stem cell research

Stem Cell Research

DR.MOHAMMAD ABBAS

Assistant Professor& Orthopedic ConsultantFaculty of MedicineKing Abdulaziz University

Basic Lab Research Orthopedic Surgery Molecular Hematology Biochemistry Radiology

Research Groups

1. Isolation & characterization of BM-MSCs from OA patients

Basic Lab Research

Basic Lab Research

• Primary cultures of BM aspirate from OA patients showed characteristic spindle shaped cells which expressed MSCs related CD surface markers

• BM- MSCs demonstrated good viability , increased proliferation rate and differentiation into :

ADIPOCYTES , CHONDROCYTE , OSTEOCYTE


Basic Lab Research

Collagen secretion and Alkaline phosphates activity where increased with chondrogenic and osteogenic differentiation

Isolation & characterization were successful in both the OR stem cell Lab. & stem cells unit in KFMRC


2. Effect of Heat shock on BM- MSCs from OA patients

Basic Lab Research

After MSCs characterization and differentiation BM-MSCs were exposed to illuminated Arthroscope either as cell suspension or cell pellet to 37,45,55 degrees for 10,20 & 30 minutes followed by cell proliferation assay for 72 hrs which showed :

Basic Lab Research2. Effect of Heat shock on BM- MSCs from OA patients

The study concluded that BM-MSCs cell pellet appears better protected from temperature alterations compared to cell suspension

1- 63% cell prolifration in the cell suspension group2- 62 – 68 % in cell prolifration in the cell pellet group


Results :

Transplantation of BM-MSCs as pellet rather than as a single cells suspension to the site of cartilage defect would therefore support their viability and aid cartilage prolifration


Conclusion :

3. Evaluation of Ex-vivo cartilage regeneration using BM- MSCs of OA patients.

Basic Lab Research

Basic Lab Research

TKA patients were consented for collecting BM-MSCs and osteochondral bone removed during surgery , using the less damaged articular surface of lateral tibia plateau.

Bone pieces were trimmed to 1cm X 1cm & 1cm depth and a central 2mm drill defect was made

4 groups with osteochondral bone defect (OBD) were made :


Basic Lab Research

Group 1 Control Group 2 BM-MSCs pellet Group 3 Homogenized cartilage pelletGroup 4 BM-MSCs + Homogenized cartilage pellet

All samples were maintained in standard BM-MSCs chondrogenic medium for 28 days


Basic Lab Research

Results :• Light microscopy showed cartilagenus filling in group 4 with

full OBD closure with more mature matrix revealed byH&E staining .• Group 1 & 3 showed no filling of defect • Group2 showed partial filling of OBD with immture

cartilagenus matrix


Basic Lab Research

Conclusion :The study concludes that adding cartilage fragments to MSCs provide better formation in Ex – vivo models


1- Impact f cartilage paste impregnated with MSCs on regeneration of focal articular cartilage defects in rabbits

Orthopedic Animal Research

20 New Zealand rabbit knees all had focal surgical defect created into their medial femoral condyle and divided into 4 groups :

Group 1 Control (untreated)Group 2 Human umbilical Cord MSCsGroup 3 Human umbilical MSCs + Commercial fibrin sealant scaffold .Group 4 Human umbilical MSCs + Minced cartilage paste.

h-MSCs Impregnated with Autologous Cartilage Paste repair fresh focal Osteochondral defects in Rabbits



Rabbits were left to move freely for 8 weeks then sacrificed and healing of the defects was assessed :

1. Grossly 2. MRI using Biochemical T2 mapping 3. Histopathology



Group 1 showed no cartilage filling of defect.

Group 2 Group 3

Showed partial filling of the defect but was a bit better in group 3 ( MOCART score 5 points )

Group 4 - Complete filling of defect -Intact cartilage surface -Complete integration with adjacent cartilage as seen

in Histopathology & T2 mapping MRI ( MOCART score 80 points )

h-MSCs Impregnated with Autologous Cartilage Paste repair fresh focal Osteochondral defects in RabbitsResults :


Conclusions:

Repair of focal osteochondral defects in rabbit knees using human umbilical cord MSCs impregnated with autologous cartilage paste appears to be successful as proven clinically, radiological, as well Pathologically


ولرنين عادية للركبة صور حازم د صور من يستعمل انسجه و

2- Impact of hylofast scaffold impregnated with human MSCs & cartilage paste on surgically induced total arthritis in rabbits knees


فاست هيلو صورة

2- Impact of hylofast scaffold impregnated with human MSCs & cartilage paste on surgically induced total arthritis in rabbits knees


16 newzland rabbit knees were used having surgically induced total arthritis and divided into 4 groups

Group 1 control (untreated)Group 2 MSCs + cartilage pasteGroup 3 MSCs + hylofast scaffold Group 4 MSCs + hylofast scaffold +cartilage paste

Study still in progress

- Darweish- Chaudary- Hamdi

Orthopedic Colleagues

1. Genetic mapping of osteoarthritis2. Epigenetic analysis of osteoarthritis patient3. Exome sequence analysis for osteoarthritis

patients4. Molecular regulation of chondrogenic human

induced pluripotent stem cells

Molecular Hematology Research

Genetic mapping of osteoarthritis


Epigenetic analysis of osteoarthritis patient


Exome sequence analysis for osteoarthritis patients


Molecular regulation of chondrogenic human induced pluripotent stem cells




PurposeHuman induced pleuripotent stem cells (hiPSC) are a promising source for chondrogenic stem cells. Sequentialdifferentiation of hiPSC provides a platform for dissecting the molecular pathways associated withchondrogenesis in vivo and could reveal targets for better control of chondrocyte fate for cartilage repairapplications. The aim of this study was to use nextgenerationsequencing (NGS) to investigate the transcriptomeof chondrogenic hiPSCs.



Methods and MaterialsThe hiPSC line (C19) was derived through reprogramming of human dermal fibroblasts using viral vectorsexpressing Oct4, Sox2 and Klf4. A protocol of sequential growth factors including Activin A, FGF2and BMP4was used to drive the formation of chondroprogenitors directly from hiPSC colonies. The chondrogenic hiPSCswere characterised exhaustively by tissue engineering, histochemical analysis and biochemical analysis. Thetranscriptome of undifferentiated hiPSCs, hiPSCderivedchondrocytes and native chondrocytes was interrogatedutilizing RNASeqon the SOLiD 5500 XL platform where the polyAfraction was sequenced at a coverage levelof at least 25 million reads.



ResultsDifferential gene expression revealed the induction of several collagen genes including type 1 to type 12, type 14and type 18 during transition from the pluripotent state to the chondrogenic state (Figure 1). Collagenregulatorygenes such as PCOLCE which drives the endopeptidase cleavage of procollagen as well as regulators ofcollagen glycosylation were upregulated. The expression of various fibroblasts growth factors (FGFs) includingFGF11,FGFR2 and insulin growth factor2(IGF2)was upgregulated as well as the Wntinducedsecretedprotein, WISP2.Mitotic genes were downregulated in derived and differentiated chondrocytes.



ConclusionNGS analysis demonstrated the recapitulation of early events in cartilage development during hiPSCchondrogenesis. The upregulation of many members of the collagen family indicate the intricate nature ofcollagen expression during chondrogenesis. Further analysis of nonchondrogenictargets may reveal novelpathways for controlling the fate of chondrogenic hiPSCs.

1- EFFECT OF CATECHOLAMINES ON VIABILITY, PROLIFERATION,CHONDROGENIC & OSTEOGENIC DIFFERETIATION OF HUMAN MESENCHMAL STEM CELLS. 2- EFFECT OF NON STEROIDAL ANTI- INFLAMMATORY DRUGS ON VIABILITY, PROLIFERATION,CHONDROGENIC & OSTEOGENIC DIFFERETIATION OF HUMAN MESENCHMAL STEM CELLS.

Biochemistry Research

1. From Dr. Qutb)

Radiological Research

One oral presentation One poster

ICRS 2015 Chicago

One poster

EULAR Conference

- Not yet- Planning on high tibial ostetomy for unicompartmental osteoarthritis

Human Research

stem cell research

Education