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Published on: May 6, 2015
CAMK2D and Complement Factor I-Involved Calcium/Calmodulin Signaling Modulates Sodium Iodate-Induced Mouse Retinal
Weixing Xu1,2,3, Liu Cao4, Hua Liu2,3
1Henan Eye Hospital, Henan Provincial People's Hospital, People's Hospital of Zhengzhou University, Zhengzhou City, China.
Purpose:
To investigate the effect of Ca2+/calmodulin-dependent protein kinase II (CAMKII) δ subtypes (CAMK2D) on sodium iodate (NaIO3)-induced retinal degeneration in mice.
Methods:
Bioinformatics analysis and Western blot experiments were used to screen the significantly differentially expressed genes in age-related macular degeneration (AMD) disease. CAMK2D knockdown and overexpression models were constructed by lentivirus (LV) infection of adult retinal pigment epithelial cell line-19 (ARPE-19) cells in vitro. Flow cytometry was used to detect ARPE-19 cell apoptosis induced by NaIO3. In vivo, CAMK2D knockdown and overexpression mouse models were generated by infecting mouse retinal pigment epithelium (RPE) with adeno-associated virus (AAV). Retinography, optical coherence tomography (OCT), and histological analysis (hematoxylin and eosin staining) were used to detect NaIO3-induced retinal structural changes in mice. Electroretinography (ERG) was used to detect NaIO3-induced retinal function changes in mice. TdT-mediated dUTP nick-end labeling (TUNEL) staining was used to detect the apoptosis of retinal cells induced by NaIO3. RNA sequencing (RNA-Seq) and bioinformatics analysis were used to screen for target genes affected by CAMK2D in CAMK2D-overexpressing ARPE-19 cells. And flow cytometry, OCT, and ERG were used to evaluate the regulatory effect of CAMK2D on target genes.
Results:
Bioinformatics analysis found the expression of genes related to Ca2+ signal was significantly reduced in AMD patients. Western blot showed that in a mouse model of dry AMD induced by NaIO3, CAMK2D expression in RPE-Choroid tissue significantly lower than normal mice. In vitro, our results showed that overexpression of CAMK2D in ARPE-19 cells decreased apoptosis induced by NaIO3 and knockdown increased apoptosis. In vivo, CAMK2D overexpression in RPE cells can attenuate the retina degeneration induced by NaIO3 and CAMK2D knockdown aggravated degeneration. The bioinformatics analysis indicated that CAMK2D might affect AMD pathology through complement factor I (CFI). In vitro, knockdown of CFI in ARPE-19 cells increased apoptosis induced by NaIO3. In knockdown CFI ARPE-19 cells, overexpression of CAMK2D reduced the above apoptosis. In mice retina, CFI knockdown can aggravate the retina degeneration induced by NaIO3. In knockdown CFI mice, overexpression of CAMK2D in RPE can attenuate the above retina degeneration. Western blot confirmed that CAMK2D regulated the expression of CFI in mice.
Conclusions:
CAMK2D can attenuate the retinal degeneration induced by NaIO3, which was achieved by regulating the CFI.
Insights
Calcium/calmodulin-dependent protein kinase II delta (CAMK2D) protects against sodium iodate-induced retinal degeneration by regulating complement factor I (CFI). This study reveals CAMK2D as a potential therapeutic target for age-related macular degeneration (AMD).
Area of Science:
- Ophthalmology
- Molecular Biology
- Genetics
Background:
- Age-related macular degeneration (AMD) is a leading cause of vision loss.
- Dysregulation of calcium signaling pathways is implicated in AMD pathogenesis.
- The role of Ca2+/calmodulin-dependent protein kinase II δ (CAMK2D) in retinal degeneration is not fully understood.
Purpose of the Study:
- To investigate the protective effect of CAMK2D against sodium iodate (NaIO3)-induced retinal degeneration in a mouse model.
- To elucidate the molecular mechanism by which CAMK2D influences retinal health, particularly its interaction with complement factor I (CFI).
Main Methods:
- Bioinformatics and Western blot analyses were used to identify differentially expressed genes in AMD.
- In vitro studies utilized ARPE-19 cells with CAMK2D knockdown/overexpression to assess apoptosis.
- In vivo studies employed adeno-associated virus (AAV) vectors for CAMK2D manipulation in mouse retinas, followed by retinography, OCT, ERG, and TUNEL staining.
- RNA sequencing (RNA-Seq) identified target genes of CAMK2D, and flow cytometry, OCT, and ERG evaluated regulatory effects.
Main Results:
- CAMK2D expression was significantly reduced in AMD patients and in a NaIO3-induced mouse model of dry AMD.
- Overexpression of CAMK2D reduced NaIO3-induced apoptosis in ARPE-19 cells, while knockdown increased it.
- In vivo, CAMK2D overexpression attenuated retinal degeneration, whereas knockdown aggravated it.
- CAMK2D was found to regulate CFI expression, and manipulating CFI levels affected retinal cell apoptosis and degeneration, confirming CAMK2D's role via CFI.
Conclusions:
- CAMK2D plays a protective role in mitigating NaIO3-induced retinal degeneration.
- The protective mechanism of CAMK2D involves the regulation of complement factor I (CFI).
- CAMK2D emerges as a potential therapeutic target for AMD and related retinal diseases.
