LSU Health Sciences Center Research Articles

Development of the Cardiovascular Undergraduate Research Initiative for Underrepresented Students (CURIOUS)

The Center for Cardiovascular Diseases and Sciences at LSU Health Sciences Center at Shreveport supports cardiovascular disease research at multiple levels from predoctoral fellows to established faculty. To extend our support to undergraduate students, we developed the Cardiovascular Undergraduate Research Initiative fOr Underrepresented Students (CURIOUS). CURIOUS is an 8-week summer research program (with housing) funded by an NHLBI R25 grant, and is targeted towards underrepresented groups interested in pursuing cardiovascular research as part of their scientific/clinical career goals. We primarily recruit in our region, but the program is open to students across the USA. CURIOUS provides an intensive experience at the bench alongside multiple enrichments. Professional development includes meeting administrators involved in admissions, and students from our schools of Graduate Studies, Medicine and Allied Health Professions, financial advice for planning graduate education, CV writing, and presentation skills. The students also have discussions with faculty about challenges & opportunities for underrepresented minorities in research, and diversity, inclusion & equity. Other enrichments cover cardiovascular basics and state-of-the-art techniques available on our campus. Students receive training in the responsible conduct of research, held in conjunction with other undergraduate programs and graduate students. We invite a nationally recognized cardiovascular researcher to give a seminar and meet with the CURIOUS students. The program ends with poster presentations for all first-year students. Several students are selected to present at national/international conferences with their mentor. In addition, 1-2 students are invited back for a second year of the program during which they have more time for research, advanced enrichments, and an oral presentation at the end of the program. To date, the acceptance rate has been 26%, with 39 students having completed the 1st year and 2 returning students. CURIOUS provided 59% of students with their first research experience. 80% of students gave the program the top rating of excellent. Based on end-of-program feedback, we have improved pre-program interaction with mentors, refined enrichments, streamlined the on-boarding process, and enhanced social activities. Of the 25 students who have graduated college, 2 are in MD/PhD programs, 1 is in a PhD program, and 10 are in medical school, with 11 others planning one of these programs (10 are working in science-related jobs during gap years). Overall, the program has successfully improved the students’ consideration of including cardiovascular research as part of their future career. Funded by the NIH National Heart, Lung and Blood Institute, Award R25HL147665, to KYS. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Trends in Medicare utilization and reimbursement for hematology/oncology procedures.

e13641 Background: Medicare Part B pays for physician services such as office visits and procedures based on the Medicare Physician Fee Schedule which is re-evaluated annually to maintain budget neutrality. Moreover, national cancer-attributed medical care costs in 2015 were $183 billion and projected to increase 34% to $246 billion by 2030 (Green et al: J Clin Oncol, PMID: 31804856). The aim of this study is to evaluate trends in Medicare reimbursement for procedures in hematology/oncology between 2012-2022. Methods: The data analyzed were extracted from the Physician Fee Schedule Look-Up Tool. CPT Codes were obtained from the Medicare Coverage Database. The following CPT codes were extracted: antineoplastic chemotherapy administration (96405, 96406, 96401, 96409, 96411, 96413, 96415, 96416, 96417, 96420, 96422, 96423, 96425, 96440, 96446, 96450, 96542), antineoplastic hormone therapy administration (96402), non-chemotherapy infusion (96360, 96361, 96365, 96366, 96367, 96368, 96369, 96370, 96371, 96372, 96373, 96374, 96375, 96376 ), bone marrow sampling (38220, 38221, 38222), bone marrow harvest (38230, 38232) and bone marrow transplant (38240, 38241, 38242). Consumer Price Index (CPI) obtained from the U.S. Department of Labor's Bureau of Labor Statistics was used to adjust reimbursement rates for cumulative inflation to 2022 U.S. dollars. The T-test was used to compare the mean prices for each procedure. This research contains publicly available data and as such is exempt from the IRB according to the Institutional Review Board at LSU Health Sciences Center in New Orleans, Louisiana. Results: The procedure with the highest reimbursement rate in 2012 was bone marrow harvest and the procedure with the lowest reimbursement rate in the same year was antineoplastic hormone therapy administration. The procedure with the highest reimbursement rate in 2022 was bone marrow harvest. The procedure with the lowest reimbursement rate in 2022 was antineoplastic hormone therapy. All procedure reimbursement fell significantly (p value of <0.001) over the timer period studied. Conclusions: Between 2012 and 2022 the reimbursement rates for common hematology oncology services fell significantly when adjusted for inflation due to reforms in Medicare part B. [Table: see text]

Trends in Drug Tests among Children: A 22-Year Retrospective Analysis.

There are several pathophysiological outcomes associated with substance abuse including metabolic disbalance, neurodegeneration, and disordered redox. Drug use in pregnant women is a topic of great concern due to developmental harm which may occur during gestation and the associated complications in the neonate after delivery. We sought to determine what the trajectory of drug use is like in children aged 0-4 years and mothers of neonates. Urine drug screen (UDS) results were obtained of our target demographic during 1998-2011 and 2012-2019 from LSU Health Sciences Center in Shreveport (LSUHSC-S). Statistical analysis was performed using R software. We observed an increase in cannabinoid-positive UDS results in both Caucasian (CC) and African American (AA) groups between 1998-2011 and 2012-2019 periods. Cocaine-positive UDS results decreased in both cohorts. CC children had higher UDS positive results for opiates, benzodiazepines, and amphetamines, while AA children had a higher percentage for illicit drugs such as cannabinoids and cocaine. Neonate's mothers had similar UDS trends to that in children during 2012-2019. Overall, while percentage of positive UDS results for both AA and CC 0-4 year old children started to decline for opiate, benzodiazepine, and cocaine during 2012-2019, cannabinoid- and amphetamine (CC)-positive UDS steadily increased. These results suggest a shift in the type of drug use by mothers from opiates, benzodiazepines, and cocaine to cannabinoids and/or amphetamines. We also observed that 18-year-old females who tested positive for opiates, benzodiazepine, or cocaine had higher than average chances of testing positive for cannabinoids later in life.

Abstract 1240: mSin1 regulates epithelial-mesenchymal transition

Abstract The mammalian target of rapamycin (mTOR) functions as two complexes, mTORC1 and mTORC2. Extensive studies have focused on mTORC1 in the regulation of cell growth, autophagy, and metabolism. However, the role of mTORC2 is poorly understood. mTORC2 has been found to control cell migration, but the underlying mechanism remains to be determined. Here we show that mammalian stress-activated protein kinase interacting protein 1 (mSin1), a unique component of mTORC2, plays an important role in cell migration. Knockout of mSin1 reduced the migration of mouse embryo fibroblasts (MEFs). Similarly, knockdown of mSin1 also inhibited the migration of tumor cells (Rh30 and HeLa). Furthermore, we observed that mSin1 is crucial for the epithelial-mesenchymal transition (EMT). Knockout or knockdown of mSin1 promoted the mesenchymal-epithelial transition (MET), a transition from multipolar or spindle shape to apico-basal polar shape. In addition, depletion of mSin1 increased the cellular protein level of E-cadherin (an MET marker) and decreased the cellular protein levels of N-cadherin and Twist (EMT markers). The results suggest that mSin1 positively regulates cell migration at least partly by promoting induction of EMT. Our findings support that mSin1 is crucial for mTORC2-mediated cell migration. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA) Citation Format: Shile Huang, Yan Luo, Lei Liu, Bing Cheng. mSin1 regulates epithelial-mesenchymal transition [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1240.

Abstract 2406: Mechanism of mSin1 regulation of cell migration

Abstract Studies have shown that mSin1, a major component of mTORC2, plays an important role in tumor cell migration and invasion as well as cancer metastasis. However, how mSin1 regulates cell migration is poorly understood. In this study, we found that knockout of mSin1 suppressed cell spreading and migration in mouse embryo fibroblasts (MEFs). Similarly, knockdown of mSin1 also inhibited cell spreading and migration in rhabdomyosarcoma (Rh30) and cervical cancer (HeLa) cells. Furthermore, we observed that knockout or knockdown of mSin1 reduced the activities of the small GTPases (RhoA and Rac1) in the cells. Ectopic expression of constitutively active Rac1, but not RhoA, partially attenuated the reduced cell spreading and migration induced by mSin1 deficiency. In addition, depletion of mSin1 remarkedly inhibited the phosphorylation of focal adhesion proteins, including focal adhesion kinase (FAK) at Tyr397 and paxillin at Tyr118 in the cells. The results suggest that mSin1 controls cell spreading and migration at least partly by mediating the activity of Rac1 and the phosphorylation of FAK. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA) Citation Format: Shile Huang, Lei Liu, Yan Luo. Mechanism of mSin1 regulation of cell migration [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2406.

Abstract 2891: Protein phosphatase 5 regulation of cell motility

Abstract Metastasis has been considered as one of the cancer hallmarks. Approximately 90% of cancer-related death is due to cancer metastasis. Tumor cell migration is a prerequisite for cancer metastasis. Protein phosphatase 5 (PP5) is a serine/threonine protein phosphatase that belongs to the phosphoprotein phosphatase (PPP) family including PP1 and PP2A. It is well known that PP5 regulates apoptosis, proliferation, and stress response. However, the role of PP5 in the regulation of cell motility is only beginning to be recognized, and the mechanism of PP5 regulation of cell motility is largely unknown. In this study, our tissue microarray (TMA) studies showed the expression of PP5 increased with the stages of prostate cancer, which is consistent with the previous findings that there is a positive correlation between PP5 overexpression and breast cancer metastases. Furthermore, by the single-cell motility assay, we found that overexpression of PP5 increased the motility of various tumor cells, whereas knockdown of PP5 decreased the cell motility, suggesting that PP5 positively regulates cell motility. As focal adhesion kinase (FAK) is a key regulator of cell motility, and a report has shown that PP5 forms a complex with ASK1, FAK, CXCR4 in wounded alveolar epithelial cancer cells, we examined whether PP5 activates FAK. The Western blotting results showed that overexpression of PP5 did not obviously affect the phosphorylation of FAK. The results suggest that PP5 regulates cell motility through a new mechanism. Further research is on the way to identify how PP5 positively regulates cell motility. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA.) Citation Format: n Li, Shile Huang. Protein phosphatase 5 regulation of cell motility [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2891.

Do the 2013 United States Preventive Services Task Force guidelines for lung cancer screening fail high-risk African American smokers? An institutional retrospective observational cohort study.

Lung cancer cause nearly 1.76 million deaths worldwide in 2018. In 2011, the National-Lung-Cancer-Screening-Trial showed 20% relative risk reduction with LDCT and subsequently led to the current USPSTF screening guidelines. However, the predominant focus on elderly, Caucasian questions its generalizability to communities with young, African Americans such as our institution. Hence, the objective of our study is to investigate the need to modify the current screening guidelines at our institution by assessing the applicability of newer individual risk-based prediction models for LDCT screening. This is a retrospective observational cohort study of newly diagnosed lung cancer patients at LSU Health Sciences Center Shreveport from 2011 to 2015. One-third of the patients did not meet the current USPSTF screening guidelines. We categorized them into high-risk (groups1 and 2), moderate-risk, and low-risk according to 2018 NCCN Lung Cancer Screening Guidelines Version 1.2020. The high-risk groups were differentiated using the Tammemagi lung cancer risk calculator. Among those who did not meet the screening guidelines, nearly 50% were African American, 95% with known smoking history, and 80% diagnosed at advanced stage at the time of diagnosis. After employing the Tammemagi Risk based calculator, 12.5% were categorized into high-risk group 2, who are also eligible for annual LDCT. The current USPSTF guidelines have failed in our population consisting of young African American smokers, questioning the health disparity in medicine. By employing individual risk-based prediction models, we could potentially identify tailored high-risk populations leading to appropriate use of LDCT screening.

A Journal Usage Analysis During the COVID-19 Pandemic: Serials Trends and Implications

The 2020 COVID-19 pandemic had wide-reaching effects throughout all of society. For libraries, this often translated to a quick pivot to support activities that moved to almost-exclusively online and remote for all patrons. Although the LSU Health Sciences Center New Orleans Library was somewhat unique in that it never closed during the 2020 height of the pandemic, the majority of its patrons were accessing its resources remotely. Spurred by local anecdotal evidence journal usage had surprisingly declined at a significant rate during 2020, this study aims to determine whether this decline could be demonstrated through statistical analysis of COUNTER 5 usage reports for 2019 and 2020 for a sampling of titles. It also illustrates how COUNTER statistics may provide just a window of overall serials use.

Abstract 657: Inhibition of mTORC1 by dihydroartemisinin

Abstract mTOR functions as two complexes, mTORC1 and mTORC2, and is a central controller for cell growth and metabolism. Both mTORC1 and mTORC2 are activated in numerous cancers, and have become the focus of anticancer drug development. Rapalogs and mTOR kinase inhibitors (TORKIs) have been developed. However, the anticancer efficacy of rapalogs is clinically weak or mild to most cancers, and the adverse effects of rapalogs and TORKIs are greatly concerned. So, it is imperative to discover and develop new generation of mTOR inhibitors. Dihydroartemisinin (DHA) is an anti-malarial agent showing good safety in both children and adults. Recently, we have shown that DHA, at pharmacological concentrations, inhibits proliferation and induces apoptosis in cells derived from various cancer types but not in normal or immortalized cell lines, implying that DHA is potentially a selective anticancer agent and may be repurposed for cancer therapy. Of interest, DHA potently suppresses mTORC1-mediated phosphorylation of S6K1 and 4E-BP1, but does not obviously affect mTORC2-mediated phosphorylation of Akt, which is often activated by classic mTOR inhibitors (rapalogs) via a feedback mechanism. The results suggest that DHA is a novel mTORC1 inhibitor. This study was set to determine how DHA inhibits mTORC1. Here we found that DHA did not bind to any mTORC1 components (mTOR, mLST8 or raptor) directly, as determined by in vivo [3H]-DHA radiolabeling. Besides, our molecular docking revealed that DHA did not have the ability to bind FKBP12 or mTOR kinase domain, in contrast to the positive controls rapamycin (binding FKBP12) and INK128 (binding mTOR kinase domain). These data suggest that DHA inhibits mTORC1 via indirect mechanism(s). Further research revealed that DHA altered neither the phosphorylation of IGF-1R/PI3K/PTEN and ERK, nor the expression of REDD1, but induced phosphorylation of AMPKα (T172). Interestingly, DHA-induced mTORC1 inhibition was profoundly attenuated by inhibition with Compound C (AMPK inhibitor) or ectopic expression of dominant negative AMPKα2 (AMPKα2-DN), indicating that activation of AMPK links to inhibition of mTORC1. Collectively, the results support that DHA inhibits mTORC1 by activating AMPK. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA.) Citation Format: Wang Liu, Jun Luo, Yoshinobu Odaka, Shile Huang. Inhibition of mTORC1 by dihydroartemisinin [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 657.

Abstract 4932: mTORC1 regulates FAK phosphorylation

Abstract The mammalian target of rapamycin (mTOR) functions as two complexes, mTORC1 and mTORC2, regulating cell growth, proliferation, survival, and motility. Previous studies have shown that mTORC2 controls cytoskeleton and cell motility. Recently, we have demonstrated that both mTORC1 and mTORC2 participate in the regulation of cell motility. Further studies have shown that rapamycin suppresses IGF-I induced cell motility by inhibiting S6K1-mediated phosphorylation of focal adhesion kinase (FAK), protein phosphatase 2A (PP2A)-mediated phosphorylation of Erk1/2, as well as expression and activities of the small GTPases (RhoA, Cdc42 and Rac1). As FAK plays a pivotal role in the regulation of cell motility, this study was set to determine how mTORC1 regulates the phosphorylation of FAK. By co-immunoprecipitation (co-IP) and immunoblotting (IB), we failed to detect a physical interaction between FAK and S6K1, suggesting that S6K1 may regulate the phosphorylation of FAK indirectly. Besides, knockdown of protein phosphatase 2A (PP2A) enhanced the phosphorylation of FAK and conferred resistance to rapamycin inhibition of IGF-I-stimulated phosphorylation of FAK. However, the co-IP/IB results revealed no direct interaction between FAK and PP2A either. Of interest, knockdown of protein phosphatase 5 (PP5) suppressed IGF-I stimulated cell motility, while knockdown of ATG13 increased IGF-I stimulated cell motility, suggesting that PP5 positively regulates cell motility, whereas ATG13 negatively regulates cell motility. It is well known that PP5 is an anti-apoptotic phosphatase, negatively regulating the ASK1-JNK cascade, and mTORC1 regulates autophagy through the ULK1/2-ATG13-FIP200 complex. Further research will determine how mTORC1 regulates cell motility in part by regulating the phosphorylation of FAK via S6K1, PP2A, PP5 and ATG13. (Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA.) Citation Format: Lin Li, Yan Luo, Lei Liu, Shile Huang. mTORC1 regulates FAK phosphorylation [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4932.

Abstract 2961: Ganoderma lucidum extracts inhibit mTORC1/2 by activating AMPK and inhibiting IGFR/PI3K/Rheb in tumor cells

Abstract Ganoderma lucidum (G. lucidum) extracts, as dietary supplements, have been found to possess potent anticancer activity, which is attributed to the presence of polysaccharides and triterpenes. However, the molecular mechanism underlying the anticancer action of G. lucidum extracts remains to be elucidated. Here we show that ReishiMax GLp, containing both polysaccharides and triterpenes of G. lucidum (GLPT), inhibited cell proliferation and induced cell death in human lung cancer cells (A549 and A427), and concurrently suppressed the signaling pathways mediated by the mammalian target of rapamycin (mTOR), a central regulator of cell proliferation and survival. Interestingly, GLPT not only inhibited mTORC1-mediated phosphorylation of p70 S6 kinase 1 (S6K1) and eukaryotic initiation factor 4E binding protein 1 (4E-BP1), but also repressed mTORC2-mediated phosphorylation of Akt. Mechanistically, GLPT downregulated the phosphorylation and protein levels of insulin-like growth factor 1 receptor (IGFR) and phosphoinositide 3-kinase (PI3K), as well as the protein level of RAS homolog enriched in brain (Rheb). Besides, GLPT also activated AMP-activated protein kinase (AMPK) network. This is supported by the findings that GLPT increased the phosphorylation of AMPKα (T172), as well as its substrates tuberous sclerosis complex 2 (TSC2, S1387) and regulatory-associated protein of mTOR (raptor, S792). Ectopic expression of dominant negative AMPKα partially attenuated the inhibitory effect of GLPT on mTORC1, indicating that GLPT inhibits mTORC1 partly via activating AMPK. The results suggest that G. lucidum extracts execute the anticancer action at least partly by inhibiting the mTORC1/2 signaling through activation of AMPK and inhibition of IGFR/PI3K/Rheb in tumor cells. Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA, USA. Citation Format: Shile Huang, Didem Sohretoglu, Chao Zhang, Jun Luo. Ganoderma lucidum extracts inhibit mTORC1/2 by activating AMPK and inhibiting IGFR/PI3K/Rheb in tumor cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2961.

Erratum. hZnT8 (Slc30a8) Transgenic Mice That Overexpress the R325W Polymorph Have Reduced Islet Zn2+ and Proinsulin Levels, Increased Glucose Tolerance After a High-Fat Diet, and Altered Levels of Pancreatic Zinc Binding Proteins. Diabetes 2017;66:551-559.

According to an investigation conducted by the LSU Health Sciences Center in New Orleans (LSU HSCNO), Dr. Nirmala Tumarada, a former graduate student at …

GatewayNet: a form of sequential rule mining

BackgroundThe gateway hypothesis (and particularly the prediction of developmental stages in drug abuse) has been a subject of protracted debate since the 1970s. Extensive research has gone into this subject, but has yielded contradictory findings. We propose an algorithm for detecting both association and causation relationships given a discrete sequence of events, which we believe will be useful in addressing the validity of the gateway hypothesis.To assess the gateway hypothesis, we developed the GatewayNet algorithm, a refinement of sequential rule mining called initiation rule mining. After a brief mathematical definition, we describe how to perform initiation rule mining and how to infer causal relationships from its rules (“gateway rules”).We tested GatewayNet against data for which relationships were known. After constructing a transaction database using a first-order Markov chain, we mined it to produce a gateway network. We then discuss various incarnations of the gateway network.We then evaluated the performance of GatewayNet on urine drug screening data collected from the emergency department at LSU Health Sciences Center in Shreveport. A de-identified database of urine drug screenings ordered by the department between August 1998 and June 2011 was collected and then restricted to patients having at least one screening succeeding their first positive drug screening result.ResultsIn the synthetic data, a chain of gateway rules was found in the network which demonstrated causation. We did not find any evidence of gateway rules in the empirical data, but we were able to isolate two documented transitions into benzodiazepine use.ConclusionsWe conclude that GatewayNet may show promise not only for substance use data, but other data involving sequences of events. We also express future goals for GatewayNet, including optimizing it for speed.

First person – Rini Ravindran

ABSTRACT First Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Rini Ravindran is the first author on ‘New ubiquitin-dependent mechanisms regulating the Aurora B–protein phosphatase 1 balance in Saccharomyces cerevisiae’, published in Journal of Cell Science. Rini is a PhD student in the lab of Kelly Tatchell at LSU Health Sciences Center in Shreveport, Louisiana, USA, investigating the maturation and regulation of protein phosphatase 1 (PP1).

Function and Evolution of Ubiquitin HECT Ligases

The blueprint for enzyme structure and function resides in its amino acid sequence. Within evolutionarily‐related protein superfamilies, functional specificity and speciation are argued to arise through co‐evolving subsets (sectors) of sequence positions. Herein we investigate the functional divergence and evolution of the family of Homologous to the E6AP Carboxyl Terminus (HECT) E3 ligases. The HECT ligase superfamily is catalytically promiscuous despite sharing a common, well‐studied catalytic cycle. Ubiquitin chain length and linkage specificity varies among family members. We use an evolutionary approach to pinpoint residues that underlie concerted interactions of HECT E3 ligases. Statistical Coupling Analysis (SCA) is a bioinformatics predictive method that identifies residue sectors that change in tandem during evolution within a multiple sequence alignment. Our SCA results revealed a network of co‐evolving residues within the catalytic domain that are functionally and thermodynamically coupled. Furthermore, our results suggest that the HECT domain has evolved independently of the N‐terminal targeting domains. We also find that SCA uncovers potential allosteric signaling pathways for HECT ligase enzyme function.Support or Funding Information[This work was supported by the School of Graduate Studies at LSU Health Sciences Center to A.L.H. and E.D.K.]This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

A miRNA Signature for Cognitive Deficits and Alcohol Use Disorder in Persons Living with HIV/AIDS.

HIV-associated neurocognitive disorders (HAND) affects more than half of persons living with HIV-1/AIDS (PLWHA). Identification of biomarkers representing the cognitive status of PLWHA is a critical step for implementation of successful cognitive, behavioral and pharmacological strategies to prevent onset and progression of HAND. However, the presence of co-morbidity factors in PLWHA, the most common being substance abuse, can prevent the identification of such biomarkers. We have optimized a protocol to profile plasma miRNAs using quantitative RT-qPCR and found a miRNA signature with very good discriminatory ability to distinguish PLWHA with cognitive impairment from those without cognitive impairment. Here, we have evaluated this miRNA signature in PLWHA with alcohol use disorder (AUD) at LSU Health Sciences Center (LSUHSC). The results show that AUD is a potential confounding factor for the miRNAs associated with cognitive impairment in PLWHA. Furthermore, we have investigated the miRNA signature associated with cognitive impairment in an independent cohort of PLWHA using plasma samples from the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) program. Despite differences between the two cohorts in socioeconomic status, AUD, and likely misuse of illicit or prescription drugs, we validated a miRNA signature for cognitive deficits found at LSUHSC in the CHARTER samples.

Abstract 2111: Ciclopirox inhibits tumor cell motility by suppressing protein expression of small GTPases and phosphorylation of paxillin

Abstract Ciclopirox olamine (CPX), an off-patent antifungal drug, is used for the treatment of superficial mycoses. Recent studies have demonstrated that CPX also possesses potent anticancer activity by inhibiting cell proliferation and inducing cell death in tumor cells. However, it is unknown whether CPX inhibits cell motility. In the present study, we found that CPX potently inhibited cell motility in a concentration-dependent manner in rhabdomyosarcoma (Rh30 and RD) cells, which was independent of the reduction of cell viability. As small GTPases (RhoA, Cdc42, and Rac1) and focal adhesion proteins (paxillin) play critical roles in the regulation of cell motility, we further studied whether CPX affects these proteins. Our Western blot analysis revealed that CPX did inhibit cellular protein expression of RhoA, Cdc42 and Rac1. However, by RT-PCR analysis, CPX did not alter the mRNA levels of the small GTPases. As microRNAs (miRNAs) can regulate protein expression at transcriptional and post-transcriptional levels, we investigated the effect of CPX on the expression of miRNAs. Our miRNA PCR array revealed that treatment with 10 μM of CPX for 24 hours upregulated the expression of 27 miRNAs by 2.04-6.10 fold, and downregulated the expression of 7 miRNAs by 2.00-7.89 fold in Rh30 cells. Further research is ongoing to identify whether these up/downregulated miRNAs are linked to the reduced expression of small GTPases and potentially more proteins. In addition, we found that CPX inhibited the phosphorylation of paxillin, despite no effect on the total cellular protein expression. The results suggest that CPX inhibits tumor cell motility at least by suppressing the protein expression of small GTPases and the phosphorylation of paxillin. Supported by the Feist-Weiller Cancer Center, LSU Health Sciences Center, Shreveport, LA. Citation Format: Shile Huang, Tao Shen. Ciclopirox inhibits tumor cell motility by suppressing protein expression of small GTPases and phosphorylation of paxillin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2111. doi:10.1158/1538-7445.AM2017-2111

Better targeting, better efficiency of Adeno‐associated virus gene transfer in the Central Nervous System for expression of Retromer proteins

Researchers are using AAV gene transfer more and more in their neuroscience studies, including optogenetics, cre‐lox targeting, and CRISPR gene editing. Our lab has been using the AAV9 vector serotype to express genes on a wide‐scale basis throughout the central nervous system in order to study a disease that affects cells throughout the central nervous system, amyotrophic lateral sclerosis. This current project explored ways to achieve more efficient expression and in a more targeted manner than our previous work. The recently described AAV PHP.B serotype was administered to rats for the first time, and it did result in significantly more green fluorescent protein expression than did the AAV9 vector in a systematic comparison. In studies comparing the neuron‐specific synapsin promoter with our previous cytomegalovirus/ chicken β‐actin promoter, the latter promoter was noticeably more efficient yet the synapsin promoter did yield a transduction pattern with greater neuron‐selectivity, which was the goal. We also explored intracerebroventricular injections to achieve wide‐scale transduction and better avoid unwanted transduction of peripheral organs. We are combining the synapsin promoter in AAV PHP.B vectors to take advantage of these efficiency and targeting features. Our specific genes of interest that we wish to express are called the retromer proteins. Retromers make up a protein complex that is associated with the trafficking of cellular vesicles through the endosome and the trans‐Golgi network. Viral constructs were made for epitope tagged versions of the retromers VPS29 and VPS35. We hypothesize that the retromers can act to prevent the formation of beta‐amyloid plaques in Alzheimer's disease by altering the trafficking of amyloid precursor protein.Support or Funding InformationDr. Ronald Klein, Kasey Jackson, Robbie Dayton, Fidelity Biosciences Research Initiative, Karyopharm Therapeutics, Inc., ALS Association, Meira GTx, The LSU Health Sciences Center Foundation in Shreveport, The American Society for Pharmacology and Experimental Therapeutics, The Society for Toxicology

Using Social Media to Identify Those With Mental Illness and Substance Use Disorders

Back to table of contents Previous article Next article CommentaryFull AccessUsing Social Media to Identify Those With Mental Illness and Substance Use DisordersShawn E. McNeil, M.D.Shawn E. McNeilSearch for more papers by this author, M.D.Published Online:10 Mar 2017https://doi.org/10.1176/appi.ajp-rj.2016.111205AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail The increasingly invasive nature of modern social media platforms presents a unique opportunity for identifying individuals at risk for mental illness. Social media allows individuals to create material and to choose with whom they wish to share it (1). Like scenes leaping to life from the pages of A Midsummer Night’s Dream, the drama and passion in the lives of today’s youths (and a growing number of adults) seem to jump from the edifices of their digital selves. These ideas, statements, links, and photographs sent out via social media comprise the digital persona of any given person.Social media presents a unique platform for identifying and interacting with persons suffering from mental illness. Computer algorithms can scan online profiles, seeking out the digital signs and symptoms of mental health issues. For example, DrugAbuse.com examined over 3 million posts on the social media site Instagram that were related to various music festivals and examined them for references to drug use. It found that 43% of posts about the Electric Daisy Carnival contained references to ecstasy (methylenedioxymethamphetamine), and 82% of posts about Marley Fest contained references to marijuana (2). The direct correlation between music festival attendance and substance use disorder is a premature conclusion. However, the association may justify the use of targeted advertisements for substance use disorder treatment programs toward this population.Crisis Text Line is a crisis intervention service that connects individuals struggling with problems such as suicidal ideation, addiction, sexual abuse, and eating disorders with counselors, who field their text messages and help them navigate difficult situations. Data from the millions of texts received reveal trends that could be used to predict the likelihood of certain behaviors among persons reaching out for professional help. Thirty percent of texts this service receives are about suicide and depression. Language used in the texts may correlate with certain behaviors such as substance abuse or self-injurious activity (3).Although social media can be used to reach out to those with mental illness, we know that technology can also exacerbate crises. The “Werther effect,” also referred to as “contagion,” is a term describing the genesis of suicidal behavior spawned by media reports (4). This is an interesting phenomenon that should be addressed when clinicians are screening patients for suicide risk. Social media will affect the majority of our patients, such that we should hope to clarify its role as part of our social history taking.As mental health clinicians, we need to be aware of the connection between social media and human behavior. Scientists should be able to harness the predictive potential of these technologies in identifying those most vulnerable. We should seek to understand the significance of a patient’s interaction with social media when taking a thorough history. Future research should focus on the development of advanced algorithms that can efficiently identify the highest-risk individuals. Additionally, research into the effectiveness and appropriateness of various interventions should be done to guide clinicians and public health officials in finding the best way to engage these patients.Dr. McNeil is a first-year child and adolescent psychiatry fellow in the Department of Psychiatry, LSU Health Sciences Center, Shreveport, La.The author thanks Spencer Hansen, M.D., for insightful guidance on this commentary.

Abstract 4655: Iron chelation inhibits mTORC1 signaling in tumor cells

Abstract Iron chelators are commonly used for treatment of iron overload diseases. Recent studies have shown that iron chelators possess potent anticancer activities. Iron chelators (ciclopirox and 3-AP) are in clinical trials for cancer treatment. However, the molecular mechanism underlying the anticancer effect of iron chelation is not well understood. Mammalian/mechanistic target of rapamycin (mTOR) is a master kinase, regulating cell growth/proliferation and survival through sensing environmental cues. mTOR functions as at least two complexes (mTORC1/2). Here we show that two iron chelators, ciclopirox olamine (CPX) and Dp44mT, inhibit tumor cell proliferation by suppressing mTORC1 signaling in human rhabdomyosarcoma (Rh30) and lung cancer (A549 and A427) cells. This is evidenced by the findings that treatment with CPX or Dp44mT inhibited the phosphorylation of 4E-BP1 and S6K1, two best known effector molecules of mTORC1, which could be blocked by addition of ferrous sulfate. Addition of ferrous sulfate prevented the growth inhibitory effect of CPX. Ectopic expression of constitutively active mTOR also conferred resistance to CPX-induced growth inhibition. Mechanistically, iron chelation inhibition of mTORC1 was partially linked to the activation of AMPK, a negative regulator of mTORC1. Overexpression of a dominant-negative AMPK (DN-AMPK) in Rh30 cells attenuated the inhibitory effect of CPX or Dp44mT on the phosphorylation of S6K1 and 4E-BP1. In addition, iron chelation also transiently stabilized HIF-1α and further upregulated the expression of its downstream effector Bnip3, another negative regulator of mTORC1. Knockdown of Bnip3 partially attenuated the inhibitory effect of iron chelation on mTORC1. Furthermore, we found that iron chelation increased the translocation of mTOR from the cytoplasm to the nucleus. The co-localization of mTOR with the third negative regulator of mTOR, PML (promyelocytic leukemia), increased in the nucleus upon iron chelation. Moreover, iron chelation did not obviously alter the phosphorylation of IGF-1 receptor, PI3K or PTEN. The effect of iron chelation on mTORC2-mediated phosphorylation of Akt was cell line dependent. Taken together, the results suggest that the anticancer effect of iron chelation is in part related to inhibition of mTORC1 signaling, and iron chelation inhibits mTORC1 signaling via multiple mechanisms. (Supported by the FWCC, LSU Health Sciences Center) Citation Format: Chaowei Shang, Hongyu Zhou, Shile Huang. Iron chelation inhibits mTORC1 signaling in tumor cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4655.