory proteins controls many cellular processes such as cell cycle progression, morphogenesis and signal transduction. In this study, we evaluated the meaning of ubiquitination in chronic liver diseases, especially human hepatocellular carcinoma, with regard to recurrence.

METHODS

A total 74 of liver tissues (8 of chronic hepatitis [CH], 9 of liver cirrhosis [LC], 7 of dysplastic nodule low grade (DSL), or dysplastic nodule high grade (DSH)and 50 of hepatocellular carcinoma [HCC]) were analyzed for ubiquitination by immunohistochemistry. Cell proliferation was also analyzed using Ki-67 staining. As a comparative marker for progression of HCC, PIVKA-II (protein induced by vitamin K absence-II) was employed to examine the recurrence rate of HCC.

RESULTS

Ubiquitin (Ub) was positive in nuclei and cytoplasm of HCC in immunohistochemistry. The labeling index (L.I.) of ubiquitination was significantly higher with HCC than with other chronic liver diseases and tended to correlate with the lack of poorly-differentiated of HCC. The L.I. of Ki-67 staining was also correlated (P < 0.0001) with that of ubiquitination. The hepatocellular carcinoma (HCC) samples from potentially curatively operated patients having a ubiquitination L.I. of more than 20% suffered significantly higher recurrence of HCC than did patients with an L.I. of less than 20%. On the other hand, PIVA-II did not show such a difference.

CONCLUSION

Ubiquitin (Ub) may reflect the growth activity of neoplasms and will be a possible new predictive marker for the recurrence of human hepatocellular carcinoma after potentially curative operation.

Gas-phase separations of protein and peptide ion fragments generated by collision-induced dissociation in an ion trap

Ion mobility/time-of-flight mass spectrometry techniques have been used to examine distributions of fragment ions generated by collision-induced dissociation (CID) in a quadrupole ion trap. The mobility-based separation step prior to mass-to-charge (m/z) analysis reduces spectral congestion and provides information that complements m/z-based assignments of peaks. The approach is demonstrated by examining fragmentation patterns of insulin chain B (a 30-residue peptide), and ubiquitin (a protein containing 76 amino acids). Some fragments of ubiquitin show evidence for multiple stable conformations.

Muscle ubiquitin m-rNA levels in patients with end-stage renal disease on maintenance hemodialysis

BACKGROUND

Loss of lean body mass is frequently reported in patients with end-stage renal disease (ES-RD). Inadequate nutrient intake, superimposed illnesses, endocrine disorders, uremia and acidosis are some of the potential causes of muscle depletion. Previous reports on experimental models show that lean body mass depletion results from enhancement of muscle tissue protein catabolism, mainly associated with activation of ATP-ubiquitin-dependent proteolysis. Little is known, however, about the affects on this proteolytic system in ESRD patients on maintenance hemodialysis (HD). The present study was designed to investigate the expression of ubiquitin mRNAs in skeletal muscle of patients with ESRD on maintenance HD.

METHODS

Biopsies from the rectus abdominis muscle were obtained from eight ESRD patients and from six control subjects undergoing surgery for benign disease. Ubiquitin mRNA levels were measured by Northern blotting analysis.

RESULTS

Patients with ESRD had mild metabolic acidosis, as a result of chronic intermittent HD. There were no significant differences between HD patients and controls with regard to the 1.2kb polyubiquitin mRNA species (332.9+/-139 vs 324.2+/-60; ns), but the levels of the 2.4 kb mRNA species were significantly lower in HD patients than in controls (1687+/-542 vs 2529.9+/-325, p=0.01). No correlation was observed between ubiquitin mRNA levels and nutritional parameters and degree of acidosis.

CONCLUSIONS

The present study found that the ubiquitin mRNA levels were not increased in the muscle of stable, mildly acidotic hemodialysis patients.

Heterogeneity of nigral and cortical Lewy bodies differentiated by amplified triple-labeling for alpha-synuclein, ubiquitin, and thiazin red

Alpha-synuclein(alpha-S) and ubiquitin(Ub) are constituents of the Lewy bodies (LBs), composed of fibrillary structures. To clarify morphological heterogeneity of LBs, we looked for localization of these epitopes in relation to fibrillary structure possibly detectable by a fluorochrome, thiazin red (TR). On the sections of the substantia nigra (SN) and the cingulate gyrus (CG) obtained from Parkinson's disease brains, double amplification by CARD fluorescent immunohistochemistry with anti-alpha-S monoclonal (LB509) and anti-Ub polyclonal antibodies was performed, followed by staining with TR. These triple-labeled images were captured by a confocal laser microscope and subsequently stained with Campbell-Switzer method, a silver staining specific for LBs. Staining profiles of LBs were different between those in the SN and in the CG. Immunolabeling either with the anti-alpha-S or anti-Ub antibody was diffuse without halo structure in LBs of CG. In addition to this diffuse staining, a lot of LBs of SN exhibited a halo structure immunopositive for alpha-S and Ub, probably representing later stages of LB evolution. Irrespective of the presence of this halo structure, the TR signal was always concentrated in the center of LBs, as the silver-stained material was, suggesting that fibrillary components in the central portion of LBs undergo some conformational changes detectable by TR and the silver-staining. This technique reveals different epitopes in relation to LB evolution in vivo. Heterogeneity in staining profile of LBs, as clarified by this method, may represent evolutional changes of LBs, related to conformational states of their constituents.

Single-pulse nanoelectrospray ionization

A new electrospray ionization (ESI) source that provides a means of generating single packets of ions for mass spectrometric analysis is presented. Sample solution held at a high potential is ejected from a glass capillary with a small dispensing aperture (20-microm i.d.) by constriction of a cylindrical piezoelectric element. Unlike conventional ESI sources that are continuous, this source dispenses fixed volumes of solution as small as 10 pL and provides detection sensitivity in the attomole range when coupled to an orthogonal time-of-flight mass spectrometer. In addition to picoliter-level control over the dispensed volume, the source permits control of the frequency with which ionization pulses are generated as well as the ability to start and stop the pulses without altering the applied solution potential. The source was characterized by analysis of both protein and DNA samples from a variety of different solution compositions. This source design should be compatible with virtually any ESI mass analyzer.

Morphometrical reappraisal of motor neuron system of Pick's disease and amyotrophic lateral sclerosis with dementia

The conventional concept of Pick's disease does not distinguish Pick's disease with Pick bodies (Pick body disease, PBD) from Pick's disease without Pick bodies [lobar atrophy without Pick bodies, LA-PB(-)]. Recently, intraneuronal ubiquitin-positive inclusions (ub-inclusions), which are thought to be a hallmark of amyotrophic lateral sclerosis with dementia (ALS-D), have been found also in LA-PB(-). We reconfirmed that ub-inclusions are consistently detected in LA-PB(-) as well as ALS-D. Subsequently, morphometric evaluation for involvement of the upper and lower motor neuron systems were performed in seven cases each of PBD, LA-PB(-), ALS-D and controls. As an indicator of upper motor neuron involvement, the total number of axons through the pyramis of the medulla oblongata was employed and for lower motor neuron involvement, the number of hypoglossal neurons per unit area was calculated. In LA-PB(-), axons of the pyramidal tract were significantly reduced in comparison to PBD and controls, while the lower motor neurons were preserved. Contrary to LA-PB(-), ALS-D revealed significant reduction of hypoglossal neurons but its pyramidal tract tends to be relatively preserved. These results seem to indicate that LA-PB(-) and ALS-D belong to the same spectrum and consist of subgroups with ub-inclusions and involvement of motor neuron system in common. The involvement of the upper motor neuron system is emphasized in LA-PB(-), while ALS-D accentuates the lower motor neuron system. However, the border between the two group is not always clear and there are patients who can not be definitively classified.

Cellular distribution of proteolytic enzymes in the skeletal muscle of sarcoid myopathy

To clarify the mechanism of muscle fiber destruction in sarcoid myopathy, muscle biopsy specimens were examined from patients with sarcoid myopathy, polymyositis, or dermatomyositis. In sarcoid myopathy, noncaseating granulomatous lesions were located in the perimysium or endomysium or both. Little fiber atrophy, caused by mechanical compression of the granuloma, was seen, and there was no evidence of ischemia-induced changes (i.e., perifascicular atrophy) due to microangiopathy in muscles. Immunoreactivity for membrane-associated cytoskeletal proteins such as dystrophin and merosin was detected homogeneously along the surface of many small granulomas in intrafascicular lesions. These granulomas showed a characteristic phenotypic cellular distribution: CD68(+) and CD4(+) cells were present in the center, and some CD8(+) cells were found at the periphery, indicating typical sarcoid granuloma formation in each muscle fiber. Strong expression of proteases such as cathepsin B, calpain II and ubiquitin-proteasome was observed in macrophages and epithelioid cells but not in lymphocytes in granulomas within muscle fibers or those in the endomysium or perimysium. The expression intensity was stronger in premature-stage granulomas than in late-stage granulomas. Weak expression of these proteases was detected mainly in some muscle fibers invaded by epithelioid cells and macrophages and in a few atrophic or necrotic fibers adjacent to inflammatory foci but not in fibers of fascicles without granuloma formation or in fibers in perifascicular areas. Our results suggest that muscle fiber destruction in sarcoid myopathy is caused mainly by direct invasion of granulomatous inflammatory cells into muscle fibers during the process of granuloma formation rather than by mechanical compression or ischemia. Furthermore, the proteases derived from epithelioid cells and macrophages may play an important role in muscle fiber destruction.

Expression of the stress proteins, ubiquitin, heat shock protein 72, and myofibrillar protein content after 12 weeks of leg cycling in persons with spinal cord injury

OBJECTIVE

To determine the effects of leg cycling exercise on ubiquitin (UBI), heat shock protein 72 (HSP-72) mRNA, protein expression, and myofibrillar protein content in individuals with spinal cord injury (SCI).

DESIGN

Case series.

SETTING

Motor behavior laboratory.

PARTICIPANTS

Seven subjects with motor-complete SCI (4 men, 3 women).

INTERVENTION

A 12-week exercise program involving an electromagnetically braked recumbent bicycle ergometer, which allowed for passive exercise of the legs. Training occurred 2 days a week at approximately 75% of each subject's maximum heart rate.

MAIN OUTCOME MEASURES

Total body mass (TBM) and muscle biopsies were obtained pre- and posttraining. The mRNA and protein expression of UBI, HSP-72, and myofibrillar protein content were determined.

RESULTS

Nonsignificant increases (P > .05) of 2.45% were observed for TBM. There were significant increases (P < .05) in the expression of both HSP-72 mRNA (33.71%) and protein (30.23%). For UBI, there were also significant decreases (P < .05) in the expression of both mRNA (26.86%) and protein (69.43%). Myofibrillar protein content increased significantly (P < .05, 41.86%).

CONCLUSION

Leg cycling exercise in SCI increases myofibrillar protein content, possibly because of up-regulation in the expression of HSP-72 with concomitant down-regulation in the expression of UBI.

Mallory body--a disease-associated type of sequestosome

Mallory bodies (MBs) consist of abnormal keratins, ubiquitin, heat shock proteins, and the protein p62. p62 is encoded by an immediate-early response gene that rapidly responds to a variety of extracellular signals involved in cell proliferation, differentiation, and particularly oxidative stress. It acts as an adapter in signal transduction and binds noncovalently to ubiquitin, possibly being involved in the regulation of the fate of ubiquitinated proteins by segregation (i.e., sequestosome or aggresome formation). The presence of p62 together with ubiquitinated abnormal keratins in the MB characterizes MBs as a disease-associated type of sequestosome. A detailed study on the expression of p62 and its relationship to MB formation in the 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC)-treated mouse liver is reported based on immunohistochemical, immunoblot, and Northern blot analyses. The results indicate that p62 is rapidly induced in hepatocytes of intoxicated animals preceding MB formation. As suggested by experiments with short-term DDC-treated naive mice and mice refed DDC after recovery from long-term DDC treatment (primed mice), p62 does not exert an initiating effect on MB formation but the appearance of MBs requires the presence of abnormal keratins, which associate with p62 after ubiquitination. The rapid induction of p62 and its association with MBs further support the role of oxidative stress in MB formation. In conclusion, the constant presence of p62 in MBs suggests that binding of p62 to abnormal keratins may allow hepatocytes to dispose potentially harmful proteins in a biologically inert manner.

Cerebellar cortical tau pathology in progressive supranuclear palsy and corticobasal degeneration

Immunohistochemical localization of tau in the cerebellar cortex was carried out using a mouse monoclonal antibody against phosphorylation-dependent tau (AT8) in brain tissue (cerebellum) from 13 patients with progressive supranuclear palsy (PSP), 7 patients with corticobasal degeneration (CBD) and 5 age-matched control subjects. Purkinje cell somata that showed diffuse granular accumulation of cytoplasmic tau were found occasionally in 9 of the 13 patients with PSP (69%) and in 4 of the 7 patients with CBD (57%). Tau-positive doughnut-shaped structures were also found occasionally in the cerebellar molecular layer in 6 of the 13 patients with PSP (46%) and 2 of the 7 patients with CBD (29%). No tau immunoreactivity was detected in the cerebellar cortex in the control tissue. In the tissue from one patient with PSP, we also performed a double-labeling immunofluorescence study with anti-glial fibrillary acidic protein (GFAP) antibody and AT8, as well as an immuno-electron microscopic study with AT8. In tau-positive Purkinje cell somata and dendrites, the reaction product was localized mainly within the rough endoplasmic reticulum and free ribosomes. Tau-positive doughnut-shaped structures were located in the GFAP-positive radial processes of Bergmann's glia and were present in the outer areas of inclusions reminiscent of Lewy bodies, which consist of aggregated pathological tau filaments. In conclusion, we have demonstrated a novel tau pathology that affects Purkinje cells and Bergmann's glia in patients with PSP and CBD, indicating that the cerebellar cortex can be involved in the disease processes in PSP and CBD.

Cytochrome P450 3A conjugation to ubiquitin in a process distinct from classical ubiquitination pathway

We characterize a novel microsome system that forms high-molecular-mass (HMM) CYP3A, CYP2E1, and ubiquitin conjugates, but does not alter CYP4A or most other microsomal proteins. The formation of the HMM bands was observed in hepatic microsomes isolated from rats treated 1 week or more with high doses (50 mg/kg/day) of nicardipine, clotrimazole, or pregnenolone 16alpha-carbonitrile, but not microsomes from control, dexamethasone-, nifedipine-, or diltiazem-treated rats. Extensive washing of the microsomes to remove loosely attached proteins or cytosolic contaminants did not prevent the conjugation reaction. In contrast to prototypical ubiquitination pathways, this reaction did not require addition of ubiquitin, ATP, Mg(2+), or cytosol. Addition of cytosol did result in the degradation of the HMM CYP3A bands in a process that was not blocked by proteasome inhibitors. Immunoprecipitated CYP3A contained HMM ubiquitin. Even so, mass spectrometric analysis of tryptic peptides indicated that the HMM CYP3A was in molar excess to ubiquitin, suggesting that the formation of the HMM CYP3A may have resulted from conjugation to itself or a diffuse pool of ubiquitinated proteins already present in the microsomes. Addition of CYP3A substrates inhibited the formation of the HMM CYP3A and the cytosol-dependent degradation of HMM CYP3A. These results suggest that after extended periods of elevated CYP3A expression, microsomal factors are induced that catalyze the formation of HMM CYP3A conjugates that contain ubiquitin. This conjugation reaction, however, seems to be distinct from the classical ubiquitination pathway but may be related to the substrate-dependent stabilization of CYP3A observed in vivo.

Pallido-nigral spheroids in nonhuman primates: accumulation of heat shock proteins in astroglial processes

Alpha-B crystallin, ubiquitin and heat shock protein 27 (hsp27) belong to a class of proteins that are overexpressed in response to pathological conditions associated with increased cellular stress. In the present study, brain sections of old rhesus monkeys ( Macaca mulatta; n=10; mean age, 29.4 years) and baboons ( Papio anubis; n=8; mean age, 18.3 years) were examined for ubiquitin, alpha-B crystallin and hsp27-immunopositive structures. In both species, immunoreactive spheroid-like bodies were found in the globus pallidus and in the substantia nigra, pars reticulata. These structures frequently were associated with abnormally swollen cellular processes. To further clarify the origin of the pallido-nigral spheroids, single- and double-immunostaining was performed for hsp27, alpha-B crystallin and the astroglial marker glial fibrillary acidic protein (GFAP) as well as for neuronal markers against neurofilament and dendritic microtubule-associated protein 2. Confocal microscopic analysis demonstrated that spheroids were localized in swollen astroglial processes, whereas they were not seen in neuronal structures. Thus, pallido-nigral spheroids can be classified as astroglial accumulations of heat shock proteins. Further investigations of these structures may provide information pertinent to our understanding of astroglial heat shock protein inclusions developing in degenerative human brain diseases.

Environmental enrichment slows disease progression in R6/2 Huntington's disease mice

Huntington's disease is a genetic disorder that causes motor dysfunction, personality changes, dementia, and premature death. There is currently no effective therapy. Several transgenic models of Huntington's disease are available, the most widely used of which is the R6/2 mouse, because of its rapid disease progression. Environmental enrichment alters gene expression in the normal mouse brain, and modulates the course of several neurological disorders. Environmentally enriched mice may actually mimic human disease more accurately. We found that even limited environmental enrichment slows decline in RotaRod performance in R6/2 mice, despite rapid disease progression, whereas in normal littermates, maximal enrichment was required to induce a marked improvement in behavioral tests. Enrichment also delayed the loss of peristriatal cerebral volume in R6/2 brains. These results could provide the basis for a rational approach to ameliorate the effects of Huntington's disease.

Vasculopathy and amyloid beta reactivity in brains of patients with acquired immune deficiency (AIDS)

The authors examined multiple brain sections from 15 autopsy cases of AIDS for the vascular changes, presence of amyloid plaques and signs of axonal damage. The mean patients age was 33.8 years (range 24-48 years). Neuropathological findings included: HIV-specific changes (5), opportunistic infections (7), lymphoma (1) and two cases with nonspecific changes. All sections were stained with hematoxylin-eosin (H-E), selected sections were stained with Masson trichrome, Gomori reticulin, Congo red and thioflavine S method. Two sections from each case were immunostained for the presence of beta-amyloid (4G8). ubiquitin, alpha-smooth muscle actin and CD31. The different forms of vascular changes were found in all cases. The common changes were: lymphocytic perivascular or transmural infiltrations and hyalinization, thickening or fibrosis of the arterial and arteriolar wall. The perivascular space widening up to status lacunaris was a frequent phenomenon in the basal ganglia and deep white matter. Some of the cortical arterioles formed little multiluminal structures. Immunohistochemical examination revealed features of hypertrophy of the vascular muscular layer and signs of the slight endothelial cells proliferation. In three cases 4G8 immunopositive. Congo red and thioflavine S-negative, diffuse beta-amyloid deposits were present in the gray matter, focally their localization was perivascular. Ubiquitin immunoreactivity presented as numerous dot-like structures or focal bundles of positive widened axons in the white matter, spheroids and scattered positive neurons were also found. The authors suggest that some of morphological changes within the brain and consecutive neuropsychological symptoms in AIDS are of the vascular origin. Presence of amyloid plaques and axonal damage are the elements of the complex degenerative and inflammatory process in the brain caused by chronic inflammatory stimulation in HIV infection.

Intranuclear ubiquitin immunoreactivity in the pigmented neurons of the substantia nigra in fire fatalities

To evaluate the significance of immunohistochemical staining of ubiquitin (heat shock protein) in the midbrain for medico-legal investigation of death in fires, we examined forensic autopsy cases of fire fatalities (n = 35) in comparison with controls (n = 27; brain stem injury, acute myocardial infarction and carbon monoxide poisoning other than fire fatality). There were two intranuclear staining patterns in the nuclei of pigmented substantia nigra neurons: a type of inclusion (possible Marinesco bodies) and a diffuse staining. Percentage of nuclear ubiquitin positivity (Ub-positive %) in fire fatalities (2.7-44.7%; mean, 18.5%) was significantly higher than in brain stem injury (n = 9; 0-10.4%; mean, 4.5%) and myocardial infarction (n = 14; 1.5-14.6%; mean, 6.9%), independently of blood carboxyhemoglobin (COHb) levels. Age-dependent increase in Ub-positive % was observed in lower COHb (< 60%) cases. The intranuclear diffuse ubiquitin staining was not observed in cases of high blood cyanide level (> 1.0 microg/ml). These observations showed that intranuclear ubiquitin immunoreactivity of the pigmented substantia nigra neurons in the midbrain was induced by severe stress in fires.

Study of the regression process in cardiac rhabdomyomas

Rhabdomyomas are the most common primary cardiac tumors in children, and have been shown to undergo spontaneous regression. The aim of our study was to investigate morphologically and immunohistochemically some mechanisms that may explain this clinical phenomenon. Eleven tumors from three term newborn girls who had physical and radiographic features pathognomonic of tuberous sclerosis were evaluated. Control specimens were left and right heart sections from five autopsies of age- and sex-matched patients who died of causes unrelated to the cardiovascular system. The tumors had been surgically excised from various regions in the heart, and all had similar "typical" histology. Histomorphologic evaluation with von Kossa and alizarin-red stains and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling (TUNEL) method were performed to evaluate cell calcifications, necrosis, and apoptosis. Ubiquitin immunohistochemical study was also conducted to evaluate intracytoplasmic protein degradation. In cardiac rhabdomyomas (CR), all myocytes with acidophilic cytoplasmic myofibrils showed strong intracytoplasmic ubiquitin immunoreactivity, compared with the occasional weak cytoplasmic and focal nuclear positivity in control heart sections. Calcified myocyte nuclei were commonly seen in CR tumoral and nontumoral rhabdomyocytes, whereas control nontumoral cardiac myocytes did not show any calcification. The incidence of TUNEL reactivity seen in CR (4.8 nuclei per 100 cardiac rhabdomyocyte nuclei) was higher than that seen in control heart sections (1.7 nuclei per 106 cardiac myocytes, P < 0.005). The data led us to conclude that the cytoplasmic contents in CR were degraded via the ubiquitin pathway, and from our observation of increased TUNEL positivity, the rate of cell death in CR appeared increased. These findings may explain, to some extent, the mechanism of tumor regression.

Increased expression of manganese superoxide dismutase is associated with that of nitrotyrosine in myopathies with rimmed vacuoles

Oxidative stress has been suggested as one of the pathogenetic mechanisms of inclusion body myositis (IBM). To study the role of antioxidant enzymes in myopathies with rimmed vacuoles, we examined expressions of copper, zinc superoxide dismutase (Cu, Zn-SOD) and manganese superoxide dismutase (Mn-SOD), and the relationship between SODs and other proteins localized in rimmed vacuoles in muscle biopsy specimens from three cases of sporadic IBM and two of distal myopathy with rimmed vacuoles (DMRV) as well as eight control cases of myopathies without rimmed vacuoles. Immunoblot analysis showed distinct protein bands of both SODs in IBM and DMRV using subtype-specific antibodies. Intensities of immunoreactive bands for Mn-SOD in IBM and DMRV were stronger than those in the control cases. Immunohistochemistry disclosed accumulation of both SODs in vacuolated muscle fibers in all cases of IBM and DMRV. Immunoreactivity for Mn-SOD was often colocalized with that of nitrotyrosine, cytochrome oxidase, tau, and lysosome-associated membrane proteins 2 (LAMP-2) in vacuolated fibers. Some of the Cu, Zn-SOD-positive vacuolated fibers were associated with ubiquitin. The two SODs may have different roles for cell protection, and the expression of Mn-SOD is associated with nitric oxide-induced oxidative damage in myopathies with rimmed vacuoles.

Altered ubiquitin/proteasome expression in anastomotic intimal hyperplasia

OBJECTIVE

Anastomotic intimal hyperplasia remains a leading mechanism of prosthetic arterial graft failure. Recent studies using messenger RNA differential display have demonstrated altered proteasome gene expression at the anastomoses in an expanded polytetrafluoroethylene canine carotid model. However, this technique is technically limited because of a paucity of available hyperplastic tissue at early time periods after arterial injury. Microarray gene chip technology offers a new and sensitive technique to assay early gene expression, requiring far less tissue for analysis. The purpose of this study was to screen for altered proteasome gene expression at 48 hours and 14 days after prosthetic arterial grafting.

METHODS

Expanded polytetrafluoroethylene grafts (6-mm diameter, n = 9) were implanted into 25-kg mongrel dogs. The normal intervening carotid artery was used as control. At 48 hours and 14 days, RNA was extracted from the perianastomotic tissue and compared with RNA from the control carotid. Messenger RNA was then hybridized to microarray genomes screening for differential gene expression.

RESULTS

Two 26S proteasome genes and five ubiquitin pathway genes were significantly underexpressed at 48 hours, among several hundred significantly expressed clones. The two 26S proteasome genes were 26S proteasomal subunit p55 (0.26), and 26S proteasomal subunit p40.5 (0.13). The underexpressed ubiquitin genes included ubiquitin (0.31), Nedd-4-like ubiquitin-protein ligase (0.30), ubiquitin conjugating enzyme UbcH2 (0.25), putative ubiquitin C-terminal hydrolase UHX1 (0.11), and ubiquitin-conjugating enzyme UbcH7 (0.12). At 14 days, six ubiquitin genes were underexpressed, and 17 26S proteasome genes were significantly downregulated.

CONCLUSIONS

This study shows decreased expression of the ubiquitin/proteasome pathway 48 hours after graft implantation and similar diminished expression patterns after 14 days. This early and sustained underexpression after arterial bypass may lead to altered cell cycle control and matrix protein signaling, contributing to the unregulated proliferation of smooth muscle cells and extracellular matrix in anastomotic intimal hyperplasia after prosthetic arterial grafting.

Frontotemporal dementia: a clinical-pathological study

We report a 44-year-old female patient without any familial history of dementia presenting with increasing disturbances in behaviour and language followed by a progressive cognitive deterioration. Neuropsychological evaluation revealed a significant impairment on frontal lobe tests. A brain PET scan disclosed a severe frontal hypometabolism. The tentative diagnosis of frontotemporal dementia was made. Her condition rapidly worsened and she died 2 years after the beginning of her disease. Gross examination of the brain showed a selective symmetrical atrophy of both frontal and anterior part of the temporal lobes. Microscopical examination revealed severe neuronal loss in the frontal and anterior temporal cortex associated with gliosis and microvascular spongiosis in the superficial cortical layers in the absence of any specific neuronal or glial inclusions. These neuropathological findings were consistent with the diagnosis of dementia lacking distinctive histology. We discuss the nosology of the frontotemporal dementias, the diagnostic value of PET scan, the recent genetical developments which strongly support the pathogenic role of tau and we emphasize the importance of immunohistochemical examination for a definite neuropathological diagnosis.

Cognitive dysfunction in patients with amyotrophic lateral sclerosis is associated with spherical or crescent-shaped ubiquitinated intraneuronal inclusions in the parahippocampal gyrus and amygdala, but not in the neostriatum

Skeins or skein-like inclusions, one of the two types of ubiquitinated intraneuronal inclusions in amyotrophic lateral sclerosis (ALS), in the neostriatum are not specific to the disease, but it has not yet been determined whether the other, spherical or crescent-shaped inclusions (SCI) are pathognomonic. To clarify this and also to investigate whether the distribution of SCI in particular brain regions is associated with clinical parameters, we examined the occurrence of SCI in the brains of 24 patients with ALS and 94 controls. SCI in the neostriatum were specifically detected in 54% of the ALS cases, but not in any of the controls. No apparent phenotypic denominator, such as disease duration or the occurrence of dementia, correlated to the distribution of SCI in the neostriatum in ALS cases. On the other hand, the occurrence of SCI in both the second and third layers of the parahippocampal gyrus and amygdala was significantly correlated to the presence of dementia in ALS cases. SCI were distributed in association with each other among the parahippocampal gyrus, dentate gyrus of the hippocampus and amygdala, but not between the spinal anterior horn and any non-motor-associated brain regions. These findings suggest that these particular brain regions might be significantly involved in the neurodegenerative process associated with ALS. The relationship of SCI to either ALS pathogenesis or cognitive dysfunction depends on the brain regions in which they are distributed, and this indicates that the neurodegenerative processes in ALS proceed differentially in particular motor-associated and nonmotor-associated brain regions.

Presymptomatic motor neuron loss and reactive astrocytosis in the SOD1 mouse model of amyotrophic lateral sclerosis

In familial amyotrophic lateral sclerosis (fALS), there is a need to establish more precisely the progression of the disease, particularly whether there is gradual presymptomatic neuronal loss or an abrupt loss coinciding with the symptomatic stage. To elucidate this, we investigated the progression of motor neuron loss through morphological techniques, reactive astrocytosis, and expression of ubiquitin and neurofilament proteins, by immunohistochemistry, in SOD1 G93A mice with a protracted disease course and control mice. Loss of motor neurons in SOD1 G93A mice followed a biphasic progression, with an initial loss at 126 days of age, followed by a gradual loss from onset of symptoms through to end-stage disease. Reactive astrocytosis was first observed at 70 days of age and showed a gradual increase through to end-stage disease. This suggests that there is a need for early detection of fALS cases, and potential therapeutic treatments may be more beneficial if administered at an early stage.

The genetic and pathological classification of familial frontotemporal dementia

BACKGROUND

Frontotemporal dementia (FTD) is an important cause of neurodegenerative dementia, particularly in younger patients. TAU has been identified as the gene responsible for FTD linked to chromosome 17, but it is likely that there is pathological and genetic heterogeneity among families with FTD.

OBJECTIVE

To explore the genetic and pathological basis of familial FTD.

DESIGN

Clinical case series with genetic analysis of each family, and pathological confirmation of diagnosis where possible.

SETTING

Specialist dementia research group, particularly recruiting patients with young-onset dementia.

PATIENTS

Twenty-two families with an index member with FTD, meeting Lund-Manchester criteria, and a family history of other affected members with dementia were ascertained.

RESULTS

Half of the families had mutations in the TAU gene (TAU exon 10 +14, +16, and P301S), and pathological diagnoses were available in 17 of 22 families. Three main pathological diagnoses were made: FTD with neuronal and glial tau deposition, FTD with ubiquitin inclusions, and FTD with neuronal loss and spongiosis but without intracellular inclusions. No cases of familial Pick disease were identified. With the use of the pathological diagnoses, each family with FTD with neuronal and glial tau deposition had a TAU mutation, whereas TAU mutations were not identified in families in the other 2 diagnostic groups.

CONCLUSIONS

This study illustrates the value of TAU sequencing in FTD and suggests that around one half of individuals with familial FTD have TAU mutations and dementia with tau pathological findings. Furthermore, these data suggest that there are at least 2 additional genes to be identified among families with autosomal dominant FTD.

Ultrastructural changes in paravertebral muscles associated with degenerative spondylolisthesis

STUDY DESIGN

The paravertebral muscle of 30 patients with spondylolisthesis and 30 control patients were investigated histologically.

OBJECTIVE

To propose myopathologic paravertebral muscle changes in cases of degenerative lumbar spondylolisthesis.

SUMMARY OF BACKGROUND DATA

The stability of the vertebral column is based on both active and passive systems. The passive system is composed of the vertebrae, the intervertebral discs, and the ligaments. Surrounding muscles and tendons constitute the active system. The autochthonous back muscles take over support functions if the passive system is ineffective. In some cases, muscles are overstrained for a long period, ultimately leading to muscular changes. This study was performed to determine the histopathologic correlates of this permanent strain.

METHODS

Between July 1998 and July 1999, paravertebral muscle biopsies were performed for 30 patients with monosegmental degenerative spondylolisthesis undergoing posterior lumbar interbody fusion. The tissue samples were submitted to histologic analysis including immune and enzyme histochemistry and electron microscopy. In addition, the muscle fibers were submitted to morphometry.

RESULTS

Severe pathologic alterations were found. The findings showed that 22 patients (73.3%) had ragged red fibers with evident ultrastructural mitochondrial anomalies. The cristae appeared irregular in 12 patients (40%) Type 1 paracrystalline inclusions were detected in five samples (16.6%) and dense bodies in eight (26.6%). Fibers with ubiquitin-positive inclusions were detected by immunohistochemistry in 13 patients (43.3%). As shown by the electron microscope, these corresponded to granulofilamentous inclusions and polyglucosan bodies. The samples were submitted to genetical analysis because biochemical studies showed reduced activity of the respiratory chain enzymes. Normal mitochondrial deoxyribonucleic acids of unchanged length were detected.

CONCLUSIONS

Apart from nonspecific myopathic changes such as those observed in rimmed vacuoles and rods, increased numbers of polyglucosan bodies were detected. This increase in polyglucosan bodies currently has not been described in patients with otherwise normal muscles.

Cortical Lewy body pathology in the diagnosis of dementia

Dementia with Lewy bodies (DLB) and Parkinson's disease (PD) are distinguishable clinically but often not neuropathologically. This study aims to test whether the distribution of cortical Lewy bodies differs in these clinicopathological groups and to develop diagnostic protocols for their differentiation. Brains were obtained at autopsy from cases recruited from prospective clinical studies of dementia or movement disorders. All cases with significant pathologies other than Lewy bodies or plaques were excluded. Cases were categorised into either PD without dementia, DLB (dementia first or within 2 years of disease onset), or PD with a later onset of dementia (PDD). The distribution and density of Lewy bodies and Lewy neurites was determined using antibodies to ubiquitin and alpha-synuclein. Cortical Lewy body densities could not separate cases of DLB from those with PDD. However, semiquantitative thresholds in the parahippocampus could separate demented from non-demented cases with high sensitivity and specificity. Interactions between multiple pathologies were determined using factor analysis. Although many cases had CA2 Lewy neurites, this was not associated with severity or duration of either dementia or parkinsonism. Most DLB cases had significant plaque pathology, and severity and duration of dementia was related to both increasing parahippocampal Lewy body densities and neuritic plaque grade. Weighted kappa statistics revealed that the combination of these pathologies indicated a more severe dementia. These results suggest that dual pathologies cause DLB, and high densities of parahippocampal Lewy bodies indicate dementia regardless of additional pathologies.

Widespread occurrence of argyrophilic glial inclusions in Parkinson's disease

Argyrophilic glial inclusions, which are immunohistochemically positive for alpha-synuclein but negative for tau protein, were examined in the brain of Parkinson's disease (PD) patients. Autopsied brains of 10 individuals who died from PD, of two incidental Lewy body disease cases and of five age-matched individuals whose deaths were caused by non-neurological diseases were studied, histopathologically, by Gallyas-Braak staining and, immunohistochemically, with anti-alpha-synuclein antibody, anti-ubiquitin, and anti-tyrosine hydroxylase. All postmortem PD brains showed a significant number of argyrophilic glial inclusions, but no glial inclusions were found in control brains. The inclusions were found not only in the regions showing neuronal loss and gliosis, such as the substantia nigra, locus ceruleus and dorsal vagal nucleus, but also in regions without neuronal loss and gliosis, such as the cerebral cortex, cerebral white matter, striatum, globus pallidus, thalamus, cerebellum and spinal cord. The distribution and density of glial inclusions in PD brains varied from case to case but, in the cerebral cortex, the number of glial inclusions were fairly well correlated with the number of Lewy bodies. The distribution pattern of glial inclusions also showed a striking resemblance to that of catecholaminergic neurones and fibres. The abnormal accumulation of alpha-synuclein in glial cells was more widespread than neurone loss, and appears to be an important pathological feature of PD.

Ubiquitin immunoreactivity in presumed spinal interneurones in motor neurone disease

Previous studies have demonstrated the presence of ubiquitin-immunoreactivity (Ub-IR) as inclusions and skeins in motor neurones of both the familial and sporadic forms of motor neurone disease (MND). There is evidence that interneurones also degenerate in MND, but Ub-IR in ventral horn spinal interneurones has not been studied previously. Here, Ub-IR was investigated in 1445 presumed interneurones and 1086 presumed motor neurones counted in three random 20-microm sections of the ventral horn of the third lumbar segment of the spinal cord of each of seven controls and seven patients with MND. The ventral horn was divided into four quadrants; the dorsomedial quadrant contains almost exclusively interneurones and the ventrolateral quadrant largely motor neurones. The neurones were also classified by morphological and size criteria into presumed interneurones (< 25 microm) and presumed motor neurones (>or= 25 microm). Ub-IR was classified as inclusions, skeins and dispersed cytoplasmic and nuclear staining. Ub-IR inclusions or skeins were not observed in the controls but 6.6% of neurones (motor neurones and interneurones) showed the presence of dispersed cytoplasm staining and nuclear staining. The incidence of Ub-IR cytoplasmic and nuclear staining was significantly greater in both motor neurones and interneurones of MND patients than controls. Ub-IR was less frequent in MND cases in which a great loss of neurones was observed. Ub-IR was significantly more frequent in motor neurones than interneurones, both in patients and controls. Ub-IR inclusions and skeins were only observed in motor neurones from MND patients. Ub-IR inclusions were not observed in presumed spinal interneurones, while skeins were only seen in three out of 565 of these cells (two of them in the dorsomedial quadrant) in two out of seven patients. Thus, although presumed spinal interneurones occasionally revealed Ub-IR features similar to motor neurones, the rare staining of Ub-IR skeins and the lack of Ub-IR inclusions in interneurones in MND suggests that these neurones only occasionally form ubiquitin-protein conjugates. Neuronal size, rather than type, may be important in determining whether ubiquitin-protein conjugates form in the ventral horn neurones in MND.

Immunohistochemical localisation of ubiquitin and the proteasome in sunflower (Helianthus annuus cv. Giganteus)

This study provides an immunohistochemical demonstration of the involvement of the ubiquitin- and proteasome-dependent pathway during differentiation and organogenesis in plants. The localisation of ubiquitin and the proteasome was studied in meristems, leaves, stems and roots of sunflower (Helianthus annuus L. cv. Giganteus). By using a new technique that enhances very low antigen signals, we obtained information on the structural distribution of the ubiquitin- and proteasome-dependent pathway, and of the importance of this pathway during organogenesis and plant development. Ubiquitin and the proteasome showed overall similarities in their cellular localisation. The highest antigenic signal was observed in the root and shoot apical meristems, in leaf primordia and vascular tissue. The cambium showed less expression than the apical meristems. During adventitious root formation in cuttings, no sign of increased expression was observed within dedifferentiating tissue, but as organogenesis progressed, the antigenic signal of ubiquitin and the proteasome gradually increased in the developing roots. Comparison of immunochemical results and Western blots demonstrated that important changes in the cellular antigen signal could only be detected by immunochemistry.

Homology and the optimization of DNA sequence data

Three methods of nucleotide character analysis are discussed. Their implications for molecular sequence homology and phylogenetic analysis are compared. The criterion of inter-data set congruence, both character based and topological, are applied to two data sets to elucidate and potentially discriminate among these parsimony-based ideas.

Effects of simulated microgravity on immunoreactivity of conjugated-ubiquitin of muscle spindles of soleus in rats

It is well known that the muscle spindle is a receptor of muscle's tension and length, it plays an important role in maintaining the muscle's tension. The aim of the present study is to compare the cross-section area (CSA) and the immunoreactivity of conjugated-ubiquitin in soleus extrafusal and intrafusal fibers after simulated-microgravity in order to demonstrate the role of muscle spindle in muscle atrophy induced by simulated microgravity.

[Immunohistochemical findings in the central nervous system in sudden infant death]

In a group of 7 infants suddenly dying at the age up to 1 year a histological and immunohistochemical investigation was performed aimed to prove possible chronic hypoxic and latent traumatic changes. Presence of ubiquitin and neuron-specific enolase (NSE) was detected in axon and neurons. In six suddenly dying infants an immunohistochemical positivity was found with antibodies against ubiquitin in brain stem neurons. Antibodies against NSE showed positivity of the white matter was lacking in the detection both of ubiquitin and NSE. Among 12 persons dying of craniocerebral injury an intensive NSE immunopositivity was found in traumatized axons of 7 cases and ubiquitin positivity in 5 cases while brain stem neurons did not show any ubiquitin positivity. Bain stem neurons at sudden death were strongly NSE positive in 5 case, weakly positive in 3 cases and negative in 4 deceased. The combined proof of ubiquitin and NSE in neurons and axons at infant sudden death appears to he advantageous because it combines the detection of traumatic changes and chronic hypoxic lesions as well.