MACUB (2021) Conference

Abstract: Glutathione plays an important role in protecting the brain from oxidative stress, a major factor contributing to cell death in neurodegenerative diseases such as Alzheimer and Parkinson disease. Astrocytes are integral in facilitating glutathione production in neurons. The volume regulated anion channel (VRAC) represents a potential mechanism by which astrocytes release glutathione and its precursor molecule glutamate; however, VRAC’s role in coupling astrocyte-neuron glutathione synthesis is unknown. We hypothesize that VRAC activation in astrocytes leads to increased glutathione production in neighboring neurons. To address this hypothesis, primary neural cells (astrocytes and neurons) were cultured from chick embryonic brain tissue. Astrocytes were swollen with hypoosmotic media to activate VRACs and astrocyte conditioned media was transferred to neurons, followed by neuronal measurements of glutathione through an enzymatic assay. While preliminary results do not show an increase in neuronal glutathione in response to hypoosmotic astrocyte-conditioned media treatment, our data suggests that the hypoosmotic conditioned media itself may contribute to glutathione loss in neurons through the VRAC channel pore (negating any potential increases in glutathione production in response to an astrocytic mechanism). Experiments are hence underway to determine if isosmotic conditioned media from VRAC-activated astrocytes contributes to neuronal glutathione production. Understanding the precise mechanism by which astrocytes increase neuronal glutathione production will aid in the development of neurotherapeutics aimed at combatting oxidative stress.

Abstract: Major Depressive Disorder (MDD) and Cancer are some of the major ailments ravaging across many major modern societies. While there is ample research aimed at treating either MDD or Cancer, there is substantially less research aimed at treating both MDD and Cancer concurrently. This project aims to provide further insight in this vacancy of knowledge by displaying that there is evidence for antidepressant treatment, specifically Selective Serotonin Reuptake Inhibitors (SSRI) effectively decreasing cancer proliferation through targeting specific genes associated with both SSRIs, depression and cancer proliferation. This was accomplished by first identifying the genes targeted a number of SSRIs and which display an inverse association between expression in MDD and cancer proliferation, thus that the up-regulation of said gene’s expression in MDD is associated with cancer cell growth and down-regulation of the gene’s expression in MDD being associated with cancer cell death. The gene targeted by the SSRIs, depression and cancer proliferation was the SLC6A4 gene. Upon analysis of the SLC6A4 gene dependency on cell death and SSRI treatments (Fluvoxamine, Zimelidine & Paroxetine) on cell death, there was sufficient enough evidence towards the claims that the increased presence of the SSRI treatments; Fluvoxamine, Zimelidine & Paroxetine led to the death of the cancer-cell lines through knocking out the SLC614 gene. Further research on the impact of Fluvoxamine, Zimelidine & Paroxetine treatment on epithelial cells may be required to provide further evidence to the claim of SSRIs having the ability to treat cancers and MDD.

Abstract:

Chronic pain poses a heavy burden for the individual and society, comprising personal suffering, comorbid psychiatric symptoms, cognitive decline, and disability. Chronic pain is characterized by changes in nociception, affect, and cognition and is often resistant to classical treatment partly due to comorbid maladaptive plastic changes in the central nervous system (CNS). The mechanisms by which peripheral changes can influence CNS plasticity in the context of pain are not well understood. We hypothesize that peripheral injury is accompanied by blood-brain-barrier (BBB) compromise and microvascular changes in select brain regions, thereby resulting in pain chronification and the establishment of pain-related co-morbidities.

We will use the spared nerve injury (SNI) model of peripheral neuropathy to measure behavioral signs of nociception, anxiety, and cognitive decline. Evans Blue dye staining will be used to quantify BBB compromise, laser speckle imaging will be used to quantify cerebral blood flow, and microfil perfusion followed by micro-computed tomography will be used for the quantification of anatomical changes in brain microvasculature. The biochemical analysis will be conducted to measure the regional changes in vascular markers and tight junction proteins.

The proposed experiments will help identify the link between peripheral changes and CNS plasticity in the context of painful injuries. Our results will provide a mechanistic understanding of chronic pain as well as open entirely novel therapeutic venues for the treatment of chronic pain.

Abstract: The inflammatory response is characterized by a transient loss of function of the vascular barrier, manifested in a rapid increase in endothelial permeability (hyperpermeability) to macromolecules, which leads to tissue swelling. Pro-inflammatory molecules released by injured tissues or cells activate vascular endothelial cells (EC), which in turn respond by rearranging intercellular junctions, thus increasing paracellular transport of fluids and solutes across the vascular wall. EC activation leads to mobilization of the endothelial nitric oxide synthase (eNOS) from the cell membrane, and nitric oxide (NO) production and delivery to subcellular targets. We have observed that cAMP signalling via Exchange protein activated by cAMP-1 (Epac1) triggers the mobilization of eNOS back to the membrane, concomitant with the termination of hyperpermeability. However, the mechanisms that enable the return of eNOS to the EC membrane are not known. We hypothesize that eNOS may interact with the recycling endosomal system in EC. To accomplish this, we established a culture protocol for immortalized (EAhy926) and primary human umbilical vein EC (HUVEC). We stimulated EAhy926 cells with platelet-activating factor (PAF) to simulate inflammation, and with 8cPT-cAMP, an Epac1-selective cAMP analog, to model the cAMP-mediated termination of hyperpermeability. We used immunocytochemistry to determine the localization of eNOS, actin, vascular endothelial (VE)-cadherin, and the recycling endosomal marker Rab11a. Our results suggest that the termination of inflammatory endothelial hyperpermeability may involve the endothelial endosomal recycling system.

Abstract:

Present-day sedentary lifestyle and unlimited access to food caused an increasing number of people to get obese and suffer from Type-2 diabetes (T2D). T2D patients show insulin resistance (IR), when pancreatic hormone insulin fails to lower circulating blood glucose levels as cells cannot uptake glucose. AKT is an insulin sensitizing enzyme and research in both humans and rodents has shown abnormalities in phosphorylation of AKT in T2D. Our research targets an enzyme called IP6K1 (inositol hexakisphosphate kinase 1) of the inositol phosphate pathway. IP6K1 phosphorylates IP6 into a pyrophosphate IP7. IP7 has been shown to be a physiologic inhibitor of AKT and thus promotes insulin resistance. Our overall research hypothesis is that genetic deletion or inhibition of IP6K1 will improve AKT phosphorylation and in turn ameliorate IR. During our research, we reviewed the impact of genetic deletion as well as pharmacological inhibition of IP6K1 in mice fed a high fat diet (HFD). Our analysis shows that genetic deletion and pharmacological inhibition of IP6K1 in HFD fed mice significantly protect them from diet-induced obesity, as also improves insulin sensitivity in comparison to wild-type mice. In comparison to control mice, mice with genetic deletion or treatment with IP6K1 inhibitor showed improved glucose and insulin tolerance tests, as well as maintained phosphorylation of AKT in liver, skeletal muscle and adipose tissue as evident from Western Blotting experiments. In conclusion, IP6K1 can be a potential target for treating T2D and insulin resistance.

Abstract: Histamine is a biogenic amine found in a wide variety of invertebrates. Histamine is particularly well studied in arthropods and gastropods where it is involved in local immune responses as well as regulating physiological functions in the gut. Histamine also functions as a neurotransmitter, especially for sensory systems. Previous physiology work of our lab found that histamine activates the sensory system of Crassostraea virginica, eliciting a motor response in the gill. Our earlier cell biology and immunofluorescence work also showed the presence of histamine receptors in ganglia and mantle of C. virginica. Recently the genome of C. virginica and other bivalves have begun to be mapped. By conducting BLAST searches of the NCBI (National Center for Biotechnology Information) database using DNA and protein sequences of C. virginica and other invertebrate and mammalian species we found matches for histamine receptor H1R genes on chromosome 8; H2R on chromosomes 1, 2, 5 and 10; and H3R on chromosome 3. BLASTS of other invertebrates and mammals found matches with very low Expect Values (E Values) and moderately high Percent Identity, signifying similarities of H1R, H2R and H3R of C. virginica to those of other bivalves, gastropods, insects, mice, rats and humans. We hypothesize that the ligand binding sites (LBS) for H1R, H2R and H3R receptors in C. virginica are evolutionarily conserved and will closely match those of other animals. To study this, we conducted searches of the NCBI database for H1R, H2R and H3R receptors LBS of C. virginica and compared them to other animals. We found the LBS for H2R in C. virginica was identified and match some other invertebrates well, but did not match humans of other mammals very well. The LBS for H3R matched some other bivalves, invertebrates as well as humans and other mammals well. The LBS for H1R in C. virginica and other invertebrates we looked at has not yet been identified. The LBS for H1R in humans and other mammals is very highly conserved. This study complements our earlier physiology and cell biology studies demonstrating the presence and function for histamine in C. virginica, and shows that the genome of C. virginica contains genes to produce histamine receptor LBS that are similar to those of other animals where it has been identified. This new information is valuable as it shows that the simple nervous system of histamine can be used to expand studies on histamine neurotransmission. This work was supported in part by grant 2R25GM06003 of the Bridge Program of NIGMS, NIH grant K12GM093854-07A1 IRACDA Program of Rutgers University and PSC-CUNY grants 62344-00 50 and 63434-00 51.

Abstract: Horseshoe crabs have been around for more than 455 million years ago. Data from two coastal study sites showed that several species of hitchhikers live on the shell of most American horseshoe crabs (Limulus polyphemus), which includes the acorn barnacles (Semibalanus balanoides). Once attached, the settlement of those sessile organisms as an adult is permanent. It has been reported that high levels of chlorophyll-a concentration contribute to the growth of barnacles. Therefore, it was hypothesized that the density of acorn barnacles on horseshoe crabs in Jamaica Bay will be higher than other epibionts, and barnacle density will correlate with chlorophyll-a levels. Data was collected through field of observations of epibionts on horseshoe crabs in Jamaica Bay, NY (2012-2019). Epibionts on horseshoe crabs were identified and recorded on Excel Spreadsheets. In 2021, due to COVID, a pilot study consisting of 100 photographs of horseshoe crabs was used to further understand the dominance and percent cover of each epibiont. This new methodology will allow new students to participate virtually using photographs taken in the field. Preliminary data reveal support the hypothesis that barnacles exhibit higher density on the carapace compared to Crepidula. In addition, the frequency of barnacles in correlation with chlorophyll-a levels was analyzed by using years of data ranging from 2012 to 2020. Future work is needed to further expand on the correlation of barnacles’ density with chlorophyll-a levels.