Differential genomic imprinting and expression of imprinted microRNAs in testes-derived male germ-line stem cells in mouse

Paternal genetic effects of cadmium exposure during pregnancy on hormone synthesis disorders in ovarian granulosa cells of offspring

The aim of this study was to investigate the paternal genetic intergenerational and transgenerational genetic effects of cadmium (Cd) exposure during pregnancy on estradiol (E₂) and progesterone (Pg) synthesis in the ovarian granulosa cells (GCs) of offspring. Pregnant SD rats were intragastrically exposed to CdCl₂ (0, 0.5, 2.0, 8.0 mg/kg) from days 1 to 20 to produce the F1 generation, F1 males were mated with newly purchased females to produce the F2 generation, and the F3 generation was obtained in the same way. Using this model, Cd-induced hormone synthesis disorders in GCs of F1 have been observed [8]. In this study, altered serum E₂ and Pg levels in both F2 and F3 generations showed a nonmonotonic dose‒response relationship. In addition, hormone synthesis-related genes (Star, Cyp11a1, Cyp17a1, Cyp19a1, Sf-1) and miRNAs were observed to be altered in both F2 and F3. No differential changes in DNA methylation modifications of hormone synthesis-related genes were observed, and only the Adcy7 was hypomethylated. In summary, paternal genetic intergenerational and transgenerational effects exist in ovarian GCs E₂ and Pg synthesis disorders induced by Cd during pregnancy. In F2, the upregulation of StAR and CYP11A1, and changes in the miR-27a-3p, miR-27b-3p, and miR-146 families may be important, while changes in the miR-10b-5p and miR-146 families in F3 may be important.

Paternal genetic intergenerational and transgenerational effects of cadmium exposure on hormone synthesis disorders in progeny ovarian granulosa cells

To investigate the paternal genetic effects of cadmium (Cd) exposure on hormone synthesis disorders in the ovarian granulosa cells (GCs) of offspring. Here, male Sprague‒Dawley (SD) rats were gavaged with CdCl₂ (0, 0.5, 2, 8 mg/kg) from postnatal day (PND) 28-56, followed by mating with newly purchased healthy adult females to produce F1, and F1 adult males (PND 56) were mated with newly purchased healthy adult females to produce F2. The serum levels of estradiol (E₂) and progesterone (Pg) decreased in F1 but essentially returned to normal in F2. The levels of StAR, CYP11A1, CYP17A1, CYP19A1, and SF-1 showed different alterations in F1 and F2 ovarian GCs. The expression patterns of miRNAs and imprinted genes related to hormone synthesis in GCs of F1 and F2 differed, but methylation of hormone synthesis-related genes was not significantly altered (except for individual loci in F1). In addition, there were significant changes in the expression of imprinted genes and miRNAs in F0 and F1 sperm. We conclude that paternal Cd exposure causes intergenerational genetic effects (hormone synthesis disorders) and transgenerational effects (reparative changes in hormone synthesis function) in ovarian GCs. These genetic effects were related to the downregulation of StAR in F1 and the upregulation of CYP17A1, CYP19A1, StAR and SF-1 in F2. Important changes in miRNAs and imprinted genes were also observed, but not all alterations originated from paternal inheritance.

CircSCAPER knockdown attenuates IL-1β-induced chondrocyte injury by miR-127-5p/TLR4 axis in osteoarthritis

PURPOSE

Osteoarthritis (OA) is a chronic inflammatory degenerative disease characterized by articular cartilage degradation. Circular RNAs have been shown to play significant roles in OA process. Herein, this work aimed to investigate the potential role and mechanism of circSCAPER in OA progression.

METHODS

Levels of circSCAPER, miR-127-5p and toll-like receptor 4 (TLR4) were detected by qRT-PCR or western blotting. Cell apoptosis was determined by flow cytometry. The expression of Aggrecan and Matrix metallopeptidase was examined using western blot to assess extracellular matrix (ECM) degradation. Inflammatory response and oxidative stress were determined by measuring the release of inflammatory factors, along with the generation of intracellular reactive oxygen species and malondialdehyde. The interaction between miR-127-5p and circSCAPER or TLR4 was determined by dual-luciferase reporter, RNA immunoprecipitation and pull-down assays.

RESULTS

Chondrocytes were treated with interleukin-1β (IL-1β) to mimic OA condition in vitro. CircSCAPER was increased in OA cartilages and IL-1β-induced chondrocytes. Functionally, knockdown of circSCAPER attenuated IL-1β-evoked apoptosis, ECM degradation, inflammation and oxidative stress in vitro. CircSCAPER up-regulation in OA cartilages was discovered to be accompanied by decreased miR-127-5p and increased TLR4. Mechanistically, circSCAPER acted as a sponge for miR-127-5p to positively regulate TLR4 expression in chondrocytes. IL-1β treatment reduced miR-127-5p expression but up-regulated TLR4 expression, re-expression of miR-127-5p suppressed IL-1β-caused chondrocyte injury, which was abolished by TLR4 overexpression. Moreover, miR-127-5p inhibition reversed the protective action of circSCAPER knockdown on chondrocytes under IL-1β treatment.

CONCLUSION

CircSCAPER silencing protected against IL-1β-induced apoptosis, ECM degradation, inflammation and oxidative stress in chondrocytes via miR-127-5p/TLR4 axis.

Comparison of miRNA and mRNA Expression in Sika Deer Testes With Age

To elucidate the complex physiological process of testis development and spermatogenesis in Sika deer, this study evaluated the changes of miRNA and mRNA profiles in the four developmental stages of testis in the juvenile (1-year-old), adolescence (3-year-old), adult (5-year-old), and aged (10-year-old) stages. The results showed that a total of 198 mature, 66 novel miRNAs, and 23,558 differentially expressed (DE) unigenes were obtained; 14,918 (8,413 up and 6,505 down), 4,988 (2,453 up and 2,535 down), and 5,681 (2,929 up and 2,752 down) DE unigenes, as well as 88 (43 up and 45 down), 102 (44 up and 58 down), and 54 (18 up and 36 down) DE miRNAs were identified in 3- vs. 1-, 5- vs. 3-, and 10- vs. 5-year-old testes, respectively. By integrating miRNA and mRNA expression profiles, we predicted 10,790 mRNA-mRNA and 69,883 miRNA-mRNA interaction sites. The target genes were enriched by GO and KEGG pathways to obtain DE mRNA (IGF1R, ALKBH5, Piwil, HIF1A, BRDT, etc.) and DE miRNA (miR-140, miR-145, miR-7, miR-26a, etc.), which play an important role in testis development and spermatogenesis. The data show that DE miRNAs could regulate testis developmental and spermatogenesis through signaling pathways, including the MAPK signaling pathway, p53 signaling pathway, PI3K-Akt signaling pathway, Hippo signaling pathway, etc. miR-140 was confirmed to directly target mutant IGF1R-3'UTR by the Luciferase reporter assays. This study provides a useful resource for future studies on the role of miRNA regulation in testis development and spermatogenesis.

Significance and Relevance of Spermatozoal RNAs to Male Fertility in Livestock

Livestock production contributes to a significant part of the economy in developing countries. Although artificial insemination techniques brought substantial improvements in reproductive efficiency, male infertility remains a leading challenge in livestock. Current strategies for the diagnosis of male infertility largely depend on the evaluation of semen parameters and fail to diagnose idiopathic infertility in most cases. Recent evidences show that spermatozoa contains a suit of RNA population whose profile differs between fertile and infertile males. Studies have also demonstrated the crucial roles of spermatozoal RNA (spRNA) in spermatogenesis, fertilization, and early embryonic development. Thus, the spRNA profile may serve as unique molecular signatures of fertile sperm and may play pivotal roles in the diagnosis and treatment of male fertility. This manuscript provides an update on various spRNA populations, including protein-coding and non-coding RNAs, in livestock species and their potential role in semen quality, particularly sperm motility, freezability, and fertility. The contribution of seminal plasma to the spRNA population is also discussed. Furthermore, we discussed the significance of rare non-coding RNAs (ncRNAs) such as long ncRNAs (lncRNAs) and circular RNAs (circRNAs) in spermatogenic events.

A Boolean Logical model for Reprogramming of Testes-derived male Germline Stem Cells into Germline pluripotent stem cells

BACKGROUND AND OBJECTIVE

Male germline stem (GS) cells are responsible for the maintenance of spermatogenesis throughout the adult life of males. Upon appropriate in vitro culture conditions, these GS cells can undergo reprogramming to become germline pluripotent stem (GPS) cells with the loss of spermatogenic potential. In recent years, voluminous data of gene transcripts in GS and GPS cells have become available. However, the mechanism of reprogramming of GS cells into GPS cells remains elusive. This study was designed to develop a Boolean logical model of gene regulatory network (GRN) that might be involved in the reprogramming of GS cells into GPS cells.

METHODS

The gene expression profile of GS and GPS cells (GSE ID: GSE11274 and GSE74151) were analyzed using R Bioconductor to identify differentially expressed genes (DEGs) and were functionally annotated with DAVID server. Potential pluripotent genes among the DEGs were then predicted using a combination of machine learning [Support Vector Machine (SVM)] and BLAST search. Protein isoforms were identified by pattern matching with UniProt database with in-house scripts written in C++. Both linear and non-linear interaction maps were generated using the STRING server. CellNet is used to study the relationship of GRNs between the GS and GPS cells. Finally, the GRNs involving all the genes from integrated methods and literature was constructed and qualitative modelling for reprogramming of GS to GPS cells were done by considering the discrete, asynchronous, multivalued logical formalism using the GINsim modeling and simulation tool.

RESULTS

Through the use of machine learning and logical modeling, the present study identified 3585 DEGs and 221 novel pluripotent genes including Tet1, Cdh1, Tfap2c, Etv4, Etv5, Prdm14, and Prdm10 in GPS cells. Pathway analysis revealed that important signaling pathways such as core pluripotency network, PI3K-Akt, WNT, GDNF and BMP4 signalling pathways were important for the reprogramming of GS cells to GPS cells. On the other hand, CellNet analysis of GRNs of GS and GPS cells revealed that GS cells were similar to gonads whereas GPS cells were similar to ESCs in gene expression profile. A logical regulatory model was developed, which showed that TGFβ negatively regulated the reprogramming of the GS to GPS cells, as confirmed by perturbations studies.

CONCLUSION

The study identified novel pluripotent genes involved in the reprogramming of GS cells into GPS cells. A multivalued logical model of cellular reprogramming is proposed, which suggests that reprogramming of GS cells to GPS cells involves signalling pathways namely LIF, GDNF, BMP4, and TGFβ along with some novel pluripotency genes.

Identification and Characterization of MicroRNAs from Longitudinal Muscle and Respiratory Tree in Sea Cucumber (Apostichopus japonicus) Using High-Throughput Sequencing

MicroRNAs (miRNAs), as a family of non-coding small RNAs, play important roles in the post-transcriptional regulation of gene expression. Sea cucumber (Apostichopus japonicus) is an important economic species which is widely cultured in East Asia. The longitudinal muscle (LTM) and respiratory tree (RPT) are two important tissues in sea cucumber, playing important roles such as respiration and movement. In this study, we identified and characterized miRNAs in the LTM and RPT of sea cucumber (Apostichopus japonicus) using Illumina HiSeq 2000 platform. A total of 314 and 221 conserved miRNAs were identified in LTM and RPT, respectively. In addition, 27 and 34 novel miRNAs were identified in the LTM and RPT, respectively. A set of 58 miRNAs were identified to be differentially expressed between LTM and RPT. Among them, 9 miRNAs (miR-31a-3p, miR-738, miR-1692, let-7a, miR-72a, miR-100b-5p, miR-31b-5p, miR-429-3p, and miR-2008) in RPT and 7 miRNAs (miR-127, miR-340, miR-381, miR-3543, miR-434-5p, miR-136-3p, and miR-300-3p) in LTM were differentially expressed with foldchange value being greater than 10. A total of 14,207 and 12,174 target genes of these miRNAs were predicted, respectively. Functional analysis of these target genes of miRNAs were performed by GO analysis and pathway analysis. This result provided in this work will be useful for understanding biological characteristics of the LTM and RPT of sea cucumber and assisting molecular breeding of sea cucumber for aquaculture.

MicroRNA deregulation in parathyroid tumours suggests an embryonic signature

Primary hyperparathyroidism is a common endocrine disorder caused by abnormal tumour parathyroid cell proliferation. Parathyroid tumours show a great variability both in clinical features, such as the severity of PTH secretion, the rate and the pattern of cell proliferation, and genetic background. Studies aiming to develop new diagnostic markers and therapeutic approaches need a deeper definition of this variability. Dysregulation of microRNAs (miRNAs) has been shown to play an essential role in the development and progression of cancer. MiRNAs are small noncoding RNAs that inhibit the translation and stability of messenger RNAs (mRNAs). Here, data about the miRNA expression pattern in parathyroid normal and tumour glands were reviewed. Though available data in parathyroid tumours are very limited, the expression pattern of a subset of specific miRNAs clearly discriminated parathyroid carcinomas from normal parathyroid glands and, more clinically relevant, from parathyroid adenomas. Investigation showed that parathyroid tumours were characterized by an embryonic expression pattern of miRNAs such as miR-296, or the miRNA clusters C19MC and miR-371-3, typically in stem cells committed to differentiation or during human embryonic development, respectively. Further, miRNA profiles were correlated with tumour aggressive behaviour. Moreover, the interaction with the oncosuppressor menin suggests that miRNAs might modulate the function of the known oncosuppressors or oncogenes involved in parathyroid tumourigenesis and thus overseeing the tumour phenotype. In conclusion, miRNAs might provide new diagnostic markers and new therapeutic approaches by developing molecular miRNA-targeted therapies for the cure of parathyroid tumours, whose unique option is surgery.

MicroRNA-127-5p regulates matrix metalloproteinase 13 expression and interleukin-1β-induced catabolic effects in human chondrocytes

OBJECTIVE

MicroRNAs (miRNAs), small noncoding RNA molecules, are involved in the pathogenesis of various diseases such as cancer and arthritis. The aim of this study was to determine whether miR-127-5p regulates interleukin-1β (IL-1β)-induced expression of matrix metalloproteinase 13 (MMP-13) and other catabolic factors in human chondrocytes.

METHODS

Expression of miR-127-5p and MMP-13 by normal and osteoarthritic (OA) human cartilage was determined using real-time polymerase chain reaction. The effect of miR-127-5p on MMP-13 expression was evaluated using transient transfection of human chondrocytes or chondrogenic SW-1353 cells with miR-127-5p or its antisense inhibitor (anti-miR-127-5p). MMP-13 protein production was quantified by enzyme-linked immunosorbent assay, and the involvement of miR-127-5p in IL-1β-mediated catabolic effects was examined by immunoblotting. MicroRNA-127-5p binding with the putative site in the 3'-untranslated region (3'-UTR) of MMP-13 messenger RNA (mRNA) was validated by luciferase reporter assay.

RESULTS

There was a significant reduction in miR-127-5p expression in OA cartilage compared with normal cartilage. Up-regulation of MMP-13 expression by IL-1β was correlated with down-regulation of miR-127-5p expression in human chondrocytes. MicroRNA-127-5p suppressed IL-1β-induced MMP-13 production as well as the activity of a reporter construct containing the 3'-UTR of human MMP-13 mRNA. In addition, mutation of the miR-127-5p binding site in the 3'-UTR of MMP-13 mRNA abolished miR-127-5p-mediated repression of reporter activity. Conversely, treatment with anti-miR-127-5p remarkably increased reporter activity and MMP-13 production. Interestingly, the IL-1β-induced activation of JNK, p38, and NF-κB and expression of MMP-1 and cyclooxygenase 2 were significantly inhibited by miR-127-5p.

CONCLUSION

MicroRNA-127-5p is an important regulator of MMP-13 in human chondrocytes and may contribute to the development of OA.

Human spermatagonial stem cells: a novel therapeutic hope for cardiac regeneration and repair?

Although the identification and characterization of human spermatogonial stem cells was reported nearly 50 years ago, great progress has been made only in the last few years. Spermatogonial stem cells attract a great deal of researchers’ attention because of their unique characteristics, including the ability to be converted spontaneously into pluripotent germline stem cells with embryonic stem cell-like properties. Pluripotent stem cells are able to differentiate into any desired cell type in the body; therefore, they are the most promising cell source for organ regeneration. The advantages of pluripotent germline stem cells over other stem cells are that they maintain a high degree of DNA integrity and can resolve some ethical and immunological problems related to human embryonic stem cells. In this article we address the origin, characteristics and pluripotency of spermatogonial stem cells. Their contribution to stem cell-based organ regeneration therapy with special emphasis on cardiac regeneration and repair in the future is also discussed.