Life science
Regenerative medicine, Ageless life

Development of regenerative therapies using
iPS cell-derived cartilage
Assistant Professor Kengo Abe				https://researchmap.jp/kabe1109?lang=en

Specially Appointed Assistant Professor Nobuyuki Shima

https://researchmap.jp/maychan?lang=en

Professor Noriyuki Tsumaki					https://researchmap.jp/cart?lang=en

Abstract
Safranin OExpression Level

PRG4

NormalCartilage

UMAP_1
Normal Cartilage▍ Significance of the research and Future perspective
Transplantation of iPS-Cart could be applied to regenerative
therapies for diseases that are difficult to heal naturally, such ascartilage damage, intervertebral disc degeneration, and severebone defects. A clinical study is currently underway to transplant
allogeneic iPS-Cart into cartilage-injured areas in patients witharticular cartilage damage, and the acquisition of clinical proof ofconcept is expected to pave the way for social implementation.

Post-transplant

Similar▍ Background & Results

Fig.１. Evaluation of allogenic iPS-Cart transplantation into cartilage defects in primate models
iPS-Cart
survived and wasintegrated withthe hostcartilage. Chondralinto
defectsin the empty
groupinwere
Fig.1. Evaluationof allogenic
iPS-Cart
transplantation
cartilage
defects
prifilled with non-cartilaginous fibrous tissues, while defects in the transplantation group were filled withmate models.
cartilaginous
tissue. Gene expression profiles of iPS-Cart after transplantation and normal articularcartilage
werevery similar,
expression of
PRG4
which
is crucialfor joint
lubrication.defects iniPS-Cart
survived
andacquiring
was integratedwith
thehostcartilage.
Chondralthe empty group were filled with non-cartilaginous fibrous tissues, while defects
in the transplantation group were filled with cartilaginous tissue. Gene expression
profiles of iPS-Cart after transplantation and normal articular cartilage were very
similar, acquiring expression of PRG4 which is crucial for joint lubrication.
補足図表

scRNA-seq analysis of nucleus pulposus（NP) and articular cartilage（AC) cells
AC only

NP only

scRNA-seq of human iPS-Cart
AC/NP

Histological evaluation
hiPS-Cart

Safranin O

6 M after
6 W aftertransplantation transplantation

Existing cell transplantation therapies for cartilage damages are considered to repair the damage by activating host tissue with factors transiently
produced by the transplanted cells, and their repair ability is limited. Therefore, we are aiming to establish a curative regenerative therapy in which thegraft itself constitutes the reparative tissue by transplanting iPS-Cart into thedamaged tissue. Allogeneic cartilage transplantation into primate models
had never been assessed. We therefore evaluated the efficacy and immune
response of allogeneic iPS-Cart transplantation using a monkey model ofknee joint cartilage defect. The allogenic iPS-Cart in chondral defects elicited no immune reaction and directly contributed to tissue repair for at least
four months. iPS-Cart was integrated with the host native articular cartilage
and prevented degeneration of the surrounding cartilage. ScRNA-seq analysis indicated that iPS-Cart differentiated after transplantation, acquiring
expression of PRG4 which is crucial for joint lubrication.
Degeneration of nucleus pulposus of intervertebral disk is a major causeof low back pain. Because intervertebral disk degeneration is an irreversible condition, there is a need for regenerative treatments. The results ofscRNA-seq analysis of the nucleus pulposus and cartilage showed that thegene expression profiles of the two were very similar. When iPS-Cart wastransplanted into a nude rat model of caudal disc degeneration, disc degeneration was prevented for at least six months after the implantation indicating spatial and functional replacement of lost nucleus pulposus by iPS-Cart.
A large bone defect formed after surgical treatments of open fracture orbone tumor is difficult to be treated. iPS-Cart has properties of primordial
cartilage. We transplanted iPS-Cart into a bone defect model of the femur ofimmunodeficient mice and found new bone formation in the bone defects.

iPS-Cart

Pre-transplant

PRG4

Induced pluripotent stem cells (iPSCs) are a promising resource for allogeneic
cartilage transplantation to treat articular cartilage defects that do not heal naturally. We showed that allogeneic iPSC-derived cartilage (iPS-Cart) survived and was
integrated with the host cartilage without immune response in a primate model ofchondral defects in the knee joints. Single-cell RNA-sequence (scRNA-seq) analysis indicated that iPS-Cart differentiated after transplantation, acquiring expressionof PRG4 which is crucial for joint lubrication. We also investigated the applicationof iPS-Cart to diseases other than cartilage-related conditions and found that transplantation of human iPS-Cart into an immunodeficient rat model of intervertebral
disc degeneration suppressed disc degeneration, and transplantation into a largebone defect model in immunodeficient mice resulted in a new bone formation.

主要図表

iPS-Cart transplantation

Empty

scRNA-seq

Life science

Department of Biochemistry and Molecular Biology, Graduate School of Medicine→Gene expression profiles of the AC/NPcluster and human iPS-Cart were very
similarhVimentin IHC

Biomechanical test

hiPS-Cart

ShamNP removed
Empty

NP removed
hiPS-Cart transplanted

ShamNP removed NP removed
hiPS-Cart transplanted
Empty

Fig.2. Effect of human iPS-Cart transplantation on intervertebral disc regeneration

Fig.2. Effect of human iPS-Cart transplantation on intervertebral disc regeneration.
Disc degeneration was prevented for at least six months after transplantation. The
補足図表
mean storage modulus of the hiPS-Cart group was significantly lower thanthat ofthe empty group and not significantly different from that of the Sham group.
Disc degeneration was prevented for at least six months after transplantation. The mean storage modulus of the hiPSCart group was significantly lower than that of the empty group and not significantly different from that of the Shamgroup.

Empty

iPS-Cart transplantation

Fig.3.3.New
Newbonebone
formation
afterhiPS-Cart
transplantation
femoraldefects.
Fig.
formation
afterhiPS-Cart
transplantation
into into
femoralbonebonedefects.
iPS-Cart
wastransplanted
into a bonemodelof the model
femur ofof
SCIDNew
wasmice.
iPS-Cart
wastransplantedinto defecta bone
defectthemice.
femurofbone
SCID
formed in the defect 16 weeks after transplantation of iPS-Cart.
New bone was formed in the defect 16 weeks after transplantation of iPS-Cart.

P a t e n t JP6694215B2, JP6635505B2Abe, Kengo; Yamashita, Akihiro; Morioka, Miho et al. Engraftment of allogeneic iPS cell-derived cartilage organoid in a primate model of articular cartilage
defect. Nature Communications. 2023, 14, 804. doi:10.1038/s41467-023-36408-0
Kamatani,Takashi; Hagizawa, Hiroki; Yarimitsu, Seido et al. Human iPS cell-derived cartilaginous tissue spatially and functionally replaces nucleus
Tr e a t i s epulposus. Biomaterials. 2022, 284, 121491. doi: 10.1016/j.biomaterials.2022.121491
Iimori, Yuki; Morioka, Miho; Koyamatsu Saeko et al. Implantation of Human-Induced Pluripotent Stem Cell-Derived Cartilage in Bone Defects of Mice.
Tissue Eng Part A. 2021, 10, 20915. doi: 10.1089/ten.TEA.2020.0346
URL
K e y w o r d articular cartilage damage, allogenic transplantation, intervertebral disk degeneration, bone defect, induced pluripotent stem cells