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Background Major Depressive Disorder (MDD) afflicts up to 10% of adolescents. However, nearly 50% of those afflicted are considered non-responsive to available treatments. Ketamine, a non-competitive N-methyl-D-aspartate (NMDA) receptor antagonist has shown potential as a rapid-acting and long-lasting treatment for MDD in adults. Thus, the effectiveness and functional consequences of ketamine exposure during adolescence were explored. Methods Adolescent male rats (postnatal day [PD] 35) received two ketamine (0, 5, 10 or 20 mg/kg) injections, 4 hours apart, after exposure to day 1 of the forced swim test (FST). The next day, rats were re-exposed to the FST to assess ketamine-induced antidepressant-like responses. Separate groups were exposed to chronic unpredictable stress (CUS) to confirm findings from the FST. After these initial experiments, adolescent naïve rats were exposed to either 1 or 15 consecutive days (PD35–49) of ketamine (20 mg/kg) twice/daily. Ketamine's influence on behavioral reactivity to rewarding (i.e., sucrose preference) and aversive (i.e., elevated plus-maze, FST) circumstances was then assessed 2 months after treatment. To control for age-dependent effects, adult rats (PD75–89) were exposed to identical experimental conditions. Results Ketamine (20 mg/kg) reversed the CUS-induced depression-like behaviors in the FST. Repeated ketamine exposure resulted in anxiolytic- and antidepressant-like responses 2 months after drug exposure. None of the ketamine doses used were capable of inducing drug-seeking behaviors as measured by place preference conditioning. Conclusions Repeated ketamine exposure induces enduring resilient-like responses regardless of age of exposure. These findings point to ketamine, and its repeated exposure, as a potentially useful antidepressant during adolescence.

Endoplasmic reticulum (ER) stress and the unfolded protein response (UPR) signaling have been shown to be dysregulated in multiple cancer types. Glucose regulatory protein 78 (GRP78), the master regulator of the UPR, plays a role in proliferation, invasion, and metastasis in cancer. Cancer stem cells (CSCs) make up a crucial component of the tumor heterogeneity in pancreatic cancer, as well as other cancers. “Stemness” in pancreatic cancer defines a population of cells within the tumor that have increased therapeutic resistance as well as survival advantage. In the current study, we investigated how GRP78 was responsible for maintaining “stemness” in pancreatic cancer thereby contributing to its aggressive biology. We determined that GRP78 downregulation decreased clonogenicity and self-renewal properties in pancreatic cancer cell lines in vitro. In vivo studies resulted in delayed tumor initiation frequency, as well as smaller tumor volume in the shGRP78 groups. Additionally, downregulation of GRP78 resulted in dysregulated fatty acid metabolism in pancreatic tumors as well as the cells. Further, our results showed that shGRP78 dysregulates multiple transcriptomic and proteomic pathways that involve DNA damage, oxidative stress, and cell death, that were reversed upon treatment with a ROS inhibitor, N-acetylcysteine. This study thus demonstrates for the first time that the heightened UPR in pancreatic cancer may be responsible for maintenance of the “stemness” properties in these cells that are attributed to aggressive properties like chemoresistance and metastasis.

Pancreatic adenocarcinoma (PDAC) claims more than 90% of the patients diagnosed with the disease owing to its aggressive biology that is manifested by high rate of tumor recurrence. Aberrant upregulation in the transcriptional activity of proteins involved in self-renewal like Sox2, Oct4 and Nanog is instrumental in these recurrence phenomena. In cancer, Sox2 is aberrantly “turned-on” leading to activation of downstream genes those results in relapse of the tumor. Molecular mechanisms that regulate the activity of Sox2 in PDAC are not known. In the current study, we have studied the how glycosylation of Sox2 by O-GlcNAc transferase (OGT) can affect its transcriptional activity and thus regulate self-renewal in cancer. Methods: RNA-Seq analysis of CRISPR-OGTi PDAC cells indicated a deregulation of differentiation and self-renewal pathways in PDAC. Pancreatic tumor burden following inhibition of OGT in vivo was done by using small molecule inhibitor, OSMI, on subcutaneous implantation of PDAC cells. Sox2 activity assay was performed by Dual Luciferase Reporter Assay kit. Results: Our study shows for the first time that in PDAC, glycosylation of Sox2 by OGT stabilizes it in the nucleus. Site directed mutagenesis of this site (S246A) prevents this modification. We further show that inhibition of OGT delayed initiation of pancreatic tumors by inhibition of Sox2. We also show that targeting OGT in vivo with a small molecule-inhibitor OSMI, results in decreased tumor burden in PDAC. Conclusion: Understanding this mechanism of SOX2 regulation by its glycosylation is expected to pave the way for development of novel therapy that has the potential to eradicate the cells responsible for tumor-recurrence.

Neurodegenerative diseases currently affect millions of people worldwide and continues to increase in the expanding elderly population. Neurodegenerative diseases usually involve cognitive decline and are among the top causes of death. Thus, there is a critical need for the development of treatments and preventive strategies for neurodegenerative diseases. One of the risk factors of neurodegeneration is inflammaging, a low level of chronic inflammation due to old age. We have previously shown that the inflammasome contributes to inflammaging in the central nervous system (CNS). The inflammasome is a multiprotein complex of the innate immune response consisting of a sensor protein, apoptosis speck-like protein containing a CARD (ASC), and caspase-1. Our lab has developed a humanized monoclonal antibody against ASC (anti-ASC). Here, we analyzed cortical lysates from young (3 months old), aged (18 months old), and aged anti-ASC treated mice for the expression of canonical and non-canonical inflammasome proteins. We show that the protein levels of NLRP1, ASC, caspase-1, and caspase-8 were elevated in the cortex of aged mice, and that anti-ASC decreased the expression of these proteins, consistent with lower levels of the pro-inflammatory cytokine interleukin (IL)-1β. Additionally, we show that these proteins form a novel NLRP1-caspase-8 non-canonical inflammasome comprised of NLRP1, caspase-8 and ASC. Moreover, these inflammasome proteins were present in neurons in young and aged mice. Together, these results indicate that a novel NLRP1-caspase-8 non-canonical inflammasome is present in the cortex of mice and that anti-ASC is a potential therapeutic to decrease inflammasome-mediated inflammaging in the CNS.