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Background: Lupus B cells not only produce autoantibodies against nuclear antigens but also provide co-stimulation to T cells. However, there is still a lack of comprehensive understanding of the mechanism underlying lupus B cell hyperactivation., Methods: This study focuses on the detection of B cell activation status, analysis of early BCR signaling response, DNA sequencing, and quantity determination of BCR signaling regulators in murine lupus models., Results: Our result showed that there is a B cell hyperactivation with a significant elevation of B cell activation markers, and a BCR signaling hyperactivity with an abnormal increase of phosphorylated BCR signaling molecules and cytoplasmic calcium in the early response to BCR crosslinking in B6.Sle1/2/3 lupus mouse. Whole exome sequencing identified a multiple point mutation in the exon of many BCR signaling regulators in common murine lupus models, MRL/lpr, NZM2410, BXSB, NZB, and NZW strains. cNDA sequencing confirmed FcγR2b, Ly9, Pirb, Siglecg, and CD22 BCR signaling regulator variants in B6.Sle1/2/3 lupus mouse, but surface protein expression of these regulators on B cells showed an abnormal increase., Conclusion: Our findings support that these BCR signaling regulator variants are potential causative genes of B cell hyperactivation in murine lupus models through their possible functional reduction.

Since CD44 was found to be significantly inhibited in the human nasopharyngeal carcinoma cell line CNE-2L2 with profound reduction of malignant activities caused by inhibition of alpha-mannosidase Man2c1 gene expression and CD44 has been observed to be involved in many tumor-supporting functions, we studied the association of CD44 expression with the malignant activities of CNE-2L2 cells. Suppression of CD44 gene expression by RNA silencing technique resulted in profound reduction of malignant potential of the cells, including growth in vitro, colony formation, tumorigenesis and metastasis of tumors in nude mice. Direct injection of the adenoviruses harboring and producing siRNA to CD44 into the tumor inoculated with CNE-2L2 cells in nude mice caused inhibition of tumor growth. The data indicate a positive association of CD44 expression with the malignant activities of CNE-2L2 cells and suggest a possible therapeutic effect of direct introduction of siRNA to CD44 into tumors in some human solid tumors with high expression of CD44 gene.

Sisomicin binding sites are located in the cell wall. They are the carboxyl groups of peptidoglycans, which are major components of the cell wall. The carboxyl groups have negative charges which can bind the positively charged amino groups of sisomicin. When the negative charges of the carboxyl groups of the peptidoglycans are changed to neutral or positive charges, sisomicin does not bind to the cell wall. Magnesium ions bind to the cell wall in competition with sisomicin, and have a weak affinity for the cell wall binding sites compared with sisomicin. The binding molar ratio of sisomicin to magnesium ions was approximately 1 to 10.

The objective of this study was to determine developmental pattern and cell allocation to the inner cell mass and trophectoderm in haploid and diploid embryos following parthenogenetic activation. In vitro matured porcine oocytes were activated by ethanol treatment and cultured in the presence or absence of cytochalasin B for 5 h. The oocytes were then cultured in the NCSU23 for 9 days. The combined treatment with cytochalasin B following ethanol treatment did not increase (p > 0.1) the incidence of activation. The incidence of development to the blastocyst stage was higher (p < 0.05) in the combined treatments of ethanol and cytochalasin B as compared with ethanol treatment alone. The percentage of oocytes with two female pronuclei was higher (p < 0.01) in oocytes treated with cytochalasin B than that in ethanol treatment alone. Treatment with both ethanol and cytochalasin B increased (p < 0.01) the incidence of diploid chromosome spread over just the ethanol treatment alone. The average numbers of total cells and inner cell mass were significantly reduced (p < 0.05) in the ethanol treatment alone as compared with the combined cytochalasin B and ethanol treatment. These results suggested that the ploidy may affect blastocoele formation and cell allocation to inner cell mass and trophectoderm in the pig.

Pyrophosphate-dependent phosphofructokinase (PPi-PFK) was identified previously in Toxoplasma gondii as the only kinase that phosphorylates fructose-6-P to fructose-1,6-bisP. Since such an enzyme is not present in mammals, it was considered to be a good target for prospective selective inhibitors of the parasite. We have examined the effects of several phosphonic acid derivatives, analogs of pyrophosphate, on PPi-PFK activity, as well as on the replication of T. gondii in human foreskin fibroblast (HFF) cells. The most active compound in inhibiting PPi-PFK was tetrasodium carbonyldiphosphonate. Several bisphosphonates and related arylhydrazones showed inhibition of the enzyme, but with higher IC50 values. Although several phosphonoacetic acid derivatives also inhibited PPi-PFK, as a group they were less potent than the bisphosphonate derivatives. Comparison among the structures of various inhibitors and their effects against PPi-PFK indicates that a carbonyl (C=O) or amino (C=N) group between two phosphoryl moieties is associated with more potent enzyme inhibiton. Tetrasodium carbonyldiphosphonate did not show a significant effect against replication of T. gondii cells, probably because, as a charged molecule, it could not cross the cell membrane to reach the intracellular parasite. Tetraisopropyl carbonyldiphosphonate 2,4-dinitrophenylhydrazone showed some selective inhibitory effect against replication of the parasite in the HFF cells and protected the mammalian cells from damage by T. gondii. The results indicate that carbonyldiphosphonic acid is a good prototype compound that is amenable to chemical manipulation, which, in turn, may optimize selective inhibition of T. gondii PPi-PFK and increase accessibility to the intracellular parasite.