Associations of parents’ and adolescents’ active travel behavior across various destinations – a sex/gender analysis

Abstract Background Active travel behavior such as walking and cycling is associated with several health benefits. Especially the family environment seems to be important for active travel in children and adolescents. Currently, little is known regarding travel behavior in leisure time and associations of travel behavior within parent-adolescent dyads. Methods The present analysis is based on the German ARRIVE study (Active tRavel behavioR in the famIly enVironmEnt), which incorporated a large scale, representative cross-sectional online survey including 517 parent–child dyads consisting of adolescents (N = 517; boys = 263, girls = 254) aged 11–15 years and one of their parents (N = 517; fathers = 259, mothers = 258). Based on that survey which took place in June 2021 (during the COVID-19 pandemic), we calculated the prevalence of active travel to four commonly visited destinations (school/work, friends/relatives, shopping stores and recreational activities) using an adapted version of the travel to school questionnaire by Segura-Diaz JM, Rojas-Jimenez A, Barranco-Ruiz Y, Murillo-Pardo B, Saucedo-Araujo RG, Aranda-Balboa MJ, et al. (Int J Environ Res Public Health 17(14), 2020). In addition, we investigated the associations between parents’ and adolescents’ travel behavior using scores for school/work, leisure time (friends/relatives, shopping stores and recreational activities) and overall (school/work and leisure time). Results Across all destinations, prevalence of active travel in adolescents (63.08%) was higher than in parents (29.21%). Active travel to school (47.33%) as well as to work (20.43%) indicated the lowest prevalence. Linear regression models revealed significant associations in overall active travel between mothers and adolescents (girls: β = 0.308, p &lt; 0.001; boys: β = 0.302, p = 0.001) and in leisure time active travel behavior between mothers and daughters (β = 0.316, p &lt; 0.001). Related to school/work active travel there were no associations between parents and adolescents. Conclusion The associations between adolescents’ and parents’ travel behavior differ depending on gender: they are solely seen in mother-adolescents dyads. Furthermore, our findings conclude that travel is a routine and independent of the destination. </jats:sec

Mutations in GDF5 Reveal a Key Residue Mediating BMP Inhibition by NOGGIN

Signaling output of bone morphogenetic proteins (BMPs) is determined by two sets of opposing interactions, one with heterotetrameric complexes of cell surface receptors, the other with secreted antagonists that act as ligand traps. We identified two mutations (N445K,T) in patients with multiple synostosis syndrome (SYM1) in the BMP–related ligand GDF5. Functional studies of both mutants in chicken micromass culture demonstrated a gain of function caused by a resistance to the BMP–inhibitor NOGGIN and an altered signaling effect. Residue N445, situated within overlapping receptor and antagonist interfaces, is highly conserved among the BMP family with the exception of BMP9 and BMP10, in which it is substituted with lysine. Like the mutant GDF5, both BMPs are insensitive to NOGGIN and show a high chondrogenic activity. Ectopic expression of BMP9 or the GDF5 mutants resulted in massive induction of cartilage in an in vivo chick model presumably by bypassing the feedback inhibition imposed by endogenous NOGGIN. Swapping residues at the mutation site alone was not sufficient to render Bmp9 NOG-sensitive; however, successive introduction of two additional substitutions imparted high to total sensitivity on customized variants of Bmp9. In conclusion, we show a new mechanism for abnormal joint development that interferes with a naturally occurring regulatory mechanism of BMP signaling

Gdf5 mutants N445T and N445K as well as Bmp9 cause strong chondrogenic differentiation when overexpressed in chicken limbs.

<p>Retroviral overexpression of indicated proteins after injection into chicken hind limbs at stage HH10. The contralateral hind limb was used as control. Embryos were harvested at day 7.5 and skeletal preparation stained with Alcian blue and Alizarin red. WtGdf5 lead to fusion of joints in the phalanges and metatarsals. In contrast, N445T and N455K Gdf5 as well as Bmp9 overexpression in vivo caused a severe phenotype with massive cartilage production leading to complete fusion of all skeletal elements of the limb and absence of interdigital mesenchyme. Scale: 1 mm.</p

Biacore interaction analysis (n = 6) showed no binding differences for rhGDF5 and rhN445T GDF5 with BMPR1Aecd and BMPR1Becd.

<p>Biacore interaction analysis (n = 6) showed no binding differences for rhGDF5 and rhN445T GDF5 with BMPR1Aecd and BMPR1Becd.</p

rhN445T GDF5 has a different signaling effect than rhGDF5.

<p>(A) Differentiation of myoblastic mouse cell line C2C12 was documented with alkaline phosphatase (ALP) staining (for osteoblasts) and immuno-myosin staining (for myoblasts) after five days of stimulation with 10 nM of the indicated recombinant proteins. RhBMP2 and rhBMP9 strongly induced ALP activity and inhibited myoblast differentiation, whereas rhGDF5 affected osteoblast differentiation only slightly while inhibiting myoblast differentiation. Interestingly rhN445T induced a moderate ALP activity and showed no detectable myosin staining. (B) ALP activity induced by stimulating the C2C12 with BMPs for three days. RhN445T, rhBMP2, and rhBMP9 showed dose-dependent induction of ALP activity whereas rhGDF5 had almost no ability to induce ALP activity. (E–G) Luciferase reporter assay of rhGDF5, rhN445T GDF5, rhBMP2, and rhBMP9 activity co-stimulated with soluble receptor extracellular domains (ecd) of the seven TGFβ superfamily type I receptors in C2C12 cells. rhGDF5, rhN445T GDF5 as well as rhBMP2 activity was competitively inhibited by BMPR1Aecd and BMPR1Becd, whereas luciferase activity induced by rhBMP9 was inhibited by ACVRL1ecd. Luciferase activity was normalized to Renilla. The lowest unstimulated value was determined as 0% and BMP stimulation without receptor ecd as 100%. Statistically relevant interactions were calculated with a two-tailed t-test and marked as: * p≤0.05, ** p≤0.01, *** p≤0.001.</p

NOG insensitivity of rhN445T GDF5 in vitro.

<p>(A) ALP activity induced in C2C12 myoblastic mouse cells overexpressing the Bmpr1b receptor (C2C12-Bmpr1b) after three days of stimulation. All BMPs show dose-dependent induction of ALP activity. (B) Inhibition of rhBMP-induced ALP activity in the C2C12-Bmpr1b cell line by rhNOG. ALP activity was measured after co-stimulation of 5 nM rhGDF5, rhN445T GDF5, rhBMP2, and 0.05 nM rhBMP9 with up to 40 nM rhNOG (rhBMP9 up to 0.4 nM). RhBMP2 is strongly inhibited by rhNOG. In contrast to rhGDF5 the mutant rhN445T GDF5 shows no response to rhNOG inhibition.</p

Bmp9 and Bmp10 are not inhibited by Nog.

<p>Chicken limb bud micromass cultures were retrovirally infected to express the indicated proteins and stained with Alcian blue after five days of cultivation. (A) Schematic overview of the mature domain of mouse Bmp9. Conserved cysteines marked in black. (B) 3D surface model of a BMP9 dimer (light grey and dark grey; PDB∶1ZKZ) linked via a disulfide bridge. Mut2 (K371N) represents the homologous mutation site to GDF5 N445T and is indicated in red. Mut1 (K348L, yellow) and mut3 (YH415Q, blue) are additional sites, which were predicted to be important for the interaction of GDF5 with NOG. (C) Expression of wtBmp9 and wtBmp10 in chicken micromass strongly induce chondrogenesis. This effect cannot be inhibited by co-expression of Nog. The Bmp9 mutants mut1 (K348L), mut2 (K371N), mut3 (YH415Q), mut1+2, and mut2+3 are similar to wtBmp9. In contrast, the combination of K371N and YH415Q (mut2+3) results in partial inhibition by Nog. The combination of all three mutations (mut1+2+3) leads to a complete inhibition by Nog. (D) Quantification of Alcian blue staining after extraction and photometric measurement at OD₅₉₅ (n = 4).</p