| 1. |
- Mishra, A, et al.
(författare)
-
Diminishing benefits of urban living for children and adolescents' growth and development
- 2023
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 615:7954, s. 874-883
-
Tidskriftsartikel (refereegranskat)abstract
- Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1–6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.
|
|
| 2. |
|
|
| 3. |
- Berntsson, Elina, et al.
(författare)
-
Residue-specific binding of Ni(II) ions influences the structure and aggregation of amyloid beta (Aβ) peptides
- 2023
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Alzheimer's disease (AD) is the most common cause of dementia worldwide. AD brains display deposits of insoluble amyloid plaques consisting mainly of aggregated amyloid-β (Aβ) peptides, and Aβ oligomers are likely a toxic species in AD pathology. AD patients display altered metal homeostasis, and AD plaques show elevated concentrations of metals such as Cu, Fe, and Zn. Yet, the metal chemistry in AD pathology remains unclear. Ni(II) ions are known to interact with Aβ peptides, but the nature and effects of such interactions are unknown. Here, we use numerous biophysical methods-mainly spectroscopy and imaging techniques-to characterize Aβ/Ni(II) interactions in vitro, for different Aβ variants: Aβ(1-40), Aβ(1-40)(H6A, H13A, H14A), Aβ(4-40), and Aβ(1-42). We show for the first time that Ni(II) ions display specific binding to the N-terminal segment of full-length Aβ monomers. Equimolar amounts of Ni(II) ions retard Aβ aggregation and direct it towards non-structured aggregates. The His6, His13, and His14 residues are implicated as binding ligands, and the Ni(II)·Aβ binding affinity is in the low µM range. The redox-active Ni(II) ions induce formation of dityrosine cross-links via redox chemistry, thereby creating covalent Aβ dimers. In aqueous buffer Ni(II) ions promote formation of beta sheet structure in Aβ monomers, while in a membrane-mimicking environment (SDS micelles) coil-coil helix interactions appear to be induced. For SDS-stabilized Aβ oligomers, Ni(II) ions direct the oligomers towards larger sizes and more diverse (heterogeneous) populations. All of these structural rearrangements may be relevant for the Aβ aggregation processes that are involved in AD brain pathology.
|
|
| 4. |
- Svedruzic, Z. M., et al.
(författare)
-
The Binding of Different Substrate Molecules at the Docking Site and the Active Site of gamma-Secretase Can Trigger Toxic Events in Sporadic and Familial Alzheimer's Disease
- 2023
-
Ingår i: International Journal of Molecular Sciences. - : MDPI AG. - 1422-0067. ; 24:3
-
Tidskriftsartikel (refereegranskat)abstract
- Pathogenic changes in gamma-secretase activity, along with its response to different drugs, can be affected by changes in the saturation of gamma-secretase with its substrate. We analyze the saturation of gamma-secretase with its substrate using multiscale molecular dynamics studies. We found that an increase in the saturation of gamma-secretase with its substrate could result in the parallel binding of different substrate molecules at the docking site and the active site. The C-terminal domain of the substrate bound at the docking site can interact with the most dynamic presenilin sites at the cytosolic end of the active site tunnel. Such interactions can inhibit the ongoing catalytic activity and increase the production of the longer, more hydrophobic, and more toxic A beta proteins. Similar disruptions in dynamic presenilin structures can be observed with different drugs and disease-causing mutations. Both, C99-beta CTF-APP substrate and its different A beta products, can support the toxic aggregation. The aggregation depends on the substrate N-terminal domain. Thus, the C99-beta CTF-APP substrate and beta-secretase path can be more toxic than the C83-alpha CTF-APP substrate and alpha-secretase path. Nicastrin can control the toxic aggregation in the closed conformation. The binding of the C99-beta CTF-APP substrate to gamma-secretase can be controlled by substrate channeling between the nicastrin and beta-secretase. We conclude that the presented two-substrate mechanism could explain the pathogenic changes in gamma-secretase activity and A beta metabolism in different sporadic and familial cases of Alzheimer's disease. Future drug-development efforts should target different cellular mechanisms that regulate the optimal balance between gamma-secretase activity and amyloid metabolism.
|
|
