25% HUMAN SERUM ALBUMIN IMPROVES HEMODYNAMICS AND PREVENTS THE NEED FOR NEARLY ALL PREHOSPITAL RESUSCITATION IN A RAT ( RATTUS NORVEGICUS ) MODEL OF TRAUMA AND HEMORRHAGE.

ABSTRACT: Combat casualty care can be complicated by transport times exceeding the "golden hour," with intervention and resuscitation limited to what the medic can carry. Pharmaceutical albumin comes highly saturated with nonesterified fatty acids (NEFAs). We recently showed that treatment with 25% bovine serum albumin (BSA) loaded with oleic acid, but not NEFA-free BSA, improved survival for hours after severe hemorrhage and often eliminated the need for resuscitation in rats. However, it was unknown whether pharmaceutical albumin, derived from human sources and loaded with caprylic acid (CA), would have the same benefits. We compared adjunct treatment with oleic acid-saturated BSA, CA-saturated BSA, pharmaceutical human serum albumin, or a no-albumin control in a similar rat hemorrhagic shock model to determine whether the three NEFA-albumin groups provided the same benefits relative to control. We found almost no significant differences among the NEFA-albumin groups in any measure. Mortality in controls was too low to allow for detection of improvement in survival, but NEFA-albumin groups had significantly improved hemodynamics, lactate clearance, and greatly reduced fluid requirements compared with controls. Contrary to expectations of "dehydration," 25% albumins shifted little additional fluid into the vasculature. Rather, they restored protein to the autotransfusion fluid. Nonesterified fatty acids-albumin did not worsen lung permeability, but we observed a loss of circulating protein suggesting it may have increased overall vascular permeability. Our findings suggest that, though imperfect, 25% human serum albumin could be a solution for resuscitation in austere conditions requiring prolonged field care.

Transcriptional induction of NF-κB-inducing kinase by E2F4/5 facilitates collective invasion of GBM cells.

The prognosis of high-grade gliomas, such as glioblastoma multiforme (GBM), is extremely poor due to the highly invasive nature of these aggressive cancers. Previous work has demonstrated that TNF-weak like factor (TWEAK) induction of the noncanonical NF-κB pathway promotes the invasiveness of GBM cells in an NF-κB-inducing kinase (NIK)-dependent manner. While NIK activity is predominantly regulated at the posttranslational level, we show here that NIK (MAP3K14) is upregulated at the transcriptional level in invading cell populations, with the highest NIK expression observed in the most invasive cells. GBM cells with high induction of NIK gene expression demonstrate characteristics of collective invasion, facilitating invasion of neighboring cells. Furthermore, we demonstrate that the E2F transcription factors E2F4 and E2F5 directly regulate NIK transcription and are required to promote GBM cell invasion in response to TWEAK. Overall, our findings demonstrate that transcriptional induction of NIK facilitates collective cell migration and invasion, thereby promoting GBM pathogenesis.

Transcriptional Induction of NF-kB-Inducing Kinase by E2F4/5 Facilitates Collective Invasion of Glioma Cells.

The prognosis of high-grade gliomas, such as glioblastoma multiforme (GBM), is extremely poor due to the highly invasive nature of these aggressive cancers. Previous work has demonstrated that TNF-weak like factor (TWEAK) induction of the noncanonical NF-κB pathway increases the invasiveness of glioma cells in an NF-κB-inducing kinase (NIK)-dependent manner. While NIK activity is predominantly regulated at the posttranslational level, we show here that NIK ( MAP3K14 ) is upregulated at the transcriptional level in invading cell populations, with the highest expression observed in the most invasive cells. Glioma cells with high induction of NIK gene expression demonstrate characteristics of collective invasion, facilitating invasion of neighboring cells. Furthermore, we demonstrate that the E2F transcription factors E2F4 and E2F5 directly regulate NIK transcription and are required to promote glioma cell invasion in response to TWEAK. Overall, our findings demonstrate that transcriptional induction of NIK facilitates collective cell migration and invasion, thereby promoting glioma pathogenesis.

NIK/MAP3K14 Regulates Mitochondrial Dynamics and Trafficking to Promote Cell Invasion.

Although the role of NF-κB-inducing kinase (NIK) in immunity is well established, its relevance in cancer is just emerging. Here we describe novel functions for NIK in regulating mitochondrial dynamics and motility to promote cell invasion. We show that NIK is localized to mitochondria in cancer cell lines, ex vivo tumor tissue, and mouse embryonic fibroblasts (MEFs). NIK promotes mitochondrial fission, velocity, and directional migration, resulting in subcellular distribution of mitochondria to the periphery of migrating cells. Moreover, NIK is required for recruitment of Drp1 to mitochondria, forms a complex with Drp1, and regulates Drp1 phosphorylation at Ser-616 and dephosphorylation at Ser-637. Consistent with a role for NIK in regulating mitochondrial dynamics, we demonstrate that Drp1 is required for NIK-dependent, cytokine-induced invasion. Importantly, using MEFs, we demonstrate that the established downstream mediators of NIK signaling, IκB kinase α/ß (IKKα/ß) and NF-κB, are not required for NIK to regulate cell invasion, Drp1 mitochondrial localization, or mitochondrial fission. Our results establish a new paradigm for IKK-independent NIK signaling and significantly expand the current dogma that NIK is predominantly cytosolic and exclusively regulates NF-κB activity. Overall, these findings highlight the importance of NIK in tumor pathogenesis and invite new therapeutic strategies that attenuate mitochondrial dysfunction through inhibition of NIK and Drp1.