Molecular characterization and expression analysis of caveolin-1 in pig tissues

LncRNA IMFlnc1 promotes porcine intramuscular adipocyte adipogenesis by sponging miR-199a-5p to up-regulate CAV-1

Background

Local Chinese local pig breeds have thinner muscle fiber and higher intramuscular-fat (IMF) content. But its regulation mechanism has not been discussed in-depth. Studies indicated that long non coding RNAs (lncRNAs) play important role in muscle and fat development.

Results

The lncRNAs expressional differences in the longissimus dorsi (LD) muscle were identified between Huainan pigs (local Chinese pigs, fat-type, HN) and Large White pigs (lean-type, LW) at 38, 58, and 78 days post conception (dpc). In total, 2131 novel lncRNAs were identified in 18 samples, and 291, 305, and 683 differentially expressed lncRNAs (DELs) were found between these two breeds at three stages, respectively. The mRNAs that co-expressed with these DELs were used for GO and KEGG analysis, and the results showed that muscle development and energy metabolism were more active at 58 dpc in HN, but at 78 dpc in LW pigs. Muscle cell differentiation and myofibril assembly might associated with earlier myogenesis and primary-muscle-fiber assembly in HN, and cell proliferation, insulin, and the MAPK pathway might be contribute to longer proliferation and elevated energy metabolism in LW pigs at 78 dpc. The PI3K/Akt and cAMP pathways were associated with higher IMF deposition in HN. Intramuscular fat deposition-associated long noncoding RNA 1 (IMFlnc1) was selected for functional verification, and results indicated that it regulated the expressional level of caveolin-1 (CAV-1) by acting as competing endogenous RNA (ceRNA) to sponge miR-199a-5p.

Conclusions

Our data contributed to understanding the role of lncRNAs in porcine-muscle development and IMF deposition, and provided valuable information for improving pig-meat quality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12860-020-00324-8.

Caracterização das proteínas caveolinas -1 e -2 na placenta de conceptos bovinos clonados transgênicos

RESUMO:A utilização da transgenia com a proteína fluorescente verde (GFP) como marcador de células de origem fetal nas placentas de clones bovinos servirá de modelo inédito para estudo morfofisiológico e imunológico da interação materno-fetal, visto que possibilitará o seu mapeamento, diferenciando as células fetais das maternas. Tal modelo terá aplicação direta, principalmente porque estes são animais que apresentam problemas em relação ao seu desenvolvimento. Com o auxílio deste modelo, pretende-se verificar o transporte de substâncias entre a mãe e o feto via endocitose, pela imunolocalização das proteínas chamadas de caveolinas. Para tanto foram utilizados 06 bovinos clonados e 30 bovinos de inseminação artificial (IA) com idade até 90 dias de gestação, os quais tiveram seu desenvolvimento interrompido mediante abate humanitário das receptoras e ovariosalpingohisterectomia, com posterior recuperação do útero gestante. Foram coletados os placentônios e o cório. Uma parte das amostras foi recortada e fixada, por imersão, em solução de parafolmaldeído a 4% ou formoldeído a 10% em tampão fosfato de sódio (PBS) a 0,1M pH 7.4, solução de Zamboni (4% de paraformoldeído, 15% de ácido pícrico, em tampão fosfato de sódio a 0,1M pH 7.4), metacarn (60% de metanol, 30% de clorofórmio, e 10% de ácido acético glacial), para verificação da morfologia e realização de imuno-histoquímica para as proteínas caveolinas -1 e -2 (CAV -1 e CAV-2). As caveolinas -1 foram localizadas nos vilos fetais e maternos, mas sua marcação mais forte foi observada no estroma endometrial. As caveolinas -2 tiveram marcação positiva no trofoblasto e membrana córioalantoide, e, especificamente em célula trofoblástica gigante binucleada. Sendo assim, os resultados mostram que a proteína CAV-1 teve uma maior expressão em relação à proteína CAV-2 e que as proteínas CAV-1 e -2 são parte da composição das cavéolas, sendo estruturas importantes e relacionadas com a transferência de moléculas para o feto, realizando a nutrição do mesmo mediante endocitose e pinocitose.

New glimpses of caveolin-1 functions in embryonic development and human diseases

Caveolin-1 (Cav-1) isoforms, including Cav-1α and Cav-1β, were identified as integral membrane proteins and the major components of caveolae. Cav-1 proteins are highly conserved during evolution from {itCaenorhabditis elegans} to human and are capable of interacting with many signaling molecules through their caveolin scaffolding domains to regulate the activities of multiple signaling pathways. Thus, Cav-1 plays crucial roles in the regulation of cellular proliferation, differentiation and apoptosis in a cell-specific and contextual manner. In addition, Cav-1 is essential for embryonic development of vertebrates owing to its regulation of BMP, Wnt, TGF-β and other key signaling molecules. Moreover, Cav-1 is mainly expressed in terminally differentiated cells and its abnormal expression is often associated with human diseases, such as tumor progression, cardiovascular diseases, fibrosis, lung regeneration, and diseases related to virus. In this review, we will further discuss the potential of Cav-1 as a target for disease therapy and multiple drug resistance.

Effect of cavtratin, a caveolin-1 scaffolding domain peptide, on oligodendroglial signaling cascades

Caveolin and caveolin containing rafts are involved in the signaling of growth factors in various cell types. Previous reports of our lab indicated a co-localization of caveolin and the high affinity nerve growth factor (NGF) receptor tyrosine kinase A (TrkA). Mutual effects have been observed among which a caveolin-1 knock-down resulted in an impairment of the NGF signaling cascade rather than in an increase of activity as expected from other growth factor reports. On the other hand, an over-expression of caveolin-1 impaired the NGF stimulated activity of p42/44 mitogen activated protein kinases (MAPK). In this study, we used a caveolin-1 scaffolding domain (CSD) peptide (cavtratin) of which an inhibitory effect on growth factor receptors was reported. Our data showed that cavtratin suppresses the NGF-induced phosphorylation of TrkA as well as the activation of MAPK in porcine oligodendrocytes significantly.

Molecular characterization of caveolin-1 in pigs infected with Haemophilus parasuis

Caveolin-1 (Cav1) plays a critical role in the invasion of pathogenic microbes into host cells, yet little is known about porcine Cav1. In this study, we provide the molecular characterization of Cav1 in pigs following stimulation with LPS/polyinosinic-polycytidylic acid as well as during infection with Haemophilus parasuis. The porcine Cav1 gene is 35 kb long and is located at SSC18q21; two isoforms (Cav1-α and Cav1-β) are produced by alternative splicing. Three point mutations were identified in the coding region of the gene, two of which were significantly associated with nine immunological parameters in Landrace pigs, including the Ab response against porcine reproductive and respiratory syndrome virus and lymphocyte counts. Promoter analysis indicated that NF-κB activates both Cav1 transcripts, but the forkhead gene family specifically regulates Cav1-β in the pig. Porcine Cav1 is expressed ubiquitously, with Cav1-α more abundantly expressed than Cav1-β in all tissues investigated. Basal expression levels of Cav1 in PBMCs are relatively similar across different pig breeds. LPS and polyinosinic-polycytidylic acid markedly induced the expression of Cav1 in porcine kidney-15 cells in vitro, likely through NF-κB activation. Pigs infected with H. parasuis exhibited decreased expression of Cav1, particularly in seriously impaired organs such as the brain. This study provides new evidence that supports the use of Cav1 as a potential diagnostic and genetic marker for disease resistance in animal breeding. In addition, our results suggest that Cav1 may be implicated in the pathogenesis of Glasser's disease, which is caused by H. parasuis.