Sequence and expression analysis of a novel Xenopus laevis cDNA that encodes a protein similar to bacterial and chloroplast ribosomal protein L24

Identification of ribosomal protein L24 (RPL24) from the oriental river prawn, Macrobrachium nipponense, and its roles in ovarian development

Ribosomal proteins exhibit various extraribosomal functions in addition to their roles in protein synthesis. In this study, complementary DNA (cDNA) of ribosomal protein L24 in Macrobrachium nipponense (MnRPL24) was isolated, and its role in ovarian development was investigated using quantitative real-time PCR (qPCR), immunohistochemistry (IHC), RNA interference (RNAi) and histological observations. The complete cDNA of MnRPL24 is 564 base pairs (bps) and contains a 486 bp open reading frame (ORF) encoding 162 amino acids (aas). The highest expression level of MnRPL24 among eight tissues was found in the ovary, specifically in the stage I ovary. The MnRPL24 protein existed in the cytoplasm and nucleus of developing oocytes, and also existed in the cytoplasm of follicle cells in developing ovaries. After MnRPL24 knockdown by RNAi, the expression levels of vitellogenin (Vg), vitellogenin receptor (Vgr), cyclin-dependent kinase 2 (Cdc2) and M-phase cyclin (Cyclin B) genes and the gonadsomatic index (GSI) did not show the typical trend of gradually elevation with ovarian development and finally decrease in the later stage of ovarian cycle. Moreover, the oviposition rate (OR) was downregulated, and oocyte development was delayed after MnRPL24 knockdown. After eyestalk ablation, the MnRPL24 expression level was considerably elevated in the initial stages and decreased in the late stage of the ovarian development cycle. This investigation illustrates a possible regulatory role of MnRPL24 in the ovarian development of M. nipponense, and MnRPL24 may act as a stimulator of early ovarian development.

Cloning and characterization of a ribosomal protein L24 from Haemaphysalis longicornis eggs

A fragment of ribosomal protein L24 was obtained from the complementary deoxyribonucleic acid (cDNA) library of Haemaphysalis longicornis eggs. The complete sequence of the clone was subsequently obtained using rapid amplification of the cDNA ends (RACE). Ribosomal protein L24 from H. longicornis had a high percentage similarity to this protein from different species. Conserved domains were also identified in RpL24. Real-time polymerase chain reaction (PCR) analysis showed that this gene is expressed in various tissues and different developmental stages of H. longicornis. Furthermore, HLL24 is mostly expressed in ovaries and salivary glands compared with other tissues in partially fed adult female ticks, and the expression level of HLL24 is significantly lower in eggs and larvas than in other developmental stages. RpL24 was also cloned from Haemaphysalis qinghaiensis and Hyalomma anatolicum anatolicum ticks, respectively. Comparison of their amino acid sequences revealed difference only in several amino acids. A vaccine based on the HLL24 recombinant protein could not protect rabbits against H. longicornis.

Growth arrest and induction of apoptotic and non-apoptotic programmed cell death by, Physalis minima L. chloroform extract in human ovarian carcinoma Caov-3 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The decoction of the whole plant of Physalis minima L. is traditionally consumed to treat cancer. Its anticancer property has been previously verified (using in vitro cytotoxicity assays) against NCI-H23 lung, CORL23 lung and MCF7 breast cancer cell lines but the mechanism underlying the anticancer potency towards ovarian carcinoma cells remain unclear.

AIM OF THE STUDY

The present study is aimed to systematically determine the cytotoxicity and possible cell death mechanism elicited by the chloroform extract of Physalis minima in human ovarian Caov-3 carcinoma.

MATERIALS AND METHODS

Cytotoxicity of the extract was measured using the methylene blue assay. The mechanism of cell death was determined using four independent methods, namely DeadEnd assay to label the DNA fragmentation nuclei cells, RT-PCR analysis to determine the mRNA expression level of three apoptotic genes (c-myc, p53 and caspase-3 genes), Transmission Electron Microscope (TEM) analysis to describe the ultra structural characteristics and annexin V and propidium iodide staining to confirm the types and stages of cell deaths.

RESULTS

Cytotoxicity screening of the extract on Caov-3 cells exhibited concentration- and time-dependent inhibitory effects. A combination of apoptotic and autophagic programmed cell death was detected. The apoptotic characteristic was initially determined by DNA fragmentation followed by the expression of c-myc and p53 genes that was much earlier than caspase-3. Apoptotic ultra structural changes (including clumping and magination of chromatin, blebbing and convolution of nucleus membrane and formation of apoptotic bodies) and autophagy (Type II non-apoptotic programmed cell death) with distinct vacuolated morphology were detected in TEM analysis. The existence of these programmed cell deaths was then corroborated using annexin V and propidium iodide staining.

CONCLUSIONS

The chloroform extract of Physalis minima exerted anticancer effect due to a combination of apoptotic and autophagic cell death mechanisms on Caov-3 cells. The induction of these programmed cell deaths was mediated via c-myc, p53 and caspase-3 dependent pathway. The results could provide a valuable insight in cancer therapy.

Identification of Wap65, a human homologue of hemopexin as a copper-inducible gene in swordtail fish, Xiphophorus helleri

Copper is one of the major heavy metal pollutants found in the aquatic environment. Therefore, it is important for determining the genes that play a key role in copper metabolism in aquatic organisms. This study, thus, aimed to identify a new copper-inducible gene in swordtail fish, Xiphophorus helleri. Using ACP-based RT-PCR coupled with RLM-RACE, we cloned Wap65, a mammalian homologue of hemopexin gene. The gene exhibits high identity at amino acid levels with the Wap65 gene of other fish species (42-68%) and mammalian hemopexin gene (35-37%). In addition, ten cysteine and two histidine residues are conserved in the swordtail fish Wap65 gene. These cysteine residues are vital for structural integrity, and histidine residues provide high binding affinity towards heme. As revealed by RT-PCR, the gene was upregulated in swordtail fish that were exposed to copper in a dose- and time-dependent manner. Therefore, the identification of Wap65, a mammalian homologue of hemopexin, as a new copper-inducible gene will provide greater insight into the role of this gene in copper metabolism.

Cloning, sequence analysis and identification of a nonsense mutation-mediated mRNA decay of porcine GSTM2 gene

The glutathione S-transferase mu 2 gene (GSTM2) encodes a GST functioning in the elimination of electrophilic compounds and the regulation of cell growth. In this study, the sequence of porcine GSTM2 gene that contains the complete sequence encoding a protein of 218 amino acids was cloned. The deduced amino acid sequence shared 76%, 78% and 76% identity with that of human, mouse and rat, respectively. mRNA expression analysis showed that the porcine GSTM2 gene was expressed at a high level in liver and testis, at a medium level in longissimus dorsi muscle, adipose tissue, spleen and lung, at a low level in kidney, and at a very low level in heart and embryo. A nonsense mutation (CGA-->TGA) resulted from C27T substitution in the fifth exon to produce a premature translation termination codon was identified, and it was discovered that nonsense-mediated mRNA decay might have an effect on the regulation of porcine GSTM2 gene expression. This polymorphism was analyzed in Large White, Landrace, Meishan and Qingping pig populations using the Taq I-polymerase chain reaction-restriction fragment length polymorphism method. The result showed that allele C had a higher frequency than allele T in each population.

Ribosomal protein L24 is differentially expressed in ovary and testis of the marine shrimp Marsupenaeus japonicus

In order to identify genes involved in oogenesis in shrimp, an ovarian cDNA library of Marsupenaeus japonicus was screened using a suppression-subtraction hybridization (SSH)-enriched probe. More than 20 genes were identified as differentially expressed genes between the ovary and the testis. Unexpectedly, one of these genes is a ribosomal protein that is normally considered a housekeeping gene. Northern blot shows that the shrimp ribosomal protein L24 gene (srpl24) is 0.6 kb in length. The expression level of srpl24 in the ovary is much higher than in the testis. Bioinformatics analyses show that srpl24 encodes a protein of 164 aa with a predicted molecular mass of 18.2 kDa, which is a cytoplasmic ribosomal protein. Real time PCR analyses demonstrated that the relative abundance of srpl24 mRNA in the different organs is: ovary >> testis, hepatopancreas, muscle and eye. The highest expression level of srpl24 in the ovary suggests that srpl24 has an important role in oogenesis. It is the first reported rpl24 in crustaceans and is the first reported rpl24 that is differentially expressed between the ovary and the testis in animals.

cDNA cloning, sequence analysis of the porcine LIM and cysteine-rich domain 1 gene

LIM domain proteins are important regulators in cell growth, cell fate determination, cell differentiation and remodeling of the cell cytoskeleton by their interaction with various structural proteins, kinases and transcriptional regulators. Using molecular biology combined with in silico cloning, we have cloned the complete coding sequence of pig LIM and the cysteine-rich domain 1 gene (LMCD1) which encodes a 363 amino acid protein. The estimated molecular weight of the LMCD1 protein is 40,788 Da with a pI of 8.39. It was found to be highly expressed in both skeletal muscle and cardiac muscle. Alignment analysis revealed that the deduced protein sequence shares 86%, 91% and 93% homology with that of its human, mouse and rat counterparts, respectively. The LMCD1 protein was predicted by bioinformatics software to contain a novel cysteine-rich domain in the N-terminal region, two LIM domains in the C-terminal region, nine potential protein kinase C phosphorylation sites, seven casein kinase II phosphorylation sites, a tyrosine kinase phosphorylation site, seven N-glycosylation and N-myristoylation sites and a single potential N-glycosylation site, which is similar to the protein's human counterpart. Phylogenetic tree was constructed by aligning the amino acid sequences of the LIM domain from different species. In addition, four base mutations were detected by comparing the sequences of Large White pigs with those of Chinese Meishan pigs. The G294A mutation site was confirmed by polymerase chain reaction-single-strand conformation polymorphism analysis. Its allele frequencies were studied in five pig breeds.

Growth arrest and non-apoptotic programmed cell death associated with the up-regulation of c-myc mRNA expression in T-47D breast tumor cells following exposure to Epipremnum pinnatum (L.) Engl. hexane extract

Epipremnum pinnatum (L.) Engl. hexane extract produced a significant growth inhibition against T-47D breast carcinoma cells and analysis of cell death mechanisms indicated that the extract elicited a non-apoptotic programmed cell death. T-47D cells exposed to the extract at EC(50) concentration (72 h) for 24 h failed to demonstrate typical DNA fragmentation associated with apoptosis, as carried out using a modified TUNEL assay. In addition, acute exposure to the extract produced an insignificant regulation of caspase-3 and p53 mRNA expression but increased in the c-myc mRNA expression. Ultrastructural analysis using transmission electron microscope demonstrated distinct vacuolated cells, which strongly indicated a Type II non-apoptotic cell death although the changes in chromatin were also detected. The presence of non-apoptotic programmed cell death was then reconfirmed with annexin-V and propidium iodide staining. These findings suggested that up-regulation of c-myc mRNA expression may have contributed to the growth arrest and Type II non-apoptotic programmed cell death in the Epipremnum pinnatum (L.) Engl. hexane extract-treated T-47D cells.

Methanolic extract of Pereskia bleo (Kunth) DC. (Cactaceae) induces apoptosis in breast carcinoma, T47-D cell line

Currently, breast cancer is the leading cause of cancer-related death in women. Therefore, there is an urgent need to develop alternative therapeutic measures against this deadly disease. Here, we report the cytotoxicity activity and the mechanism of cell death exhibited by the methanol extract prepared from Pereskia bleo (Kunth) DC. (Cactaceae) plant against human breast carcinoma cell line, T-47D. In vitro cytotoxicity screening of methanol extract of Pereskia bleo plant indicated the presence of cytotoxicity activity of the extract against T-47D cells with EC50 of 2.0 microg/ml. T-47D cell death elicited by the extract was found to be apoptotic in nature based a clear indication of DNA fragmentation which is a hallmark of apoptosis. In addition, ultrastructural analysis also revealed apoptotic characteristics (the presence of chromatin margination and apoptotic bodies) in the extract-treated cells. RT-PCR analysis showed the mRNA expression levels of c-myc, and caspase 3 were markedly increased in the cells treated with the plant extract. However, p53 expression was only slightly increased as compared to caspase 3 and c-myc. Thus, the results from this study strongly suggest that the methanol extract of Pereskia bleo may contain bioactive compound(s) that caused breast carcinoma, T-47D cell death by apoptosis mechanism via the activation of caspase-3 and c-myc pathways.

Molecular cloning and characterisation of peroxisome proliferator activated receptor gamma1 (PPARgamma1) cDNA gene from guinea pig (Cavia porcellus): tissue distribution

The coding region of guinea pig peroxisome proliferator activated receptor gamma1 (gpPPARgamma1) cDNA was successfully cloned from adipose tissue by reverse transcription polymerase chain reaction (RT-PCR) using the designated primers based on the conserved regions of the other mammalian PPARgamma1 sequence. From RT-PCR, a combination of three cDNA fragments that comprised of the full length coding region PPARgamma1 cDNA gene were amplified, with the size of 498, 550 and 557 bp, respectively. All three fragments were then successfully assembled by utilising the internal restriction sites present at the overlapping regions to give rise to the full-length coding region of gpPPARgamma1 with the size of 1428 bp and consisting of 475 amino acids. Guinea pig PPARgamma1 is highly conserved with those of other species at protein and nucleotide levels. Gene expression studies showed that gpPPARgamma mRNA was predominantly expressed in adipose tissue followed by lung and spleen. However, at the protein level, PPARgamma was also found to be expressed in skeletal muscle.