| Summary: | 碩士 === 高雄醫學大學 === 生理及分子醫學研究所 === 97 === Articular cartilage defect is usually a consequence of mechanical or
biological damage that destabilizes tissue homeostasis in cartilage.
Cell-based tissue engineering has been indicated to be one of the ideal
treatments to regenerate articular cartilage. Adipose derived stem cells
(ADSCs) were reported to be obtained with relatively little discomforts
and lower donor site morbidity, and can be expanded in larger number in
vitro. The well-known factors for inducing chondrogenesis of
mesenchymal stem cells are transforming growth factor-βs (TGF-βs), etc.
The pulse electromagnetic field (PEMF) has been approved by FDA,
USA for treating non-union bone fracture. Several studies have been
reported that PEMF also increased proliferation and proteoglycan
synthesis in human chondrocytes. Furthermore, PEMF stimulation was
indicated to up-regulated TGF-β and also had a chondroprotective effect
during osteoarthritis progression in the knee joint of guinea pigs.
However, it remains unclear whether PEMF affects chondrogenic
differentiation of human adipose-derived stem cells (hADSCs) for
regenerating articular cartilage. In this study, PEMF and an innovative
single pulsed electromagnetic field (SPEMF) stimulation are
hypothesized to enhance chondrogenic differentiation of hADSCs. We
investigated whether PEMF or SPEMF can further enhance the
chondrogenesis in hADSCs culture where there the environments are
favor for chondrogenesis including pellet cultured system and hyaluronan
-coated dishes, without the induction of chondrogenesis.
The stimulation module of PEMF was pulsed period 5 ms repeated
in 15 Hz, magnetic magnitude in 20 Gauss, stimulated for 8 hrs per day.Module of SPEMF was magnitude in 0.8 Tesla (8*103 Gauss) per pulse,
pulsed period 5 ms for 30 times per day. The daily stimulation period was
less than 3 min. The chondrogenesis in hADSCs were evaluated by
Q-PCR to quantify mRNA expressions of chondrogeneic related genes by
and by DMMB assay and Alcian blue stain to quantify
glycosaminoglycans (GAGs) synthesis. The results showed that in both
pellet cultured system and hyaluronan-coated dishes, the expressions of
chondrogenic marker genes including, SOX-9, type II collagen and
aggrecan, of hADSCs were significantly increased on day 1, 3, 5, and 7
upon PEMF or SPEMF treatment in comparison with non-treated control
cultured. This effect was not significantly difference among PEMF,
SPEMF, and chondroinduction groups. For hADSCs cultured in pellet
cultured system and hyaluronan-coated dishes, the GAG formed
significantly more than that of control cultures after 10 days of either
PEMF or SPEMF. This chondrogeneic effect was also similar to that in
the chondroinduction medium
Our results also showed that the chondrogeneic related gene
expressions on hADSCs were similar in the pellet cultured system by
PEMF or SPEMF stimulation in the hyaluronan-coated dishes. More
importantly, there was no obviously enhanced expressions of osteogenic
marker genes including, osteocalcin and collagen type I by SPEMF
treatments on hADSCs in pellet cultured system or in the
hyaluronan-coated dishes, while PEMF stimulation significantly
increased osteoclcin expression (p<0.01). From these results, we suggest
that SPEMF might be an alternative method to enhance chondrogeneic
differentiation of hADSCs for articular cartilage regeneration.
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