CERKL is upregulated in cutaneous squamous cell carcinoma and maintains cellular sphingolipids and resistance to oxidative stress

CERKL-Associated Retinal Dystrophy: Genetics, Phenotype, and Natural History

PURPOSE

To analyze the clinical characteristics, natural history, and genetics of CERKL-associated retinal dystrophy in the largest series to date.

DESIGN

Multicenter retrospective cohort study.

SUBJECTS

Forty-seven patients (37 families) with likely disease-causing CERKL variants.

METHODS

Review of clinical notes, ophthalmic images, and molecular diagnosis from 2 international centers.

MAIN OUTCOME MEASURES

Visual function, retinal imaging, and characteristics were evaluated and correlated.

RESULTS

The mean age at the first visit was 29.6 ± 13.9 years, and the mean follow-up time was 9.1 ± 7.4 years. The most frequent initial symptom was central vision loss (40%), and the most common retinal feature was well-demarcated areas of macular atrophy (57%). Seventy-seven percent of the participants had double-null genotypes, and 64% had electrophysiological assessment. Among the latter, 53% showed similar severity of rod and cone dysfunction, 27% revealed a rod-cone, 10% a cone-rod, and 10% a macular dystrophy dysfunction pattern. Patients without double-null genotypes tended to have fewer pigment deposits and included a higher proportion of older patients with a relatively mild electrophysiological phenotype. Longitudinal analysis showed that over half of the cohort lost 15 ETDRS letters or more in ≥ 1 eye during the first 5 years of follow-up.

CONCLUSIONS

The phenotype of CERKL-retinal dystrophy is broad, encompassing isolated macular disease to severe retina-wide involvement, with a range of functional phenotypes, generally not fitting in the rod-cone/cone-rod dichotomy. Disease onset is often earlier, with more severe retinal degenerative changes and photoreceptor dysfunction, in nullizygous cases.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Whole-genome identification and construction of the lncRNA-mRNA co-expression network in patients with actinic keratosis

BACKGROUND

Actinic keratosis (AK) is a common premalignant lesion induced by chronic exposure to ultraviolet radiation and may develop into invasive cutaneous squamous carcinoma (cSCC). The identification of specific biomarkers in AK are still unclear. Long non-coding RNAs (lncRNAs), as transcripts of more than 200 nucleotides, significantly involving in multiple biologic processes, especially in the development of tumors.

METHODS

In our study, we obtained data from RNA-sequencing analysis using two AK lesion tissues and three normal cutaneous tissues to comparatively analyze the differentially expressed (DE) lncRNAs and messenger RNAs (mRNAs). Firstly, we used microarray analyses to identify DE lncRNAs and DE mRNAs. Secondly, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis to analyze the primary function and find out significant pathways of these DE mRNA and lncRNAs. Finally, we used the top ten DE lncRNAs to construct a lncRNA-mRNA co-expression network.

RESULTS

Our results showed that there were a total of 2,097 DE lncRNAs and 2,043 DE mRNAs identified. GO and KEGG analysis and the lncRNA-mRNA co-expression network (using the top 10 DE lncRNAs comprises 130 specific co-expressed mRNAs to construct) indicated that lncRNA uc011fnr.2 may negatively regulate SCIMP and Toll-like receptor 4 (TLR4) and play an important role in Janus kinase-signal transducer and activator of transcription 3 (JAK-STAT3) signaling pathway of AK.

CONCLUSIONS

lncRNA uc011fnr.2 may play an important role in JAK-STAT3 signaling pathway of AK by modulating SCIMP, TLR4 and IL-6. Further research is required to validate the value of lncRNA uc011fnr.2 in the progression of AK.

CERKL, a Retinal Dystrophy Gene, Regulates Mitochondrial Transport and Dynamics in Hippocampal Neurons

Mutations in the Ceramide Kinase-like (CERKL) gene cause retinal dystrophies, characterized by progressive degeneration of retinal neurons, which eventually lead to vision loss. Among other functions, CERKL is involved in the regulation of autophagy, mitochondrial dynamics, and metabolism in the retina. However, CERKL is nearly ubiquitously expressed, and it has been recently described to play a protective role against brain injury. Here we show that Cerkl is expressed in the hippocampus, and we use mouse hippocampal neurons to explore the impact of either overexpression or depletion of CERKL on mitochondrial trafficking and dynamics along axons. We describe that a pool of CERKL localizes at mitochondria in hippocampal axons. Importantly, the depletion of CERKL in the Cerkl^KD/KO mouse model is associated with changes in the expression of fusion/fission molecular regulators, induces mitochondrial fragmentation, and impairs axonal mitochondrial trafficking. Our findings highlight the role of CERKL, a retinal dystrophy gene, in the regulation of mitochondrial health and homeostasis in central nervous system anatomic structures other than the retina.

CERKL alleviates ischemia reperfusion-induced nervous system injury through modulating the SIRT1/PINK1/Parkin pathway and mitophagy induction

Recent studies showed that Ceramide Kinase-Like Protein (CERKL)was expressed in the nerve cells and could regulate autophagy. Sirtuin-1 (SIRT1) is the regulator of the mitophagy, which can be stabilized by CERKL. Furthermore, the study also revealed that the SIRT1 induced mitophagy by activating PINK1/Parkin signaling. Therefore, we speculated that CERKL has potential to activate the SIRT1/PINK1/Parkin pathway to induce mitophagy. In this study, cerebral ischemia reperfusion mouse model was established. CERKL was overexpressed in those mice and human neuroblastoma cells. Tunel staining and flow cytometry were applied for the detection of cell apoptosis. The ratios of LC3Ⅱ to LC3Ⅰ and the expression of LC3Ⅱ in mitochondria were determined by gel electrophoresis. Overexpression of CERKL alleviated the cerebral ischemia reperfusion injury and damage to OGD/R human neuroblastoma cells. Overexpression of CERKL enhanced the expression of LC3 Ⅱ in mitochondria and induced occurrence of mitophagy. Overexpression of CERKL promoted the stability of SIRT1 and facilitated the expression of PINK1 and Parkin in those cells. Knockdown of PINK1 impeded the mitophagy and suppressed the expression of LC3 Ⅱ in mitochondria. It can be concluded that CERKL alleviated the ischemia reperfusion induced nervous system injury through inducing mitophagy in a SIRT1/PINK1/Parkin dependent pathway.