IU Indianapolis ScholarWorks :: Browsing by Subject "pathology"

Browsing by Subject "pathology"

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Advances in translational bioinformatics facilitate revealing the landscape of complex disease mechanisms
(Springer (Biomed Central Ltd.), 2014) Yang, Jack Y.; Dunker, A. Keith; Liu, Jun S.; Qin, Xiang; Arabnia, Hamid R.; Yang, William; Niemierko, Andrzej; Chen, Zhongxue; Luo, Zuojie; Wang, Liangjiang; Liu, Yunlong; Xu, Dong; Deng, Youping; Tong, Weida; Yang, Mary Qu; Department of Biochemistry and Molecular Biology, IU School of Medicine
Advances of high-throughput technologies have rapidly produced more and more data from DNAs and RNAs to proteins, especially large volumes of genome-scale data. However, connection of the genomic information to cellular functions and biological behaviours relies on the development of effective approaches at higher systems level. In particular, advances in RNA-Seq technology has helped the studies of transcriptome, RNA expressed from the genome, while systems biology on the other hand provides more comprehensive pictures, from which genes and proteins actively interact to lead to cellular behaviours and physiological phenotypes. As biological interactions mediate many biological processes that are essential for cellular function or disease development, it is important to systematically identify genomic information including genetic mutations from GWAS (genome-wide association study), differentially expressed genes, bidirectional promoters, intrinsic disordered proteins (IDP) and protein interactions to gain deep insights into the underlying mechanisms of gene regulations and networks. Furthermore, bidirectional promoters can co-regulate many biological pathways, where the roles of bidirectional promoters can be studied systematically for identifying co-regulating genes at interactive network level. Combining information from different but related studies can ultimately help revealing the landscape of molecular mechanisms underlying complex diseases such as cancer.
Aging impairs dendrite morphogenesis of newborn neurons and is rescued by 7, 8-dihydroxyflavone
(Wiley Blackwell (Blackwell Publishing), 2017-04) Wang, Xiaoting; Romine, Jennifer Lynn; Gao, Xiang; Chen, Jinhui; Neurological Surgery, School of Medicine
All aging individuals will develop some degree of decline in cognitive capacity as time progresses. The molecular and cellular mechanisms leading to age-related cognitive decline are still not fully understood. Through our previous research, we discovered that active neural progenitor cells selectively become more quiescent in response to aging, thus leading to the decline of neurogenesis in the aged hippocampus. Here, we further find that aging impaired dendrite development of newborn neurons. Currently, no effective approach is available to increase neurogenesis or promote dendrite development of newborn neurons in the aging brain. We found that systemically administration of 7, 8-dihydroxyflavone (DHF), a small molecule imitating brain-derived neurotrophic factor (BDNF), significantly enhanced dendrite length in the newborn neurons, while it did not promote survival of immature neurons, in the hippocampus of 12-month-old mice. DHF-promoted dendrite development of newborn neurons in the hippocampus may enhance their function in the aging animal leading to a possible improvement in cognition.
Altered mRNA Splicing in SMN-Depleted Motor Neuron-Like Cells
(Public Library of Science (PLoS), 2016) Custer, Sara K.; Gilson, Timra D.; Li, Hongxia; Todd, A. Gary; Astroski, Jacob W.; Lin, Hai; Liu, Yunlong; Androphy, Elliot J.; Department of Dermatology, School of Medicine
Spinal muscular atrophy (SMA) is an intractable neurodegenerative disease afflicting 1 in 6-10,000 live births. One of the key functions of the SMN protein is regulation of spliceosome assembly. Reduced levels of the SMN protein that are observed in SMA have been shown to result in aberrant mRNA splicing. SMN-dependent mis-spliced transcripts in motor neurons may cause stresses that are particularly harmful and may serve as potential targets for the treatment of motor neuron disease or as biomarkers in the SMA patient population. We performed deep RNA sequencing using motor neuron-like NSC-34 cells to screen for SMN-dependent mRNA processing changes that occur following acute depletion of SMN. We identified SMN-dependent splicing changes, including an intron retention event that results in the production of a truncated Rit1 transcript. This intron-retained transcript is stable and is mis-spliced in spinal cord from symptomatic SMA mice. Constitutively active Rit1 ameliorated the neurite outgrowth defect in SMN depleted NSC-34 cells, while expression of the truncated protein product of the mis-spliced Rit1 transcript inhibited neurite extension. These results reveal new insights into the biological consequence of SMN-dependent splicing in motor neuron-like cells.
Ames hypopituitary dwarf mice demonstrate imbalanced myelopoiesis between bone marrow and spleen
(Elsevier, 2015-06) Capitano, Maegan L.; Chitteti, Brahmananda R.; Cooper, Scott; Srour, Edward F.; Bartke, Andrzej; Broxmeyer, Hal E.; Department of Microbiology & Immunology, IU School of Medicine
Ames hypopituitary dwarf mice are deficient in growth hormone, thyroid-stimulating hormone, and prolactin. The phenotype of these mice demonstrates irregularities in the immune system with skewing of the normal cytokine milieu towards a more anti-inflammatory environment. However, the hematopoietic stem and progenitor cell composition of the bone marrow (BM) and spleen in Ames dwarf mice has not been well characterized. We found that there was a significant decrease in overall cell count when comparing the BM and spleen of 4-5 month old dwarf mice to their littermate controls. Upon adjusting counts to differences in body weight between the dwarf and control mice, the number of granulocyte-macrophage progenitors, confirmed by immunophenotyping and colony-formation assay was increased in the BM. In contrast, the numbers of all myeloid progenitor populations in the spleen were greatly reduced, as confirmed by colony-formation assays. This suggests that there is a shift of myelopoiesis from the spleen to the BM of Ames dwarf mice; however, this shift does not appear to involve erythropoiesis. The reasons for this unusual shift in spleen to marrow hematopoiesis in Ames dwarf mice are yet to be determined but may relate to the decreased hormone levels in these mice.
Anoikis resistance is a critical feature of highly aggressive ovarian cancer cells
(Nature Publishing Group, 2015-06) Cai, Q.; Yan, L.; Xu, Y.; Department of Microbiology & Immunology, IU School of Medicine
High-grade serous ovarian cancer is an aggressive form of epithelial ovarian cancer (EOC), and accounts for the majority of deaths due to EOC. The critical cellular processes and underlying molecular mechanisms that define this malignancy remain poorly understood. Using a syngeneic murine model, we investigated the changes that accompanied the progression to increased aggressiveness induced by in vivo passage of mouse EOC cells. We found that enhanced anoikis resistance was a key cellular process associated with greater aggressiveness and tumorigenicity in vivo. Biochemical studies revealed that the enhanced anoikis resistance was associated with the activation of the Src/Akt/Erk signaling pathway. A higher rate of metabolism and autophagy were also associated with increased anoikis resistance. Blocking these pathways with specific inhibitors and/or genetic modifications significantly increased anoikis in vitro and inhibited tumor development in vivo. In addition, we demonstrated that similar signaling pathways were also involved in a human EOC cell line model. Collectively, our data suggest that anoikis resistance represents a critical and a distinguishing feature underlying the aggressiveness of ovarian cancer cells.
Assessment of white matter loss using bond-selective photoacoustic imaging in a rat model of contusive spinal cord injury
(Mary Ann Liebert, 2014-12-15) Wu, Wei; Wang, Pu; Cheng, Ji-Xin; Xu, Xiao-Ming; Department of Neurological Surgery, IU School of Medicine
White matter (WM) loss is a critical event after spinal cord injury (SCI). Conventionally, such loss has been measured with histological and histochemical approaches, although the procedures are complex and may cause artifact. Recently, coherent Raman microscopy has been proven to be an emerging technology to study de- and remyelination of the injured spinal cord; however, limited penetration depth and small imaging field prevent it from comprehensive assessments of large areas of damaged tissues. Here, we report the use of bond-selective photoacoustic (PA) imaging with 1730-nm excitation, where the first overtone vibration of CH2 bond is located, to assess WM loss after a contusive SCI in adult rats. By employing the first overtone vibration of CH2 bond as the contrast, the mapping of the WM in an intact spinal cord was achieved in a label-free three-dimensional manner, and the physiological change of the spinal cord before and after injury was observed. Moreover, the recovery of the spinal cord from contusive injury with the treatment of a neuroprotective nanomedicine ferulic-acid-conjugated glycol chitosan (FA-GC) was also observed. Our study suggests that bond-selective PA imaging is a valuable tool to assess the progression of WM pathology after SCI as well as neuroprotective therapeutics in a label-free manner.
Association of TDP-43 Pathology With Domain-specific Literacy in Older Persons
(Wolters Kluwer, 2019-10-01) Kapasi, Alifiya; Yu, Lei; Stewart, Christopher C.; Schneider, Julie A.; Bennett, David A.; Boyle, Patricia A.; Neurology, School of Medicine
Background Low health and financial literacy may be an early behavioral manifestation of cognitive impairment, dementia, and accumulating Alzheimer’s pathology. However, there are limited studies investigating the behavioral features associated with hyperphosphorylated transactive response DNA-binding protein-43 (TDP-43), a common age-related pathology, and even fewer studies investigating the neurobiological basis underlying low literacy in aging. Objective To test the hypothesis that TDP-43 pathology is associated with lower literacy. Methods Data came from 293 community-based older persons who were enrolled in two ongoing studies of aging. Participants completed literacy and cognitive assessments, consented to brain donation, and underwent detailed neuropathological evaluation for AD and TDP-43. Linear regression models assessed the association of TDP-43 with literacy after adjusting for demographics, and AD pathology. Post-hoc pairwise comparisons examined whether the level of literacy differed by TDP-43 stage. Results TDP-43 pathology was associated with lower literacy (estimate=−3.16; SE=0.86; p<0.001), above and beyond demographics and AD pathology, and this association persisted even after additionally adjusting for global cognition (estimate=−1.53; SE=0.74; p=0.038). Further, literacy was lower among persons with neocortical TDP-43 pathology compared to those without TDP-43 pathology. Conclusion TDP-43 pathology is associated with lower health and financial literacy in old age, above and beyond AD pathology.
Automated assessment of steatosis in murine fatty liver
(PLOS, 2018-05-10) Sethunath, Deepak; Morusu, Siripriya; Tuceryan, Mihran; Cummings, Oscar W.; Zhang, Hao; Yin, Xiao-Ming; Vanderbeck, Scott; Chalasani, Naga; Gawrieh, Samer; Computer and Information Science, School of Science
Although mice are commonly used to study different aspects of fatty liver disease, currently there are no validated fully automated methods to assess steatosis in mice. Accurate detection of macro- and microsteatosis in murine models of fatty liver disease is important in studying disease pathogenesis and detecting potential hepatotoxic signature during drug development. Further, precise quantification of macrosteatosis is essential for quantifying effects of therapies. Here, we develop and validate the performance of automated classifiers built using image processing and machine learning methods for detection of macro- and microsteatosis in murine fatty liver disease and study the correlation of automated quantification of macrosteatosis with expert pathologist’s semi-quantitative grades. The analysis is performed on digital images of 27 Hematoxylin & Eosin stained murine liver biopsy samples. An expert liver pathologist scored the amount of macrosteatosis and also annotated macro- and microsteatosis lesions on the biopsy images using a web-application. Using these annotations, supervised machine learning and image processing techniques, we created classifiers to detect macro- and microsteatosis. For macrosteatosis prediction, the model’s precision, sensitivity and area under the receiver operator characteristic (AUROC) were 94.2%, 95%, 99.1% respectively. When correlated with pathologist’s semi-quantitative grade of steatosis, the model fits with a coefficient of determination value of 0.905. For microsteatosis prediction, the model has precision, sensitivity and AUROC of 79.2%, 77%, 78.1% respectively. Validation by the expert pathologist of classifier’s predictions made on unseen images of biopsy samples showed 100% and 63% accuracy for macro- and microsteatosis, respectively. This novel work demonstrates that fully automated assessment of steatosis is feasible in murine liver biopsies images. Our classifier has excellent sensitivity and accuracy for detection of macrosteatosis in murine fatty liver disease.
Bone marrow fat is increased in chronic kidney disease by magnetic resonance spectroscopy
(Springer-Verlag, 2015-06) Moorthi, R. N.; Fadel, W.; Eckert, G. J.; Ponsler-Sipes, K.; Moe, S. M.; Lin, C.; Department of Medicine, IU School of Medicine
In aging, the bone marrow fills with fat and this may lead to higher fracture risk. We show that a bone marrow fat measurement by magnetic resonance spectroscopy (MRS), a newer technique not previously studied in chronic kidney disease (CKD), is useful and reproducible. CKD patients have significantly higher bone marrow fat than healthy adults. INTRODUCTION: Renal osteodystrophy leads to increased morbidity and mortality in patients with CKD. Traditional bone biopsy histomorphometry is used to study abnormalities in CKD, but the bone marrow, the source of osteoblasts, has not been well characterized in patients with CKD. METHODS: To determine the repeatability of bone marrow fat fraction assessment by MRS and water-fat imaging (WFI) at four sites in patients with CKD, testing was performed to determine the coefficients of reproducibility and intraclass coefficients (ICCs). We further determined if this noninvasive technique could be used to determine if there are differences in the percent bone marrow fat in patients with CKD compared to matched controls using paired t tests. RESULTS: The mean age of subjects with CKD was 59.8 ± 7.2 years, and the mean eGFR was 24 ± 8 ml/min. MRS showed good reproducibility at all sites in subjects with CKD and controls, with a coefficient of reproducibilities ranging from 2.4 to 13 %. MRS and WFI assessment of bone marrow fat showed moderate to strong agreement (ICC 0.6-0.7) at the lumbar spine, with poorer agreement at the iliac crest and no agreement at the tibia. The mean percent bone marrow fat at L2-L4 was 13.8 % (95 % CI 8.3-19.7) higher in CKD versus controls (p < 0.05). CONCLUSIONS: MRS is a useful and reproducible technique to study bone marrow fat in CKD. Patients with CKD have significantly higher bone marrow fat than healthy adults; the relationship with bone changes requires further analyses.
Brief report: Endothelial colony-forming cells and inflammatory monocytes in HIV
(Ovid Technologies (Wolters Kluwer) - Lippincott Williams & Wilkins, 2015-04-15) Hays, Travis R.; Mund, Julie A.; Liu, Ziyue; Case, Jamie; Ingram, David A.; Gupta, Samir K.; Department of Medicine, IU School of Medicine
The relationships between HIV infection, monocyte activation, and endothelial colony-forming cells (ECFCs) are unknown. We compared ECFC, intermediate monocytes (CD14 CD16), and nonclassical monocytes (CD14 CD16) levels in HIV-infected participants virologically suppressed on antiretroviral therapy, HIV-infected treatment-naive participants, and HIV-uninfected healthy controls. ECFC levels were significantly higher in the HIV-infected virologically suppressed group compared with the uninfected controls. CD14 CD16 percentages (but not CD14 CD16 cells) were significantly higher in both HIV-infected groups vs. uninfected controls. In the HIV-infected groups, ECFCs and CD14 CD16 intermediate monocytes were significantly and inversely correlated. Lower availability of ECFCs may partly explain the relationship between greater intermediate monocytes and atherosclerosis in HIV.

Browsing by Subject "pathology"

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