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•The effect of a multidisciplinary intervention on the presence of neuropsychiatric symptoms, particularly agitation and aggression, and psychotropic drug use in nursing home residents with young-onset dementia was evaluated.•The intervention for the management of neuropsychiatric symptoms in nursing home residents with young-onset dementia was not more effective in reducing agitation, aggression, other neuropsychiatric symptoms, or psychotropic drug use compared with care as usual.•The perceived overlap between the intervention and current working methods and lower psychotropic drug use rates compared with approximately 10 years ago suggests that Dutch young-onset dementia special care units had already (to some degree) developed effective working methods for structuring the management of neuropsychiatric symptoms in young-onset dementia before implementation of our intervention.

The R120G mutation in αB-crystallin causes desmin-related myopathy. There have been a number of mechanisms proposed to explain the disease process, from altered protein processing to loss of chaperone function. Here, we show that the mutation alters the in vitro binding characteristics of αB-crystallin for desmin filaments. The apparent dissociation constant of R120G αB-crystallin was decreased while the binding capacity was increased significantly and as a result, desmin filaments aggregated. These data suggest that the characteristic desmin aggregates seen as part of the disease histopathology can be caused by a direct, but altered interaction of R120G αB-crystallin with desmin filaments. Transfection studies show that desmin networks in different cell backgrounds are not equally affected. Desmin networks are most vulnerable when they are being made de novo and not when they are already established. Our data also clearly demonstrate the beneficial role of wild-type αB-crystallin in the formation of desmin filament networks. Collectively, our data suggest that R120G αB-crystallin directly promotes desmin filament aggregation, although this gain of a function can be repressed by some cell situations. Such circumstances in muscle could explain the late onset characteristic of the myopathies caused by mutations in αB-crystallin.

The R120G mutation in alphaB-crystallin causes desmin-related myopathy. There have been a number of mechanisms proposed to explain the disease process, from altered protein processing to loss of chaperone function. Here, we show that the mutation alters the in vitro binding characteristics of alphaB-crystallin for desmin filaments. The apparent dissociation constant of R120G alphaB-crystallin was decreased while the binding capacity was increased significantly and as a result, desmin filaments aggregated. These data suggest that the characteristic desmin aggregates seen as part of the disease histopathology can be caused by a direct, but altered interaction of R120G alphaB-crystallin with desmin filaments. Transfection studies show that desmin networks in different cell backgrounds are not equally affected. Desmin networks are most vulnerable when they are being made de novo and not when they are already established. Our data also clearly demonstrate the beneficial role of wild-type alphaB-crystallin in the formation of desmin filament networks. Collectively, our data suggest that R120G alphaB-crystallin directly promotes desmin filament aggregation, although this gain of a function can be repressed by some cell situations. Such circumstances in muscle could explain the late onset characteristic of the myopathies caused by mutations in alphaB-crystallin.

Desmin-related myopathy and cataract are both caused by the R120G mutation in alphaB-crystallin. Desmin-related myopathy is one of several diseases characterized by the coaggregation of intermediate filaments with alphaB-crystallin, and it identifies intermediate filaments as important physiological substrates for alphaB-crystallin. Using recombinant human alphaB-crystallin, the effects of the disease-causing mutation R120G upon the structure and the chaperone activities of alphaB-crystallin are reported. The secondary, tertiary, and quaternary structural features of alphaB-crystallin are all altered by the mutation as deduced by near- and far-UV circular dichroism spectroscopy, size exclusion chromatography, and chymotryptic digestion assays. The R120G alphaB-crystallin is also less stable than wild type alphaB-crystallin to heat-induced denaturation. These structural changes coincide with a significant reduction in the in vitro chaperone activity of the mutant alphaB-crystallin protein, as assessed by temperature-induced protein aggregation assays. The mutation also significantly altered the interaction of alphaB-crystallin with intermediate filaments. It abolished the ability of alphaB-crystallin to prevent those filament-filament interactions required to induce gel formation while increasing alphaB-crystallin binding to assembled intermediate filaments. These activities are closely correlated to the observed disease pathologies characterized by filament aggregation accompanied by alphaB-crystallin binding. These studies provide important insight into the mechanism of alphaB-crystallin-induced aggregation of intermediate filaments that causes disease.

Stress‐activated protein kinase 2a, also called p38, is inhibited by SB 203580 and this drug has been used widely to implicate this enzyme in the regulation of many physiological processes. Here, we introduce a novel method of general application, which can be used to establish whether the effects of SB 203580 are mediated via inhibition of stress‐activated protein kinase 2a/p38 or whether they result from ‘non‐specific’ effects. Four events thought to occur upon activation of stress‐activated protein kinase 2a/p38 have been established unequivocally. These are the activation of mitogen‐activated protein kinase‐activated protein kinase‐2 and mitogen‐ and stress‐activated protein kinase‐1 and the phosphorylation of their presumed substrates, heat shock protein 27 and the transcription factor cyclic AMP response element binding protein, respectively. In contrast, the SB 203580‐induced activation of c‐Raf is independent of stress‐activated protein kinase 2a/p38 inhibition.

Desmin-related myopathy and cataract are both caused by the R120G mutation in αB-crystallin. Desmin-related myopathy is one of several diseases characterized by the coaggregation of intermediate filaments with αB-crystallin, and it identifies intermediate filaments as important physiological substrates for αB-crystallin. Using recombinant human αB-crystallin, the effects of the disease-causing mutation R120G upon the structure and the chaperone activities of αB-crystallin are reported. The secondary, tertiary, and quaternary structural features of αB-crystallin are all altered by the mutation as deduced by near- and far-UV circular dichroism spectroscopy, size exclusion chromatography, and chymotryptic digestion assays. The R120G αB-crystallin is also less stable than wild type αB-crystallin to heat-induced denaturation. These structural changes coincide with a significant reduction in thein vitrochaperone activity of the mutant αB-crystallin protein, as assessed by temperature-induced protein aggregation assays. The mutation also significantly altered the interaction of αB-crystallin with intermediate filaments. It abolished the ability of αB-crystallin to prevent those filament-filament interactions required to induce gel formation while increasing αB-crystallin binding to assembled intermediate filaments. These activities are closely correlated to the observed disease pathologies characterized by filament aggregation accompanied by αB-crystallin binding. These studies provide important insight into the mechanism of αB-crystallin-induced aggregation of intermediate filaments that causes disease.

Of all aspartyl residues in bovine αA-crystallin, only Asp-151 exhibits pronounced racemization. Asp-151 is also one of the sites where peptide bond cleavage occurs in in vivo aging αA-crystallin. This aspartyl residue is followed by an alanyl residue and resides in a flexible carboxyl terminal extension of α-crystallin. Both in vivo and in vitro racemization studies indicate that the pronounced and site-specific racemization of Asp-151 proceeds via formation of a succinimide intermediate. The in vivo racemization of aspartyl residues in αA-crystallin is discussed with regard to the proposed tertiary structure of α-crystallin.

Three members of the small heat shock protein family, αA-, αB-crystallin, and HSP27, confer thermoresistance upon their overexpression in mammalian cells. Phosphorylation, in conjunction with the molecular chaperone-like activity of these small HSPs, is believed to be important for thisin situfunctional property. We here report the influence of heat shock and other kinds of stress on the phosphorylation of αA-, αB-crystallin, and HSP27 in stably transfected HeLa cells. It is observed that αB-crystallin becomes phosphorylated upon exposure to the same inducers as is HSP27, although to a lesser extent. In contrast, phosphorylation of αA-crystallin is very low upon heat stress and even absent when other stressors are used. This indicates that phosphorylation is not in all instances essential for the stress protective functioning of the various small HSPs.

Two members of the small heat shock protein family, αB-crystallin and hsp25, occur at high levels in the mammalian heart. To try and understand any differences in functioning, we compared their properties in cultured rat neonatal cardiac myocytes. Both proteins are stress-inducible, but the level of hsp25 is only slightly increased in cultured cardiac myocytes subjected to hyperthermic stress, while αB-crystallin levels even remain unchanged. Phosphorylation of αB-crystallin and to a lesser extent also of hsp2S is induced after the heat shock. Directly after heat stress, αB-crystallin and hsp25 are partly found in detergent-insoluble fractions, representing cytoskeletal/nuclear structures. Additionally, we show by confocal laser scanning microscopy that αB-crystallin and hsp25 become associated with sarcomeric structures directly after the heat shock, indicating a cytoskeletal protective function. Four to six hours after the heat shock, both proteins reoccupy their original positions in the cytoplasm again. In contrast to αB-crystallin, hsp25 not only translocates to the cytoskeleton but also migrates to positions inside the nucleus. Despite the fact that both proteins are normally part of the same complex, their behavior in neonatal cardiac myocytes appears to be very different. The sarcomeric association of αB-crystallin occurs under milder conditions and persists for a longer period of time in comparison with hsp25. Our findings suggest that αB-crystallin and hsp25 are both involved in protection of the cytoskeleton during stress situations in the heart, although in different manners. In addition, hsp25 also plays a role inside the nucleus.

Hsp20 is a mammalian small heat shock protein with some deviatingin vitrocharacteristics. We now compare thein vivocellular thermoprotective abilities of Hsp20 with those of its direct relative, αB-crystallin. In a clonal survival assay Chinese hamster ovary (CHO) cells stably overexpressing Hsp20 survive equally well as αB-crystallin-expressing cells, after a heat shock. In a transient assay, however, overexpression of Hsp20 did not result in an enhanced recovery of coexpressed firefly luciferase after heat shock, in contrast to αB-crystallin. This might indicate that these highly homologous stress proteins are involved in at least partially distinct protective activities in cultured cells.

The bovine eye lens protein αA-crystallin has been overexpressed both by stable transfection of HeLa cells and by transient transfection of NIH 3T3 cells. In both experimental systems αA-crystallin overexpression results in an increased cellular thermoresistance as judged by different clonal survival assays. In contrast, similar overexpression of another stable lens protein, βB2-crystallin, does not confer thermoresistance. These results indicate that the structural relationship of αA-crystallin to the small heat shock proteins HSP25/27 and to αB-crystallin is sufficient for the shared thermoprotective function of all of these molecules and strongly suggests that the chaperone-like properties that they have in common are responsible for the conferred cellular thermoresistance.

Small heat shock proteins have been the Cinderellas of the molecular chaperone world, but now the crystal structure of a small heat shock protein has been solved and mutation of two human homologues implicated in genetic disease. Intermediate filaments appear to be one of the key targets of their chaperone activity.