The mouse intron-nested gene, Israa, is expressed in the lymphoid organs and involved in T-cell activation and signaling

MIB2 promotes the progression of non-small cell lung cancer by regulating cell cycle control pathways

BACKGROUND

Although numerous measures have been used to improve the outcome of lung cancer patients, lung cancer, as the second most common diagnosed cancer, is still the main cause of cancer death. It becomes increasingly urgent for us to deeply deplore the molecular mechanism of lung cancer and to discover the potential therapeutic targets. In our study, we are dedicated to discovering the role of MIB2 in lung cancer development.

METHODS

The public databases were used to compare the expression level of MIB2 in cancer and non-cancer tissue. We analyzed the expression of MIB2 in lung cancer samples by performing Rt-PCR and western blot. We carried out CCK8 and clone assays to study the influence of MIB2 in lung cancer proliferation. The transwell assays and wound healing assays were implemented to study the function of MIB2 in metastasis and invasion. Proteins of cell cycle control pathways are detected to verify the potential mechanism of MIB2 in lung cancer progression.

RESULTS

MIB2 is up regulated in lung cancer tissue compared to adjacent normal lung tissue according to both public databases and our clinical lung cancer samples. Knockdown of MIB2 inhibits proliferation, metastasis, and invasion of lung cancer cell lines. Cyclins and cyclin dependent kinases (CDK) including CDK2, CDK4, and cyclinB1 were down regulated in MIB2 knockdown cells.

CONCLUSION

Our results prove that MIB2 acts as a driver in NSCLC tumorigenesis by regulating cell cycle control pathways.

Heterogeneity of T cells and macrophages in chlorine-induced acute lung injury in mice using single-cell RNA sequencing

OBJECTIVE

Chlorine (Cl₂), as an asphyxiant toxicant, induced poisoning incidents and acute lung injury (ALI) occur frequently. The specific pathogenesis of Cl₂-induced ALI remains unclear. Immune cells play an important role in the process of lung damage. We used single-cell RNA sequencing (scRNA-seq) technology to explore T cells and macrophages molecular mechanism.

METHODS

Female BALB/c mice were exposed to 400 ppm Cl₂ for 15 min. scRNA-seq technology was used to observe the heterogeneity of T cells and macrophages. Hematoxylin-eosin (H&E) staining was used to evaluate the degree of lung injury. Immunofluorescence was used to verify the highly expressed genes of our interest.

RESULTS

A total of 5316 to 7742 cells were classified into eight different cell types. Several new highly expressed anti-inflammatory and pro-inflammatory genes were found in T cells and macrophages, which were further verified in vitro. Through the pseudotime analysis of macrophages, it was found that the expression of pro-inflammatory and anti-inflammatory genes showed opposite trends in the development of Cl₂-induced ALI. This study also mapped T cells-macrophage communication and identified the development of several important receptor-ligand complexes in Cl₂-induced ALI.

CONCLUSIONS

These findings are worthy of further exploration and provide new resources and directions for the study of Cl₂-induced ALI in mice, especially in immune and inflammation mechanisms.

Knocking down Israa, the Zmiz1 intron-nested gene, unveils interrelated T cell activation functions in mouse

We previously reported Israa (immune-system-released activating agent), a novel gene nested in intron 6 of the mouse Zmiz1 gene. Zmiz1 is involved in several functions such as fertility and T cell development and its knockout leads to non-viable embryos. We also reported ISRAA's expression in lymphoid organs, particularly in the thymus CD³⁺ T cells during all developmental stages. In addition, we showed that ISRAA is a binding partner of Fyn and Elf-1 and regulates the expression of T cell activation-related genes in vitro. In this paper, we report the generation and characterization of an Israa ^-/- constitutive knockout mouse. The histological study shows that Israa ^-/- mice exhibit thymus and spleen hyperplasia. Israa ^-/- derived T cells showed increased proliferation compared to the wild-type mice T cells. Moreover, gene expression analysis revealed a set of differentially expressed genes in the knockout and wild-type animals during thymus development (mostly genes of T cell activation pathways). Immunological phenotyping of the thymocytes and splenocytes of Israa ^-/- showed no difference with those of the wild-type. Moreover, we observed that knocking out the Zmiz1 intron embedded Israa gene does not affect mice fertility, thus does not disturb this Zmiz1 function. The characterization of the Israa ^-/- mouse confirms the role ISRAA plays in the expression regulation of genes involved in T cell activation established in vitro. Taken together, our findings point toward a potential functional interrelation between the intron nested Israa gene and the Zmiz1 host gene in regulating T cell activation. This constitutively Israa ^-/- mice can be a good model to study T cell activation and to investigate the relationship between host and intron-nested genes.

A role for the immune system-released activating agent (ISRAA) in the ontogenetic development of brain astrocytes

The Immune System-Released Activating Agent (ISRAA) was discovered as a novel molecule that functions as a mediator between the nervous and immune systems in response to a nervous stimulus following an immune challenge. This research investigated the role of ISRAA) in promoting the ontogeny of the mouse brain astrocytes. Astrocyte cultures were prepared from two-month-old BALB/c mice. Recombinant ISRAA protein was used to stimulate astrocyte cultures. Immunohistochemistry and ELISA were utilized to measure ISRAA and IFN-γ levels, IFN-γR expression and STAT1 nuclear translocation. MTT-assay was used to evaluate cellular survival and proliferation. To assess astrocyte cell lysates and tyrosine-phosphorylated proteins, SDS-PAGE and western blot were used. ISRAA was highly expressed in mouse embryonic astrocytes, depending on cell age. Astrocytes aged seven days (E7) showed increased proliferation and diminished differentiation, while 21-day-old (E21) astrocytes depicted reversed effects. IFN-γ was involved in the ISRAA action as ISRAA induced IFN-γ in both age groups, but only E21 astrocytes expressed IFN-γR. ISRAA stimulation of E21 resulted in tyrosine phosphorylation of numerous cellular proteins and the nuclear translocation of STAT1, a signalling pathway utilized by IFN-γ. The results suggest that ISRAA is involved in mouse brain development through the cytokine network involving IFN-γ.