Adipose tissue-derived stromal cells protect hair cells from aminoglycoside

IGF-1 Mediated Neuroprotective Effects of Olfactory-Derived Mesenchymal Stem Cells on Auditory Hair Cells

IMPORTANCE

Mesenchymal stem cells (MSCs) have the capability of providing ongoing paracrine support to degenerating tissues. Since MSCs can be extracted from a broad range of tissues, their specific surface marker profiles and growth factor secretions can be different. We hypothesized that MSCs derived from different sources might also have different neuroprotective potential.

OBJECTIVE

In this study, we extracted MSCs from rodent olfactory mucosa and compared their neuroprotective effects on auditory hair cell survival with MSCs extracted from rodent adipose tissue.

METHODS

Organ of Corti explants were dissected from 41 cochlea and incubated with olfactory mesenchymal stem cells (OMSCs) and adipose mesenchymal stem cells (AMSCs). After 72 hours, Corti explants were fixed, stained, and hair cells counted. Growth factor concentrations were determined in the supernatant and cell lysate using Enzyme-Linked Immunosorbent Assay (ELISA).

RESULTS

Co-culturing of organ of Corti explants with OMSCs resulted in a significant increase in inner and outer hair cell stereocilia survival, compared to control. Comparisons between both stem cell lines, showed that co-culturing with OMSCs resulted in superior inner and outer hair cell stereocilia survival rates over co-culturing with AMSCs. Assessment of growth factor secretions revealed that the OMSCs secrete significant amounts of insulin-like growth factor 1 (IGF-1). Co-culturing OMSCs with organ of Corti explants resulted in a 10-fold increase in IGF-1 level compared to control, and their secretion was 2 to 3 times higher compared to the AMSCs.

CONCLUSIONS

This study has shown that OMSCs may mitigate auditory hair cell stereocilia degeneration. Their neuroprotective effects may, at least partially, be ascribed to their enhanced IGF-1 secretory abilities compared to AMSCs.

Adipose-derived stromal cell in regenerative medicine: A review

The application of appropriate cell origin for utilizing in regenerative medicine is the major issue. Various kinds of stem cells have been used for the tissue engineering and regenerative medicine. Such as, several stromal cells have been employed as treat option for regenerative medicine. For example, human bone marrow-derived stromal cells and adipose-derived stromal cells (ADSCs) are used in cell-based therapy. Data relating to the stem cell therapy and processes associated with ADSC has developed remarkably in the past 10 years. As medical options, both the stromal vascular and ADSC suggests good opportunity as marvelous cell-based therapeutics. The some biological features are the main factors that impact the regenerative activity of ADSCs, including the modulation of the cellular immune system properties and secretion of bioactive proteins such as cytokines, chemokines and growth factors, as well as their intrinsic anti-ulcer and anti-inflammatory potential. A variety of diseases have been treated by ADSCs, and it is not surprising that there has been great interest in the possibility that ADSCs might be used as therapeutic strategy to improve a wider range of diseases. This is especially important when it is remembered that routine therapeutic methods are not completely effective in treat of diseases. Here, it was discuss about applications of ADSC to colitis, liver failure, diabetes mellitus, multiple sclerosis, orthopaedic disorders, hair loss, fertility problems, and salivary gland damage.

G-CSF attenuates noise-induced hearing loss

In this study, we investigated the effects of granulocyte colony-stimulating factor (G-CSF) for the treatment of noise-induced hearing loss (NIHL) in a guinea pig model. Forty guinea pigs were randomly divided into four groups: control, noise (white noise, 3 h/d for 2 days at 115 dB), noise+G-CSF (350 μg/kg/d for 5 days), and noise+saline. Auditory brainstem response (ABR) and distortion product otoacoustic emission (DPOAE) were used to determine the hearing threshold and outer hair cell function, respectively, in each group. Cochlear morphology was examined to evaluate hair cell injury induced by intense noise exposure. Fourteen days after noise exposure, the noise+G-CSF group had a lower ABR value than the noise group (P<0.05) or the noise+saline group (P<0.01). At most frequencies, the DPOAE value of the noise+G-CSF group showed a significant rise (P<0.05) compared to the noise group or the noise+saline group. Neither the ABR value nor the DPOAE value differed between the noise group and the noise+saline group. The morphology of the phalloidin-stained organ of Corti was consistent with the functional measurements. In conclusion, G-CSF can preserve hearing in an experimental model of NIHL in guinea pigs, by preserving hair cells after intense noise exposure.

Insulin-like growth factor 1 promotes the proliferation and adipogenesis of orbital adipose-derived stromal cells in thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is characterised by increased volume of the orbital contents involving adipose tissue, but the factors responsible for stimulation of orbital adipogenesis remain uncertain. Previous studies have shown that insulin-like growth factor 1 (IGF-1) is increased in the orbital fatty connective tissues of patients with TAO. The present study was conducted to investigate the effects of IGF-1 on orbital adipose-derived stromal cells (OADSCs) derived from TAO patients and to identify the signalling mechanisms involved. Our results showed that IGF-1 significantly promoted the cell proliferation and lipid accumulation of TAO OADSCs. The mRNA expression of adipogenic markers (adiponectin, leptin, adipocyte fatty acid binding protein [AP2] and fatty acid synthase [FAS]) was increased in TAO cultures treated with IGF-1. Further research demonstrated that the protein levels of peroxisome proliferator-activated receptor-γ (PPARγ) were up-regulated when OADSCs were treated with IGF-1. We also found that the inhibition of either IGF-1 receptor (IGF-1R) or phosphoinositide 3-kinase (PI3K) activity decreased the levels of IGF-1-stimulated mRNA encoding adiponectin, leptin, AP2, and FAS, as well as PPARγ protein levels. Moreover, the expression of phosphorylated Akt (p-Akt) protein in TAO cells was up-regulated by IGF-1, while a specific PI3K inhibitor (LY294002) or an antibody of IGF-1R blocked this effect. These results indicate that IGF-1 is a pro-proliferative and pro-adipogenic factor in TAO OADSCs. IGF-1 enhances the adipogenesis of TAO OADSCs by up-regulation of PPARγ via the activation of the IGF-1R and PI3K pathways, suggesting that the blocking of IGF-1R or inhibition of PI3K signalling might be a potential novel therapeutic approach to TAO.

Regeneration of radiation damaged salivary glands with adipose-derived stromal cells

OBJECTIVES

Radiotherapy is one of the most effective treatments for head and neck cancer. However, the development of dry mouth syndrome is an unavoidable side effect because, in addition to the tumor, the normal salivary glands are included in the irradiation field. Previously, we investigated the protective efficacy of basic fibroblast growth factor (bFGF) in radiation-damaged salivary glands. In this study, we investigated the efficacy of adipose-derived stromal cell (ADSC) transplantation for the regeneration of radiation damaged salivary glands.

STUDY DESIGN

Prospective animal experiment with control.

METHODS

ADSCs (500,000 cells isolated from green fluorescent protein mice) were transplanted into submandibular glands of C57BL/6 mice 10 weeks after 10 Gy irradiation (ADSC group). Phosphate-buffered saline was administered to mice as a control (sham group). Submandibular gland morphology and saliva flow rate were assessed just prior to transplantation and at 5 and 10 weeks posttransplantation. Quantitative RT-PCR was performed to examine the response of irradiated submandibular glands to ADSC transplantation.

RESULTS

Saliva flow rate in the ADSC group was improved compared to the sham group. Although acinar cell damage was detected in both groups, the proliferation of blood vessels and other paracrine effects were observed only in the ADSC group. Additionally, the differentiation of ADSCs into blood endothelial cells and ductal cells was also observed.

CONCLUSIONS

Our study indicates that ADSCs have the potential to restore salivary gland function after irradiation. The restoration of blood flow within submandibular gland tissue may explain the beneficial effects of ADSCs.

Local drug delivery to the inner ear using biodegradable materials

The lack of an effective method of drug delivery has been a considerable obstacle in the development of novel therapeutics for inner ear diseases. However, several strategies have been investigated to achieve drug delivery to the inner ear, particularly for local application. Here, we review recent advances in the development of inner ear drug-delivery systems, focusing on biodegradable materials. Both synthetic and natural biodegradable materials have shown efficacy for inner ear drug delivery, resulting in an attenuation of hearing loss in animal models. We expect the further development of such drug-delivery systems to help translate the findings of experimental studies to clinical applications.