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1.
Am J Pathol ; 193(12): 2182-2202, 2023 12.
Article in English | MEDLINE | ID: mdl-37673329

ABSTRACT

Liver is the largest lymph-producing organ. In cirrhotic patients, lymph production significantly increases concomitant with lymphangiogenesis. The aim of this study was to determine the mechanism of lymphangiogenesis in liver and its implication in liver fibrosis. Liver biopsies from portal hypertensive patients with portal-sinusoidal vascular disease (n = 22) and liver cirrhosis (n = 5) were evaluated for lymphangiogenesis and compared with controls (n = 9 and n = 6, respectively). For mechanistic studies, rats with partial portal vein ligation (PPVL) and bile duct ligation (BDL) were used. A gene profile data set (GSE77627), including 14 histologically normal liver, 18 idiopathic noncirrhotic portal hypertension, and 22 cirrhotic patients, was analyzed. Lymphangiogenesis was significantly increased in livers from patients with portal-sinusoidal vascular disease, cirrhotic patients, as well as PPVL and BDL rats. Importantly, Schwann cells of sympathetic nerves highly expressed vascular endothelial growth factor-C in PPVL rats. Vascular endothelial growth factor-C neutralizing antibody or sympathetic denervation significantly decreased lymphangiogenesis in livers of PPVL and BDL rats, which resulted in progression of liver fibrosis. Liver specimens from cirrhotic patients showed a positive correlation between sympathetic nerve/Schwann cell-positive areas and lymphatic vessel numbers, which was supported by gene set analysis from patients with noncirrhotic portal hypertension and cirrhotic patients. Sympathetic nerves promote hepatic lymphangiogenesis in noncirrhotic and cirrhotic livers. Increased hepatic lymphangiogenesis can be protective against liver fibrosis.


Subject(s)
Vascular Diseases , Vascular Endothelial Growth Factor C , Rats , Humans , Animals , Lymphangiogenesis , Rats, Sprague-Dawley , Disease Models, Animal , Liver Cirrhosis/pathology , Liver/pathology , Vascular Diseases/pathology , Sympathetic Nervous System
2.
Hepatology ; 78(2): 649-669, 2023 08 01.
Article in English | MEDLINE | ID: mdl-36626620

ABSTRACT

LSECs are a unique population of endothelial cells within the liver and are recognized as key regulators of liver homeostasis. LSECs also play a key role in liver disease, as dysregulation of their quiescent phenotype promotes pathological processes within the liver including inflammation, microvascular thrombosis, fibrosis, and portal hypertension. Recent technical advances in single-cell analysis have characterized distinct subpopulations of the LSECs themselves with a high resolution and defined their gene expression profile and phenotype, broadening our understanding of their mechanistic role in liver biology. This article will review 4 broad advances in our understanding of LSEC biology in general: (1) LSEC heterogeneity, (2) LSEC aging and senescence, (3) LSEC role in liver regeneration, and (4) LSEC role in liver inflammation and will then review the role of LSECs in various liver pathologies including fibrosis, DILI, alcohol-associated liver disease, NASH, viral hepatitis, liver transplant rejection, and ischemia reperfusion injury. The review will conclude with a discussion of gaps in knowledge and areas for future research.


Subject(s)
Endothelial Cells , Liver Diseases , Humans , Endothelial Cells/metabolism , Liver/pathology , Liver Diseases/pathology , Fibrosis , Inflammation/metabolism
3.
Aust J Rural Health ; 2024 Jun 25.
Article in English | MEDLINE | ID: mdl-38924584

ABSTRACT

AIMS: This article explores the crucial role of 'place' as an ecological, social and cultural determinant of health and well-being, with a focus on the benefits and challenges of living rurally and remotely in Australia. CONTEXT: The health system, including health promotion, can contribute actively to creating supportive environments and places that foster health and well-being among individuals residing in rural and remote locations. For First Nations peoples, living on Country, and caring for Country and its people, are core to Indigenous worldviews, and the promotion of Aboriginal and Torres Strait Islander health and well-being. Their forced removal from ancestral lands has been catastrophic. For all people, living in rural and remote areas can deliver an abundance of the elements that contribute to a 'liveable' community, including access to fresh air, green and blue space, agricultural employment, tight-knit communities, a sense of belonging and identity, and social capital. However, living remotely also can limit access to employment opportunities, clean water, affordable food, reliable transport, social infrastructure, social networks and preventive health services. 'Place' is a critical enabler of maintaining a healthy life. However, current trends have led to a reduction in local services and resources, and increased exposure to the impacts of climate change. APPROACH: This commentary suggests ideas and strategies through which people in rural and remote locations can strengthen the liveability, resilience and identity of their communities, and regain access to essential health care and health promotion services and resources. CONCLUSION: Recommended strategies include online access to education, employment and telehealth; flexible provision of social infrastructure; and meaningful and responsive university-health service partnerships.

4.
Am J Physiol Gastrointest Liver Physiol ; 325(5): G379-G390, 2023 11 01.
Article in English | MEDLINE | ID: mdl-37605828

ABSTRACT

The liver lymphatic system is essential for maintaining tissue fluid balance and immune function. The detailed structure of lymphatic vessels (LVs) in the liver remains to be fully demonstrated. The aim of this study is to reveal LV structures in normal and diseased livers by developing a tissue-clearing and coimmunolabeling protocol optimized for the tissue size and the processing time for three-dimensional (3-D) visualization and quantification of LVs in the liver. We showed that our optimized protocol enables in-depth exploration of lymphatic networks in the liver, consisting of LVs along the portal tract (deep lymphatic system) and within the collagenous Glisson's capsule (superficial lymphatic system) in different species. With this protocol, we have shown 3-D LVs configurations in relation to blood vessels and bile ducts in cholestatic mouse livers, in which LVs were highly dilated and predominantly found around highly proliferating bile ducts and peribiliary vascular plexuses in the portal tract. We also established a quantification method using a 3-D volume-rendering approach. We observed a 1.6-fold (P < 0.05) increase in the average diameter of LVs and a 2.4-fold increase (P < 0.05) in the average branch number of LVs in cholestatic/fibrotic livers compared with control livers. Furthermore, cholestatic/fibrotic livers showed a 4.3-fold increase (P < 0.05) in total volume of LVs compared with control livers. Our optimized protocol and quantification method demonstrate an efficient and simple liver tissue-clearing procedure that allows the comprehensive analysis of liver lymphatic system.NEW & NOTEWORTHY This article showed a comprehensive 3-D-structural analysis of liver lymphatic vessel (LV) in normal and diseased livers in relation to blood vessels and bile ducts. In addition to the LVs highly localized at the portal tract, we revealed capsular LVs in mouse, rat, and human livers. In cholestatic livers, LVs are significantly increased and dilated compared with normal livers. Our optimized protocol provides detailed spatial information for LVs remodeling in normal and pathological conditions.


Subject(s)
Cholestasis , Lymphatic Vessels , Rats , Humans , Mice , Animals , Liver/pathology , Bile Ducts , Lymphatic Vessels/diagnostic imaging , Lymphatic Vessels/pathology , Cholestasis/pathology , Liver Cirrhosis/pathology
5.
Gastroenterology ; 160(4): 1315-1329.e13, 2021 03.
Article in English | MEDLINE | ID: mdl-33227282

ABSTRACT

BACKGROUND & AIMS: Hepatic encephalopathy (HE) is a serious neurologic complication in patients with liver cirrhosis. Very little is known about the role of the meningeal lymphatic system in HE. We tested our hypothesis that enhancement of meningeal lymphatic drainage could decrease neuroinflammation and ameliorate HE. METHODS: A 4-week bile duct ligation model was used to develop cirrhosis with HE in rats. Brain inflammation in patients with HE was evaluated by using archived GSE41919. The motor function of rats was assessed by the rotarod test. Adeno-associated virus 8-vascular endothelial growth factor C (AAV8-VEGF-C) was injected into the cisterna magna of HE rats 1 day after surgery to induce meningeal lymphangiogenesis. RESULTS: Cirrhotic rats with HE showed significantly increased microglia activation in the middle region of the cortex (P < .001) as well as increased neuroinflammation, as indicated by significant increases in interleukin 1ß, interferon γ, tumor necrosis factor α, and ionized calcium binding adaptor molecule 1 (Iba1) expression levels in at least 1 of the 3 regions of the cortex. Motor function was also impaired in rats with HE (P < .05). Human brains of patients with cirrhosis with HE also exhibited up-regulation of proinflammatory genes (NFKB1, IbA1, TNF-α, and IL1ß) (n = 6). AAV8-VEGF-C injection significantly increased meningeal lymphangiogenesis (P = .035) and tracer dye uptake in the anterior and middle regions of the cortex (P = .006 and .003, respectively), their corresponding meninges (P = .086 and .006, respectively), and the draining lymph nodes (P = .02). Furthermore, AAV8-VEGF-C decreased microglia activation (P < .001) and neuroinflammation and ameliorated motor dysfunction (P = .024). CONCLUSIONS: Promoting meningeal lymphatic drainage and enhancing waste clearance improves HE. Manipulation of meningeal lymphangiogenesis could be a new therapeutic strategy for the treatment of HE.


Subject(s)
Glymphatic System/pathology , Hepatic Encephalopathy/immunology , Liver Cirrhosis/complications , Motor Disorders/immunology , Vascular Endothelial Growth Factor C/metabolism , Animals , Cell Line , Cerebral Cortex/immunology , Cerebral Cortex/pathology , Cisterna Magna/immunology , Cisterna Magna/pathology , Dependovirus/genetics , Disease Models, Animal , Genetic Vectors/administration & dosage , Genetic Vectors/genetics , Glymphatic System/immunology , Hepatic Encephalopathy/pathology , Humans , Liver Cirrhosis/immunology , Lymphangiogenesis/immunology , Male , Microglia/immunology , Microglia/pathology , Motor Disorders/pathology , Rats , Vascular Endothelial Growth Factor C/genetics
6.
J Hepatol ; 75(2): 377-386, 2021 08.
Article in English | MEDLINE | ID: mdl-33675874

ABSTRACT

BACKGROUND & AIMS: Liver sinusoidal endothelial cell (LSEC) dysfunction has been reported in alcohol-related liver disease, yet it is not known whether LSECs metabolize alcohol. Thus, we investigated this, as well as the mechanisms of alcohol-induced LSEC dysfunction and a potential therapeutic approach for alcohol-induced liver injury. METHODS: Primary human, rat and mouse LSECs were used. Histone deacetylase 6 (HDAC6) was overexpressed specifically in liver ECs via adeno-associated virus (AAV)-mediated gene delivery to decrease heat shock protein 90 (Hsp90) acetylation in ethanol-fed mice. RESULTS: LSECs expressed CYP2E1 and alcohol dehydrogenase 1 (ADH1) and metabolized alcohol. Ethanol induced CYP2E1 in LSECs, but not ADH1. Alcohol metabolism by CYP2E1 increased Hsp90 acetylation and decreased its interaction with endothelial nitric oxide synthase (eNOS) leading to a decrease in nitric oxide (NO) production. A non-acetylation mutant of Hsp90 increased its interaction with eNOS and NO production, whereas a hyperacetylation mutant decreased NO production. These results indicate that Hsp90 acetylation is responsible for decreases in its interaction with eNOS and eNOS-derived NO production. AAV8-driven HDAC6 overexpression specifically in liver ECs deacetylated Hsp90, restored Hsp90's interaction with eNOS and ameliorated alcohol-induced liver injury in mice. CONCLUSION: Restoring LSEC function is important for ameliorating alcohol-induced liver injury. To this end, blocking acetylation of Hsp90 specifically in LSECs via AAV-mediated gene delivery has the potential to be a new therapeutic strategy. LAY SUMMARY: Alcohol metabolism in liver sinusoidal endothelial cells (LSECs) and the mechanism of alcohol-induced LSEC dysfunction are largely unknown. Herein, we demonstrate that LSECs can metabolize alcohol. We also uncover a mechanism by which alcohol induces LSEC dysfunction and liver injury, and we identify a potential therapeutic strategy to prevent this.


Subject(s)
Acetylation/drug effects , Liver Diseases, Alcoholic/genetics , Adult , Alcohol Drinking/adverse effects , Alcohol Drinking/physiopathology , Analysis of Variance , Animals , Endothelial Cells/drug effects , Endothelial Cells/enzymology , HSP90 Heat-Shock Proteins , Humans , Liver Diseases, Alcoholic/etiology , Mice , Rats
7.
J Hepatol ; 75(3): 647-658, 2021 09.
Article in English | MEDLINE | ID: mdl-33991637

ABSTRACT

BACKGROUND AND AIMS: COVID-19 is associated with liver injury and elevated interleukin-6 (IL-6). We hypothesized that IL-6 trans-signaling in liver sinusoidal endothelial cells (LSECs) leads to endotheliopathy (a proinflammatory and procoagulant state) and liver injury in COVID-19. METHODS: Coagulopathy, endotheliopathy, and alanine aminotransferase (ALT) were retrospectively analyzed in a subset (n = 68), followed by a larger cohort (n = 3,780) of patients with COVID-19. Liver histology from 43 patients with COVID-19 was analyzed for endotheliopathy and its relationship to liver injury. Primary human LSECs were used to establish the IL-6 trans-signaling mechanism. RESULTS: Factor VIII, fibrinogen, D-dimer, von Willebrand factor (vWF) activity/antigen (biomarkers of coagulopathy/endotheliopathy) were significantly elevated in patients with COVID-19 and liver injury (elevated ALT). IL-6 positively correlated with vWF antigen (p = 0.02), factor VIII activity (p = 0.02), and D-dimer (p <0.0001). On liver histology, patients with COVID-19 and elevated ALT had significantly increased vWF and platelet staining, supporting a link between liver injury, coagulopathy, and endotheliopathy. Intralobular neutrophils positively correlated with platelet (p <0.0001) and vWF (p <0.01) staining, and IL-6 levels positively correlated with vWF staining (p <0.01). IL-6 trans-signaling leads to increased expression of procoagulant (factor VIII, vWF) and proinflammatory factors, increased cell surface vWF (p <0.01), and increased platelet attachment in LSECs. These effects were blocked by soluble glycoprotein 130 (IL-6 trans-signaling inhibitor), the JAK inhibitor ruxolitinib, and STAT1/3 small-interfering RNA knockdown. Hepatocyte fibrinogen expression was increased by the supernatant of LSECs subjected to IL-6 trans-signaling. CONCLUSION: IL-6 trans-signaling drives the coagulopathy and hepatic endotheliopathy associated with COVID-19 and could be a possible mechanism behind liver injury in these patients. LAY SUMMARY: Patients with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection often have liver injury, but why this occurs remains unknown. High levels of interleukin-6 (IL-6) and its circulating receptor, which form a complex to induce inflammatory signals, have been observed in patients with COVID-19. This paper demonstrates that the IL-6 signaling complex causes harmful changes to liver sinusoidal endothelial cells and may promote blood clotting and contribute to liver injury.


Subject(s)
COVID-19/complications , Endothelial Cells/pathology , Interleukin-6/physiology , Liver Diseases/etiology , SARS-CoV-2 , Adult , Blood Coagulation Disorders/etiology , Fibrinogen/analysis , Humans , Interleukin-6/blood , Janus Kinase 1/metabolism , Nitriles , Pyrazoles/pharmacology , Pyrimidines , Retrospective Studies , STAT3 Transcription Factor/metabolism , Signal Transduction/physiology , von Willebrand Factor/analysis
8.
Hepatol Res ; 51(9): 1000-1006, 2021 Sep.
Article in English | MEDLINE | ID: mdl-34260803

ABSTRACT

AIM: Coronavirus disease (COVID-19) is characterized by pneumonia with secondary damage to multiple organs including the liver. Liver injury (elevated alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) often correlates with disease severity in COVID-19 patients. The aim of this study is to identify pathological microthrombi in COVID-19 patient livers by correlating their morphology with liver injury, and examine hyperfibrinogenemia and von Willebrand factor (vWF) as mechanisms of their formation. METHODS: Forty-three post-mortem liver biopsy samples from COVID-19 patients were obtained from Papa Giovanni XXIII Hospital in Bergamo, Italy. Three morphological features of microthrombosis (sinusoidal erythrocyte aggregation [SEA], platelet microthrombi [PMT], and fibrous thrombi) were evaluated. RESULTS: We found liver sinusoidal microthrombosis in 23 COVID-19 patients (53%) was associated with a higher serum ALT and AST level compared to those without (ALT: 10-fold, p = 0.04; AST: 11-fold, p = 0.08). Of 43 livers, PMT and SEA were observed in 14 (33%) and 19 (44%) cases, respectively. Fibrous thrombi were not observed. Platelet microthrombi were associated with increased ALT (p < 0.01), whereas SEA was not (p = 0.73). In COVID-19 livers, strong vWF staining in liver sinusoidal endothelial cells was associated with significantly increased platelet adhesion (1.7-fold, p = 0.0016), compared to those with weak sinusoidal vWF (2-fold, p < 0.0001). Sinusoidal erythrocyte aggregation in 19 (83%) liver samples was mainly seen in zone 2. Livers with SEA had significantly higher fibrinogen (1.6-fold, p = 0.031) compared to those without SEA in COVID-19 patients. CONCLUSIONS: Liver PMT is a pathologically important thrombosis associated with liver injury in COVID-19, while SEA is a unique morphological feature of COVID-19 patient livers. Sinusoidal vWF and hyperfibrinogenemia could contribute to PMT and SEA formation.

9.
Biochem J ; 477(13): 2421-2438, 2020 07 17.
Article in English | MEDLINE | ID: mdl-32391876

ABSTRACT

One of the fundamental questions in bone biology is where osteoblasts originate and how osteoblast differentiation is regulated. The mechanism underlying which factors regulate chondrocyte to osteoblast lineage commitment remains unknown. Our data showed that Runt-related transcription factor 1 (Runx1) is expressed at different stages of both chondrocyte and osteoblast differentiation. Runx1 chondrocyte-specific knockout (Runx1f/fCol2α1-cre) mice exhibited impaired cartilage formation, decreased bone density, and an osteoporotic phenotype. The expressions of chondrocyte differentiation regulation genes, including Sox9, Ihh, CyclinD1, PTH1R, and hypertrophic chondrocyte marker genes including Col2α1, Runx2, MMP13, Col10α1 in the growth plate were significantly decreased in Runx1f/fCol2α1-cre mice chondrocytes. Importantly, the expression of osteoblast differentiation regulation genes including Osx, Runx2, ATF4, and osteoblast marker genes including osteocalcin (OCN) and osteopontin (OPN) were significantly decreased in the osteoblasts of Runx1f/fCol2α1-cre mice. Notably, our data showed that osteoblast differentiation regulation genes and marker genes are also expressed in chondrocytes and the expressions of these marker genes were significantly decreased in the chondrocytes of Runx1f/fCol2α1-cre mice. Our data showed that chromatin immunoprecipitation (ChIP) and promoter mapping analysis revealed that Runx1 directly binds to the Indian hedgehog homolog (Ihh) promoter to regulate its expression, indicating that Runx1 directly regulates the transcriptional expression of chondrocyte genes. Collectively, we revealed that Runx1 signals chondrocyte to osteoblast lineage commitment and promotes endochondral bone formation through enhancing both chondrogenesis and osteogenesis genes expressions, indicating Runx1 may be a therapeutic target to enhance endochondral bone formation and prevent osteoporosis fractures.


Subject(s)
Chondrocytes/cytology , Chondrocytes/metabolism , Core Binding Factor Alpha 2 Subunit/metabolism , Osteoblasts/cytology , Osteoblasts/metabolism , Adipogenesis/genetics , Adipogenesis/physiology , Animals , Blotting, Western , Cells, Cultured , Chondrogenesis/genetics , Chondrogenesis/physiology , Chromatin Immunoprecipitation , Core Binding Factor Alpha 2 Subunit/genetics , Fluorescent Antibody Technique , Immunohistochemistry , Mice , Osteogenesis/genetics , Osteogenesis/physiology , Real-Time Polymerase Chain Reaction
10.
J Biol Chem ; 293(3): 819-829, 2018 01 19.
Article in English | MEDLINE | ID: mdl-29167268

ABSTRACT

Mutations in the MYO7A gene, encoding the motor protein myosin VIIa, can cause Usher 1B, a deafness/blindness syndrome in humans, and the shaker-1 phenotype, characterized by deafness, head tossing, and circling behavior, in mice. Myosin VIIa is responsible for tension bearing and the transduction mechanism in the stereocilia and for melanosome transport in the retina, in line with the phenotypic outcomes observed in mice. However, the effect of the shaker-1 mutation, a R502P amino acid substitution, on the motor function is unclear. To explore this question, we determined the kinetic properties and the effect on the filopodial tip localization of the recombinant mouse myosin VIIa-5IQ-SAH R502P (myoVIIa-sh1) construct. Interestingly, although residue 502 is localized to a region thought to be involved in interacting with actin, the kinetic parameters for actin binding changed only slightly for the mutant construct. However, the rate constant for ATP hydrolysis (k+H + k-H) was reduced by ∼200-fold from 12 s-1 to 0.05 s-1, making the hydrolysis step the rate-limiting step of the ATPase cycle in the presence and absence of actin. Given that wild-type mouse myosin VIIa is a slow, high-duty ratio, monomeric motor, this altered hydrolysis rate would reduce activity to extremely low levels. Indeed, the translocation to the filopodial tips was hampered by the diminished motor function of a dimeric construct of the shaker-1 mutant. We conclude that the diminished motor activity of this mutant is most likely responsible for impaired hearing in the shaker-1 mice.


Subject(s)
Adenosine Triphosphate/metabolism , Myosins/genetics , Myosins/metabolism , Adenosine Triphosphatases/genetics , Adenosine Triphosphatases/metabolism , Animals , Mice , Mutation/genetics , Myosin VIIa , Retina/metabolism
11.
Proc Natl Acad Sci U S A ; 111(23): 8482-7, 2014 Jun 10.
Article in English | MEDLINE | ID: mdl-24850862

ABSTRACT

The pathogenesis of cleidocranial dysplasia (CCD) as well as the specific role of core binding factor ß (Cbfß) and the Runt-related transcription factor (RUNX)/Cbfß complex in postnatal skeletogenesis remain unclear. We demonstrate that Cbfß ablation in osteoblast precursors, differentiating chondrocytes, osteoblasts, and odontoblasts via Osterix-Cre, results in severe craniofacial dysplasia, skeletal dysplasia, abnormal teeth, and a phenotype recapitulating the clinical features of CCD. Cbfß(f/f)Osterix-Cre mice have fewer proliferative and hypertrophic chondrocytes, fewer osteoblasts, and almost absent trabecular bone, indicating that Cbfß may maintain trabecular bone formation through its function in hypertrophic chondrocytes and osteoblasts. Cbfß(f/f)Collagen, type 1, alpha 1 (Col1α1)-Cre mice show decreased bone mineralization and skeletal deformities, but no radical deformities in teeth, mandibles, or cartilage, indicating that osteoblast lineage-specific ablation of Cbfß results in milder bone defects and less resemblance to CCD. Activating transcription factor 4 (Atf4) and Osterix protein levels in both mutant mice are dramatically reduced. ChIP assays show that Cbfß directly associates with the promoter regions of Atf4 and Osterix. Our data further demonstrate that Cbfß highly up-regulates the expression of Atf4 at the transcriptional regulation level. Overall, our genetic dissection approach revealed that Cbfß plays an indispensable role in postnatal skeletal development and homeostasis in various skeletal cell types, at least partially by up-regulating the expression of Atf4 and Osterix. It also revealed that CCD may result from functional defects of the Runx2/Cbfß heterodimeric complex in various skeletal cells. These insights into the role of Cbfß in postnatal skeletogenesis and CCD pathogenesis may assist in the development of new therapies for CCD and osteoporosis.


Subject(s)
Chondrocytes/physiology , Cleidocranial Dysplasia/physiopathology , Core Binding Factor beta Subunit/physiology , Osteoblasts/physiology , Osteogenesis/physiology , Activating Transcription Factor 4/genetics , Activating Transcription Factor 4/metabolism , Animals , Animals, Newborn , Blotting, Western , Cells, Cultured , Chondrocytes/metabolism , Cleidocranial Dysplasia/genetics , Cleidocranial Dysplasia/metabolism , Collagen Type I/genetics , Collagen Type I/metabolism , Collagen Type I, alpha 1 Chain , Core Binding Factor Alpha 1 Subunit/genetics , Core Binding Factor Alpha 1 Subunit/metabolism , Core Binding Factor beta Subunit/genetics , Core Binding Factor beta Subunit/metabolism , Gene Expression Regulation, Developmental , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microscopy, Confocal , Microscopy, Fluorescence , Osteoblasts/metabolism , Osteogenesis/genetics , Promoter Regions, Genetic/genetics , Protein Binding , Protein Multimerization , Reverse Transcriptase Polymerase Chain Reaction , Skull/cytology , Skull/metabolism , Sp7 Transcription Factor , Transcription Factors/genetics , Transcription Factors/metabolism
12.
Infect Immun ; 83(4): 1235-45, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25583522

ABSTRACT

Periapical disease, an inflammatory disease mainly caused by dental caries, is one of the most prevalent infectious diseases of humans, affecting both children and adults. The infection travels through the root, leading to inflammation, bone destruction, and severe pain for the patient. Therefore, the development of a new class of anti-periapical disease therapies is necessary and critical for treatment and prevention. A small molecule, odanacatib (ODN), which is a cathepsin K (Ctsk) inhibitor, was investigated to determine its ability to treat this disease in a mouse model of periapical disease. While Ctsk was originally found in osteoclasts as an osteoclast-specific lysosomal protease, we were surprised to find that ODN can suppress the bacterium-induced immune response as well as bone destruction in the lesion area. X rays and microcomputed tomography (micro-CT) showed that ODN treatment had significant bone protection effects at different time points. Immunohistochemical and immunofluorescent staining show that ODN treatment dramatically decreased F4/80+ macrophages and CD3+ T cells in the lesion areas 42 days after infection. Consistent with these findings, quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) analysis showed low levels of proinflammatory mRNAs (for tumor necrosis factor alpha, interleukin 6, and interleukin 23α) and corresponding cytokine expression in the ODN-treated disease group. The levels of mRNA for Toll-like receptors 4, 5, and 9 also largely decreased in the ODN-treated disease group. Our results demonstrated that ODN can inhibit endodontic disease development, bone erosion, and immune response. These results indicate that application of this small molecule offers a new opportunity to design effective therapies that could prevent periapical inflammation and revolutionize current treatment options.


Subject(s)
Alveolar Bone Loss/drug therapy , Biphenyl Compounds/therapeutic use , Cathepsin K/antagonists & inhibitors , Periapical Periodontitis/drug therapy , Animals , Dental Caries/complications , Disease Models, Animal , Interleukin-23 Subunit p19/genetics , Interleukin-6/genetics , Macrophages/immunology , Male , Mice , Mice, Inbred BALB C , Osteoclasts/drug effects , RNA, Messenger/genetics , T-Lymphocytes/immunology , Toll-Like Receptor 4/genetics , Toll-Like Receptor 5/genetics , Toll-Like Receptor 9/genetics , Tumor Necrosis Factor-alpha/genetics
13.
Biomacromolecules ; 16(12): 4013-4021, 2015 Dec 14.
Article in English | MEDLINE | ID: mdl-26580410

ABSTRACT

Preparations of the highly ordered monoantennary, homofunctional diantennary, and heterofunctional diantennary neoglycopolymers of α-d-mannose and ß-d-glucose residues were achieved via ring-opening metathesis polymerization. Isothermal titration calorimetry measurements of these synthetic neoglycopolymers with Concanavalin A (Con A), revealed that heterofunctional diantennary architectures bearing both α-mannose and nonbinding ß-glucose units, poly(Man-Glc), binds to Con A (Ka = 16.1 × 10(6) M(-1)) comparably to homofunctional diantennary neoglycopolymer (Ka = 30 × 10(6) M(-1)) bearing only α-mannose unit, poly(Man-Man). In addition, poly(Man-Glc) neoglycopolymer shows a nearly 5-fold increasing in binding affinity compared to monoantennary neoglycopolymer, poly(Man). Although the exact mechanism for the high binding affinity of poly(Man-Glc) to Con A is unclear, we hypothesize that the α-mannose bound to Con A might facilitate interaction of ß-glucose with the extended binding site of Con A due to the close proximity of ß-glucose to α-mannose residues in the designed polymerizable scaffold.


Subject(s)
Concanavalin A/chemistry , Glucose/chemistry , Mannose/chemistry , Binding Sites , Calorimetry/methods , Carbohydrate Conformation , Kinetics , Polymerization
14.
Proc Natl Acad Sci U S A ; 109(4): 1257-62, 2012 Jan 24.
Article in English | MEDLINE | ID: mdl-22232695

ABSTRACT

To measure molecular changes underlying pathogen adaptation, we generated a searchable dataset of more than 12,000 mass spectrometry events, corresponding to lipids and small molecules that constitute a lipidome for Mycobacterium tuberculosis. Iron is essential for M. tuberculosis survival, and the organism imports this metal using mycobactin and carboxymycobactin siderophores. Detection of an unexpected siderophore variant and deletions of genes for iron scavenging has led to a revised mycobactin biosynthesis model. An organism-wide search of the M. tuberculosis database for hypothetical compounds predicted by this model led to the discovery of two families of previously unknown lipids, designated monodeoxymycobactins and monodeoxycarboxymycobactins. These molecules suggest a revised biosynthetic model that alters the substrates and order of action of enzymes through the mycobactin biosynthetic pathway. We tested this model genetically by solving M. tuberculosis lipidomes after deletion of the iron-dependent regulator (ideR), mycobactin synthase B (mbtB), or mycobactin synthase G (mbtG). These studies show that deoxymycobactins are actively regulated during iron starvation, and also define essential roles of MbtG in converting deoxymycobactins to mycobactin and in promoting M. tuberculosis growth. Thus, lipidomics is an efficient discovery tool that informs genetic relationships, leading to a revised general model for the biosynthesis of these virulence-conferring siderophores.


Subject(s)
Biosynthetic Pathways/physiology , Lipids/chemistry , Models, Biological , Mycobacterium tuberculosis/metabolism , Oxazoles/metabolism , Siderophores/metabolism , Chromatography, High Pressure Liquid , DNA Primers/genetics , Databases, Factual , Iron/metabolism , Mass Spectrometry
15.
bioRxiv ; 2024 Jan 16.
Article in English | MEDLINE | ID: mdl-38293189

ABSTRACT

As the most common degenerative joint disease, osteoarthritis (OA) contributes significantly to pain and disability during aging. Several genes of interest involved in articular cartilage damage in OA have been identified. However, the direct causes of OA are poorly understood. Evaluating the public human RNA-seq dataset showed that Cbfß, (subunit of a heterodimeric Cbfß/Runx1,Runx2, or Runx3 complex) expression is decreased in the cartilage of patients with OA. Here, we found that the chondrocyte-specific deletion of Cbfß in tamoxifen-induced Cbfßf/fCol2α1-CreERT mice caused a spontaneous OA phenotype, worn articular cartilage, increased inflammation, and osteophytes. RNA-sequencing analysis showed that Cbfß deficiency in articular cartilage resulted in reduced cartilage regeneration, increased canonical Wnt signaling and inflammatory response, and decreased Hippo/YAP signaling and TGF-ß signaling. Immunostaining and western blot validated these RNA-seq analysis results. ACLT surgery-induced OA decreased Cbfß and Yap expression and increased active ß-catenin expression in articular cartilage, while local AAV-mediated Cbfß overexpression promoted Yap expression and diminished active ß-catenin expression in OA lesions. Remarkably, AAV-mediated Cbfß overexpression in knee joints of mice with OA showed the significant protective effect of Cbfß on articular cartilage in the ACLT OA mouse model. Overall, this study, using loss-of-function and gain-of-function approaches, uncovered that low expression of Cbfß may be the cause of OA. Moreover, Local admission of Cbfß may rescue and protect OA through decreasing Wnt/ß-catenin signaling, and increasing Hippo/Yap signaling and TGFß/Smad2/3 signaling in OA articular cartilage, indicating that local Cbfß overexpression could be an effective strategy for treatment of OA.

16.
Elife ; 132024 May 28.
Article in English | MEDLINE | ID: mdl-38805545

ABSTRACT

As the most common degenerative joint disease, osteoarthritis (OA) contributes significantly to pain and disability during aging. Several genes of interest involved in articular cartilage damage in OA have been identified. However, the direct causes of OA are poorly understood. Evaluating the public human RNA-seq dataset showed that CBFB (subunit of a heterodimeric Cbfß/Runx1, Runx2, or Runx3 complex) expression is decreased in the cartilage of patients with OA. Here, we found that the chondrocyte-specific deletion of Cbfb in tamoxifen-induced Cbfbf/f;Col2a1-CreERT mice caused a spontaneous OA phenotype, worn articular cartilage, increased inflammation, and osteophytes. RNA-sequencing analysis showed that Cbfß deficiency in articular cartilage resulted in reduced cartilage regeneration, increased canonical Wnt signaling and inflammatory response, and decreased Hippo/Yap signaling and Tgfß signaling. Immunostaining and western blot validated these RNA-seq analysis results. ACLT surgery-induced OA decreased Cbfß and Yap expression and increased active ß-catenin expression in articular cartilage, while local AAV-mediated Cbfb overexpression promoted Yap expression and diminished active ß-catenin expression in OA lesions. Remarkably, AAV-mediated Cbfb overexpression in knee joints of mice with OA showed the significant protective effect of Cbfß on articular cartilage in the ACLT OA mouse model. Overall, this study, using loss-of-function and gain-of-function approaches, uncovered that low expression of Cbfß may be the cause of OA. Moreover, Local admission of Cbfb may rescue and protect OA through decreasing Wnt/ß-catenin signaling, and increasing Hippo/Yap signaling and Tgfß/Smad2/3 signaling in OA articular cartilage, indicating that local Cbfb overexpression could be an effective strategy for treatment of OA.


Subject(s)
Cartilage, Articular , Hippo Signaling Pathway , Homeostasis , Osteoarthritis , Transforming Growth Factor beta , YAP-Signaling Proteins , Animals , Cartilage, Articular/metabolism , Mice , Osteoarthritis/genetics , Osteoarthritis/metabolism , Transforming Growth Factor beta/metabolism , Transforming Growth Factor beta/genetics , YAP-Signaling Proteins/metabolism , YAP-Signaling Proteins/genetics , Wnt Signaling Pathway , beta Catenin/metabolism , beta Catenin/genetics , Signal Transduction , Protein Serine-Threonine Kinases/metabolism , Protein Serine-Threonine Kinases/genetics , Humans , Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/genetics
17.
ACS Omega ; 9(11): 13447-13457, 2024 Mar 19.
Article in English | MEDLINE | ID: mdl-38524494

ABSTRACT

Herein, we report a general route for the uniform coating of hard carbon (HC) powders via fluidized bed chemical vapor deposition. Carbon-based fine powders are excellent substrate materials for many catalytic and electrochemical applications but intrinsically difficult to fluidize and prone to elutriation. The reactor was designed to achieve as much retention of powders as possible, supported by a computational fluid dynamics study to assess the hydrodynamic behavior for varying gaseous flow rates. Solutions of the tin seleno- and thio-ether complexes [SnCl4{nBuSe(CH2)3SenBu}] and [SnCl4{nBuS(CH2)3SnBu}] were used as single source precursors and injected at high temperature into a fluidized bed of HC powders under nitrogen flow. The method allowed for the synthesis of HC-SnSx-SnSe2 composites at the gram scale with potential applications in electrocatalysis and sodium-ion battery anodes.

18.
JHEP Rep ; 6(7): 101069, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38966234

ABSTRACT

Background & Aims: The lymphatic system plays crucial roles in maintaining fluid balance and immune regulation. Studying the liver lymphatics has been considered challenging, as common lymphatic endothelial cell (LyEC) markers are expressed by other liver cells. Additionally, isolation of sufficient numbers of LyECs has been challenging because of their extremely low abundance (<0.01% of entire liver cell population) in a normal liver. Methods: Potential LyEC markers was identified using our published single-cell RNA sequencing (scRNA-seq) dataset (GSE147581) in mouse livers. Interleukin-7 (IL7) promoter-driven green fluorescent protein knock-in heterozygous mice were used for the validation of IL7 expression in LyECs in the liver, for the development of liver LyEC isolation protocol, and generating liver ischemia/reperfusion (I/R) injury. Scanning electron microscopy was used for the structural analysis of LyECs. Changes in LyEC phenotypes in livers of mice with I/R were determined by RNA-seq analysis. Results: Through scRNA-seq analysis, we have identified IL7 as an exclusive marker for liver LyECs, with no overlap with other liver cell types. Based on IL7 expression in liver LyECs, we have established an LyEC isolation method and observed distinct cell surface structures of LyECs with fenestrae and cellular pores (ranging from 100 to 400 nm in diameter). Furthermore, we identified LyEC genes that undergo alterations during I/R liver injuries. Conclusions: This study not only identified IL7 as an exclusively expressed gene in liver LyECs, but also enhanced our understanding of LyEC structures and demonstrated transcriptomic changes in injured livers. Impact and implications: Understanding the lymphatic system in the liver is challenging because of the absence of specific markers for liver LyEC. This study has identified IL7 as a reliable marker for LyECs, enabling the development of an effective method for their isolation, elucidating their unique cell surface structure, and identifying LyEC genes that undergo changes during liver damage. The development of IL7 antibodies for detecting it in human liver specimens will further advance our understanding of the liver lymphatic system in the future.

20.
Curr Hepatol Rep ; 22(2): 67-73, 2023.
Article in English | MEDLINE | ID: mdl-37214274

ABSTRACT

Purpose of Review: This review article will examine portal hypertension in alcoholic hepatitis (AH) from both a basic mechanistic and a clinical perspective. Recent Findings: Alcoholic hepatitis is a major public health problem in the USA, accounting for over 300,000 hospital admissions in a recent year of data (Jinjuvadia et al. J Clin Gastroenterol. 60;49:506-511). Portal hypertension is a key consequence of AH and a driver of liver-related morbidity and mortality. Alcohol may directly mediate portal hypertension via multiple possible mechanisms, including increased portal inflow, increased intrahepatic vasoconstriction, inflammation, and changes in the liver vasculature such as perisinusoidal fibrosis and phlebosclerosis. Summary: Portal hypertension is a key consequence of AH and a critical area for future research.

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