All posts by Katarzyna
The registration for the spring BSMB meeting in Liverpool is now open
Early Bird registration and Abstract submission deadline is on 8th February 2019 (£80 students, £100 members or £130 non-members; late registration: £100 students, £120 members, non-member £150). For more details, please login to bsmb.ac.uk or mbi.ie
Lab Christmas in Northumberland
ARMET/MANF paper accepted for publication in Cell Stress and Chaperones
Mesencephalic astrocyte-derived neurotrophic factor is an important factor in chondrocyte ER homeostasis.
Bell PA, Dennis EP, Hartley CL, Jackson RM, Porter A, Boot-Handford RP, Pirog KA, Briggs MD.
Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an endoplasmic reticulum (ER) resident protein that can be secreted due to an imperfect KDEL motif. MANF plays a cytoprotective role in several soft tissues and is upregulated in conditions resulting from intracellular retention of mutant protein, including two skeletal diseases, metaphyseal chondrodysplasia type Schmid (MCDS) and multiple epiphyseal dysplasia (MED).
The role of MANF in skeletal tissue homeostasis is currently unknown. Interestingly, cartilage-specific deletion of Manf in a mouse model of MED resulted in increased disease severity, suggesting its upregulation may be chondroprotective. Treatment of MED chondrocytes with exogenous MANF led to a decrease in the cellular levels of BiP (GRP78), confirming MANF’s potential to modulate ER stress responses. However, it did not alleviate the intracellular retention of mutant matrilin-3, suggesting that it is the intracellular MANF that is of importance in the pathobiology of skeletal dysplasias.
The Col2Cre-driven deletion of Manf from mouse cartilage resulted in a chondrodysplasia-like phenotype. Interestingly, ablation of MANF in cartilage did not have extracellular consequences, but led to an upregulation of several ER-resident chaperones including BiP. This apparent induction of ER-stress in turn led to dysregulated chondrocyte apoptosis and decreased proliferation, resulting in reduced long bone growth.
We have previously shown that ER stress is an underlying disease mechanism for several skeletal dysplasias. The cartilage-specific deletion of Manf described in this study phenocopies our previously published chondrodysplasia models, further confirming that ER-stress itself is sufficient to disrupt skeletal growth and thus represents a potential therapeutic target.
First paper of 2018 published!
Calcium activated nucleotidase 1 (CANT1) is critical for glycosaminoglycan biosynthesis in cartilage and endochondral ossification.
Desbuquois dysplasia type 1 (DBQD1) is a chondrodysplasia caused by mutations in CANT1 gene encoding an ER/Golgi calcium activated nucleotidase 1 that hydrolyses UDP. Here, using Cant1 knock-in and knock-out mice recapitulating DBQD1 phenotype, we report that CANT1 plays a crucial role in cartilage proteoglycan synthesis and in endochondral ossification. Specifically, the glycosaminoglycan synthesis was decreased in chondrocytes from Cant1 knock-out mice and their hydrodynamic size was reduced, whilst the sulfation was increased and the overall proteoglycan secretion was delayed. Interestingly, knock-out chondrocytes had dilated ER cisternae suggesting delayed protein secretion and cellular stress; however, no canonical ER stress response was detected using microarray analysis, Xbp1 splicing and protein levels of BiP and ATF4. The observed proteoglycan defects caused deregulated chondrocyte proliferation and maturation in the growth plate resulting in the reduced skeletal growth. In conclusion, the pathogenic mechanism of DBQD1 comprises deregulated chondrocyte performance due to defective intracellular proteoglycan synthesis and altered proteoglycan properties in the extracellular matrix.
3rd International ECM & ER Stress Meeting, 9th-12th October 2018, Allendale, UK
Congratulations Dr Beth Gibson!
Beth defended her PhD thesis on investigation of the pathomolecular mechanism of two aggrecan mutations leading to OCD and SEMD using mouse models of disease.
Thank you to Prof Frank Zaucke from Frankfurt and Dr Andy Knight from Newcastle University for examining the thesis and well done Beth, all the best in your future career!
4th October 2018 – Dame Allan’s Schools biennial Higher Education & Careers Convention
Dame Allan’s Schools holds a biennial Higher Education & Careers Convention and invire presenters, employers, and universities to inspire and inform their students as they make plans for their future. We’ll be there on the 4th of October, chatting about genetic research and academic life and inspiring the young minds. We’ll show some cool science too!
Lab day out in Blanchland
Final SYBIL meeting, Newcastle September 2018
The SYBIL EU FP-7 project is sadly finishing, and we had a great final meeting here on home turf in Newcastle. SYBIL led to many exciting collaborations and papers and we hope to keep in touch with everyone and continue on the SYBIL projects and beyond. Watch this space..
Thank you all for amazing 5 years!