Pathology Commons^™

Activin A Secretion By Muscle-Repairing Macrophages Induces Heterotopic Ossification In Mice, Wenqiang Yin, Kazuo Okamoto, Asuka Terashima, Warunee Pluemsakunthai, Takehito Ono, Taku Ito-Kureha, Shizuo Akira, Yoshinobu Hashizume, Roland Baron, Satoshi Ueha, Kouji Matsushima, Martin M Matzuk, Yuji Mishina, Hiroshi Takayanagi

Faculty, Staff and Students Publications

The immune system is not only essential for host defense, but it is also involved in tissue maintenance and disease pathogenesis. Macrophages play a key role in tissue repair, fibrosis, and tumorigenesis, but the mechanisms underlying their multifunctionality have not been fully explored. Here, we identified Mrep (Ly6ChiCX3CR1loPDPN+CD9+) as a crucial subset of macrophages for muscle regeneration after muscle injury. Muscle regeneration required Mrep-derived activin A, which was produced via the TLR4/TIR domain-containing adapter-inducing interferon-β/TANK-binding kinase 1/interferon regulatory factor 3/7 signaling pathway in response to muscle injury. Mrep exerted pathological effects by secreting activin A in a model of genetically …

Mbnl Loss Of Function In Smooth Muscle As A Model For Myotonic Dystrophy Associated Gastrointestinal Dysmotility, Janel A M Peterson, Jesus A Frias, Andrew N Miller, Krishnakant G Soni, Yi Zhang, Zheng Xia, John W Day, Geoffrey A Preidis, Thomas A Cooper

Faculty, Staff and Students Publications

Myotonic dystrophy type 1 (DM1) is the most common adult-onset muscular dystrophy and severely affects multiple organ systems, including the brain, heart, skeletal muscle, and gastrointestinal (GI) tract. Despite 80% of individuals with DM1 experiencing GI dysfunction that affects their daily life, the mechanisms of GI dysmotility in DM1 remain an understudied aspect of the disease. DM1 is caused by a CTG repeat expansion in the DMPK gene that, when expressed as an expanded CUG repeat RNA, sequesters and reduces the activity of the muscleblind-like (MBNL) RNA-binding protein family. We developed a mouse line with conditional, smooth muscle-specific knockout of …

Sex-Specific Angiogenic Responses In Endothelial Cells-Role Of The Pluripotency Factor Oct4, Junchul Shin, Junyoung Hong, Iuliia Molokotina, Irene Krukovets, Ellin Kim, Svyatoslav Tkachenko, Eugene Podrez, Tatiana V Byzova, Olga A Cherepanova

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The study investigates the sex-specific effects of the pluripotency factor OCT4 deficiency in endothelial cells (ECs) on angiogenesis. OCT4 is known for its role in embryonic stem cells, but we recently found that it plays a protective role in ECs during atherosclerosis. Herein, we utilized cultured mouse aortic ECs (MAECs) and several in vivo models, including skin wounding, melanoma tumor implantation, and hindlimb ischemia, to explore the role of OCT4 in angiogenesis in both male and female mice. Our findings revealed significant sexual dimorphism in wild type mice, along with sex differences in responses to OCT4 deficiency across all three …

Tgfbr2 Coordinates The Endometrial Response To Estrogen, Regulating Endometrial Hyperplasia And Fertility, Sydney E Parks, Suni Tang, Anna Catherine Unser, Ananya L Bhonsley, Eunbi M Chung, Peixin Jiang, Audrey Savolainen, Vanessa J Joseph, Dominique I Cope, Ramya P Masand, Renata Prunskaite-Hyyryläinen, Diana Monsivais

Faculty, Staff and Students Publications

Proper endometrial function is critical for establishing and maintaining healthy pregnancies, as well as preventing the pathogenesis of conditions such as endometrial hyperplasia and endometrial cancer. The TGFβ signaling pathway regulates key aspects of endometrial biology, although the direct effects of many individual receptors remain unstudied. In this study, we characterize the role of TGFβR2 within the endometrium using a progesterone receptor-cre conditional knock-out mouse model (Tgfbr2flox/flox;Pgrcre/+; “Tgfbr2 cKO”). We found that conditional deletion of TGFβR2 resulted in female infertility, endometrial hyperplasia, altered estrogen and progesterone response, and, only in bred females, reproductive tract …

A Mouse Model Of Lipoatrophy Reveals Relationships Between Beige Fat Appearance And Female Fertility, Elizabeth S Anaya, William Dion, Pradip K Saha, Aaron R Cox, Evelyn De Groot, Avery A Ahmed, Jessica B Felix, Bokai Zhu, Stephanie A Pangas, Sean M Hartig

Faculty, Staff and Students Publications

White adipose tissue (WAT) performs vital metabolic and endocrine functions, but roles in female reproduction remain understudied and poorly understood. Here, we report that female mice experiencing progressive lipoatrophy after knockout of Ubc9 in adipocytes (Ubc9fKO) displayed disrupted estrous cycles, reduced ovarian reserve, and subfertility. During aging, female Ubc9fKO mice lose subcutaneous WAT more quickly than their male counterparts and weigh less than littermate controls. Subcutaneous WAT excised from female Ubc9fKO mice strongly enriched for thermogenesis genes generally associated with metabolic benefits. Female Ubc9fKO mice exhibited hypermetabolism and accumulated thermogenic, Uncoupling Protein 1-expressing beige fat cells in residual subcutaneous WAT …

Transcriptional Coregulator Zmiz1 Modulates Estrogen Responses That Are Essential For Healthy Endometrial Function, Sylvia C Hewitt, Frank Orellana, Ryan M Marquardt, Myeongjin Yi, Cynthia J Willson, Mark Y Chiang, Yong Song, Goutham Venkata Naga Davuluri, Christopher Day, Ramakrishna Kommagani, Joseph Rodriguez, Asgerally T Fazleabas, John P Lydon, Francesco J Demayo

Faculty, Staff and Students Publications

Estrogen is a critical regulator of endometrial health. Aberrant estrogen stimulation can result in infertility, endometrial cancer, and endometriosis. Here, we identified Zinc Finger MIZ-Type Containing 1 (Zmiz1) as a coregulator of uterine estrogen signaling. ZMIZ1 is colocalized with an estrogen receptor α–binding (ESR1-binding) super enhancer. ZMIZ1 mutations are found in endometrial cancer and its RNA levels trend toward reduction in endometrium of patients with endometriosis. ZMIZ1 is dynamically expressed in human endometrial tissues during the menstrual cycle. Disrupting ZMIZ1 in cultured human endometrial stromal cells resulted in impaired cell proliferation and decidual differentiation. Ablation of Zmiz1 using …

Protein Kinase Rock1 Activates Mitochondrial Fission Linking To Oxidative Stress And Muscle Atrophy, Meijun Si, Jihong Chen, Rizhen Yu, Hongchun Lin, Feng Li, Sungyun Jung, Sandhya S Thomas, Farhard R Danesh, Yanlin Wang, Hui Peng, Zhaoyong Hu

Faculty, Staff and Students Publications

Introduction: Chronic kidney disease (CKD) is associated with protein-energy wasting, characterized by a reduction in muscle mass and strength. Although mitochondrial dysfunction and oxidative stress are implicated in the pathogenesis of muscle wasting, underlying mechanisms remain unclear.

Methods: Here, we used transcriptomic analysis, metabolomics analyses, and mouse gene manipulation to investigate the effects of mitochondrial plasticity and oxidative stress on muscle wasting the subtotal nephrectomy mouse models of CKD. The mice with CKD were age- and sex-matched to sham-operated controls.

Results: Through these approaches, Rho-associated kinase ROCK1 emerged as a key molecule responsible for the observed mitochondrial fission and oxidative …

Testis Expressed 50 Is Essential For Maintaining Sperm Acrosome Integrity During Epididymal Transit, Saori Haga, Kaori Nozawa, Ferheen Abbasi, Katarzyna Kent, Naoko Nagasawa, Tsutomu Endo, Haruhiko Miyata, Masahito Ikawa, Martin M Matzuk, Yoshitaka Fujihara

Faculty, Staff and Students Publications

In mammals, sperm formation is completed in the seminiferous tubules within the testis, and sperm maturation occurs during the epididymal transit of the spermatozoa. Sperm morphology drastically changes when abnormal spermatozoa migrate from the testis to the epididymis. Detailed molecular mechanisms for sperm survival in the epididymis have not been determined yet. Globozoospermia is a cause of male infertility and is characterized by round-headed spermatozoa without acrosomes, an abnormal sperm nuclear membrane, and sperm midpiece defects. Testis expressed 50 (Tex50) is a testis-enriched gene that is expressed in mice and humans. Using CRISPR-Cas9, we generated Tex50 knockout (KO) …

Interferon-Gamma Receptor Signaling Regulates Innate Immunity During Staphylococcus Aureus Craniotomy Infection, Zachary Van Roy, Gunjan Kak, Rachel W. Fallet, Tammy Kielian

Journal Articles: Pathology and Microbiology

A craniotomy is a neurosurgical procedure performed to access the intracranial space. In 3-5% of cases, infections can develop, most caused by Staphylococcus aureus biofilm formation on the skull surface. Medical management of this infection is difficult, as biofilm properties confer immune and antimicrobial recalcitrance to the infection and necessitate additional surgical procedures. Furthermore, treatment failure rates can be appreciably high. These factors, compounded with rapidly expanding rates of antimicrobial resistance, highlight the need to develop alternative treatment strategies to target and reverse the immune dysfunction that occurs during biofilm infection. Our recent work has identified CD4+ Th1 and Th17 …

Cd4+ T Cell-Innate Immune Crosstalk Is Critical During Staphylococcus Aureus Craniotomy Infection, Gunjan Kak, Zachary A. Van Roy, Rachel W. Fallet, Lee E. Korshoj, Tammy Kielian

Journal Articles: Pathology and Microbiology

Access to the brain for treating neurological sequalae requires a craniotomy, which can be complicated by infection. Staphylococcus aureus accounts for half of craniotomy infections, increasing morbidity in a medically fragile patient population. T cells preferentially traffic to the brain during craniotomy infection; however, their functional importance is unknown. Using a mouse model of S. aureus craniotomy infection, CD4+ T cells were critical for bacterial containment, as treatment of WT animals with anti-CD4 exacerbated infection that was similar to phenotypes in Rag1-/- mice. Single-cell RNA-Seq (scRNA-Seq) revealed transcriptional heterogeneity in brain CD3+ infiltrates, with CD4+ cells most prominent that displayed …

Individual Disruption Of 12 Testis-Enriched Genes Via The Crispr/Cas9 System Does Not Affect The Fertility Of Male Mice, Akira Suzuki, Norikazu Yabuta, Keisuke Shimada, Daisuke Mashiko, Keizo Tokuhiro, Yuki Oyama, Haruhiko Miyata, Thomas X Garcia, Martin M Matzuk, Masahito Ikawa

Faculty, Staff and Students Publications

More than 1200 genes have been shown in the database to be expressed predominantly in the mouse testes. Advances in genome editing technologies such as the CRISPR/Cas9 system have made it possible to create genetically engineered mice more rapidly and efficiently than with conventional methods, which can be utilized to screen genes essential for male fertility by knocking out testis-enriched genes. Finding such genes related to male fertility would not only help us understand the etiology of human infertility but also lead to the development of male contraceptives. In this study, we generated knockout mice for 12 genes (Acrv1, Adgrf3, …

C1q Is Elevated During Chronic Staphylococcus Epidermidis Central Nervous System Catheter Infection, Matthew K. Beaver, Lara Bergdolt, Anna Dunaevsky, Tammy Kielian, Gwenn Skar

Journal Articles: Pathology and Microbiology

INTRODUCTION: Significant neurologic morbidity is caused by pediatric cerebrospinal fluid (CSF) shunt infections. The underlying mechanisms leading to impaired school performance and increased risk of seizures are unknown, however, a better understanding of these mechanisms may allow us to temper their consequences. Recent evidence has demonstrated important roles for complement proteins in neurodevelopment and neuroinflammation.

METHODS: We examined complement activation throughout

RESULTS: We found that MASP2 predominated early in catheter infection, but that Factor B was elevated at intermediate time points. Unexpectedly C1q was elevated at late timepoints when bacterial burdens were low or undetectable. Based on these findings and …

Aconitate Decarboxylase 1 Mediates The Acute Airway Inflammatory Response To Environmental Exposures, Aaron Schwab, Amy J. Nelson, Angela Gleason, Oliver Schanze, Todd A. Wyatt, Dhananjay Shinde, Peng Xiao, Vinai Chittezham Thomas, Chittibabu Guda, Kristina L. Bailey, Tammy Kielian, Geoffrey M. Thiele, Jill A. Poole

Journal Articles: Pathology and Microbiology

Background: Environmental lipopolysaccharide (LPS) and microbial component-enriched organic dusts cause significant lung disease. These environmental exposures induce the recruitment and activation of distinct lung monocyte/macrophage subpopulations involved in disease pathogenesis. Aconitate decarboxylase 1 (Acod1) was one of the most upregulated genes following LPS (vs. saline)exposure of murine whole lungs with transcriptomic profiling of sorted lung monocyte/macrophage subpopulations also highlighting its significance. Given monocyte/macrophage activation can be tightly linked to metabolism, the objective of these studies was to determine the role of the immunometabolic regulator ACOD1 inenvironmentalexposure-induced lung inflammation.

Methods: Wild-type (WT) mice were intratracheally (i.t.) instilled with 10 …

Generation Of Humanized Ldhc Knock-In Mice As A Tool To Assess Human Ldhc-Targeting Contraceptive Drugs, Rie Iida-Norita, Haruhiko Miyata, Yuki Kaneda, Chihiro Emori, Taichi Noda, Tatsuya Nakagawa, Martin M Matzuk, Masahito Ikawa

Faculty, Staff and Students Publications

Background: Lactate dehydrogenase C (LDHC) is specifically expressed in male germ cells and plays critical roles in glycolysis. Glycolysis is required to supply energy for sperm motility. Previous studies showed that Ldhc knock-out mice exhibit impaired sperm motility.

Objectives: We established human LDHC knock-in (hLDHC KI) mice and examined whether hLDHC KI mice can be used to assess LDHC-targeting drugs.

Material and methods: HLDHC was knocked-in to the mouse Ldhc (mLdhc) allele using the CRISPR/Cas9 system. Mating tests, sperm motility examinations with a computer-assisted sperm analysis (CASA) system, and in vitro fertilization (IVF) were performed. Furthermore, the effect of an …

The Role Of Limch1 Alternative Splicing In Skeletal Muscle Function, Matthew S Penna, Rong-Chi Hu, George G Rodney, Thomas A Cooper

Faculty, Staff and Students Publications

Postnatal skeletal muscle development is a highly dynamic period associated with widespread alternative splicing changes required to adapt tissues to adult function. These splicing events have significant implications because the reversion of adult mRNA isoforms to fetal isoforms is observed in forms of muscular dystrophy. LIMCH1 is a stress fiber–associated protein that is alternatively spliced to generate uLIMCH1, a ubiquitously expressed isoform, and mLIMCH1, a skeletal muscle–specific isoform containing six additional exons simultaneously included after birth in the mouse. CRISPR/Cas9 was used to delete the six alternatively spliced exons of LIMCH1 in mice, thereby forcing the constitutive expression of the …

Novel Role Of Ghrelin Receptor In Gut Dysbiosis And Experimental Colitis In Aging, Ji Yeon Noh, Chia-Shan Wu, Jennifer A A Deluca, Sridevi Devaraj, Arul Jayaraman, Robert C Alaniz, Xiao-Di Tan, Clinton D Allred, Yuxiang Sun

Faculty, Staff and Students Publications

Chronic low-grade inflammation is a hallmark of aging, which is now coined as inflamm-aging. Inflamm-aging contributes to many age-associated diseases such as obesity, type 2 diabetes, cardiovascular disease, and inflammatory bowel disease (IBD). We have shown that gut hormone ghrelin, via its receptor growth hormone secretagogue receptor (GHS-R), regulates energy metabolism and inflammation in aging. Emerging evidence suggests that gut microbiome has a critical role in intestinal immunity of the host. To determine whether microbiome is an integral driving force of GHS-R mediated immune-metabolic homeostasis in aging, we assessed the gut microbiome profiles of young and old GHS-R global knockout …

Ifn-Γ Transforms The Transcriptomic Landscape And Triggers Myeloid Cell Hyperresponsiveness To Cause Lethal Lung Injury, Atul K. Verma, Michael Mckelvey, Md Bashir Uddin, Sunil Palani, Meng Niu, Christopher Bauer, Shengjun Shao, Keer Sun

Journal Articles: Pathology and Microbiology

Acute Respiratory Distress Syndrome (ARDS) is an inflammatory disease that is associated with high mortality but no specific treatment. Our understanding of initial events that trigger ARDS pathogenesis is limited. We have developed a mouse model of inflammatory lung injury by influenza and methicillin-resistant Staphylococcus aureus (MRSA) coinfection plus daily antibiotic therapy. Using this pneumonic ARDS model, here we show that IFN-γ receptor signaling drives inflammatory cytokine storm and lung tissue damage. By single-cell RNA sequencing (scRNA-seq) analysis, we demonstrate that IFN-γ signaling induces a transcriptional shift in airway immune cells, particularly by upregulating macrophage and monocyte expression of genes …

Crispr/Cas9-Mediated Genome Editing Reveals 12 Testis-Enriched Genes Dispensable For Male Fertility In Mice, Yuki Oyama, Haruhiko Miyata, Keisuke Shimada, Yoshitaka Fujihara, Keizo Tokuhiro, Thomas X Garcia, Martin M Matzuk, Masahito Ikawa

Faculty, Staff and Students Publications

Gene expression analyses suggest that more than 1000-2000 genes are expressed predominantly in mouse and human testes. Although functional analyses of hundreds of these genes have been performed, there are still many testis-enriched genes whose functions remain unexplored. Analyzing gene function using knockout (KO) mice is a powerful tool to discern if the gene of interest is essential for sperm formation, function, and male fertility in vivo. In this study, we generated KO mice for 12 testis-enriched genes, 1700057G04Rik, 4921539E11Rik, 4930558C23Rik, Cby2, Ldhal6b, Rasef, Slc25a2, Slc25a41, Smim8, Smim9, Tmem210, and Tomm20l, using the clustered regularly interspaced short palindromic repeats /CRISPR-associated …

Cyclin D1 Restrains Oncogene-Induced Autophagy By Regulating The Ampk-Lkb1 Signaling Axis., Mathew C. Casimiro, Gabriele Disante, Agnese Di Rocco, Emanuele Loro, Claudia Pupo, Timothy G. Pestell, Sara Bisetto, Marco A. Velasco-Velázquez, Xuanmao Jiao, Zhiping Li, Christine M. Kusminski, Erin L. Seifert, Chenguang Wang, Daniel Ly, Bin Zheng, Che-Hung Shen, Philipp E. Scherer, Richard Pestell

Department of Cancer Biology Faculty Papers

Autophagy activated after DNA damage or other stresses mitigates cellular damage by removing damaged proteins, lipids, and organelles. Activation of the master metabolic kinase AMPK enhances autophagy. Here we report that cyclin D1 restrains autophagy by modulating the activation of AMPK. In cell models of human breast cancer or in a cyclin D1-deficient model, we observed a cyclin D1-mediated reduction in AMPK activation. Mechanistic investigations showed that cyclin D1 inhibited mitochondrial function, promoted glycolysis, and reduced activation of AMPK (pT172), possibly through a mechanism that involves cyclin D1-Cdk4/Cdk6 phosphorylation of LKB1. Our findings suggest how AMPK activation by cyclin D1 …

Loss Of Cbl And Cbl-B Ubiquitin Ligases Abrogates Hematopoietic Stem Cell Quiescence And Sensitizes Leukemic Disease To Chemotherapy., Wei An, Scott A. Nadeau, Bhopal C. Mohapatra, Dan Feng, Neha Zutshi, Matthew D. Storck, Priyanka Arya, James E. Talmadge, Jane L. Meza, Vimla Band, Hamid Band

Journal Articles: Pathology and Microbiology

Cbl and Cbl-b are tyrosine kinase-directed RING finger type ubiquitin ligases (E3s) that negatively regulate cellular activation pathways. E3 activity-disrupting human Cbl mutations are associated with myeloproliferative disorders (MPD) that are reproduced in mice with Cbl RING finger mutant knock-in or hematopoietic Cbl and Cbl-b double knockout. However, the role of Cbl proteins in hematopoietic stem cell (HSC) homeostasis, especially in the context of MPD is unclear. Here we demonstrate that HSC expansion and MPD development upon combined Cbl and Cbl-b deletion are dependent on HSCs. Cell cycle analysis demonstrated that DKO HSCs exhibit reduced quiescence associated with compromised reconstitution …

Expression Of Suppressor Of Cytokine Signaling 1 (Socs1) Impairs Viral Clearance And Exacerbates Lung Injury During Influenza Infection., Keer Sun, Sharon Salmon, Vijaya Kumar Yajjala, Christopher Bauer, Dennis W. Metzger

Journal Articles: Pathology and Microbiology

Suppressor of cytokine signaling (SOCS) proteins are inducible feedback inhibitors of cytokine signaling. SOCS1-/- mice die within three weeks postnatally due to IFN-γ-induced hyperinflammation. Since it is well established that IFN-γ is dispensable for protection against influenza infection, we generated SOCS1-/-IFN-γ-/- mice to determine whether SOCS1 regulates antiviral immunity in vivo. Here we show that SOCS1-/-IFN-γ-/- mice exhibited significantly enhanced resistance to influenza infection, as evidenced by improved viral clearance, attenuated acute lung damage, and consequently increased survival rates compared to either IFN-γ-/- or WT animals. Enhanced viral clearance in SOCS1-/-IFN-γ-/- mice coincided with a rapid onset of adaptive immune …

Evidence For Aberrant Astrocyte Hemichannel Activity In Juvenile Neuronal Ceroid Lipofuscinosis (Jncl)., Maria Burkovetskaya, Nikolay Karpuk, Juan Xiong, Megan Bosch, Michael D. Boska, Hideyuki Takeuchi, Akio Suzumura, Tammy Kielian

Journal Articles: Pathology and Microbiology

Juvenile Neuronal Ceroid Lipofuscinosis (JNCL) is a lysosomal storage disease caused by an autosomal recessive mutation in CLN3 that leads to vision loss, progressive cognitive and motor decline, and premature death. Morphological evidence of astrocyte activation occurs early in the disease process and coincides with regions where neuronal loss eventually ensues. However, the consequences of CLN3 mutation on astrocyte function remain relatively ill-defined. Astrocytes play a critical role in CNS homeostasis, in part, by their ability to regulate the extracellular milieu via the formation of extensive syncytial networks coupled by gap junction (GJ) channels. In contrast, unopposed hemichannels (HCs) have …

Differential Effects Of Interleukin-17 Receptor Signaling On Innate And Adaptive Immunity During Central Nervous System Bacterial Infection., Debbie Vidlak, Tammy Kielian

Journal Articles: Pathology and Microbiology

Although IL-17A (commonly referred to as IL-17) has been implicated in the pathogenesis of central nervous system (CNS) autoimmune disease, its role during CNS bacterial infections remains unclear. To evaluate the broader impact of IL-17 family members in the context of CNS infection, we utilized IL-17 receptor (IL-17R) knockout (KO) mice that lack the ability to respond to IL-17, IL-17F and IL-17E (IL-25). In this article, we demonstrate that IL-17R signaling regulates bacterial clearance as well as natural killer T (NKT) cell and gamma-delta (γδ) T cell infiltrates during Staphylococcus aureus-induced brain abscess formation. Specifically, when compared with wild-type (WT) …

Il-1ri (Interleukin-1 Receptor Type I) Signalling Is Essential For Host Defence And Hemichannel Activity During Acute Central Nervous System Bacterial Infection., Juan Xiong, Maria Burkovetskaya, Nikolay Karpuk, Tammy Kielian

Journal Articles: Pathology and Microbiology

Staphylococcus aureus is a common aetiological agent of bacterial brain abscesses. We have previously established that a considerable IL-1 (interleukin-1) response is elicited immediately following S. aureus infection, where the cytokine can exert pleiotropic effects on glial activation and blood-brain barrier permeability. To assess the combined actions of IL-1α and IL-1β during CNS (central nervous system) infection, host defence responses were evaluated in IL-1RI (IL-1 receptor type I) KO (knockout) animals. IL-1RI KO mice were exquisitely sensitive to intracerebral S. aureus infection, as demonstrated by enhanced mortality rates and bacterial burdens within the first 24 h following pathogen exposure compared …

Decorin-Mediated Inhibition Of Colorectal Cancer Growth And Migration Is Associated With E-Cadherin In Vitro And In Mice., Xiuli Bi, Nicole M Pohl, Zhibin Qian, George R Yang, Yuan Gou, Grace Guzman, Andre Kajdacsy-Balla, Renato V Iozzo, Wancai Yang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Previous studies have shown that decorin expression is significantly reduced in colorectal cancer tissues and cancer cells, and genetic deletion of the decorin gene is sufficient to cause intestinal tumor formation in mice, resulting from a downregulation of p21, p27(kip1) and E-cadherin and an upregulation of β-catenin signaling [Bi,X. et al. (2008) Genetic deficiency of decorin causes intestinal tumor formation through disruption of intestinal cell maturation. Carcinogenesis, 29, 1435-1440]. However, the regulation of E-cadherin by decorin and its implication in cancer formation and metastasis is largely unknown. Using a decorin knockout mouse model (Dcn(-/-) mice) and manipulated expression of decorin …

Myd88-Dependent Signaling Influences Fibrosis And Alternative Macrophage Activation During Staphylococcus Aureus Biofilm Infection., Mark L. Hanke, Amanda Angle, Tammy Kielian

Journal Articles: Pathology and Microbiology

Bacterial biofilms represent a significant therapeutic challenge based on their ability to evade host immune and antibiotic-mediated clearance. Recent studies have implicated IL-1β in biofilm containment, whereas Toll-like receptors (TLRs) had no effect. This is intriguing, since both the IL-1 receptor (IL-1R) and most TLRs impinge on MyD88-dependent signaling pathways, yet the role of this key adaptor in modulating the host response to biofilm growth is unknown. Therefore, we examined the course of S. aureus catheter-associated biofilm infection in MyD88 knockout (KO) mice. MyD88 KO animals displayed significantly increased bacterial burdens on catheters and surrounding tissues during early infection, which …

Myd88 Is Pivotal For Immune Recognition Of Citrobacter Koseri And Astrocyte Activation During Cns Infection., Shuliang Liu, Tammy Kielian

Journal Articles: Pathology and Microbiology

Citrobacter koseri (C. koseri) is a Gram-negative bacterium that can cause a highly aggressive form of neonatal meningitis, which often progresses to establish multi-focal brain abscesses. The roles of Toll-like receptor 4 (TLR4) and its signaling adaptor MyD88 during CNS C. koseri infection have not yet been examined, which is important since recent evidence indicates that innate immune responses are tailored towards specific pathogen classes. Here TLR4 WT (C3H/FeJ) and TLR4 mutant (C3H/HeJ) mice as well as MyD88 KO animals were infected intracerebrally with live C. koseri, resulting in meningitis and ventriculitis with accompanying brain abscess formation. MyD88 KO mice …