Publications by authors named "James Varani"

100 Publications

Organoid culture to study epithelial cell differentiation and barrier formation in the colon: bridging the gap between monolayer cell culture and human subject research.

In Vitro Cell Dev Biol Anim 2021 Jan 5. Epub 2021 Jan 5.

The Department of Pathology, The University of Michigan Medical School, Ann Arbor, MI, 48109, USA.

Organoid culture provides a powerful technology that can bridge the gap between monolayer cell culture on the one hand and whole animal or human subject research on the other. Tissues from many different organs from multiple species, including human, have already been successfully adapted to organoid growth. While optimal culture conditions have not yet been established for all tissue types, it seems that most tissues will, ultimately, be amenable to this type of culture. The colon is one of the tissues in which organoid culture was first established as a technology and which has been most successfully employed. The ready availability of histologically normal tissue as well as both premalignant and malignant tissue (often from the same individual) makes this possible. While individual tumors are highly variable relative to one another in organoid culture, a high degree of genotypic consistency exists between the tumor tissue and the histologically normal counterpart from a given source. Further, source material and tumor tissue in organoid culture demonstrate a high degree of genotypic consistency. Even after 6-9 mo in continuous culture, drift in the mutational profile has been shown to be minimal. Colon tissue maintained in organoid culture, thus, provides a good surrogate for the tissue of origin-a surrogate, however, that is as amenable to intervention with molecular, pharmacological, and immunological approaches as are more-traditionally studied cell lines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11626-020-00534-6DOI Listing
January 2021

Ulcerative Colitis-Derived Colonoid Culture: A Multi-Mineral-Approach to Improve Barrier Protein Expression.

Front Cell Dev Biol 2020 23;8:577221. Epub 2020 Nov 23.

Department of Pathology, The University of Michigan Medical School, Ann Arbor, MI, United States.

Background: Recent studies demonstrated that Aquamin, a calcium-, magnesium-rich, multi-mineral natural product, improves barrier structure and function in colonoids obtained from the tissue of healthy subjects. The goal of the present study was to determine if the colonic barrier could be improved in tissue from subjects with ulcerative colitis (UC).

Methods: Colonoid cultures were established with colon biopsies from 9 individuals with UC. The colonoids were then incubated for a 2-week period under control conditions (in culture medium with a final calcium concentration of 0.25 mM) or in the same medium supplemented with Aquamin to provide 1.5 - 4.5 mM calcium. Effects on differentiation and barrier protein expression were determined using several approaches: phase-contrast and scanning electron microscopy, quantitative histology and immunohistology, mass spectrometry-based proteome assessment and transmission electron microscopy.

Results: Although there were no gross changes in colonoid appearance, there was an increase in lumen diameter and wall thickness on histology and greater expression of cytokeratin 20 (CK20) along with reduced expression of Ki67 by quantitative immunohistology observed with intervention. In parallel, upregulation of several differentiation-related proteins was seen in a proteomic screen with the intervention. Aquamin-treated colonoids demonstrated a modest up-regulation of tight junctional proteins but stronger induction of adherens junction and desmosomal proteins. Increased desmosomes were seen at the ultrastructural level. Proteomic analysis demonstrated increased expression of several basement membrane proteins and hemidesmosomal components. Proteins expressed at the apical surface (mucins and trefoils) were also increased as were several additional proteins with anti-microbial activity or that modulate inflammation. Finally, several transporter proteins that affect electrolyte balance (and, thereby affect water resorption) were increased. At the same time, growth and cell cycle regulatory proteins (Ki67, nucleophosmin, and stathmin) were significantly down-regulated. Laminin interactions, matrix formation and extracellular matrix organization were the top three up-regulated pathways with the intervention.

Conclusion: A majority of individuals including patients with UC do not reach the recommended daily intake for calcium and other minerals. To the extent that such deficiencies might contribute to the weakening of the colonic barrier, the findings employing UC tissue-derived colonoids here suggest that adequate mineral intake might improve the colonic barrier.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fcell.2020.577221DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7719760PMC
November 2020

Differentiation of human colon tissue in culture: Effects of calcium on trans-epithelial electrical resistance and tissue cohesive properties.

PLoS One 2020 5;15(3):e0222058. Epub 2020 Mar 5.

Department of Pathology, The University of Michigan Medical School, Ann Arbor, Michigan, United States of America.

Background And Aims: Human colonoid cultures maintained under low-calcium (0.25 mM) conditions undergo differentiation spontaneously and, concomitantly, express a high level of tight junction proteins, but not desmosomal proteins. When calcium is included to a final concentration of 1.5-3.0 mM (provided either as a single agent or as a combination of calcium and additional minerals), there is little change in tight junction protein expression but a strong up-regulation of desmosomal proteins and an increase in desmosome formation. The aim of this study was to assess the functional consequences of calcium-mediated differences in barrier protein expression.

Methods: Human colonoid-derived epithelial cells were interrogated in transwell culture under low- or high-calcium conditions for monolayer integrity and ion permeability by measuring trans-epithelial electrical resistance (TEER) across the confluent monolayer. Colonoid cohesiveness was assessed in parallel.

Results: TEER values were high in the low-calcium environment but increased in response to calcium. In addition, colonoid cohesiveness increased substantially with calcium supplementation. In both assays, the response to multi-mineral intervention was greater than the response to calcium alone. Consistent with these findings, several components of tight junctions were expressed at 0.25 mM calcium but these did not increase substantially with supplementation. Cadherin-17 and desmoglein-2, in contrast, were weakly-expressed under low calcium conditions but increased with intervention.

Conclusions: These findings indicate that low ambient calcium levels are sufficient to support the formation of a permeability barrier in the colonic epithelium. Higher calcium levels promote tissue cohesion and enhance barrier function. These findings may help explain how an adequate calcium intake contributes to colonic health by improving barrier function, even though there is little change in colonic histological features over a wide range of calcium intake levels.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0222058PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7058309PMC
March 2020

A Calcium-Rich Multimineral Intervention to Modulate Colonic Microbial Communities and Metabolomic Profiles in Humans: Results from a 90-Day Trial.

Cancer Prev Res (Phila) 2020 01 26;13(1):101-116. Epub 2019 Nov 26.

Department of Pathology, The University of Michigan Medical School, Ann Arbor, Michigan.

Aquamin is a calcium-, magnesium-, and multiple trace element-rich natural product with colon polyp prevention efficacy based on preclinical studies. The goal of this study was to determine the effects of Aquamin on colonic microbial community and attendant metabolomic profile. Thirty healthy human participants were enrolled in a 90-day trial in which Aquamin (delivering 800 mg of calcium per day) was compared with calcium alone or placebo. Before and after the intervention, colonic biopsies and stool specimens were obtained. All 30 participants completed the study without serious adverse event or change in liver and renal function markers. Compared with pretreatment values, intervention with Aquamin led to a reduction in total bacterial DNA ( = 0.0001) and a shift in the microbial community measured by thetaYC (θ; = 0.0087). Treatment with calcium also produced a decline in total bacteria, but smaller than seen with Aquamin, whereas no reduction was observed with placebo in the colon. In parallel with microbial changes, a reduction in total bile acid levels ( = 0.0375) and a slight increase in the level of the short-chain fatty acid (SCFA) acetate in stool specimens ( < 0.0001) from Aquamin-treated participants were noted. No change in bile acids or SCFAs was observed with calcium or placebo. We conclude that Aquamin is safe and tolerable in healthy human participants and may produce beneficial alterations in the colonic microbial community and the attendant metabolomic profile. Because the number of participants was small, the findings should be considered preliminary.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1940-6207.CAPR-19-0325DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7528938PMC
January 2020

Calcium-induced differentiation in normal human colonoid cultures: Cell-cell / cell-matrix adhesion, barrier formation and tissue integrity.

PLoS One 2019 17;14(4):e0215122. Epub 2019 Apr 17.

Department of Pathology, The University of Michigan Medical School, Ann Arbor, Michigan, United States of America.

Background And Aims: The goal of the study was to assess calcium alone and Aquamin, a multi-mineral natural product that contains magnesium and detectable levels of 72 trace elements in addition to calcium, for capacity to affect growth and differentiation in colonoid cultures derived from histologically-normal human colon tissue.

Methods: Colonoid cultures were maintained in a low-calcium (0.25 mM) medium or in medium supplemented with an amount of calcium (1.5-3.0 mM), either from calcium alone or Aquamin for a period of two weeks. This was shown in a previous study to induce differentiation in colonoids derived from large adenomas. Changes in growth, morphological features and protein expression profile were assessed at the end of the incubation period using a combination of phase-contrast and scanning electron microscopy, histology and immunohistology, proteomic assessment and transmission electron microscopy.

Results: Unlike the previously-studied tumor-derived colonoids (which remained un-differentiated in the absence of calcium-supplementation), normal tissue colonoids underwent differentiation as indicated by gross and microscopic appearance, a low proliferative index and high-level expression of cytokeratin 20 in the absence of intervention (i.e., in control condition). Only modest additional changes were seen in these parameters with either calcium alone or Aquamin (providing up to 3.0 mM calcium). In spite of this, proteomic analysis and immunohistochemistry revealed that both interventions induced strong up-regulation of proteins that promote cell-cell and cell-matrix adhesive functions, barrier formation and tissue integrity. Transmission electron microscopy revealed an increase in desmosomes in response to intervention.

Conclusions: These findings demonstrate that colonoids derived from histologically normal human tissue can undergo differentiation in the presence of a low ambient calcium concentration. However, higher calcium levels induce elaboration of proteins that promote cell-cell and cell-matrix adhesion. These changes could lead to improved barrier function and improved colon tissue health.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0215122PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6469792PMC
December 2019

Atrophic and hypertrophic photoaging: Clinical, histologic, and molecular features of 2 distinct phenotypes of photoaged skin.

J Am Acad Dermatol 2019 Aug 5;81(2):480-488. Epub 2019 Apr 5.

Department of Dermatology, University of Michigan, Ann Arbor, Michigan.

Background: Exposure to the sun causes premature skin aging, known as photoaging. Clinical features of photoaging vary widely among individuals. In one form, skin appears thin with telangiectasia, and in another form, skin appears thickened with coarse wrinkles. Etiologic, clinical, and therapeutic distinctions among different forms of photoaging remain largely unknown.

Objective: To characterize the clinical, histologic, and molecular features of hypertrophic and atrophic photoaging.

Methods: In total, 53 individuals were clinically classified as having primarily atrophic or hypertrophic photoaging or neither (controls). Participants' demographic and sun exposure-related lifestyle data were captured by questionnaire. Fifteen clinical features of participants were qualitatively or quantitively scored. Facial biopsies were analyzed for gene expression and histologic characteristics.

Results: Actinic and seborrheic keratosis, telangiectasia, and prior incidence of skin cancers were statistically significantly greater and photoaging scale severity, coarse wrinkles, thickness, and sallowness were significantly reduced in atrophic versus hypertrophic groups. Histology also revealed significantly less elastotic material in atrophic photoaging. Gene expression of matrix metalloproteinases and collagens did not differ between the 2 forms of photoaging.

Limitations: The study was not designed to identify other possible subtypes of photoaging.

Conclusion: Systematic, categorical, and quantitative clinical and histologic assessments distinguish atrophic and hypertrophic photoaging.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jaad.2019.03.081DOI Listing
August 2019

Pro-inflammatory agents released by pathogens, dying host cells, and neutrophils act synergistically to destroy host tissues: a working hypothesis.

J Inflamm Res 2019 23;12:35-47. Epub 2019 Jan 23.

Department of Pathology, The University of Michigan Medical School, Ann Arbor, MI, USA.

We postulate that the extensive cell and tissue damage inflicted by many infectious, inflammatory and post-inflammatory episodes is an enled result of a synergism among the invading microbial agents, host neutrophils and dead and dying cells in the nidus. Microbial toxins and other metabolites along with the plethora of pro-inflammatory agents released from activated neutrophils massively recruited to the infectious sites and high levels of cationic histones, other cationic peptides, proteinases and Th1 cytokines released from activated polymorphonuclear neutrophils (PMNs) and from necrotized tissues may act in concert (synergism) to bring about cell killing and tissue destruction. Multiple, diverse interactions among the many potential pro-inflammatory moieties have been described in these complex lesions. Such infections are often seen in the skin and aerodigestive tract where the tissue is exposed to the environment, but can occur in any tissue. Commonly, the tissue-destructive infections are caused by group A streptococci, pneumococci, , meningococci, and , although many other microbial species are seen on occasion. All these microbial agents are characterized by their ability to recruit large numbers of PMNs. Given the complex nature of the disease process, it is proposed that, to treat these multifactorial disorders, a "cocktail" of anti-inflammatory agents combined with non-bacteriolytic antibiotics and measures to counteract the critical toxic role of cationic moieties might prove more effective than a strategy based on attacking the bacteria alone.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.2147/JIR.S190007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6350637PMC
January 2019

Calcium-Induced Differentiation of Human Colon Adenomas in Colonoid Culture: Calcium Alone versus Calcium with Additional Trace Elements.

Cancer Prev Res (Phila) 2018 07 10;11(7):413-428. Epub 2018 Apr 10.

Department of Pathology, The University of Michigan Medical School, Ann Arbor, Michigan.

Previous murine studies have demonstrated that dietary Aquamin, a calcium-rich, multi-mineral natural product, suppressed colon polyp formation and transition to invasive tumors more effectively than calcium alone when provided over the lifespan of the animals. In the current study, we compared calcium alone to Aquamin for modulation of growth and differentiation in human colon adenomas in colonoid culture. Colonoids established from normal colonic tissue were examined in parallel. Both calcium alone at 1.5 mmol/L and Aquamin (provided at 1.5 mmol/L calcium) fostered differentiation in the adenoma colonoid cultures as compared with control (calcium at 0.15 mmol/L). When Aquamin was provided at an amount delivering 0.15 mmol/L calcium, adenoma differentiation also occurred, but was not as complete. Characteristic of colonoids undergoing differentiation was a reduction in the number of small, highly proliferative buds and their replacement by fewer but larger buds with smoother surface. Proliferation marker (Ki67) expression was reduced and markers of differentiation (CK20 and occludin) were increased along with E-cadherin translocalization to the cell surface. Additional proteins associated with differentiation/growth control [including histone-1 family members, certain keratins, NF2 (merlin), olfactomedin-4 and metallothioneins] were altered as assessed by proteomics. Immunohistologic expression of NF2 was higher with Aquamin as compared with calcium at either concentration. These findings support the conclusions that (i) calcium (1.5 mmol/L) has the capacity to modulate growth and differentiation in large human colon adenomas and (ii) Aquamin delivering 0.15 mmol/L calcium has effects on proliferation and differentiation not observed when calcium is used alone at this concentration. .
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1940-6207.CAPR-17-0308DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6030430PMC
July 2018

Identification, isolation and characterization of human LGR5-positive colon adenoma cells.

Development 2018 03 14;145(6). Epub 2018 Mar 14.

Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA

The intestine is maintained by stem cells located at the base of crypts and distinguished by the expression of LGR5. Genetically engineered mouse models have provided a wealth of information about intestinal stem cells, whereas less is known about human intestinal stem cells owing to difficulty detecting and isolating these cells. We established an organoid repository from patient-derived adenomas, adenocarcinomas and normal colon, which we analyzed for variants in 71 colorectal cancer (CRC)-associated genes. Normal and neoplastic colon tissue organoids were analyzed by immunohistochemistry and fluorescent-activated cell sorting for LGR5. LGR5-positive cells were isolated from four adenoma organoid lines and were subjected to RNA sequencing. We found that LGR5 expression in the epithelium and stroma was associated with tumor stage, and by integrating functional experiments with LGR5-sorted cell RNA sequencing data from adenoma and normal organoids, we found correlations between LGR5 and CRC-specific genes, including dickkopf WNT signaling pathway inhibitor 4 () and SPARC-related modular calcium binding 2 (). Collectively, this work provides resources, methods and new markers to isolate and study stem cells in human tissue homeostasis and carcinogenesis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1242/dev.153049DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5897593PMC
March 2018

Neuronal Protein 3.1 Deficiency Leads to Reduced Cutaneous Scar Collagen Deposition and Tensile Strength due to Impaired Transforming Growth Factor-β1 to -β3 Translation.

Am J Pathol 2017 Feb 8;187(2):292-303. Epub 2016 Dec 8.

Department of Pathology, The University of Chicago Medical School, Chicago, Illinois. Electronic address:

Neuronal protein 3.1 (P311), a conserved RNA-binding protein, represents the first documented protein known to stimulate transforming growth factor (TGF)-β1 to -β3 translation in vitro and in vivo. Because TGF-βs play critical roles in fibrogenesis, we initiated efforts to define the role of P311 in skin scar formation. Here, we show that P311 is up-regulated in skin wounds and in normal and hypertrophic scars. Genetic ablation of p311 resulted in a significant decrease in skin scar collagen deposition. Lentiviral transfer of P311 corrected the deficits, whereas down-regulation of P311 levels by lentiviral RNA interference reproduced the deficits seen in P311 mice. The decrease in collagen deposition resulted in scars with reduced stiffness but also reduced scar tensile strength. In vitro studies using murine and human dermal fibroblasts showed that P311 stimulated TGF-β1 to -β3 translation, a process that involved eukaryotic translation initiation factor 3 subunit b as a P311 binding partner. This resulted in increased TGF-β levels/activity and increased collagen production. In addition, P311 induced dermal fibroblast activation and proliferation. Finally, exogenous TGF-β1 to -β3, each restituted the normal scar phenotype. These studies demonstrate that P311 is required for the production of normal cutaneous scars and place P311 immediately up-stream of TGF-βs in the process of fibrogenesis. Conditions that decrease P311 levels could result in less tensile scars, which could potentially lead to higher incidence of dehiscence after surgery.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajpath.2016.10.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5389364PMC
February 2017

Calcium Reduces Liver Injury in Mice on a High-Fat Diet: Alterations in Microbial and Bile Acid Profiles.

PLoS One 2016 16;11(11):e0166178. Epub 2016 Nov 16.

The Unit for Laboratory Animal Medicine, The University of Michigan, Ann Arbor, MI, 48109, United States of America.

A high-fat "Western-style" diet (HFWD) promotes obesity-related conditions including non-alcoholic steatohepatitis (NASH), the histologic manifestation of non-alcoholic fatty liver disease (NAFLD). In addition to high saturated fat and processed carbohydrates, the typical HFWD is deficient in calcium. Calcium-deficiency is an independent risk factor for many conditions associated with the Western-style diet. However, calcium has not been widely evaluated in the context of NAFLD. The goal of the present study was to determine if dietary calcium supplementation could protect mice fed a HFWD from NAFLD, specifically by decreasing non-alcoholic steatohepatitis (NASH) and its down-stream consequences. Male C57BL/6NCrl mice were maintained for 18-months on a HFWD containing dietary calcium at either 0.41 gm/kg feed (unsupplemented) or 5.25 gm/kg feed (supplemented). Although there was no difference in body weight or steatosis, calcium-supplemented mice were protected against downstream consequences of hepatic steatosis, manifested by lower inflammation, less fibrosis, and by lower overall histologic NAFLD activity scores (NAS). Calcium supplementation correlated with distinctly segregating gut fecal and cecal microbial communities as defined by 16S rRNA gene sequence. Further, calcium supplementation also correlated with decreased hepatic concentration of the major conjugated murine primary bile acid, tauro-β-muricholic acid (as well as a decrease in the parent unconjugated bile acid). Thus, calcium was protective against progression of diet-induced hepatic steatosis to NASH and end-stage liver disease, suggesting that calcium supplementation may effectively protect against adverse hepatic consequences of HFWD in cases where overall diet modification cannot be sustained. This protective effect occurred in concert with calcium-mediated gut microbial community shifts and alterations of the hepatic bile acid pool.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0166178PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5113033PMC
June 2017

Nuclear histones: major virulence factors or just additional early sepsis markers? A comment.

Inflammopharmacology 2016 Oct 9;24(5):287-289. Epub 2016 Sep 9.

Institute for Drug Research, School of Pharmacy, Hebrew University of Jerusalem, Jerusalem, Israel.

In 2009, Xu et al. and Chaput et al. in Nature Medicine had argued that the main cause of death in sepsis is the release from neutrophil nets of nuclear histone, highly toxic to endothelial cells and that these polycations are major and unique virulence factors. Since 2009, numerous researchers have also suggested the involvement of histones in the pathophysiology of many clinical disorders. If histones are indeed major unique virulence toxic agents, then heparin, activated protein C and antibodies to histone should prove excellent antisepsis agents. However, this is provided that these agents are administered to patients early enough before the activation of the cytokine storms, immune responses and the coagulation cascades are irreversibly unleashed. This may not be practical, since a diagnosis of sepsis is usually made much later. Future identifications of novel early markers are therefore needed and a compilation of cocktails of antagonists may replace the faulty single antagonists tried for many years, but in vain, to prevent death in sepsis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10787-016-0279-yDOI Listing
October 2016

Iron Uptake via DMT1 Integrates Cell Cycle with JAK-STAT3 Signaling to Promote Colorectal Tumorigenesis.

Cell Metab 2016 09 18;24(3):447-461. Epub 2016 Aug 18.

Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA. Electronic address:

Dietary iron intake and systemic iron balance are implicated in colorectal cancer (CRC) development, but the means by which iron contributes to CRC are unclear. Gene expression and functional studies demonstrated that the cellular iron importer, divalent metal transporter 1 (DMT1), is highly expressed in CRC through hypoxia-inducible factor 2α-dependent transcription. Colon-specific Dmt1 disruption resulted in a tumor-selective inhibitory effect of proliferation in mouse colon tumor models. Proteomic and genomic analyses identified an iron-regulated signaling axis mediated by cyclin-dependent kinase 1 (CDK1), JAK1, and STAT3 in CRC progression. A pharmacological inhibitor of DMT1 antagonized the ability of iron to promote tumor growth in a CRC mouse model and a patient-derived CRC enteroid orthotopic model. Our studies implicate a growth-promoting signaling network instigated by elevated intracellular iron levels in tumorigenesis, offering molecular insights into how a key dietary component may contribute to CRC.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cmet.2016.07.015DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5023486PMC
September 2016

Bone structure and function in male C57BL/6 mice: Effects of a high-fat Western-style diet with or without trace minerals.

Bone Rep 2016 Dec;5:141-149

Department of Pathology, The University of Michigan, Ann Arbor, Michigan 48109.

Purpose: Osteoporosis occurs in both women and men, but most of what we know about the condition comes from studies in females. The present study examined bone structure and function over an 18-month period in male C57BL/6 mice maintained on either a rodent chow diet (AIN76A) or a high-fat, Western-style diet (HFWD). Effects of mineral supplementation were assessed in both diets.

Methods: Trabecular and cortical bone structure in femora and vertebrae were assessed by micro-CT analysis. Following this, bone stiffness and strength measurements were made. Finally, bone levels of several cationic trace elements were quantified, and serum biomarkers of bone metabolism evaluated.

Results: Bone loss occurred over time in both diets but was more rapid and extensive in mice on the HFWD. Dietary mineral supplementation reduced bone loss in both diets and increased bone stiffness in the femora and bone stiffness and strength in the vertebrae. Bone content of strontium was increased in response to mineral supplementation in both diets.

Conclusions: Bone loss was more severe in mice on the HFWD and mineral supplementation mitigated the effects of the HFWD. In comparison to previous findings with female C57BL/6 mice, the present studies indicate that males are more sensitive to diet and benefited from a healthy diet (AIN76A), while females lost as much bone on the healthy diet as on the HFWD. Male mice benefited from mineral supplementation, just as females did in the previous study.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.bonr.2016.05.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4920365PMC
December 2016

Balanced regulation of the CCN family of matricellular proteins: a novel approach to the prevention and treatment of fibrosis and cancer.

J Cell Commun Signal 2015 Dec 23;9(4):327-39. Epub 2015 Dec 23.

Department of Pathology, The University of Michigan Medical School, Ann Arbor, MI, USA.

The CCN family of matricellular signaling proteins is emerging as a unique common link across multiple diseases and organs related to injury and repair. They are now being shown to play a central role in regulating the pathways to the initiation and resolution of normal wound healing and fibrosis in response to multiple forms of injury. Similarly, it is also emerging that they play a key role in regulating the establishment, growth, metastases and tissue regeneration in many forms of cancer via the interaction of cancer cells with the tumor stroma. Evidence has been recently provided that these proteins do not act independently but are co-regulated working in a yin/yang manner to alter the outcome of both normal physiological processes as well as pathology. The purpose of this review is to twofold. First, it will summarize work to date supporting CCN2 as a therapeutic target in the formation and progression of renal, skin, and other organ fibrosis, as well as cancer stroma formation. Second, it will highlight recent evidence for CCN3 as a counter-regulator and a potential therapeutic agent in these diseases with an exciting, novel potential to both treat and then restore tissue homeostasis in those afflicted by these devastating disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12079-015-0309-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4715828PMC
December 2015

Tumor-selective proteotoxicity of verteporfin inhibits colon cancer progression independently of YAP1.

Sci Signal 2015 Oct 6;8(397):ra98. Epub 2015 Oct 6.

Department of Molecular and Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI 48109, USA. Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA.

Yes-associated protein 1 (YAP1) is a transcriptional coactivator in the Hippo signaling pathway. Increased YAP1 activity promotes the growth of tumors, including that of colorectal cancer (CRC). Verteporfin, a drug that enhances phototherapy to treat neovascular macular degeneration, is an inhibitor of YAP1. We found that verteporfin inhibited tumor growth independently of its effects on YAP1 or the related protein TAZ in genetically or chemically induced mouse models of CRC, in patient-derived xenografts, and in enteroid models of CRC. Instead, verteporfin exhibited in vivo selectivity for killing tumor cells in part by impairing the global clearance of high-molecular weight oligomerized proteins, particularly p62 (a sequestrome involved in autophagy) and STAT3 (signal transducer and activator of transcription 3; a transcription factor). Verteporfin inhibited cytokine-induced STAT3 activity and cell proliferation and reduced the viability of cultured CRC cells. Although verteporfin accumulated to a greater extent in normal cells than in tumor cells in vivo, experiments with cultured cells indicated that the normal cells efficiently cleared verteporfin-induced protein oligomers through autophagic and proteasomal pathways. Culturing CRC cells under hypoxic or nutrient-deprived conditions (modeling a typical CRC microenvironment) impaired the clearance of protein oligomers and resulted in cell death, whereas culturing cells under normoxic or glucose-replete conditions protected cell viability and proliferation in the presence of verteporfin. Furthermore, verteporfin suppressed the proliferation of other cancer cell lines even in the absence of YAP1, suggesting that verteporfin may be effective against multiple types of solid cancers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1126/scisignal.aac5418DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4818013PMC
October 2015

Ulcerative Dermatitis in C57BL/6NCrl Mice on a Low-Fat or High-Fat Diet With or Without a Mineralized Red-Algae Supplement.

J Am Assoc Lab Anim Sci 2015 Sep;54(5):487-96

Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, Michigan, USA.

Ulcerative dermatitis (UD) is a spontaneous idiopathic disease that often affects C57BL/6 mice or mice on a C57BL/6 background. UD is characterized by intense pruritus and lesion formation, most commonly on the head or dorsal thorax. Self-trauma likely contributes to wound severity and delayed wound healing. Histologically, changes are nonspecific, consisting of ulceration with neutrophilic and mastocytic infiltration and epithelial hyperplasia and hyperkeratosis. Diet appears to have a profound effect on the development and progression of UD lesions. We investigated the incidence and severity of UD in C57BL/6NCrl mice on a high-fat western-style diet (HFWD) compared with a standard rodent chow. In addition, we examined the protective effects of dietary supplementation with a multimineral-rich product derived from marine red algae on UD in these 2 diet groups. HFWD-fed mice had an increased incidence of UD. In addition, mice on a HFWD had significantly more severe clinical and histologic lesions. Dietary mineral supplementation in mice on a HFWD decreased the histologic severity of lesions and reduced the incidence of UD in female mice in both diets. In conclusion, a high-fat western-style diet may potentiate UD in C57BL/6NCrl mice. Insufficient mineral supply and mineral imbalance may contribute to disease development. Mineral supplementation may be beneficial in the treatment of UD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4587616PMC
September 2015

Induction of calcium sensing receptor in human colon cancer cells by calcium, vitamin D and aquamin: Promotion of a more differentiated, less malignant and indolent phenotype.

Mol Carcinog 2015 Jul 17;54(7):543-53. Epub 2013 Dec 17.

Department of Microbiology, Immunology and Cell Biology Simmons Cancer Institute, Southern Illinois University School of Medicine, Springfield, IIllinois.

The calcium sensing receptor (CaSR) is a robust promoter of differentiation in colonic epithelial cells and functions as a tumor suppressor. Cancer cells that do not express CaSR (termed CaSR null) are highly malignant while acquisition of CaSR expression in these cells circumvents the malignant phenotype. We hypothesize that chemopreventive agents mediate their action through the induction of CaSR. Here, we compare the effectiveness of Ca(2+), vitamin D, and Aquamin (a marine algae product containing Ca(2+), magnesium and detectable levels of 72 additional minerals) on the induction of CaSR in the CBS and HCT116 human colon carcinoma cell lines and the corresponding CaSR null cells isolated from these lines. All three agonists induced CaSR mRNA and protein expression and inhibited cellular proliferation in the parental and CaSR null cells. Aquamin was found to be most potent in this regard. Induction of CaSR expression by these agonists resulted in demethylation of the CaSR gene promoter with a concurrent increase in CaSR promoter reporter activity. However, demethylation per se did not induce CaSR transcription. Induction of CaSR expression resulted in a down-regulated expression of tumor inducers and up-regulated expression of tumor suppressors. Again, Aquamin was found to be most potent in these biologic effects. This study provides a rationale for the use of a multi-mineral approach in the chemoprevention of colon cancer and suggests that induction of CaSR may be a measure of the effectiveness of chemopreventive agents.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/mc.22123DOI Listing
July 2015

MDI 301 suppresses myeloid leukemia cell growth in vitro and in vivo without the toxicity associated with all-trans retinoic acid therapy.

Anticancer Drugs 2015 Aug;26(7):763-73

Department of Pathology, The University of Michigan Medical School, Ann Arbor, Michigan, USA.

MDI 301 is a novel 9-cis retinoic acid derivative in which the terminal carboxylic acid group has been replaced by a picolinate ester. MDI 301, a retinoic acid receptor-α - agonist, suppressed the growth of several human myeloid leukemia cell lines (HL60, NB4, OCI-M2, and K562) in vitro and induced cell-substrate adhesion in conjunction with upregulation of CD11b. Tumor growth in HL60-injected athymic nude mice was reduced. In vitro, MDI 301 was comparable to all-trans retinoic acid (ATRA) whereas in vivo, MDI 301 was slightly more efficacious than ATRA. Most importantly, unlike what was found with ATRA treatment, MDI 301 did not induce a cytokine response in the treated animals and the severe inflammatory changes and systemic toxicity seen with ATRA did not occur. A retinoid with these characteristics might be valuable in the treatment of promyelocytic leukemia, or, perhaps, other forms of myeloid leukemia.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/CAD.0000000000000248DOI Listing
August 2015

Monoclonal antibodies specific for oncofetal antigen--immature laminin receptor protein: Effects on tumor growth and spread in two murine models.

Cancer Biol Ther 2015 ;16(5):724-32

a Department of Pathology; The University of Michigan Medical School ; Ann Arbor , MI , USA.

The oncofetal antigen - immature laminin receptor protein (OFA/iLRP) has been linked to metastatic tumor spread for several years. The present study, in which 2 highly-specific, high-affinity OFA/iLRP-reactive mouse monoclonal antibodies were examined for ability to suppress tumor cell growth and metastatic spread in the A20 B-cell leukemia model and the B16 melanoma model, provides the first direct evidence that targeting OFA/iLRP with exogenous antibodies can have therapeutic benefit. While the antibodies were modestly effective at preventing tumor growth at the primary injection site, both antibodies strongly suppressed end-organ tumor formation following intravenous tumor cell injection. Capacity of anti-OFA/iLRP antibodies to suppress tumor spread through the blood in the leukemia model suggests their use as a therapy for individuals with leukemic disease (either for patients in remission or even as part of an induction therapy). The results also suggest use against metastatic spread with solid tumors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/15384047.2015.1026484DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4622506PMC
March 2016

Clinical, Histologic, and Molecular Analysis of Differences Between Erythematotelangiectatic Rosacea and Telangiectatic Photoaging.

JAMA Dermatol 2015 Aug;151(8):825-36

Department of Dermatology, University of Michigan Medical School, Ann Arbor.

Importance: Facial erythema and telangiectasia are commonly associated with the erythematotelangiectatic subtype of rosacea (ETR). It is important for clinicians to recognize that these findings can also be associated with a subtype of photoaging, which we term telangiectatic photoaging (TP).

Objective: To demonstrate that ETR and TP are distinct dermatologic disorders.

Design: A case-control observational study comparing clinical, histologic, and gene expression features of 26 participants with ETR, 20 with TP, and 11 age- and sex-matched controls in the Program for Clinical Research in Dermatology at University of Michigan.

Main Outcomes And Measures: Findings of clinical history and examination, light and electron microscopy, immunohistochemical analyses, and real-time quantitative reverse-transcriptase polymerase chain reaction gene expression.

Results: Transient erythema was greater in the ETR group (38% graded moderate to severe) than in the TP (0%; P < .001) and control groups (0%; P = .002). Nontransient erythema was also greater in the ETR group (50% graded moderate to severe) than in the TP (25%; P = .03) and control groups (0%; P < .001). Participants with ETR tended to have erythema and telangiectasia primarily on the central face (79%), whereas those with TP tended to have more lateral involvement (57%; P < .001). Those with ETR had significantly less clinical evidence of photodamage (0% graded 6-8 on a photonumeric scale) than those with TP (40% graded 6-8; P = .01). Histologically, there was less evidence of photodamage in ETR than in TP, which had wispy collagen and solar elastosis surrounding blood vessels. Immunohistologic analysis demonstrated greater geometric mean immunostained area by mast cell tryptase staining in ETR samples (0.018%) than in TP (0.004%; P = .01) or control samples (0.001%; P < .001) but no increase in mast cell number, indicative of greater mast cell degranulation. Gene expression of matrix metalloproteinase-3 was 4-fold greater in ETR samples than in TP samples (P = .004) and 5-fold higher than in control samples (P = .004). Gene expression of the neuropeptides calcitonin gene-related peptide (CGRP-α) and substance P was significantly increased in ETR compared with TP (9-fold [P < .001] and 5-fold [P = .002], respectively) and control samples (10-fold [P < .001] and 28-fold [P < .001], respectively).

Conclusions And Relevance: Telangiectatic photoaging is characterized by less transient and nontransient erythema, a more lateral distribution of erythema and telangiectasia, less neurogenic mast cell activation, and less MMP-mediated matrix remodeling than ETR. These data demonstrate that TP is a distinct clinical entity from ETR that can be distinguished on the basis of clinical, histologic, and gene expression findings.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1001/jamadermatol.2014.4728DOI Listing
August 2015

Erlotinib-induced skin inflammation is IL-1 mediated in KC-Tie2 mice and human skin organ culture.

J Invest Dermatol 2015 Mar 13;135(3):910-913. Epub 2014 Oct 13.

Department of Dermatology, University of Michigan, Ann Arbor, Michigan, USA; Ann Arbor Veterans Affairs Hospital, Ann Arbor, Michigan, USA. Electronic address:

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/jid.2014.445DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4323891PMC
March 2015

Human colonic crypts in culture: segregation of immunochemical markers in normal versus adenoma-derived.

Lab Invest 2014 Feb 23;94(2):222-34. Epub 2013 Dec 23.

Division of Gastroenterology, Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.

In order to advance a culture model of human colonic neoplasia, we developed methods for the isolation and in vitro maintenance of intact colonic crypts from normal human colon tissue and adenomas. Crypts were maintained in three-dimensional Matrigel culture with a simple, serum-free, low Ca(2+) (0.15 mM) medium. Intact colonic crypts from normal human mucosa were viably maintained for 3-5 days with preservation of the in situ crypt-like architecture, presenting a distinct base and apex. Abnormal structures from adenoma tissue could be maintained through multiple passages (up to months), with expanding buds/tubules. Immunohistochemical markers for intestinal stem cells (Lgr5), growth (Ki67), differentiation (E-cadherin, cytokeratin 20 (CK20) and mucin 2 (MUC2)) and epithelial turnover (Bax, cleaved Caspase-3), paralleled the changes in function. The epithelial cells in normal crypts followed the physiological sequence of progression from proliferation to differentiation to dissolution in a spatially and temporally appropriate manner. Lgr5 expression was seen in a few basal cells of freshly isolated crypts, but was not detected after 1-3 days in culture. After 24 h in culture, crypts from normal colonic tissue continued to show strong Ki67 and MUC2 expression at the crypt base, with a gradual decrease over time such that by days 3-4 Ki67 was not expressed. The differentiation marker CK20 increased over the same period, eventually becoming intense throughout the whole crypt. In adenoma-derived structures, expression of markers for all stages of progression persisted for the entire time in culture. Lgr5 showed expression in a few select cells after months in culture. Ki67 and MUC2 were largely associated with the proliferative budding regions while CK20 was localized to the parent structure. This ex vivo culture model of normal and adenomatous crypts provides a readily accessible tool to help understand the growth and differentiation process in human colonic epithelium.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/labinvest.2013.145DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4108175PMC
February 2014

Preservation of bone structure and function by Lithothamnion sp. derived minerals.

Biol Trace Elem Res 2013 Dec 6;156(1-3):210-20. Epub 2013 Oct 6.

Department of Pathology, The University of Michigan, 1301 Catherine Road, Box 5602, Ann Arbor, MI, 48109, USA,

Progressive bone mineral loss and increasing bone fragility are hallmarks of osteoporosis. A combination of minerals isolated from the red marine algae, Lithothamnion sp. was examined for ability to inhibit bone mineral loss in female mice maintained on either a standard rodent chow (control) diet or a high-fat western diet (HFWD) for 5, 12, and 18 months. At each time point, femora were subjected to μ-CT analysis and biomechanical testing. A subset of caudal vertebrae was also analyzed. Following this, individual elements were assessed in bones. Serum levels of the 5b isoform of tartrate-resistant acid phosphatase (TRAP) and procollagen type I propeptide (P1NP) were also measured. Trabecular bone loss occurred in both diets (evident as early as 5 months). Cortical bone increased through month 5 and then declined. Cortical bone loss was primarily in mice on the HFWD. Inclusion of the minerals in the diet reduced bone mineral loss in both diets and improved bone strength. Bone mineral density was also enhanced by these minerals. Of several cationic minerals known to be important to bone health, only strontium was significantly increased in bone tissue from animals fed the mineral diets, but the increase was large (5-10 fold). Serum levels of TRAP were consistently higher in mice receiving the minerals, but levels of P1NP were not. These data suggest that trace minerals derived from marine red algae may be used to prevent progressive bone mineral loss in conjunction with calcium. Mineral supplementation could find use as part of an osteoporosis-prevention strategy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12011-013-9820-7DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3905747PMC
December 2013

Role of calcium sensing receptor (CaSR) in tumorigenesis.

Best Pract Res Clin Endocrinol Metab 2013 Jun 6;27(3):455-63. Epub 2013 May 6.

Southern Illinois University School of Medicine, Department of Medical Microbiology, Immunology and Cell Biology and Simmons Cancer Institute, Springfield, IL, USA.

The extracellular Ca(2+)-sensing receptor (CaSR) is a robust promoter of differentiation in colonic epithelial cells and functions as a tumor suppressor in colon cancer. CaSR mediates its biologic effects through diverse mechanisms. Loss of CaSR expression activates a myriad of stem cell-like molecular features that drive and sustain the malignant and drug-resistant phenotypes of colon cancer. This CaSR-null phenotype, however, is not irreversible and induction of CaSR expression in CaSR-null cells promotes cell death mechanisms and restores drug sensitivity. The CaSR also functions as a tumor suppressor in breast cancer and promotes cellular sensitivity to cytotoxic drugs. BRCA1 and CaSR functions intersect in breast cancer cells, and CaSR activation can rescue breast cancer cells from the deleterious effect of BRCA1 mutations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.beem.2013.04.001DOI Listing
June 2013

Progression of ulcerative dermatitis lesions in C57BL/6Crl mice and the development of a scoring system for dermatitis lesions.

J Am Assoc Lab Anim Sci 2012 ;51(5):586-93

Unit for Laboratory Animal Medicine, University of Michigan, Ann Arbor, Michigan, USA.

Ulcerative dermatitis (UD) is a common, spontaneous condition in mice with a C57BL/6 background. Although initial lesions may be mild, UD is a progressive disease that often results in ulcerations or debilitating fibrotic contractures. In addition, lesions typically are unresponsive to treatment. Euthanasia is often warranted in severe cases, thereby affecting study outcomes through the loss of research subjects. Because the clinical assessment of UD can be subjective, a quantitative scoring method and documentation of the likely time-frame of progression may be helpful in predicting when animals that develop dermatitis should be removed from a study. Such a system may also be helpful in quantitatively assessing success of various treatment strategies and be valuable to clinical laboratory animal veterinarians. In this 1.5-y, prospective cohort study, we followed 200 mice to monitor the development and course of UD. Mice were examined every 2 wk. A clinical sign (alopecia, pruritus, or peripheral lymphadenopathy) was not identified that predicted development of UD lesions in the subsequent 2-wk period. Once UD developed, pruritus, the character of the lesion (single or multiple crust, coalescing crust, erosion, or ulceration), and the size of the lesion were the only parameters that changed (increased) over the course of the disease. Pruritus was a factor in the rapid progression of UD lesions. We used these findings to develop a quantitative scoring system for the severity of UD. This enhanced understanding of the progression of UD and the quantitative scoring system will enhance the monitoring of UD.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3447447PMC
November 2013

A multimineral natural product from red marine algae reduces colon polyp formation in C57BL/6 mice.

Nutr Cancer 2012 4;64(7):1020-8. Epub 2012 Oct 4.

Department of Pathology, The University of Michigan, Ann Arbor, Michigan 48109, USA.

The goal of this study was to determine if a multimineral natural product derived from red marine algae could reduce colon polyp formation in mice on a high-fat diet. C57BL/6 mice were maintained for up to 18 mo either on a high-fat "Western-style" diet or on a low-fat diet (AIN 76A), with or without the multimineral-supplement. To summarize, colon polyps were detected in 22 of 70 mice (31%) on the high-fat diet but in only 2 of 70 mice (3%) receiving the mineral-supplemented high-fat diet (P < 0.0001). Colon polyps were detected in 16 of 70 mice (23%) in the low-fat group; not significantly different from high-fat group but significantly higher than the high-fat-supplemented group (P = 0.0006). This was in spite of the fact that the calcium level in the low-fat diet was comparable to the level of calcium in the high-fat diet containing the multimineral-product. Supplementation of the low-fat diet reduced the incidence to 8 of 70 mice (11% incidence). Taken together, these findings demonstrate that a multimineral natural product can protect mice on a high-fat diet against adenomatous polyp formation in the colon. These data suggest that increased calcium alone is insufficient to explain the lower incidence of colon polyps.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1080/01635581.2012.713160DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3660990PMC
March 2013

Growth control in colon epithelial cells: gadolinium enhances calcium-mediated growth regulation.

Biol Trace Elem Res 2012 Dec 19;150(1-3):467-76. Epub 2012 Sep 19.

Department of Pathology, University of Michigan Medical School, 1301 Catherine Street, SPC 5602, Ann Arbor, MI 48109, USA.

Gadolinium, a member of the lanthanoid family of transition metals, interacts with calcium-binding sites on proteins and other biological molecules. The overall goal of the present investigation was to determine if gadolinium could enhance calcium-induced epithelial cell growth inhibition in the colon. Gadolinium at concentrations as low as 1-5 μM combined with calcium inhibits proliferation of human colonic epithelial cells more effectively than calcium alone. Gadolinium had no detectable effect on calcium-induced differentiation in the same cells based on change in cell morphology, induction of E-cadherin synthesis, and translocation of E-cadherin from the cytosol to the cell surface. When the colon epithelial cells were treated with gadolinium and then exposed to increased calcium concentrations, movement of extracellular calcium into the cell was suppressed. In contrast, gadolinium treatment had no effect on ionomycin-induced release of stored intracellular calcium into the cytoplasm. Whether these in vitro observations can be translated into an approach for reducing abnormal proliferation in the colonic mucosa (including polyp formation) is not known. These results do, however, provide an explanation for our recent findings that a multi-mineral supplement containing all of the naturally occurring lanthanoid metals including gadolinium are more effective than calcium alone in preventing colon polyp formation in mice on a high-fat diet.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12011-012-9503-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3661021PMC
December 2012

Gadolinium-induced fibrosis is counter-regulated by CCN3 in human dermal fibroblasts: a model for potential treatment of nephrogenic systemic fibrosis.

J Cell Commun Signal 2012 Jun 31;6(2):97-105. Epub 2012 May 31.

Department of Physiology and Biophysics, Rosalind Franklin University of Science and Medicine, 3333 Green Bay Road, North Chicago, IL, USA,

We recently show that CCN3 is a counter-regulatory molecule for the pro-fibrotic protein CCN2, and a potentially novel fibrosis therapy. The goal of this study was to assess the role of CCN3 in fibroproliferative/fibrotic responses in human dermal fibroblasts exposed to Omniscan, one of the gadolinium-based contrast agents associated with development of nephrogenic systemic fibrosis (NSF) a rare but life-threatening disease thought to be complication of NMR diagnostics in renal impaired patients. Human dermal fibroblasts were exposed to Omniscan; or to platelet-derived growth factor (PDGF) and transforming growth factor-β (TGF-β) as controls. Proliferation was assessed along with matrix metalloproteinase-1, tissue inhibitor of metalloproteinases-1 and type 1 procollagen in the absence and presence of CCN3. In parallel, CCN3 production was assessed in control and Omniscan-treated cells. The results showed that PDGF stimulated fibroblast proliferation, production of Timp-1 and MMP-1 whereas exogenous CCN3 inhibited, in a dose response manner, cell proliferation (approx. 50 % max.) and production of MMP-1 (approx 35 % max.) but had little effect on TIMP-1. TGF-β stimulated type 1 procollagen production but not proliferation, Timp-1 or MMP-1 compared to non-TGF-ß treated control cells, and CCN3 treatment blocked (approx. 80 % max.) this up-regulation. Interestingly, untreated, control fibroblasts produced high constitutive levels of CCN3 and concentrations of Omniscan that induced fibroproliferative/fibrogenic changes in dermal fibroblasts correspondingly suppressed CCN3 production. The use of PDGF and TGF-β as positive controls, and the study of differential responses, including that to Omniscan itself, provide the first evidence for a role of fibroblast-derived CCN3 as an endogenous regulator of pro-fibrotic changes, elucidating possible mechanism(s). In conclusion, these data support our hypothesis of a role for fibroblast-derived CCN3 as an endogenous regulator of pro-fibrotic changes in these cells, and suggest that CCN3 may be an important regulatory molecule in NSF and a target for treatment in this and other fibrotic diseases.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12079-012-0164-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3368017PMC
June 2012