Transcript The Therapeutic Benefits of GSK-3β

Myocardial Injection With GSK-3β–
Overexpressing Bone Marrow–Derived
Mesenchymal Stem Cells Attenuates
Cardiac Dysfunction After Myocardial
Infarction
Circ Res. 2011 Feb 18;108(4):478-89.
指導老師：鄭伯智老師、林宏榮老師
學生：張維真
Outline
• Introduction
• Methods & Results
• Conclusion
Introduction
• The myocardium has been regarded as a
terminally differentiated organ lacking
regenerative potential.
Kajstura J, et al. Circ Res. 2010; 107:305–15.
• Cardiac progenitor cells localized in niches have
the ability to differentiate into cardiomyocytes
(CMs), thereby replenishing the CMs lost because
of basal turnover.
Beltrami AP, et al. Cell. 2003;114:763–76；
Bradfute SB, et al. Proc Natl Acad Sci U S A. 2003;100:12313–8
• The capacity for cardiac regeneration is
insufficient to maintain cardiac function when a
massive loss of CMs occurs in response to
myocardial infarction (MI) and heart failure.
• Various adult stem cells, including bone marrow–
derived cells, endothelial progenitor cells and
mesenchymal stem cells (MSCs), have been
shown to be capable of differentiation into CMs,
support survival of residential CMs, induce
angiogenesis, or promote infarct healing when
introduced into the heart after MI, clearly
establishing the proof of concept that cell-based
therapy (CBT) has the potential to improve
cardiac function in the post-MI heart.
• Macs have the ability to differentiate into various
cell types in the heart, and secrete paracrine
factors stimulating the survival of residential
CMs, the tissue repair process, and angiogenesis,
making MSCs an ideal source for cardiac CBT.
Zimmet JM & Hare JM. Basic Res Cardiol. 2005;100:471–81.; Shujia J et al. Cardiovasc
Res. 2008;77:525–33.; Zeng L et al. Circulation. 2007;115:1866 –75.
• CBT with MSCs in post-MI animal models caused
only modest or transient functional improvement,
possibly because of the rare survival and the very
inefficient CM differentiation of MSCs in vivo.
Hill JM et al. Circulation. 2003;108:1009 –14.
• For example, ex vivo introduction of Akt
increased the survival of MSCs and improved
cardiac function of the post-MI heart in mice
subjected to CBT.
Mangi AA et al. Nat Med. 2003;9:1195–1201
Glycogen synthase kinase-3β
• Glycogen synthase kinase (GSK)-3βis a
serine/threonine kinase that phosphorylates many
intracellular substrates, including β-catenin,
glycogen synthase, eIF2B, GATA4, myocardin,
c-Jun, cyclin D1, and N-Myc, thereby regulating
various intracellular functions.
Hirotani S et al. 2007;101:1164 –1174.
Haq S et al. Proc Natl Acad Sci U S A. 2003;100:4610–4615.
Adam Young D et al. Wiley Interdiscip Rev Syst Biol Med. 2010 Dec 31.
Aim
• To evaluate whether myocardial injection of
GSK-3β– overexpressing MSCs (GSK-3β–
MSCs) improves survival of the animals and left
ventricular (LV) function and attenuates cardiac
remodeling in the post-MI heart compared with
injection of control MSCs.
• To investigate the underlying mechanism through
which injection of GSK-3β–MSCs improves the
efficiency of CBT.
Study Design
Lac-Z、GSK-3β
transduced
2-3-week-old C57BL/6 mice
MSCs were isolated from bone marrow
LacZ-overexpressing MSCs GSK-3β-overexpressing MSCs
MI Surgery
Three-month-old C57BL/6 mice
MI
Sham
Saline 30μL
LacZ-MSCs
1.5×105 cells/ 30μL
GSK-3β-MSCs
1.5×105 cells/ 30μL
after 2、6 and 12 weeks
Survival、LVEDD、LVESD、FS％、
（-）dp/dt（mmHg）、EDP（mmHg）
Injection of GSK-3β-Overexpressing MSCs prevents cardiac
dysfunction after MI
Summary Ι
• Injection of untreated MSCs alone does not have
long-term therapeutic effects, but ex vivo
introduction of GSK-3βsignificantly improves
the therapeutic effect of CBT with MSCs after MI.
GSK-3βOverexpressing MSCs prevents cardiac hypertrophy
Remodeling
Summary ІІ
Injection with GSK-3β–MSCs promotes repair of
MI and/or suppresses MI progression, thereby
alleviating the cardiac remodeling seen with
injection with saline or LacZ-MSCs.
The Tet-Off Tetracycline-regulated
expression system
Stable Expression of GSK-3β in MSCs Improves the
Efficiency of CBT for Chronic Myocardial Infarction
Summary ІІІ
Stable overexpression of GSK-3β in MSCs is
beneficial and inhibits cardiac remodeling after
MI.
GSK-3β Overexpression in MSCs Enhances Survival and CM
Differentiation of MSCs In Vivo
Injection of GSK-3β-MSCs increases c-Kit and Ki67-positive cells
Summary Ⅳ
• Injection of GSK-3β–MSC into the MI
• mice induces CM differentiation more
• efficiently than that of control MSCs.
The Therapeutic Benefits of GSK-3β-Overexpressing MSCs Is, in
Part, Mediated by Angiogenesis Through Vegfa Production in MSCs
Injection of GSK-3 β-MSCs enhances Vegfa expression, which
partially mediates their therapeutic benefits
Summary Ⅴ
• Upregulation of Vefga is partially involved in the
improvement of LV function in the GSK-3β–
MSC injected MI mice, and that the therapeutic
benefit of GSK-3β–MSCs injection is mediated
by both Vegfa-dependent and -independent
mechanisms.
Conclusion
• Ex vivo genetic reprogramming of MSCs with
GSK-3β improves the therapeutic efficiency of
MSCs in the post-MI heart.
GSK-3β overexpression in MSCs achieves
several therapeutic benefits, most likely by
predirecting MSCs to CM differentiation and
inducing secretion of paracrine factors, including
Vegfa.
Thanks !!
Masson’s trichrome stain
Introduction
• Masson's Trichrome is most useful to differentiate
collagen from other fibres, particularly smooth
muscle and elastin.
Results
• Nuclei- Black
• Cytoplasm, muscle and erythrocytes- Red
• Collagen- Green
Masson Trichrome&H.E.(10x40)