In vitro culture models of OA
Definition of in vitro (Biology) In vitro culture models
(of a process) performed or taking place in a Valuable to the study of osteoarthritis which is a
test tube, culture dish or elsewhere outside a multifactorial disease with no single aetiological
living organism mechanism.
Require a comprehensive and multisystem approach
In vitro culture (Ex vivo) to understand the heterogeneity of the disease.
Allows experimentation on cells or tissues Can guide the development of novel therapeutic
derived from an organism under more strategies for OA
controlled conditions, at the expense of
altering the ‘Natural’ environment
Tests or measurements can be performed that Recap of OA
may not be possible in the living subjects. Three main components of joints= bone,
Tissues can be removed in part, as whole cartilage and synovial fluid
organs or as larger organ systems Cartilage consists of articular cartilage
(covers articulating surface of bone) and there
is a menisci
Loss of cartilage in vitro Whole joing is bathed in synovial fluid
Toluidine blue- binds to the negatively Joint cavity is surrounded by a joint capsule
charged Glycosaminoglycans on aggrecan In OA, there are a number of key changes that
In normal cartilage there is a robust happen to each of those joint components:
prescense of large aggregating proteoglycans o Subchondral bone cysts, osteophytes-
throughout the tissue depth can alter mechanisms of joint
In OA patients, there is massive disruption of o thickening of joint capsule
this tissue, evident by a loss of the toluidine o episodic synovitis – inflammation of
blue staining demonstrating the loss of the synovium- this adds to the disease
aggrecan, there is fibrillation, so there is mechanism
fissures running through the depth of the o degenerative articular cartilage loss-
tissue and a loss of articular cartilage. There hallmark of OA. Cartilage destruction
is also changes to the lower regions of the is due to the imbalance between
tissue, where chondrocytes try to divide to anabolism - synthesis of new ECM
regenerate tissue, but they fails to do so and catabolism – break down of ECM
molecules. Massive upregulation of
catabolism in OA
Importance of in vitro models to study cartilage LOOK AT DEGENERATIVE CHANGES ON
pathobiology LAST PAGE TO SEE MMORE PATHOLOGY
Molecular mechanisms and pathways are
complex and involve alterations in the cell
metabolism of multiple tissues within a joint,
Advantages of in vitro models
it is important to have in vitro models to
Ease of manipulation- high degree of
understand these, e,g:
flexibility and control allowing for
A study on synovial fibroblasts discovered
manipulation of experimental conditions
that these cells under inflammation, secrete
3R philosophy (ethical consideration) –
cytokine, such as interleukin1 and TNF-alpha,
refining, reducing and replacing the use of
these act on chondrocytes to upregulate
animals in research
specific NF-kB pathways, which upregulate
Early features of the development of the
enzymes, such as the matrix
disease can be studied- in humans, the disease
metalloproteinases (MMPs) and ADAMTS-5,
isn’t diagnosed until late stage, when the
which are involved in the breakdown of
cartilage is nearly all destroyed, so in order to
aggrecan and collagen in articular cartilage
understand the disease fully, in vitro models
to study the early onset of the disease can be
undertaken
Infinite number of variations exist for a single
model- so more than one parameter can be
controlled when using in vitro cell cultures
Definition of in vitro (Biology) In vitro culture models
(of a process) performed or taking place in a Valuable to the study of osteoarthritis which is a
test tube, culture dish or elsewhere outside a multifactorial disease with no single aetiological
living organism mechanism.
Require a comprehensive and multisystem approach
In vitro culture (Ex vivo) to understand the heterogeneity of the disease.
Allows experimentation on cells or tissues Can guide the development of novel therapeutic
derived from an organism under more strategies for OA
controlled conditions, at the expense of
altering the ‘Natural’ environment
Tests or measurements can be performed that Recap of OA
may not be possible in the living subjects. Three main components of joints= bone,
Tissues can be removed in part, as whole cartilage and synovial fluid
organs or as larger organ systems Cartilage consists of articular cartilage
(covers articulating surface of bone) and there
is a menisci
Loss of cartilage in vitro Whole joing is bathed in synovial fluid
Toluidine blue- binds to the negatively Joint cavity is surrounded by a joint capsule
charged Glycosaminoglycans on aggrecan In OA, there are a number of key changes that
In normal cartilage there is a robust happen to each of those joint components:
prescense of large aggregating proteoglycans o Subchondral bone cysts, osteophytes-
throughout the tissue depth can alter mechanisms of joint
In OA patients, there is massive disruption of o thickening of joint capsule
this tissue, evident by a loss of the toluidine o episodic synovitis – inflammation of
blue staining demonstrating the loss of the synovium- this adds to the disease
aggrecan, there is fibrillation, so there is mechanism
fissures running through the depth of the o degenerative articular cartilage loss-
tissue and a loss of articular cartilage. There hallmark of OA. Cartilage destruction
is also changes to the lower regions of the is due to the imbalance between
tissue, where chondrocytes try to divide to anabolism - synthesis of new ECM
regenerate tissue, but they fails to do so and catabolism – break down of ECM
molecules. Massive upregulation of
catabolism in OA
Importance of in vitro models to study cartilage LOOK AT DEGENERATIVE CHANGES ON
pathobiology LAST PAGE TO SEE MMORE PATHOLOGY
Molecular mechanisms and pathways are
complex and involve alterations in the cell
metabolism of multiple tissues within a joint,
Advantages of in vitro models
it is important to have in vitro models to
Ease of manipulation- high degree of
understand these, e,g:
flexibility and control allowing for
A study on synovial fibroblasts discovered
manipulation of experimental conditions
that these cells under inflammation, secrete
3R philosophy (ethical consideration) –
cytokine, such as interleukin1 and TNF-alpha,
refining, reducing and replacing the use of
these act on chondrocytes to upregulate
animals in research
specific NF-kB pathways, which upregulate
Early features of the development of the
enzymes, such as the matrix
disease can be studied- in humans, the disease
metalloproteinases (MMPs) and ADAMTS-5,
isn’t diagnosed until late stage, when the
which are involved in the breakdown of
cartilage is nearly all destroyed, so in order to
aggrecan and collagen in articular cartilage
understand the disease fully, in vitro models
to study the early onset of the disease can be
undertaken
Infinite number of variations exist for a single
model- so more than one parameter can be
controlled when using in vitro cell cultures
