Publications by authors named "Muhammad N Aslam"

21 Publications

  • Page 1 of 1

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

Dietary polyunsaturated fatty acids modulate adipose secretome and is associated with changes in mammary epithelial stem cell self-renewal.

J Nutr Biochem 2019 09 24;71:45-53. Epub 2019 May 24.

Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA. Electronic address:

Chronic low-grade adipose inflammation, characterized by aberrant adipokine production and pro-inflammatory macrophage activation/polarization is associated with increased risk of breast cancer. Adipocyte fatty acid composition is influenced by dietary availability and may regulate adipokine secretion and adipose inflammation. After feeding F344 rats for 20 weeks with a Western diet or a fish oil-supplemented diet, we cultured primary rat adipose tissue in a three-dimensional explant culture and collected the conditioned medium. The rat adipose tissue secretome was assayed using the Proteome Profiler Cytokine XL Array, and adipose tissue macrophage polarization (M1/M2 ratio) was assessed using the iNOS/ARG1 ratio. We then assessed the adipokine's effects upon stem cell self-renewal using primary human mammospheres from normal breast mammoplasty tissue. Adipose from rats fed the fish oil diet had an ω-3:ω-6 fatty acid ratio of 0.28 compared to 0.04 in Western diet rats. The adipokine profile from the fish oil-fed rats was shifted toward adipokines associated with reduced inflammation compared to the rats fed the Western diet. The M1/M2 macrophage ratio decreased by 50% in adipose of fish oil-fed rats compared to that from rats fed the Western diet. Conditioned media from rats fed the high ω-6 Western diet increased stem cell self-renewal by 62%±9% (X¯%±SD) above baseline compared to only an 11%±11% increase with the fish oil rat adipose. Modulating the adipokine secretome with dietary interventions therefore may alter stromal-epithelial signaling that plays a role in controlling mammary stem cell self-renewal.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jnutbio.2019.05.007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6917480PMC
September 2019

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

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

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

Clinicopathologic and Immunophenotypic Characterization of 25 Cases of Acinic Cell Carcinoma with High-Grade Transformation.

Head Neck Pathol 2016 Jun 6;10(2):152-60. Epub 2015 Aug 6.

Department of Pathology, University of Michigan Health System, 2G332 UH, 1500 E. Medical Center Drive, Ann Arbor, MI, 48109, USA.

Acinic cell carcinoma (AiCC) with high-grade transformation is a rare variant of AiCC composed of both a conventional low-grade (LG) AiCC and a separate high-grade (HG) component. We describe here, the clinicopathologic and immunohistochemical features of 25 cases diagnosed between 1990 and 2015. Available tissue was analyzed and compared with a cohort of pure LG AiCC for the morphologic and immunophenotypic profile. Incidence was higher in females (1.8:1) than males with an overall mean age at presentation of 63.2 years. All tumors occurred in the parotid gland including 76% with facial nerve trunk and branches involvement. Most patients were treated with extensive resection and adjuvant therapy. Local recurrence or distant metastasis occurred in most patients, with 72.7% dead with disease (mean 2.9 years) and 3 patients alive with disease (mean 2.4 years). The majority of the tumors were composed of a LG microcystic AiCC and a HG component consisting of invasive lobules of undifferentiated cells with predominantly solid, cribriform, and glandular patterns. Acinic differentiation was still present in HG areas but aggressive features such as perineural invasion (76%), lymphovascular invasion (62%), positive margins (72%), high mitotic rate, atypical mitoses and/or comedonecrosis (86%) were easily identified. Compared to the pure LG AiCC, the cases with HG transformation showed significantly increased expression of cyclin-D1, p53 and Ki-67. Most HG areas of AiCC expressed membranous β-catenin (92%) and were negative for p63 (three cases were focally positive), S100, SMA, androgen, and estrogen receptors. DOG1 expression was present in all LG AiCC tested with retained expression in 91% of cases with HG transformation, supporting acinic differentiation in the HG foci. Recognition of AiCC with high-grade transformation is imperative as more aggressive clinical management is warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12105-015-0645-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4838973PMC
June 2016

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

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

A multi-mineral natural product inhibits liver tumor formation in C57BL/6 mice.

Biol Trace Elem Res 2012 Jun 6;147(1-3):267-74. Epub 2012 Jan 6.

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

C57BL/6 mice were maintained for up to 18 months on high-fat and low-fat diets with or without a multi-mineral supplement derived from the skeletal remains of the red marine algae Lithothamnion calcareum. Numerous grossly observable liver masses were visible in animals on the "western-style" high-fat diet sacrificed at 12 and 18 months. The majority of the masses were in male mice (20 out of 100 males versus 3 out of 100 females; p = 0.0002). There were more liver masses in animals on the high-fat diet than on the low-fat diet (15 out of 50 on high-fat versus 5 out of 50 on low-fat; p = 0.0254). The multi-mineral supplement reduced the number of liver masses in mice on both diets (3 out of 25 male mice in the low-fat diet group without the supplement versus 1 out of 25 mice with supplement; 12 of 25 male mice in the high-fat diet group without the supplement versus 3 of 25 mice with supplement [p = 0.0129]). Histological evaluation revealed a total of 17 neoplastic lesions (9 adenomas and 8 hepatocellular carcinomas), and 18 pre-neoplastic lesions. Out of eight hepatocellular carcinomas, seven were found in unsupplemented diet groups. Steatosis was widely observed in livers with and without grossly observable masses, but the multi-mineral supplement had no effect on the incidence of steatosis or its severity. Taken together, these findings suggest that a multi-mineral-rich natural product can protect mice against neoplastic and pre-neoplastic proliferative liver lesions that may develop in the face of steatosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12011-011-9316-2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3360994PMC
June 2012

Stimulation of fibroblast proliferation by insoluble gadolinium salts.

Biol Trace Elem Res 2012 Feb 1;145(2):257-67. Epub 2011 Sep 1.

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

The purpose of this study was to assess insoluble salts containing gadolinium (Gd(3+)) for effects on human dermal fibroblasts. Responses to insoluble Gd(3+) salts were compared to responses seen with Gd(3+) solubilized with organic chelators, as in the Gd(3+)-based contrast agents (GBCAs) used for magnetic resonance imaging. Insoluble particles of either Gd(3+) phosphate or Gd(3+) carbonate rapidly attached to the fibroblast cell surface and stimulated proliferation. Growth was observed at Gd(3+) concentrations between 12.5 and 125 μM, with toxicity at higher concentrations. Such a narrow window did not characterize GBCA stimulation. Proliferation induced by insoluble Gd(3+) salts was inhibited in the presence of antagonists of mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling pathways (similar to chelated Gd(3+)) but was not blocked by an antibody to the platelet-derived growth factor receptor (different from chelated Gd(3+)). Finally, high concentrations of the insoluble Gd(3+) salts failed to prevent fibroblast lysis under low-Ca(2+) conditions, while similar concentrations of chelated Gd(3+) were effective. In conclusion, while insoluble Gd(3+) salts are capable of stimulating fibroblast proliferation, one should be cautious in assuming that GBCA dechelation must occur in vivo to produce the profibrotic changes seen in association with GBCA exposure in the subset of renal failure patients that develop nephrogenic systemic fibrosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s12011-011-9176-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3273605PMC
February 2012

Fibroblast response to gadolinium: role for platelet-derived growth factor receptor.

Invest Radiol 2010 Dec;45(12):769-77

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

Objective: The purpose of this study was to assess the effects of gadolinium (Gd3+), provided as gadolinium chloride, on fibroblast function.

Materials And Methods: Human dermal fibroblasts in monolayer culture and intact skin in organ culture were exposed to the lanthanide metal (1-20 μM).

Results: Increased proliferation was observed, in association with upregulation of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1, without an apparent increase in production of type I procollagen. A platelet-derived growth factor (PDGF) receptor-blocking antibody inhibited fibroblast proliferation in response to Gd3+ as did inhibitors of signaling pathways--that is, mitogen-activated protein kinase and phosphatidylinositol-3 kinase pathways--that are activated by PDGF.

Conclusion: The responses to gadolinium chloride are similar to responses previously seen with chelated Gd3+ in clinically used magnetic resonance imaging contrast agents. Fibroblast responses appear to reflect Gd3+-induced PDGF receptor activation and downstream signaling. Increased dermal fibroblast proliferation in conjunction with effects on matrix metalloproteinase-1 and tissue inhibitor of metalloproteinases-1 could contribute to the fibroplastic/fibrotic changes seen in the lesional skin of individuals with nephrogenic systemic fibrosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLI.0b013e3181e943d2DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3164279PMC
December 2010

A mineral-rich red algae extract inhibits polyp formation and inflammation in the gastrointestinal tract of mice on a high-fat diet.

Integr Cancer Ther 2010 Mar 11;9(1):93-9. Epub 2010 Feb 11.

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

The purpose of this study was to determine whether a mineral-rich extract derived from the red marine algae Lithothamnion calcareum could be used as a dietary supplement for chemoprevention against colon polyp formation. A total of 60 C57bl/6 mice were divided into 3 groups based on diet. One group received a low-fat, rodent chow diet (AIN76A). The second group received a high-fat "Western-style" diet (HFWD). The third group was fed the same HFWD with the mineral-rich extract included as a dietary supplement. Mice were maintained on the respective diets for 15 months. Autopsies were performed at the time of death or at the completion of the study. To summarize, the cumulative mortality rate was higher in mice on the HFWD during the 15-month period (55%) than in mice from the low-fat diet or the extract-supplemented high-fat diet groups (20% and 30%, respectively; P < .05 with respect to both). Autopsies revealed colon polyps in 20% of the animals on the HFWD and none in animals of the other 2 groups (P < .05). In addition to the grossly visible polyps, areas of hyperplasia in the colonic mucosa and inflammatory foci throughout the gastrointestinal tract were observed histologically in animals on the high-fat diet. Both were significantly reduced in animals on the low-fat diet and animals on the extract-supplemented HFWD.These data suggest that the mineral-rich algae extract may provide a novel approach to chemoprevention in the colon.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1177/1534735409360360DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2861409PMC
March 2010

Collagenolytic activity is suppressed in organ-cultured human skin exposed to a gadolinium-based MRI contrast agent.

Invest Radiol 2010 Jan;45(1):42-8

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

Objective: Human skin produces increased amounts of matrix metalloproteinase-1 (MMP-1) when exposed in organ culture to Omniscan, one of the gadolinium-based MRI contrast agents (GBCA). MMP-1, by virtue of its ability to degrade structural collagen, contributes to collagen turnover in the skin. The objective of the present study was to determine whether collagenolytic activity was concomitantly up-regulated with increased enzyme.

Materials And Methods: Skin biopsies from normal volunteers were exposed in organ culture to Omniscan. Organ culture fluids obtained from control and treated skin were examined for ability to degrade type I collagen. The same culture fluids were examined for levels of MMP-1, tissue inhibitor of metalloproteinases-1 (TIMP-1), and complexes of MMP-1 and TIMP-1.

Results: Although MMP-1 was increased in culture fluid from Omniscan-treated skin, there was no increase in collagenolytic activity. In fact, collagenolytic activity declined. Increased production of TIMP-1 was also observed in Omniscan-treated skin, and the absolute amount of TIMP-1 was greater than the amount of MMP-1. Virtually all of the MMP-1 was present in MMP-1-TIMP-1 complexes, but the majority of TIMP-1 was not associated with MMP-1. When human dermal fibroblasts were exposed to TIMP-1 (up to 250 ng/mL), no increase in proliferation was observed, but an increase in collagen deposition into the cell layer was seen.

Conclusion: Gadolinium-based MRI contrast agent exposure has recently been linked to a fibrotic skin condition in patients with impaired kidney function. The mechanism is unknown. The increase in TIMP-1 production and concomitant reduction in collagenolytic activity demonstrated here could result in decreased collagen turnover and increased deposition of collagen in lesional skin.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLI.0b013e3181bf95ebDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2819152PMC
January 2010

A combination of curcumin and ginger extract improves abrasion wound healing in corticosteroid-impaired hairless rat skin.

Wound Repair Regen 2009 May-Jun;17(3):360-6

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

Hairless rats were topically treated with a combination of 10% curcumin and 3% ginger extract (or with each agent alone) for a 21-day period. Following this, the rats were treated topically with Temovate (corticosteroid) for an additional 15 days. At the end of the treatment period, superficial abrasion wounds were induced in the treated skin. Abrasion wounds healed more slowly in the skin of Temovate-treated rats than in skin of control animals. Healing was more rapid in skin of rats that had been pretreated with either curcumin or ginger extract alone or with the combination of curcumin-ginger extract (along with Temovate) than in the skin of rats treated with Temovate and vehicle alone. Skin samples were obtained at the time of wound closure. Collagen production was increased and matrix metalloproteinase-9 production was decreased in the recently healed skin from rats treated with the botanical preparation relative to rats treated with Temovate plus vehicle. In none of the rats was there any indication of skin irritation during the treatment phase or during wounding and repair. Taken together, these data suggest that a combination of curcumin and ginger extract might provide a novel approach to improving structure and function in skin and, concomitantly, reducing formation of nonhealing wounds in "at-risk" skin.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1524-475X.2009.00483.xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2819156PMC
November 2009

Regulation of collagen turnover in human skin fibroblasts exposed to a gadolinium-based contrast agent.

Invest Radiol 2009 Aug;44(8):433-9

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

Objective: Nephrogenic systemic fibrosis is a clinical syndrome linked with exposure in renal failure patients to gadolinium-based contrast agents (GBCAs) during magnetic resonance imaging. Recently, we demonstrated that GBCA exposure led to increased matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinases-1 (TIMP-1) levels in human skin fibroblasts. The goals of the present work were to assess the relationship between altered MMP-1/TIMP-1 expression and collagen production/deposition, and the intracellular signaling events that lead from GBCA stimulation to altered MMP-1 and TIMP-1 production.

Materials And Methods: Human dermal fibroblasts were treated with one of the currently used GBCAs (Omniscan). Proliferation was quantified as were levels of MMP-1, TIMP-1, procollagen type I, and collagen type I. Signaling events were concomitantly assessed, and signaling inhibitors were used.

Results: Fibroblasts exposed to Omniscan had increases in both MMP-1 and TIMP-1 levels. Omniscan treatment interfered with collagen turnover, leading to increased type I collagen deposition without an increase in type I procollagen production. U0126, an inhibitor of mitogen-activated protein kinase signaling, and LY294002, a phosphatidylinositol-3 kinase inhibitor, reduced MMP-1 levels. U0126 also reduced TIMP-1 levels, but LY294002 increased TIMP-1.

Conclusion: These data provide evidence for complex regulation of collagen deposition in Omniscan-treated skin. They suggest that the major effect of Omniscan exposure is on an enzyme/inhibitor system that regulates collagen breakdown rather than on collagen production, per se.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/RLI.0b013e3181a4d7e9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2859439PMC
August 2009

Impaired keratinocyte function on matrix metalloproteinase-1 (MMP-1) damaged collagen.

Arch Dermatol Res 2009 Aug 8;301(7):497-506. Epub 2009 Apr 8.

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

Healing of superficial skin wounds depends on the proliferation and migration of keratinocytes at the wound margin. When human epidermal keratinocytes were incubated on polymerized type I collagen, they rapidly attached and spread. The cells underwent a proliferative response and, over the subsequent 6-day period, covered the collagen surface with a monolayer of cells. When keratinocytes were plated on collagen that had been fragmented by exposure to matrix metalloproteinase-1 (MMP-1, collagenase-1), the cells attached as readily as to intact collagen but spread more slowly and less completely. Growth was reduced by approximately 50%. Instead of covering the collagen surface, the keratinocytes remained localized to the site of attachment. Keratinocytes on fragmented collagen expressed a more differentiated phenotype as indicated by a higher level of surface E-cadherin. Based on these findings, we suggest that damage to the underlying collagenous matrix may impede efficient keratinocyte function and retard wound closure.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00403-009-0948-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2908395PMC
August 2009

7-Chloro-5-(4-hydroxyphenyl)-1-methyl-3-(naphthalen-2-ylmethyl)-4,5-dihydro-1H-benzo[b][1,4]diazepin-2(3H)-one (Bz-423), a benzodiazepine, suppresses keratinocyte proliferation and has antipsoriatic activity in the human skin-severe, combined immunodeficient mouse transplant model.

J Pharmacol Exp Ther 2008 Mar 30;324(3):938-47. Epub 2007 Nov 30.

Department of Pathology, The University of Michigan, 1301 Catherine Rd., Box 0602, Ann Arbor, MI 48109, USA.

7-Chloro-5-(4-hydroxyphenyl)-1-methyl-3-(naphthalen-2-ylmethyl)-4,5-dihydro-1H-benzo[b][1,4]diazepin-2(3H)-one (Bz-423) is a benzodiazepine that has cytotoxic and cytostatic activity against a variety of cells in vivo and in vitro. In the present study, we demonstrate that Bz-423 (formulated for topical delivery) reduces epidermal hyperplasia in human psoriatic skin after transplantation to severe, combined immunodeficient (scid) mice. Bz-423 also suppresses the hyperplasia that develops in nonpsoriatic human skin as a consequence of transplantation to scid mice. Proliferation of human epidermal keratinocytes in monolayer culture was suppressed by Bz-423 at concentrations of 0.5 to 2.0 muM (noncytotoxic concentrations). Keratinocyte growth inhibition was accompanied by increased oxidant generation in Bz-423-treated cells, and treatment with vitamin E along with Bz-423 reversed the growth inhibition. Growth inhibition was accompanied by a redistribution of beta-catenin from a cytoplasmic pool to the cell membrane and by reduced levels of c-myc and cyclin D1 (two molecules associated with Wnt pathway signaling). Several analogs of Bz-423 were examined for antiproliferative activity against human epidermal keratinocytes and human dermal fibroblasts in monolayer culture. Each of the analogs tested suppressed growth of both cell types, but in all cases, keratinocytes were more sensitive than fibroblasts. Two of the compounds were found to suppress epidermal hyperplasia induced with all-trans retinoic acid in organ cultures of human skin. Taken together, these data show that Bz-423 and certain analogs produce biological responses in skin cells in vitro and in vivo that are consistent with therapeutic goals for treating psoriasis or epidermal hyperplasia resulting from other causes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1124/jpet.107.130955DOI Listing
March 2008