In Situ Calcium Signaling of Chondrocytes Under Non-Serum and Serum Culture

2013 ◽  
Author(s):  
Yilu Zhou ◽  
Lauren Resutek ◽  
Liyun Wang ◽  
X. Lucas Lu
Keyword(s):  
Calcium Signaling ◽  
Mechanical Stimulation ◽  
Biomechanical Properties ◽  
Cellular Level ◽  
Cartilage Explants ◽  
Serum Free ◽  
Better Than

Chemically defined serum-free medium has been shown to maintain the mechanical properties of cartilage allografts better than serum supplemented medium during long-term in vitro culture [1]. Little is known about this beneficial mechanism at a cellular level. Intracellular calcium ([Ca2+]i) signaling is one of the earliest responses in chondrocytes under mechanical stimulation [2]. It was recently found that calcium signaling is involved in the regulation of chondrocyte morphology changes and its short-term anabolic and catabolic responses under mechanical stimulation [3]. In this study we hypothesized that the beneficial mechanisms of serum-free culture could be indicated by the spatiotemporal features of [Ca2+]i signaling of chondrocytes in situ. We aimed to: (i) compare the in situ spontaneous [Ca2+]i responses of chondrocytes cultured in medium with and without serum; (ii) investigate the correlation between the [Ca2+]i responses of chondrocytes and the biomechanical properties of cartilage explants.

Effects of Bisphosphonate on Long-Term Culture of Cartilage Allografts

2013 ◽  
Author(s):  
Yilu Zhou ◽  
Lauren Resutek ◽  
Liyun Wang ◽  
X. Lucas Lu
Keyword(s):  
Medial Meniscus ◽  
Biomechanical Properties ◽  
Culture Conditions ◽  
Protective Mechanisms ◽  
Post Traumatic ◽  
Biochemical Mechanisms ◽  
Altered Metabolism

Zoledronic acid (ZA), an FDA approved bisphosphonate (BP) medicine, is widely used for the treatment of osteoclast-related bone loss diseases [1]. Our previous study has found that systemic administration of ZA could dramatically suppress the development of post-traumatic osteoarthritis (PTOA) in the DMM (destabilization of the medial meniscus) mouse model, a model recapitulating the altered joint loading associated with PTOA [2]. This finding is consistent with a few similar studies using different animal models [3]. However, little is known about the cellular and biochemical mechanisms of BP mediated chondro-protection in PTOA pathogenesis. Studies have shown that PTOA often initiates from the apoptosis and altered metabolism of cartilage chondrocytes. In this study, we will investigate the direct effects of ZA on the metabolisms of chondrocytes using long-term in vitro culture of cartilage allografts. As one of the earliest responses of chondrocytes to mechanical stimulation, intracellular calcium ([Ca 2+] i) signaling is the upstream of numerous mechanotransduction pathways [4]. We hypothesize that the chondro-protective mechanisms of ZA could be represented by the characteristics of [Ca 2+] i signaling of in situ chondrocytes. Our specific aims were to: (i) compare the in situ spontaneous [Ca 2+] i responses of chondrocytes cultured in non-ZA and ZA supplemented environments, and (ii) compare the biomechanical properties of cartilage allografts under the two culture conditions.

scholarly journals The effect of prior long-term recellularization with keratocytes of decellularized porcine corneas implanted in a rabbit anterior lamellar keratoplasty model

2020 ◽  
Author(s):  
Julia Fernández-Pérez ◽  
Peter W. Madden ◽  
Robert Thomas Brady ◽  
Peter F. Nowlan ◽  
Mark Ahearne
Keyword(s):  
Stromal Cells ◽  
Scar Tissue ◽  
Dendritic Morphology ◽  
Lamellar Keratoplasty ◽  
Human Cornea ◽  
Serum Free ◽  
Anterior Lamellar Keratoplasty ◽  
Potential Alternative

AbstractDecellularized porcine corneal scaffolds are a potential alternative to human cornea for keratoplasty. Although clinical trials have reported promising results, there can be corneal haze or scar tissue. Here, we examined if recellularizing the scaffolds with human keratocytes would result in a better outcome. Scaffolds were prepared that retained little DNA (14.89 ± 5.56 ng/mg) and demonstrated a lack of cytotoxicity by in vitro. The scaffolds were recellularized using human corneal stromal cells and cultured for between 14 in serum-supplemented media followed by a further 14 days in either serum free or serum-supplemented media. All groups showed full-depth cell penetration after 14 days. When serum was present, staining for ALDH3A1 remained weak but after serum-free culture, staining was brighter and the keratocytes adopted a native dendritic morphology with an increase (p < 0.05) of keratocan, decorin, lumican and CD34 gene expression. A rabbit anterior lamellar keratoplasty model was used to compare implanting a 250 µm thick decellularized lenticule against one that had been recellularized with human stromal cells. In both groups, host rabbit epithelium covered the implants, but transparency was not restored after 3 months. Post-mortem histology showed under the epithelium, a less-compact collagen layer, which appeared to be a regenerating zone with some α-SMA staining, indicating fibrotic cells. In the posterior scaffold, ALDH1A1 staining was present in all the acellular scaffold, but in only one of the recellularized lenticules. We conclude that recellularization with keratocytes alone may not be sufficiently beneficial to justify introducing allogeneic cells without concurrent treatment to further manage keratocyte phenotype.

A functional long‐term 2D serum‐free human hepatic in vitro system for drug evaluation

2020 ◽  
Author(s):  
Carlota Oleaga ◽  
L. Richard Bridges ◽  
Keisha Persaud ◽  
Christopher W. McAleer ◽  
Christopher J. Long ◽  
...  
Keyword(s):  
Drug Evaluation ◽  
In Vitro System ◽  
Serum Free

In situ generation of human brain organoids on a micropillar array

Lab on a Chip ◽  
2017 ◽  
Vol 17 (17) ◽  
pp. 2941-2950 ◽  
Author(s):  
Yujuan Zhu ◽  
Li Wang ◽  
Hao Yu ◽  
Fangchao Yin ◽  
Yaqing Wang ◽  
...  
Keyword(s):  
Stem Cells ◽  
Human Brain ◽  
Pluripotent Stem Cells ◽  
3D Culture ◽  
In Situ Generation ◽  
Induced Pluripotent ◽  
High Throughput Manner

We present a simple and high throughput manner to generate brain organoids in situ from human induced pluripotent stem cells on micropillar arrays and to investigate long-term brain organogenesis in 3D culture in vitro.

Adaptation to calcium deprivation in the rat: effects of parathyroidectomy.

1977 ◽  
Vol 232 (3) ◽  
pp. E336
Author(s):  
J T Pento ◽  
L C Waite ◽  
P J Tracy ◽  
A D Kenny
Keyword(s):  
Adaptive Response ◽  
Calcium Transport ◽  
Parathyroid Tissue ◽  
Adaptation Period ◽  
Short Term ◽  
High Calcium

The role of parathyroid hormone (PTH) in the adaptive response in gut calcium transport to calcium deprivation has been studied in the rat using both the in vitro everted duodenal sac and the in situ ligated duodenal segment technique. Intact or parathyroidectomized (PTX) young rats were placed on a low calcium (0.01%) diet for 7-, 14-, or 21-day adaptation periods and compared with control rats maintained on a high calcium (1.5%) diet. Prior PTX (3 days before the start of the adaptation period) abolished the adaptive response (enhanced calcium transport) induced by calcium deprivation for a 7-day adaptation period, but did not abolish a response after a 21-day period. A 14-day adaptation period gave equivocal results. It is concluded that PTH appears to be necessary for short-term (7-day) adaptation, but not for long-term (21-day) adaptation to calcium deprivation. However, if accessory parathyroid tissue is present, the data could be interpreted differently: the essentiality of PTH for the adaptive response might be independent of the length of the adaptation period. The data also contribute to a possible resolution of the controversy concerning the involvement of PTH in the regulation of intestinal calcium transport in the rat.

scholarly journals Long-term conservation of potato genetic resources: Methods and status of conservation

2019 ◽  
pp. 717-725
Author(s):  
Jane Muthoni ◽  
Hussein Shimelis ◽  
Rob Melis
Keyword(s):  
Genetic Resources ◽  
Slow Growth ◽  
Plant Genetic Resources ◽  
Ex Situ ◽  
Growth Media ◽  
Medium Term ◽  
Natural Habitats

Plant genetic resources (PGRs) play an important role in agriculture, environment protection, cultural property and trade; they need to be conserved. There are two fundamental approaches for the conservation of PGRs: in situ and ex situ. In situ conservation is the conservation of ecosystems and natural habitats and the maintenance and recovery of viable populations of species in their natural surroundings. Ex situ preservation is the storage of seeds or plant materials under artificial conditions to maintain their long term viability and availability for use. Genebanks employ seed storage, field collections of living plants and in vitro storage (tissue culture or cryopreservation) for ex situ preservation of PGR. Storage of orthodox seeds, which are tolerant to low moisture content and low temperatures at appropriate temperature and humidity, is the most convenient ex situ conservation method. Plants that produce recalcitrant seeds or non-viable seeds are conserved in field genebanks as well as in-vitro in slow growth media for short-to-medium term and cryopreservation in liquid nitrogen at -1960C for long-term periods. Cryopreservation is very expensive and needs trained personnel; this could explain why this method is rarely used for conservation of plant genetic resources in most developing countries. Potato tubers are bulky and highly perishable; the crop is generally conserved as clones either in field genebanks (with annual replanting), in-vitro conservation in slow growth media for short-to-medium term and cryopreservation for long term. Field genebanks are expensive to maintain and the crop is exposed to many dangers; hence, cryopreservation is the only feasible method for long term conservation. However, given the high cost of cryopreservation, long-term conservation of potato genetic resources is poorly developed in most resource-poor countries leading to high rates of genetic erosion. This paper looks into the various methods that that can be applied to conserve potato genetic resources and the status of conservation of potatoes in major genebanks and some countries.

The Primary Investigation on Biological Effect of Mesoporous Bioactive Glass In Vivo

2013 ◽  
Vol 750-752 ◽  
pp. 1651-1655
Author(s):  
Bai Yan Sui ◽  
Cheng Tie Wu ◽  
Jiao Sun
Keyword(s):  
Bioactive Glass ◽  
Biological Effect ◽  
Degradation Products ◽  
Long Term Effect ◽  
Liver And Kidney ◽  
Mesoporous Bioactive Glass

Mesoporous bioactive glass (MBG) has superior bioactivity and degradation than non-mesoporous bioactive glass (BG) in vitro. But the biological effect of MBG in vivo is still unknown. In this study, MBG powders with 20μm were implanted into the femoral condyles in SD rats. BG powders with 20μm were used as a control. The local degradation and osteogenesis were observed at 1 week and 4 weeks after implantation, and the systemic toxicity of the degradation products were also evaluated simultaneously. The results revealed MBG powders had the faster rate of degradation and better osteogenesis effect than BG powders at 4 weeks, although the most of material still remained in situ. Histopathological analyses indicated the degradation products did not have any damage to major organs such as liver and kidney. In conclusion, this preliminary study demonstrated that MBG powders have more excellent biological effect at 4 weeks than that of BG in vivo. However the long-term effect needs to be confirmed.

scholarly journals In situ calcium signaling of chondrocytes under serum-free and serum culture

2013 ◽  
Vol 21 ◽  
pp. S124-S125
Author(s):  
Y. Zhou ◽  
L. Resutek ◽  
L. Wang ◽  
X. Lu
Keyword(s):  
Calcium Signaling ◽  
Serum Free
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