Compression Loading Induced Cellular Stress Response of Intervertebral Disc Cells in Organ Culture

Introduction: Mechanical stress is often associated to interverterbal disc (IVD) degeneration and the effect of mechanical loading on IVD has been studied and reviewed.1,2 Previously, expression of heat shock proteins, HSP70 and HSP27 has been found in pathological discs.3 However, there is no direct evidence on whether IVD cells respond to the mechanical loading by expression of HSPs. The objective of this study is to investigate the stress response of IVD cells during compressive loading in an organ culture. Materials and Methods: Fresh adult bovine caudal discs were cultured with compressive loading applied at physiological range. Effect of loading type (static and dynamic) and repeated loading (2 hours per day for 2 days) were studied. Nucleus pulposus (NP) and annulus fibrosus (AF) of the IVD were retrieved at different time points: right after loading and right after resting. Positive control discs were heat shocked (43°C). Cell activity was assessed and expression of stress response genes (HSP70 and HSF1) and matrix remodeling genes (ACAN, COL2, COL1, ADAMTS4, MMP3 and MMP13) were studied. Results: Cell activity was maintained in all groups. Both NP and AF expressed high level of HSP70 in heat shock groups, confirming their expression in response to stress. In NP, expression of HSP70 was up-regulated after static loading and dynamic loading with higher fold change was observed after static loading. During repeated loading, HSP70 appeared to be upregulated right after loading and decreased after resting. Such trend was not observed in AF and HSF1 levels. Expressions of matrix remodeling genes did not change significantly with loading except ADAMTS4 decreased in AF during static loading. Conclusion: This study demonstrated that NP cells upregulate expression of HSP70 in response to loading induced stress without changing cell activity and matrix remodeling significantly. Acknowledgments: This project was funded by AO Spine (AOSPN) (grant number: SRN_2011_14) and a fellowship exchange award by AO Spine Scientific Research Network (SRN).

El arbitraje de las pesquerías del Atlántico norte entre la Gran Bretaña y los Estados Unidos de América.

Introducción.--Convención de compromiso arbitral de 27 enero de 1909.--Notas cambiadas, relativamente al arbitraje, entre los representantes de la Gran Bretaña y los Estados Unidos.--Nombramiento del doctor Drago como árbitro.--Laudo del Tribunal.--Documentos originales.--Award.

Ann Colloton, U-M Women's Swimming, 1987-1990

[Ann Colloton with Assistant Ath. Dir. Peggy Bradley-Doppes and Ath. Dir. Jack Weidenbach, receiving Michigan Big Ten Athlete of the decade award.]

Dwight Craig.

"A Houghton Mifflin literary fellowship award."

Russell on the power and duty of an arbitrator and the law of submissions and awards : and references under order of court, with an appendix of forms, precedents, and statutes.

Mode of access: Internet.

Arbitration in international controversy,

Bibliographical foot-notes.

National juvenile custody trends, 1978-1989 : juveniles taken into custody research program /

"Cooperative agreement award no. 89-JN-CX-K003"--T.p. verso.

A concise treatise on the law of arbitrations & awards, with an appendix of precedents and statutes.

Mode of access: Internet.

Criminal violence, biological correlates and determinants : a selected bibliography /

Includes indexes.

Criminal violence and race : a selected bibliography /

Includes index.

Forgotten shrines /

Six of the poems in pt. 1 (Portraits) received the eighteenth award of the prize offered by Professor Albert Stanburrough Cook to Yale university for the best unpublished verse.

20th century bookkeeping and accounting : a treatise on modern bookkeeping, accounting, and business customs, as illustrated in the "business transactions" wthich accompany this text.

"Granted a medal of award by the Panama-Pacific international exposition, San Francisco, California, 1915."

Marketing Symposium University of Illinois : [papers].

Description based on: Oct. 1955.

X disease in chickens ...

Paper submitted in competition for the poultry disease essay award for the year 1951-1952.

Awards, agreements, orders, and decisions made under the Industrial relations act, the Apprentices act, and other industrial legislation.

At head of title : Industrial Court and Industrial Commission.