IU Indianapolis ScholarWorks :: Browsing by Author "Wang, Lin"

Browsing by Author "Wang, Lin"

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Aberrant ERG expression associates with downregulation of miR‐4638‐5p and selected genomic alterations in a subset of diffuse large B‐cell lymphoma
(Wiley, 2019-10) Zhang, Shanxiang; Wang, Lin; Cheng, Liang; Pathology and Laboratory Medicine, School of Medicine
ERG (avian v‐ets erythroblastosis virus E26 oncogene homolog), an oncoprotein in prostate carcinoma and Ewing's sarcoma is associated with poor prognosis in patients with acute myeloid leukemia and T lymphoblastic leukemia. However little is known about ERG in lymphoma. Here we studied ERG in diffuse large B‐cell lymphoma (DLBCL) by immunohistochemistry, fluorescence in situ hybridization (FISH), genome‐wide microRNA (miRNA) expression profiling, real‐time reverse‐transcriptase polymerase chain reaction (RT‐PCR) and whole exome sequencing (WES). Approximately 30% of de novo DLBCLs (37 of 118) expressed ERG (ERG+). ERG expression showed no significant correlation with DLBCL cell‐of‐origin classification, patient's age, sex, nodal, or extranodal disease status, tumor expression of p53 or p63. There was no ERG rearrangement in 10 randomly selected ERG+ DLBCLs by FISH. Forty‐three miRNAs showed significant differential expression between ERG+ and ERG− DLBCLs. Downregulation of miR‐4638‐5p was confirmed by real‐time RT‐PCR. WES not only confirmed known gene mutations in DLBCLs but also revealed multiple novel gene mutations in POLA1, E2F1, PSMD8, AXIN1, GAB2, and GNB2L1, which occur more frequently in ERG+ DLBCLs. In conclusion, our studies demonstrated aberrant ERG expression in a subset of DLBCL, which is associated with downregulation of miR‐4638‐5p. In comparison with ERG‐negative DLBCL, ERG+ DLBCL more likely harbors mutations in genes important in cell cycle control, B‐cell receptor‐mediated signaling and degradation of β‐catenin. Further clinicopathological correlation and functional studies of ERG‐related miRNAs and pathways may provide new insight into the pathogenesis of DLBCL and reveal novel targets for better management of patients with DLBCL.
The Activation and Function of Autophagy in Alcoholic Liver Disease
(Bentham Science Publishers, 2017) Khambu, Bilon; Wang, Lin; Zhang, Hao; Yin, Xiao-Ming; Pathology and Laboratory Medicine, School of Medicine
Autophagy in Alcoholic Liver Disease, Self-eating Triggered by Drinking
(Elsevier, 2015-09) Wang, Lin; Khambu, Bilon; Zhang, Hao; Yin, Xiao-Ming; Pathology and Laboratory Medicine, School of Medicine
Macroautophagy (autophagy) is an evolutionarily conserved mechanism. It is important for normal cellular function and also plays critical roles in the etiology and pathogenesis of a number of human diseases. In alcohol-induced liver disease, autophagy is a protective mechanism against the liver injury caused by alcohol. Autophagy is activated in acute ethanol treatment but could be suppressed in chronic and/or high dose treatment of alcohol. The selective removal of lipid droplets and/or damaged mitochondria is likely the major mode of autophagy in reducing liver injury. Understanding the dynamics of the autophagy process and the approach to modulate autophagy could help finding new ways to battle against alcohol-induced liver injury.
Combining Intravital Fluorescent Microscopy (IVFM) with Genetic Models to Study Engraftment Dynamics of Hematopoietic Cells to Bone Marrow Niches
(Journal of Visualized Experiments, 2017-03-21) Wang, Lin; Kamocka, Malgorzata M.; Zollman, Amy; Carlesso, Nadia; Pediatrics, School of Medicine
Increasing evidence indicates that normal hematopoiesis is regulated by distinct microenvironmental cues in the BM, which include specialized cellular niches modulating critical hematopoietic stem cell (HSC) functions1,2. Indeed, a more detailed picture of the hematopoietic microenvironment is now emerging, in which the endosteal and the endothelial niches form functional units for the regulation of normal HSC and their progeny3,4,5. New studies have revealed the importance of perivascular cells, adipocytes and neuronal cells in maintaining and regulating HSC function6,7,8. Furthermore, there is evidence that cells from different lineages, i.e. myeloid and lymphoid cells, home and reside in specific niches within the BM microenvironment. However, a complete mapping of the BM microenvironment and its occupants is still in progress. Transgenic mouse strains expressing lineage specific fluorescent markers or mice genetically engineered to lack selected molecules in specific cells of the BM niche are now available. Knock-out and lineage tracking models, in combination with transplantation approaches, provide the opportunity to refine the knowledge on the role of specific "niche" cells for defined hematopoietic populations, such as HSC, B-cells, T-cells, myeloid cells and erythroid cells. This strategy can be further potentiated by merging the use of two-photon microscopy of the calvarium. By providing in vivo high resolution imaging and 3-D rendering of the BM calvarium, we can now determine precisely the location where specific hematopoietic subsets home in the BM and evaluate the kinetics of their expansion over time. Here, Lys-GFP transgenic mice (marking myeloid cells)9 and RBPJ knock-out mice (lacking canonical Notch signaling)10 are used in combination with IVFM to determine the engraftment of myeloid cells to a Notch defective BM microenvironment.
Cryopreservation Preserves Cell-Type Composition and Gene Expression Profiles in Bone Marrow Aspirates From Multiple Myeloma Patients
(Frontiers Media, 2021-04-21) Chen, Duojiao; Abu Zaid, Mohammad I.; Reiter, Jill L.; Czader, Magdalena; Wang, Lin; McGuire, Patrick; Xuei, Xiaoling; Gao, Hongyu; Huang, Kun; Abonour, Rafat; Walker, Brian A.; Liu, Yunlong; Medical and Molecular Genetics, School of Medicine
Single-cell RNA sequencing reveals gene expression differences between individual cells and also identifies different cell populations that are present in the bulk starting material. To obtain an accurate assessment of patient samples, single-cell suspensions need to be generated as soon as possible once the tissue or sample has been collected. However, this requirement poses logistical challenges for experimental designs involving multiple samples from the same subject since these samples would ideally be processed at the same time to minimize technical variation in data analysis. Although cryopreservation has been shown to largely preserve the transcriptome, it is unclear whether the freeze-thaw process might alter gene expression profiles in a cell-type specific manner or whether changes in cell-type proportions might also occur. To address these questions in the context of multiple myeloma clinical studies, we performed single-cell RNA sequencing (scRNA-seq) to compare fresh and frozen cells isolated from bone marrow aspirates of six multiple myeloma patients, analyzing both myeloma cells (CD138+) and cells constituting the microenvironment (CD138-). We found that cryopreservation using 90% fetal calf serum and 10% dimethyl sulfoxide resulted in highly consistent gene expression profiles when comparing fresh and frozen samples from the same patient for both CD138+ myeloma cells (R ≥ 0.96) and for CD138- cells (R ≥ 0.9). We also demonstrate that CD138- cell-type proportions showed minimal alterations, which were mainly related to small differences in immune cell subtype sensitivity to the freeze-thaw procedures. Therefore, when processing fresh multiple myeloma samples is not feasible, cryopreservation is a useful option in single-cell profiling studies.
Ethanol-triggered Lipophagy Requires SQSTM1 in AML12 Hepatic Cells
(Nature Publishing group, 2017-08-26) Wang, Lin; Zhou, Jun; Yan, Shengmin; Lei, Guangsheng; Lee, Chao-Hung; Yin, Xiao-Ming; Pathology and Laboratory Medicine, School of Medicine
Ethanol-induced hepatic lipophagy plays an important cytoprotective role against liver injury, but its mechanism is not fully determined. In the present study, ethanol-induced lipophagy was studied in an immortalized mouse hepatocyte line, AML12. We found that ethanol treatment elevated lipid content in these cells, which could be regulated by autophagy. To determine the potential mechanism, we investigated the role of a key adaptor molecule SQSTM1/p62. SQSTM1 can bind to LC3 on autophagosomes and ubiquitinated molecules on cargos, thus facilitating the autophagic engulfment of the cargo. We found that both LC3 and SQSTM1 could colocalize with lipid droplets (LDs) following ethanol treatment. Colocalization of LC3 with LDs was significantly inhibited by SQSTM1 knockdown, which also reduced ethanol-induced lipid elevation. In addition, increased ubiquitin signals were found to colocalize with SQSTM1 on LDs in response to ethanol. Moreover, the SQSTM1 signal was colocalized with that of perilipin1, a major protein on LDs. Finally, perilipin1 knockdown significantly altered ethanol-induced lipophagy. Taken together, these data support a model in which autophagosomes were directed to the LDs via SQSTM1, which bound to ubiquitinated proteins, possibly including perilipin 1, on LDs. This study provides a potential mechanistic explanation to how ethanol induces lipophagy in hepatocytes.
Myeloma Genome Project Panel is a Comprehensive Targeted Genomics Panel for Molecular Profiling of Patients with Multiple Myeloma
(American Association for Cancer Research, 2022) Sudha, Parvathi; Ahsan, Aarif; Ashby, Cody; Kausar, Tasneem; Khera, Akhil; Kazeroun, Mohammad H.; Hsu, Chih-Chao; Wang, Lin; Fitzsimons, Evelyn; Salminen, Outi; Blaney, Patrick; Czader, Magdalena; Williams, Jonathan; Zaid, Mohammad I. Abu; Ansari-Pour, Naser; Yong, Kwee L.; van Rhee, Frits; Pierceall, William E.; Morgan, Gareth J.; Flynt, Erin; Gooding, Sarah; Abonour, Rafat; Ramasamy, Karthik; Thakurta, Anjan; Walker, Brian A.; Medicine, School of Medicine
Purpose: We designed a comprehensive multiple myeloma targeted sequencing panel to identify common genomic abnormalities in a single assay and validated it against known standards. Experimental design: The panel comprised 228 genes/exons for mutations, 6 regions for translocations, and 56 regions for copy number abnormalities (CNA). Toward panel validation, targeted sequencing was conducted on 233 patient samples and further validated using clinical FISH (translocations), multiplex ligation probe analysis (MLPA; CNAs), whole-genome sequencing (WGS; CNAs, mutations, translocations), or droplet digital PCR (ddPCR) of known standards (mutations). Results: Canonical immunoglobulin heavy chain translocations were detected in 43.2% of patients by sequencing, and aligned with FISH except for 1 patient. CNAs determined by sequencing and MLPA for 22 regions were comparable in 103 samples and concordance between platforms was R2 = 0.969. Variant allele frequency (VAF) for 74 mutations were compared between sequencing and ddPCR with concordance of R2 = 0.9849. Conclusions: In summary, we have developed a targeted sequencing panel that is as robust or superior to FISH and WGS. This molecular panel is cost-effective, comprehensive, clinically actionable, and can be routinely deployed to assist risk stratification at diagnosis or posttreatment to guide sequencing of therapies.
Notch ligand Delta-like 1 promotes in vivo vasculogenesis in human cord blood-derived endothelial colony forming cells
(Elsevier, 2015-05) Kim, Hyojin; Huang, Lan; Critser, Paul J.; Yang, Zhenyun; Chan, Rebecca J.; Wang, Lin; Carlesso, Nadia; Voytik-Harbin, Sherry L.; Bernstein, Irwin D.; Yoder, Mervin C.; Department of Pediatrics, IU School of Medicine
BACKGROUND AIMS: Human cord blood (CB) is enriched in circulating endothelial colony forming cells (ECFCs) that display high proliferative potential and in vivo vessel forming ability. Because Notch signaling is critical for embryonic blood vessel formation in utero, we hypothesized that Notch pathway activation may enhance cultured ECFC vasculogenic properties in vivo. METHODS: In vitro ECFC stimulation with an immobilized chimeric Notch ligand (Delta-like1(ext-IgG)) led to significant increases in the mRNA and protein levels of Notch regulated Hey2 and EphrinB2 that were blocked by treatment with γ-secretase inhibitor addition. However, Notch stimulated preconditioning in vitro failed to enhance ECFC vasculogenesis in vivo. In contrast, in vivo co-implantation of ECFCs with OP9-Delta-like 1 stromal cells that constitutively expressed the Notch ligand delta-like 1 resulted in enhanced Notch activated ECFC-derived increased vessel density and enlarged vessel area in vivo, an effect not induced by OP9 control stromal implantation. RESULTS: This Notch activation was associated with diminished apoptosis in the exposed ECFC. CONCLUSIONS: We conclude that Notch pathway activation in ECFC in vivo via co-implanted stromal cells expressing delta-like 1 promotes vasculogenesis and augments blood vessel formation via diminishing apoptosis of the implanted ECFC.
Notch-dependent repression of miR-155 in the bone marrow niche regulates hematopoiesis in an NF-κB-dependent manner
(Elsevier, 2014-07-03) Wang, Lin; Zhang, Huajia; Rodriguez, Sonia; Cao, Liyun; Parish, Jonathan; Mumaw, Christen; Zollman, Amy; Kamocka, Gosia; Mu, Jian; Chen, Danny Z.; Srour, Edward F.; Chitteti, Brahmananda R.; HogenEsch, Harm; Tu, Xiaolin; Bellido, Teresita M.; Boswell, Scott; Manshouri, Taghi; Verstovsek, Srdan; Yoder, Mervin C.; Kapur, Reuben; Cardoso, Angelo A.; Carlesso, Nadia; Department of Pediatrics, IU School of Medicine
The microRNA miR-155 has been implicated in regulating inflammatory responses and tumorigenesis, but its precise role in linking inflammation and cancer has remained elusive. Here, we identify a connection between miR-155 and Notch signaling in this context. Loss of Notch signaling in the bone marrow (BM) niche alters hematopoietic homeostasis and leads to lethal myeloproliferative-like disease. Mechanistically, Notch signaling represses miR-155 expression by promoting binding of RBPJ to the miR-155 promoter. Loss of Notch/RBPJ signaling upregulates miR-155 in BM endothelial cells, leading to miR-155-mediated targeting of the nuclear factor κB (NF-κB) inhibitor κB-Ras1, NF-κB activation, and increased proinflammatory cytokine production. Deletion of miR-155 in the stroma of RBPJ(-/-) mice prevented the development of myeloproliferative-like disease and cytokine induction. Analysis of BM from patients carrying myeloproliferative neoplasia also revealed elevated expression of miR-155. Thus, the Notch/miR-155/κB-Ras1/NF-κB axis regulates the inflammatory state of the BM niche and affects the development of myeloproliferative disorders.
Sepsis Induces Hematopoietic Stem Cell Exhaustion and Myelosuppression through Distinct Contributions of TRIF and MYD88
(Elsevier, 2016-06-14) Zhang, Huajia; Rodriguez, Sonia; Wang, Lin; Wang, Soujuan; Serezani, Henrique; Kapur, Reuben; Cardoso, Angelo A.; Carlesso, Nadia; Department of Microbiology & Immunology, IU School of Medicine
Toll-like receptor 4 (TLR4) plays a central role in host responses to bacterial infection, but the precise mechanism(s) by which its downstream signaling components coordinate the bone marrow response to sepsis is poorly understood. Using mice deficient in TLR4 downstream adapters MYD88 or TRIF, we demonstrate that both cell-autonomous and non-cell-autonomous MYD88 activation are major causes of myelosuppression during sepsis, while having a modest impact on hematopoietic stem cell (HSC) functions. In contrast, cell-intrinsic TRIF activation severely compromises HSC self-renewal without directly affecting myeloid cells. Lipopolysaccharide-induced activation of MYD88 or TRIF contributes to cell-cycle activation of HSC and induces rapid and permanent changes in transcriptional programs, as indicated by persistent downregulation of Spi1 and CebpA expression after transplantation. Thus, distinct mechanisms downstream of TLR4 signaling mediate myelosuppression and HSC exhaustion during sepsis through unique effects of MyD88 and TRIF.

Browsing by Author "Wang, Lin"

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