Dynamic neuroinflammatory profiles predict Alzheimer's disease pathology in microglia-containing cerebral organoids.

Neuroinflammation and the underlying dysregulated immune responses of microglia actively contribute to the progression and, likely, the initiation of Alzheimer's disease (AD). Fine-tuned therapeutic modulation of immune dysfunction to ameliorate disease cannot be achieved without the characterization of diverse microglial states that initiate unique, and sometimes contradictory, immune responses that evolve over time in chronic inflammatory environments. Because of the functional differences between human and murine microglia, untangling distinct, disease-relevant reactive states and their corresponding effects on pathology or neuronal health may not be possible without the use of human cells. In order to profile shifting microglial states in early AD and identify microglia-specific drivers of disease, we differentiated human induced pluripotent stem cells (iPSCs) carrying a familial AD PSEN2 mutation or its isogenic control into cerebral organoids and quantified the changes in cytokine concentrations over time with Luminex XMAP technology. We used partial least squares (PLS) modeling to build cytokine signatures predictive of disease and age to identify key differential patterns of cytokine expression that inform the overall organoid immune milieu and quantified the corresponding changes in protein pathology. AD organoids exhibited an overall reduction in cytokine secretion after an initial amplified immune response. We demonstrate that reduced synapse density observed in the AD organoids is prevented with microglial depletion. Crucially, these differential effects of dysregulated immune signaling occurred without the accumulation of pathological proteins. In this study, we used microglia-containing AD organoids to quantitatively characterize an evolving immune milieu, made up of a diverse of collection of activation patterns and immune responses, to identify how a dynamic, overall neuroinflammatory state negatively impacts neuronal health and the cell-specific contribution of microglia.

IGF2BP family of RNA-binding proteins regulate innate and adaptive immune responses in cancer cells and tumor microenvironment.

Insulin-like growth factor 2 mRNA-binding proteins (IGF2BP1, IGF2BP2, and IGF2BP3) are a family of RNA-binding proteins that play an essential role in the development and disease by regulating mRNA stability and translation of critical regulators of cell division and metabolism. Genetic and chemical inhibition of these proteins slows down cancer cell proliferation, decreases invasiveness, and prolongs life span in a variety of animal models. The role of RNA-binding proteins in the induction of tissues' immunogenicity is increasingly recognized, but, the impact of the IGF2BPs family of proteins on the induction of innate and adaptive immune responses in cancer is not fully understood. Here we report that downregulation of IGF2BP1, 2, and 3 expression facilitates the expression of interferon beta-stimulated genes. IGF2BP1 has a greater effect on interferon beta and gamma signaling compared to IGF2BP2 and IGF2BP3 paralogs. We demonstrate that knockdown or knockout of IGF2BP1, 2, and 3 significantly potentiates inhibition of cell growth induced by IFNß and IFNγ. Mouse melanoma cells with Igf2bp knockouts demonstrate increased expression of MHC I (H-2) and induce intracellular Ifn-γ expression in syngeneic T-lymphocytes in vitro. Increased immunogenicity, associated with Igf2bp1 inhibition, "inflames" mouse melanoma tumors microenvironment in SM1/C57BL/6 and SW1/C3H mouse models measured by a two-fold increase of NK cells and tumor-associated myeloid cells. Finally, we demonstrate that the efficiency of anti-PD1 immunotherapy in the mouse melanoma model is significantly more efficient in tumors that lack Igf2bp1 expression. Our retrospective data analysis of immunotherapies in human melanoma patients indicates that high levels of IGF2BP1 and IGF2BP3 are associated with resistance to immunotherapies and poor prognosis. In summary, our study provides evidence of the role of IGF2BP proteins in regulating tumor immunogenicity and establishes those RBPs as immunotherapeutic targets in cancer.

Mesenchymal Stem Cell-Derived Extracellular Vesicles for Therapeutic Use and in Bioengineering Applications.

Extracellular vesicles (EVs) are small lipid bilayer-delimited particles that are naturally released from cells into body fluids, and therefore can travel and convey regulatory functions in the distal parts of the body. EVs can transmit paracrine signaling by carrying over cytokines, chemokines, growth factors, interleukins (ILs), transcription factors, and nucleic acids such as DNA, mRNAs, microRNAs, piRNAs, lncRNAs, sn/snoRNAs, mtRNAs and circRNAs; these EVs travel to predecided destinations to perform their functions. While mesenchymal stem cells (MSCs) have been shown to improve healing and facilitate treatments of various diseases, the allogenic use of these cells is often accompanied by serious adverse effects after transplantation. MSC-produced EVs are less immunogenic and can serve as an alternative to cellular therapies by transmitting signaling or delivering biomaterials to diseased areas of the body. This review article is focused on understanding the properties of EVs derived from different types of MSCs and MSC-EV-based therapeutic options. The potential of modern technologies such as 3D bioprinting to advance EV-based therapies is also discussed.

Targeting RNA-binding proteins in acute and chronic leukemia.

RNA-binding proteins (RBPs) play a crucial role in cellular physiology by regulating RNA processing, translation, and turnover. In neoplasms, RBP support of cancer-relevant expression of alternatively spliced, modified, and stabilized mRNA transcripts is essential to self-renewal, proliferation, and adaptation to stress. In this review, we assess the impact of key families of RBPs in leukemogenesis, review progress in targeting those proteins with small molecules, and discuss how multilevel composition of posttranscriptional regulation of gene expression could be used for potential therapies in acute and chronic leukemia.

The Role of cis- and trans-Acting RNA Regulatory Elements in Leukemia.

RNA molecules are a source of phenotypic diversity and an operating system that connects multiple genetic and metabolic processes in the cell. A dysregulated RNA network is a common feature of cancer. Aberrant expression of long non-coding RNA (lncRNA), micro RNA (miRNA), and circular RNA (circRNA) in tumors compared to their normal counterparts, as well as the recurrent mutations in functional regulatory cis-acting RNA motifs have emerged as biomarkers of disease development and progression, opening avenues for the design of novel therapeutic approaches. This review looks at the progress, challenges and future prospects of targeting cis-acting and trans-acting RNA elements for leukemia diagnosis and treatment.

RNA-binding protein IGF2BP1 maintains leukemia stem cell properties by regulating HOXB4, MYB, and ALDH1A1.

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) is an oncofetal protein expressed in various cancers including leukemia. In this study, we assessed the role of IGF2BP1 in orchestrating leukemia stem cell properties. Tumor-initiating potential, sensitivity to chemotherapeutic agents, and expression of cancer stem cell markers were assessed in a panel of myeloid, B-, and T-cell leukemia cell lines using gain- and loss-of-function systems, cross-linking immunoprecipitation (CLIP), and photoactivatable ribonucleoside-enhanced cross-linking and immunoprecipitation (PAR-CLIP) techniques. Here, we report that genetic or chemical inhibition of IGF2BP1 decreases leukemia cells' tumorigenicity, promotes myeloid differentiation, increases leukemia cell death, and sensitizes leukemia cells to chemotherapeutic drugs. IGF2BP1 affects proliferation and tumorigenic potential of leukemia cells through critical regulators of self-renewal HOXB4 and MYB and through regulation of expression of the aldehyde dehydrogenase, ALDH1A1. Our data indicate that IGF2BP1 maintains leukemia stem cell properties by regulating multiple pathways of stemness through transcriptional and metabolic factors.

Extracellular vesicle-dependent effect of RNA-binding protein IGF2BP1 on melanoma metastasis.

Insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) is a multifunctional RNA-binding protein with an oncofetal pattern of expression shown to be implicated in the development of a variety of malignancies. In this study, we explored the role and mechanisms of IGF2BP1 in melanoma development and progression. In two different in vivo models, we showed that although genetic deletion or shRNA-mediated suppression of IGF2BP1 did not affect primary tumor formation, it drastically suppressed lung metastasis. Here we demonstrated that extracellular vesicles (EVs) secreted by melanoma cells mediate the effects of IGF2BP1 on metastasis: EVs from the IGF2BP1 knockdown melanoma cells failed to promote metastasis, whereas EVs isolated from IGF2BP1-overexpressed melanoma cells further accelerated EV-induced metastasis. Moreover, the EVs from IGF2BP1 knockdown melanoma cells inhibited fibronectin deposition and accumulation of CD45+ cells in the lungs compared with control EVs, thus blocking the pre-metastatic niche formation potential of EVs. IGF2BP1 knockdown did not affect size, number, or protein/RNA concentration of secreted EVs or their uptake by recipient cells in vitro or in vivo. However, RNA-sequencing and proteomics analysis of the EVs revealed differential expression in a number of mRNA, proteins, and miRNAs. This suggested that IGF2BP1 is intimately involved in the regulation of the cargo of EVs, thereby affecting the pro-metastatic function of melanoma-derived EVs. To the best of our knowledge, this is the first study that demonstrates the role of RNA-binding protein IGF2BP1 in EV-mediated promotion of melanoma metastasis and may provide novel avenues for the development of metastatic inhibitors.

Metabo-miR: miR-211 Regulates Mitochondrial Energy Metabolism in Vitiligo.

The study by Sahoo et al. established miR-211 as a critical regulator of cellular metabolism in vitiligo cells. miR-211, which is expressed from the transient receptor potential melastatin 1 intronic region, regulates oxidative phosphorylation and mitochondrial energy metabolism in vitiligo. Loss of miR-211 in melanocytes was shown to alter expression patterns of newly identified target genes, and those that regulate respiratory functions in melanocytes are among them. This study highlights the importance of miR-211 for the melanocyte biology and development of vitiligo.