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Grafting and early expression of growth factors from adipose-derived stem cells transplanted into the cochlea, in a Guinea pig model of acoustic trauma.

Fetoni AR, Lattanzi W, Eramo SL, Barba M, Paciello F, Moriconi C, Rolesi R, Michetti F, Troiani D, Paludetti G - Front Cell Neurosci (2014)

Bottom Line: ASC implantation did not modify auditory function.ASCs migrated from the perilymphatic to the endolymphatic compartment, during the analyzed time course.Immunofluorescence confirmed the increased expression, which appeared to be further strengthened by ASCs' implantation.

View Article: PubMed Central - PubMed

Affiliation: Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore , Rome , Italy.

ABSTRACT
Noise exposure causes damage of multiple cochlear cell types producing permanent hearing loss with important social consequences. In mammals, no regeneration of either damaged hair cells or auditory neurons has been observed and no successful treatment is available to achieve a functional recovery. Loads of evidence indicate adipose-derived stem cells (ASCs) as promising tools in diversified regenerative medicine applications, due to the high degree of plasticity and trophic features. This study was aimed at identifying the path of in vivo cell migration and expression of trophic growth factors, upon ASCs transplantation into the cochlea, following noise-induced injury. ASCs were isolated in primary culture from the adipose tissue of a guinea pig, transduced using a viral vector to express the green fluorescent protein, and implanted into the scala tympani of deafened animals. Auditory function was assessed 3 and 7 days after surgery. The expression of trophic growth factors was comparatively analyzed using real-time PCR in control and noise-injured cochlear tissues. Immunofluorescence was used to assess the in vivo localization and expression of trophic growth factors in ASCs and cochleae, 3 and 7 days following homologous implantation. ASC implantation did not modify auditory function. ASCs migrated from the perilymphatic to the endolymphatic compartment, during the analyzed time course. Upon noise exposure, the expression of chemokine ligands and receptors related to the PDGF, VEGF, and TGFbeta pathways, increased in the cochlear tissues, possibly guiding in vivo cell migration. Immunofluorescence confirmed the increased expression, which appeared to be further strengthened by ASCs' implantation. These results indicated that ASCs are able to migrate at the site of tissue damage and express trophic factors, upon intracochlear implantation, providing an original proof of principle, which could pave the way for further developments of ASC-based treatments of deafness.

No MeSH data available.


Related in: MedlinePlus

Functional results. The graphs in the upper panel show hearing threshold values in the Sham + ASCs and Noise-exposed groups. (A) ASCs implantation in unexposed animals does not affect significantly hearing threshold measured pre-surgery and 1, 3, and 7 days after surgery (p > 0.05). (B) Noise exposure causes a significant threshold elevation (p < 0.001) of about 40–45 dB in mid–high frequencies 1, 3, and 7 days after the end of noise exposure. The bottom panel shows the auditory mean threshold value measured in noise exposure + vehicle ear (left graph) and the noise-exposed + ASC implantation ear (right graph) before noise exposure and 1, 3, and 7 days after surgery. (C) Animals exposed to noise + vehicle show a threshold elevation of about 40–45 dB with no significant differences compared to noise-exposed animals. (D) ASCs implantation does not worsen the functional damage caused by noise.
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Figure 2: Functional results. The graphs in the upper panel show hearing threshold values in the Sham + ASCs and Noise-exposed groups. (A) ASCs implantation in unexposed animals does not affect significantly hearing threshold measured pre-surgery and 1, 3, and 7 days after surgery (p > 0.05). (B) Noise exposure causes a significant threshold elevation (p < 0.001) of about 40–45 dB in mid–high frequencies 1, 3, and 7 days after the end of noise exposure. The bottom panel shows the auditory mean threshold value measured in noise exposure + vehicle ear (left graph) and the noise-exposed + ASC implantation ear (right graph) before noise exposure and 1, 3, and 7 days after surgery. (C) Animals exposed to noise + vehicle show a threshold elevation of about 40–45 dB with no significant differences compared to noise-exposed animals. (D) ASCs implantation does not worsen the functional damage caused by noise.

Mentions: To verify the reliability of our deafening procedure, and the effects of ASC graft on hearing, functional analyses were performed by ABR measurements. All data are expressed in terms of threshold and threshold shift, which represents the difference between the pre-noise and post-noise exposure value in each animal. No significant threshold shift was observed in control unexposed animals and in both right and left ears of sham controls injected with ASCs (Figure 2A) or vehicle (data not shown). The sham controls underwent surgery for ASC implantation without noise exposure, the threshold values remained stable in each time point as compared to pre-implantation. However, consistent with previous data, in the noise-exposed animals (Figure 2B) and those injected with vehicle (Figure 2C) after noise exposure, the greatest hearing loss occurred in the 6–12 kHz region, centered around the frequency of acoustic trauma (Fetoni et al., 2004, 2009, 2010). Namely, 24 h after the end of noise exposure, the threshold shift increased to about 40–45 dB for intermediate and high frequencies, respectively, and to 25–30 dB for the low frequencies. The threshold shift remained stable at day 3 after surgery. At day 7, there was a partial recovery of about 5–10 dB, with a greater attenuation in the high frequency range. The same pattern of threshold shifts was detected in the right ears of ASC-implanted noise-exposed animals (Figure 2D). In addition, no statistical differences were observed among ears of noise-exposed animals, left ears of vehicle injected noise-exposed animals, and right ears of ASC-implanted noise-exposed guinea pigs (compare Figures 2B–D). Taken together, these data indicated that the technical procedure used to perform cell inoculation did not cause neither any alteration of hearing or any additional hearing deficit, beyond that induced by the noise exposure.


Grafting and early expression of growth factors from adipose-derived stem cells transplanted into the cochlea, in a Guinea pig model of acoustic trauma.

Fetoni AR, Lattanzi W, Eramo SL, Barba M, Paciello F, Moriconi C, Rolesi R, Michetti F, Troiani D, Paludetti G - Front Cell Neurosci (2014)

Functional results. The graphs in the upper panel show hearing threshold values in the Sham + ASCs and Noise-exposed groups. (A) ASCs implantation in unexposed animals does not affect significantly hearing threshold measured pre-surgery and 1, 3, and 7 days after surgery (p > 0.05). (B) Noise exposure causes a significant threshold elevation (p < 0.001) of about 40–45 dB in mid–high frequencies 1, 3, and 7 days after the end of noise exposure. The bottom panel shows the auditory mean threshold value measured in noise exposure + vehicle ear (left graph) and the noise-exposed + ASC implantation ear (right graph) before noise exposure and 1, 3, and 7 days after surgery. (C) Animals exposed to noise + vehicle show a threshold elevation of about 40–45 dB with no significant differences compared to noise-exposed animals. (D) ASCs implantation does not worsen the functional damage caused by noise.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4202717&req=5

Figure 2: Functional results. The graphs in the upper panel show hearing threshold values in the Sham + ASCs and Noise-exposed groups. (A) ASCs implantation in unexposed animals does not affect significantly hearing threshold measured pre-surgery and 1, 3, and 7 days after surgery (p > 0.05). (B) Noise exposure causes a significant threshold elevation (p < 0.001) of about 40–45 dB in mid–high frequencies 1, 3, and 7 days after the end of noise exposure. The bottom panel shows the auditory mean threshold value measured in noise exposure + vehicle ear (left graph) and the noise-exposed + ASC implantation ear (right graph) before noise exposure and 1, 3, and 7 days after surgery. (C) Animals exposed to noise + vehicle show a threshold elevation of about 40–45 dB with no significant differences compared to noise-exposed animals. (D) ASCs implantation does not worsen the functional damage caused by noise.
Mentions: To verify the reliability of our deafening procedure, and the effects of ASC graft on hearing, functional analyses were performed by ABR measurements. All data are expressed in terms of threshold and threshold shift, which represents the difference between the pre-noise and post-noise exposure value in each animal. No significant threshold shift was observed in control unexposed animals and in both right and left ears of sham controls injected with ASCs (Figure 2A) or vehicle (data not shown). The sham controls underwent surgery for ASC implantation without noise exposure, the threshold values remained stable in each time point as compared to pre-implantation. However, consistent with previous data, in the noise-exposed animals (Figure 2B) and those injected with vehicle (Figure 2C) after noise exposure, the greatest hearing loss occurred in the 6–12 kHz region, centered around the frequency of acoustic trauma (Fetoni et al., 2004, 2009, 2010). Namely, 24 h after the end of noise exposure, the threshold shift increased to about 40–45 dB for intermediate and high frequencies, respectively, and to 25–30 dB for the low frequencies. The threshold shift remained stable at day 3 after surgery. At day 7, there was a partial recovery of about 5–10 dB, with a greater attenuation in the high frequency range. The same pattern of threshold shifts was detected in the right ears of ASC-implanted noise-exposed animals (Figure 2D). In addition, no statistical differences were observed among ears of noise-exposed animals, left ears of vehicle injected noise-exposed animals, and right ears of ASC-implanted noise-exposed guinea pigs (compare Figures 2B–D). Taken together, these data indicated that the technical procedure used to perform cell inoculation did not cause neither any alteration of hearing or any additional hearing deficit, beyond that induced by the noise exposure.

Bottom Line: ASC implantation did not modify auditory function.ASCs migrated from the perilymphatic to the endolymphatic compartment, during the analyzed time course.Immunofluorescence confirmed the increased expression, which appeared to be further strengthened by ASCs' implantation.

View Article: PubMed Central - PubMed

Affiliation: Department of Head and Neck Surgery, Università Cattolica del Sacro Cuore , Rome , Italy.

ABSTRACT
Noise exposure causes damage of multiple cochlear cell types producing permanent hearing loss with important social consequences. In mammals, no regeneration of either damaged hair cells or auditory neurons has been observed and no successful treatment is available to achieve a functional recovery. Loads of evidence indicate adipose-derived stem cells (ASCs) as promising tools in diversified regenerative medicine applications, due to the high degree of plasticity and trophic features. This study was aimed at identifying the path of in vivo cell migration and expression of trophic growth factors, upon ASCs transplantation into the cochlea, following noise-induced injury. ASCs were isolated in primary culture from the adipose tissue of a guinea pig, transduced using a viral vector to express the green fluorescent protein, and implanted into the scala tympani of deafened animals. Auditory function was assessed 3 and 7 days after surgery. The expression of trophic growth factors was comparatively analyzed using real-time PCR in control and noise-injured cochlear tissues. Immunofluorescence was used to assess the in vivo localization and expression of trophic growth factors in ASCs and cochleae, 3 and 7 days following homologous implantation. ASC implantation did not modify auditory function. ASCs migrated from the perilymphatic to the endolymphatic compartment, during the analyzed time course. Upon noise exposure, the expression of chemokine ligands and receptors related to the PDGF, VEGF, and TGFbeta pathways, increased in the cochlear tissues, possibly guiding in vivo cell migration. Immunofluorescence confirmed the increased expression, which appeared to be further strengthened by ASCs' implantation. These results indicated that ASCs are able to migrate at the site of tissue damage and express trophic factors, upon intracochlear implantation, providing an original proof of principle, which could pave the way for further developments of ASC-based treatments of deafness.

No MeSH data available.


Related in: MedlinePlus