title: Joint analysis of IVD herniation and degeneration by rat caudal needle puncture model.
abstract: Intervertebral disc (IVD) degeneration is responsible for various spine pathologies and present clinical treatments are insufficient. Concurrently, the mechanisms behind IVD degeneration are still not completely understood, so as to allow development of efficient tissue engineering approaches. A model of rat IVD degeneration directly coupled to herniation is here proposed in a pilot study. Disc injury is induced by needle puncture, using two different needles gauges: a low caliber 25-G needle and a high caliber 21-G needle. Histological, biochemical, and radiographic degeneration was evaluated at 2 and 6 weeks post-injury. We show that the larger caliber needle results in a more extended histological and radiographic degeneration within the IVD, compared to the smaller one. TUNEL quantification indicates also increased cell death in the 21-G group. Analyses of collagen type I (Picrosirius red staining), collagen type II (immunofluorescence), and GAG content (Blyscan assay) indicate that degeneration features spontaneously recover from 2 to 6 weeks, for both needle types. Moreover, we show the occurrence of hernia proportional to the needle gauge. The number of CD68+ macrophages present, as well as cell apoptosis within the herniated tissue are both proportional to hernia volume. Moreover, hernias formed after lesion tend to spontaneously diminish in volume after 6 weeks. Finally, MMP3 is increased in the hernia in the 21-G group at 2 weeks. This model, by uniquely combining IVD degeneration and IVD herniation in the same animal, may help to understand mechanisms behind IVD pathophysiology, such as hernia formation and spontaneous regression. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:258-268, 2017.
authors.affiliation: Instituto de Investigação e Inovação em Saúde (i3S), Rua Alfredo Allen 208, 4200-135, Porto, Portugal.|Instituto de Engenharia Biomédica (INEB), Rua do Campo Alegre 823, 4150-180, Porto, Portugal.
authors.forename: Carla
authors.initials: C
authors.lastname: Cunha
authors.affiliation: Instituto de Investigação e Inovação em Saúde (i3S), Rua Alfredo Allen 208, 4200-135, Porto, Portugal.|Instituto de Biologia Molecular e Celular (IBMC), Rua do Campo Alegre 823, 4150-180, Porto, Portugal.
authors.forename: Sofia
authors.initials: S
authors.lastname: Lamas
authors.affiliation: Instituto de Investigação e Inovação em Saúde (i3S), Rua Alfredo Allen 208, 4200-135, Porto, Portugal.|Instituto de Engenharia Biomédica (INEB), Rua do Campo Alegre 823, 4150-180, Porto, Portugal.
authors.forename: Raquel M
authors.initials: RM
authors.lastname: Gonçalves
authors.affiliation: Instituto de Investigação e Inovação em Saúde (i3S), Rua Alfredo Allen 208, 4200-135, Porto, Portugal.|Instituto de Engenharia Biomédica (INEB), Rua do Campo Alegre 823, 4150-180, Porto, Portugal.|Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Rua Jorge Viterbo Ferreira 228, 4050-313, Porto, Portugal.
authors.forename: Mário A
authors.initials: MA
authors.lastname: Barbosa
mesh_terms: D000818:Animals; D016923:Cell Death; D004195:Disease Models, Animal; D005109:Extracellular Matrix / Q000378:metabolism; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000201:enzymology / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000201:enzymology / Q000473:pathology*; D007405:Intervertebral Disc Displacement / Q000000981:diagnostic imaging / Q000201:enzymology / Q000473:pathology*; D008264:Macrophages; D008297:Male; D020782:Matrix Metalloproteinases / Q000378:metabolism; D011859:Radiography; D051381:Rats; D017208:Rats, Wistar
chemical_list: D020782:Matrix Metalloproteinases
keywords: X-rays; coccygeal; collagen; histology; intervertebral disc