RESUMEN
The sleeping chironomid Polypedilum vanderplanki is capable of anhydrobiosis, a striking example of adaptation to extreme desiccation. Tolerance to complete desiccation in this species is associated with emergence of multiple paralogs of protective genes. One of the gene families highly expressed under anhydrobiosis and involved in this process is protein-L-isoaspartate (D-aspartate) O-methyltransferases (PIMTs). Recently, another closely related midge was discovered, Polypedilum pembai, which is able not only to tolerate desiccation but also to survive multiple desiccation-rehydration cycles. To investigate the evolution of anhydrobiosis in these species, we sequenced and assembled the genome of P. pembai and compared it with P. vanderplanki and also performed a population genomics analysis of several populations of P. vanderplanki and one population of P. pembai. We observe positive selection and radical changes in the genetic architecture of the PIMT locus between the two species, including its amplification in the P. pembai lineage. In particular, PIMT-4, the most highly expressed of these PIMTs, is present in six copies in the P. pembai; these copies differ in expression profiles, suggesting possible sub- or neofunctionalization. The nucleotide diversity of the genomic region carrying these new genes is decreased in P. pembai, but not in the orthologous region carrying the ancestral gene in P. vanderplanki, providing evidence for a selective sweep associated with postduplication adaptation in the former. Overall, our results suggest an extensive relatively recent and likely ongoing adaptation of the mechanisms of anhydrobiosis.
RESUMEN
We investigated the features of the morphology and cytokine profiles of neuroblastoma SH-SY5Y cells, bone marrow-derived mesenchymal stromal/stem cells (BM-MSCs), and peripheral blood mononuclear cells (PBMCs) in double (BM-MSCs + SH-SY5Y cells) and triple (BM-MSCs + SH-SY5Y cells + PBMCs) co-cultures incubated on plastic and Matrigel. Cells in the co-cultures communicated by vesicular transport and by exchanging membrane and cytoplasmic components. The cytokine profile of double and triple co-cultures incubated on Matrigel and plastic had differences and showed the highest concentration of a number of chemokines/cytokines, such as CXCL8/IL-8, I-TAC/CXCL11, IP10/CXCL10, MDC/CCL22, MIP-1α/CCL3, IL-1ß, ENA-78/CXCL5, Gro-α/CXCL1, MCP-1/CCL2, TERC/CCL25, CXCL8/IL-8, and IL-6. High concentrations of inflammatory chemokines/cytokines in the conditioned medium of triple co-culture form a chronic inflammation, which brings the presented co-cultivation system closer to a natural tumor. Triple co-cultures were more resistant to cisplatin (CDDP) than the double- and monoculture of SH-SY5Y. The mRNA levels of BCL2, BCL2L1, RAC1, CAV1, CASP3, and BAX genes were changed in cells after co-culturing and CDDP treatment in double and triple co-cultures. The expression of the BCL2, BAX, CAV1, and CASP3 proteins in SH-SY5Y cells after the triple co-culture and CAV1 and BAX protein expression in SH-SY5Y cells after the double co-culture were determined. This study demonstrated the nature of the cellular interactions between components of tumor niche and the intercellular influence on chemoresistance observed in our tumor model, which should enable the development of novel test systems for anti-tumor agents.
RESUMEN
Larvae of the sleeping chironomid Polypedilum vanderplanki are known for their extraordinary ability to survive complete desiccation in an ametabolic state called "anhydrobiosis". The unique feature of P. vanderplanki genome is the presence of expanded gene clusters associated with anhydrobiosis. While several such clusters represent orthologues of known genes, there is a distinct set of genes unique for P. vanderplanki. These include Lea-Island-Located (LIL) genes with no known orthologues except two of LEA genes of P. vanderplanki, PvLea1 and PvLea3. However, PvLIL proteins lack typical features of LEA such as the state of intrinsic disorder, hydrophilicity and characteristic LEA_4 motif. They possess four to five transmembrane domains each and we confirmed membrane targeting for three PvLILs. Conserved amino acids in PvLIL are located in transmembrane domains or nearby. PvLEA1 and PvLEA3 proteins are chimeras combining LEA-like parts and transmembrane domains, shared with PvLIL proteins. We have found that PvLil genes are highly upregulated during anhydrobiosis induction both in larvae of P. vanderplanki and P. vanderplanki-derived cultured cell line, Pv11. Thus, PvLil are a new intriguing group of genes that are likely to be associated with anhydrobiosis due to their common origin with some LEA genes and their induction during anhydrobiosis.
