Modeling Sympathetic Hyperactivity in Alzheimer’s Related Bone Loss

2021 ◽  
pp. 1-12
Author(s):  
Robert A. Culibrk ◽  
Ahmad S. Arabiyat ◽  
Carisa A. DeKalb ◽  
Mariah S. Hahn

Background: A significant subset of patients with Alzheimer’s disease (AD) exhibit low bone mineral density and are therefore more fracture-prone, relative to their similarly aged neurotypical counterparts. In addition to chronic immune hyperactivity, behavioral dysregulation of effector peripheral sympathetic neurons—which densely innervate bone and potently modulate bone remodeling—is implicated in this pathological bone reformation. Objective: Thus, there exists a pressing need for a robust in vitro model which allows interrogation of the paracrine interactions between the putative mediators of AD-related osteopenia: sympathetic neurons (SNs) and mesenchymal stem cells (MSCs). Methods: Toward this end, activated SN-like PC12 cells and bone marrow derived MSCs were cultured in poly(ethylene glycol) diacrylate (PEGDA) hydrogels in the presence or absence of the AD-relevant inflammatory cytokine tumor necrosis factor alpha (TNF-α) under mono- and co-culture conditions. Results: PC12s and MSCs exposed separately to TNF-α displayed increased expression of pro-inflammatory mediators and decreased osteopontin (OPN), respectively. These data indicate that TNF-α was capable of inducing a dysregulated state in both cell types consistent with AD. Co-culture of TNF-α-activated PC12s and MSCs further exacerbated pathological behaviors in both cell types. Specifically, PC12s displayed increased secretion of interleukin 6 relative to TNF-α stimulated monoculture controls. Similarly, MSCs demonstrated a further reduction in osteogenic capacity relative to TNF-α stimulated monoculture controls, as illustrated by a significant decrease in OPN and collagen type I alpha I chain. Conclusion: Taken together, these data may indicate that dysregulated sympathetic activity may contribute to AD-related bone loss.

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Shu-Jem Su ◽  
Yao-Tsung Yeh ◽  
Huey-Wen Shyu

Biochanin A (BCA) is a major isoflavone abundant in red clover (Trifolium pretense). The protective effect of BCA on bone loss in an ovariectomized (OVX) animal model has never been clarified. The objective of this study was to investigate the biological effects of BCA on bone loss in OVX ratsin vivoand on the development of osteoblasts and osteoclastsin vitro. Ovariectomy resulted in a marked increase in body weight and a decrease in femoral bone mineral density and trabecular bone volume that was prevented by BCA or 17β-estradiol (E2) treatment. However, an increase in uterine weight was observed in E2-treated OVX rats, but not in response to BCA treatment. Treatment with BCA increased the mRNA expression of osterix, collagen type I, alkaline phosphatase (ALP), and osteocalcin and decreased the mRNA expression of tartrate-resistant acid phosphatase (TRAP) and the receptor activator of nuclear factor-κB ligand (RANKL)/osteoprotegerin (OPG) ratio in the femur of OVX rats. Treatment with BCA or E2 prevented the OVX-induced increase in urinary deoxypyridinoline (DPD) and serum tumor necrosis factorα(TNF-α) and interleukin-1β(IL-1β).In vitro, BCA induced preosteoblasts to differentiate into osteoblasts and increased osteoblast mineralization. BCA inhibited preosteoclasts and osteoclast proliferation and decreased osteoclast bone resorption. These findings suggest that BCA treatment can effectively prevent the OVX-induced increase in bone loss and bone turnover possibly by increasing osteoblastic activities and decreasing osteoclastic activities.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1440
Author(s):  
Serena Danti ◽  
Shivesh Anand ◽  
Bahareh Azimi ◽  
Mario Milazzo ◽  
Alessandra Fusco ◽  
...  

Chitin nanofibrils (CNs) are an emerging bio-based nanomaterial. Due to nanometric size and high crystallinity, CNs lose the allergenic features of chitin and interestingly acquire anti-inflammatory activity. Here we investigate the possible advantageous use of CNs in tympanic membrane (TM) scaffolds, as they are usually implanted inside highly inflamed tissue environment due to underlying infectious pathologies. In this study, the applications of CNs in TM scaffolds were twofold. A nanocomposite was used, consisting of poly (ethylene oxide terephthalate)/(polybutylene terephthalate) (PEOT/PBT) copolymer loaded with CN/polyethylene glycol (PEG) pre-composite at 50/50 (w/w %) weight ratio, and electrospun into fiber scaffolds, which were coated by CNs from crustacean or fungal sources via electrospray. The degradation behavior of the scaffolds was investigated during 4 months at 37 °C in an otitis-simulating fluid. In vitro tests were performed using cell types to mimic the eardrum, i.e., human mesenchymal stem cells (hMSCs) for connective, and human dermal keratinocytes (HaCaT cells) for epithelial tissues. HMSCs were able to colonize the scaffolds and produce collagen type I. The inflammatory response of HaCaT cells in contact with the CN-coated scaffolds was investigated, revealing a marked downregulation of the pro-inflammatory cytokines. CN-coated PEOT/PBT/(CN/PEG 50:50) scaffolds showed a significant indirect antimicrobial activity.


1999 ◽  
Vol 67 (3) ◽  
pp. 1107-1115 ◽  
Author(s):  
Jeffrey Talkington ◽  
Steven P. Nickell

ABSTRACT The Lyme disease spirochete, Borrelia burgdorferi, is introduced into human hosts via tick bites. Among the cell types present in the skin which may initially contact spirochetes are mast cells. Since spirochetes are known to activate a variety of cell types in vitro, we tested whether B. burgdorferi spirochetes could activate mast cells. We report here that freshly isolated rat peritoneal mast cells or mouse MC/9 mast cells cultured in vitro with live or freeze-thawed B. burgdorferi spirochetes undergo low but detectable degranulation, as measured by [5-3H] hydroxytryptamine release, and they synthesize and secrete the proinflammatory cytokine tumor necrosis factor alpha (TNF-α). In contrast to findings in previous studies, where B. burgdorferi-associated activity was shown to be dependent upon protein lipidation, mast cell TNF-α release was not induced by either lipidated or unlipidated recombinant OspA. This activity was additionally shown to be protease sensitive and surface expressed. Finally, comparisons of TNF-α-inducing activity in known low-, intermediate-, and high-passage B. burgdorferi B31 isolates demonstrated passage-dependent loss of activity, indicating that the activity is probably plasmid encoded. These findings document the presence in low-passage B. burgdorferi spirochetes of a novel lipidation-independent activity capable of inducing cytokine release from host cells.


2019 ◽  
Vol 39 (1) ◽  
pp. 167-175 ◽  
Author(s):  
Katalin Gulyás ◽  
Ágnes Horváth ◽  
Edit Végh ◽  
Anita Pusztai ◽  
Ágnes Szentpétery ◽  
...  

Abstract Objectives Rheumatoid arthritis (RA) and ankylosing spondylitis (AS) have been associated with generalized and localized bone loss. We conducted a comprehensive study using imaging (dual-energy X-ray absorptiometry, DXA) and laboratory biomarkers in order to determine bone health and to study the effects of anti-tumor necrosis factor (TNF) biologics in RA and AS. Patients and methods Thirty-six RA and 17 AS patients undergoing 1-year etanercept (ETN) or certolizumab-pegol (CZP) therapy were studied. Bone density was assessed by DXA at baseline and after 12 months. Serum C-reactive protein (CRP), calcium, phosphate, parathyroid hormone (PTH), vitamin D3, osteocalcin, procollagen type I N-propeptide (P1NP), C-terminal telopeptide (βCTX), osteoprotegerin, sclerostin (SOST), Dickkopf-1 (DKK-1), soluble receptor activator nuclear kappa B ligand (sRANKL), and cathepsin K (cathK) levels were determined at baseline and after 6 and 12 months. Results TNF-α inhibition was clinically effective. Anti-TNF-α halted further bone loss over 1 year. In general, anti-TNF therapy significantly increased P1NP, SOST levels, and the P1NP/βCTX ratios, while decreased DKK-1 and CathK production at different time points in most patient subsets. In the full cohort and in RA, baseline and/or 12-month bone mineral density (BMD) at multiple sites exerted inverse relationships with CRP and βCTX, and positive correlation with SOST. In AS, L2-4 BMD after 1-year biologic therapy inversely correlated with baseline βCTX, while femoral neck BMD rather showed inverse correlations with CRP. Conclusions Anti-TNF therapy slowed down generalized bone loss, in association with clinical improvements, in both diseases. TNF blockade may enhance bone formation and suppress joint destruction. Anti-TNF therapy may act inversely on DKK-1 and SOST. Independent predictors of BMD were SOST and βCTX in RA, whilst CRP in AS.Key Points• One-year anti-TNF therapy halted generalized bone loss in association with clinical improvement in arthritides.• Anti-TNF therapy may inversely act on DKK-1 and SOST.• Independent predictors of BMD were SOST and βCTX in RA, while CRP in AS.


2007 ◽  
Vol 92 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Susan L. Greenspan ◽  
Rajib K. Bhattacharya ◽  
Susan M. Sereika ◽  
Adam Brufsky ◽  
Victor G. Vogel

Abstract Background: Few data are available on the safety and efficacy of once-weekly oral bisphosphonate therapy in breast cancer survivors. Objective: Our objective was to determine whether risedronate, 35 mg weekly, is efficacious and safe in preventing bone loss associated with chemotherapy-induced menopause. Design: The study was a randomized, double-blind, placebo-controlled clinical trial over 12 months. Setting and Participants: Participants included 87 newly postmenopausal women with status post chemotherapy, recruited from a breast cancer clinic in an academic medical center. Intervention: Participants were randomly assigned to receive risedronate 35 mg/wk or placebo. Main Outcome Measures: The primary outcomes were the 12-month changes in spine and hip bone mineral density. Secondary outcomes included changes in markers of bone resorption (urine N-telopeptide cross-linked collagen type I) and formation (osteocalcin, N-terminal propeptide of type I procollagen, and bone-specific alkaline phosphatase). Results: After 12 months, bone mineral density increased by 1.2% at the spine and 1.3% at the hip in women on risedronate vs. significant decreases for women in the placebo group of 0.9% at the spine and 0.8% at the hip (P < 0.01, difference between groups). N-telopeptide cross-linked collagen type I, a marker of bone resorption, decreased by 19.3%, and N-terminal propeptide of type I procollagen, a marker of bone formation, decreased by 26.6% in participants on active therapy compared with increases in the control group. Risedronate was well tolerated, and the retention rate was 95% at 1 yr. Conclusions: Risedronate once weekly prevented bone loss and reduced bone turnover in women with breast cancer treated with chemotherapy. Early measures to prevent bone loss should be considered in this cohort of breast cancer survivors.


2021 ◽  
Author(s):  
Pedro Lourenco Katayama ◽  
Isabela de Paula Leirao ◽  
Alexandre Kanashiro ◽  
Joao Paulo Mesquita Luiz ◽  
Fernando Queiroz Cunha ◽  
...  

Recent evidence has suggested that the carotid bodies might act as immunological sensors, detecting pro-inflammatory mediators and signalling to the central nervous system, which, in turn, orchestrates autonomic responses. Here, we demonstrated that the TNF-α receptor type I is expressed in the carotid bodies of rats. The systemic administration of TNF-α increased carotid body afferent discharge and activated glutamatergic neurons in the nucleus tractus solitarius (NTS) that project to the rostral ventrolateral medulla (RVLM), where the majority of pre-sympathetic neurons reside. The activation of these neurons was accompanied by generalized activation of the sympathetic nervous system. Carotid body ablation blunted the TNF-α-induced activation of RVLM-projecting NTS neurons and the increase in splanchnic sympathetic nerve activity. Finally, plasma and spleen levels of cytokines after TNF-α administration were higher in rats subjected to either carotid body ablation or splanchnic sympathetic denervation. Collectively, our findings indicate that the carotid body detects circulating TNF-α to activate a counteracting sympathetic anti-inflammatory mechanism.


Author(s):  
Maria Camilla Ciardulli ◽  
Luigi Marino ◽  
Erwin P. Lamparelli ◽  
Maurizio Guida ◽  
Nicholas R. Forsyth ◽  
...  

Mesenchymal Stem Cells derived from bone marrow (hBM-MSCs) are utilized in tendon tissue‐engineering protocols while extra-embryonic cord-derived, including from Wharton’s Jelly (hWJ-MSC), are emerging as useful alternatives. To explore the tenogenic responsiveness of hBM-MSCs and hWJ-MSCs to hGDF-5 we supplemented each at doses of 1, 10, and 100 ng/mL and determined proliferation, morphology and time-dependent expression of tenogenic markers. We evaluated expression of Collagen types 1 (COL1A1) and 3 (COL3A1), Decorin (DCN), Scleraxis A (SCX-A), Tenascin-C (TNC) and Tenomodulin (TNMD) noting the earliest and largest increase with 100 ng/mL. With 100 ng/mL, hBM-MSCs showed upregulation of SCX-A (1.7-fold) at day 1, TNC (1.3-fold) and TNMD (12-fold) at Day 8. hWJ-MSCs, at the same dose, showed up-regulation of COL1A1 (3-fold), DCN (2.7-fold), SCX (3.8-fold) and TNC (2.3-fold) after 3 days of culture. hWJ-MSCs also showed larger proliferation rate and marked aggregation into a tubular shaped system at Day 7 (with 100 ng/mL of hGDF-5). Simultaneous to this we explored expression of pro-inflammatory (IL-6, TNF, IL-12A, IL-1β) and anti-inflammatory (IL-10, TGF-β1) cytokines across for both cell types. hBM-MSCs exhibited a better balance of pro-inflammatory and anti-inflammatory cytokines upregulating IL-1β (11-fold) and IL-10 (10-fold) at Day 8; hWJ-MSCs, had a slight expression of IL-12A (1.5-fold) but a greater up-regulation of IL-10 (2.5-fold). Collagen type I and tenomodulin proteins, detected by immunofluorescence, confirming the greater protein expression when 100 ng/mL were supplemented. In the same conditions, both cell types showed specific alignment and shape modification (fibroblast-like) with a Lenght/Width ratio increase at value higher than 1, suggesting their response in activating tenogenic commitment events, and they both potential use in 3D in vitro tissue engineering protocols.


2021 ◽  
Vol 15 (Supplement_1) ◽  
pp. S158-S158
Author(s):  
L Kandilogiannakis ◽  
E Filidou ◽  
I Drygiannakis ◽  
G Tarapatzi ◽  
K Arvanitidis ◽  
...  

Abstract Background Organoids are self-renewing, 3D structures, consisting of different cell types, with histology and physiology features very close to the physiology of the studied organ. Specifically, human Intestinal Organoids (HIOs) develop epithelial crypts consisting of all subtypes of intestinal epithelial cells which are surrounded by mesenchymal cells. Our aim was to develop 3D HIOs from human embryonic stem cells (hESCs) and examine the expression of fibrotic and mesenchymal factors during their maturation process. Additionally, we investigated the effect of the pro-inflammatory cytokines, IL-1α and TNF-α on the expression of fibrotic and inflammatory mediators in HIOs. Methods The human ESC line (H1) was cultured and then differentiated towards HIOs using commercially available kit. HIOs were characterized by immunofluorescence in all differentiation stages. In order to examine their maturation process, we compared the mRNA expression of fibrotic and mesenchymal markers from passages 1–10. In order to examine their functionality, HIOs from different passages were stimulated with 5ng/ml IL-1α and 50ng/ml TNF-α for 12 hours, total RNA was collected and the fibrotic and inflammatory mRNA expression was examined. The mRNA transcripts of CD90, collagen type I, III, fibronectin, CXCL8, CXCL10 and CXCL11 were measured by reverse transcription quantitative PCR. Results HIOs were successfully developed as they were stained positive for all tested markers throughout their developmental process. Regarding their maturation process, we observed high expression of CD90, collagen type I, type III and fibronectin that was gradually decreased during passages. As for the fibrotic and inflammatory responses from HIOs, we found that the IL-1α and TNF-α stimulation resulted in statistically significant upregulation of the fibrotic factors, fibronectin, collagen type I and type III in culture passages 2 and 4, but had no effect in culture passages 8 and 10. Similarly, IL-1α and TNF-α stimulation led to the statistically significant induction of the inflammatory chemokines CXCL8, CXCL10 and CXCL11 in culture passages 2 and 4, while no effect was observed in culture passages 8 and 10. Conclusion Our findings indicate that HIOs contain a functional mesenchymal component that is gradually diminished during passages. Inflammatory and fibrotic responses of HIOs seem to depend on the fitness of their mesenchyme. IBD studies using HIOs as in vitro models should be performed on early passages, when HIO’s mesenchymal component is still functional.


Author(s):  
Sridhar Muthusami ◽  
R. Ileng Kumaran ◽  
Kokelavani Nampalli Babu ◽  
Sneha Krishnamoorthy ◽  
Akash Guruswamy ◽  
...  

: Chronic inflammation can lead to the development of many diseases including cancer. Inflammatory bowel disease (IBD) that includes both ulcerative colitis (UC) and Crohn's disease (CD) are risk factors for the development of colorectal cancer (CRC). Many cytokines produced primarily by the gut immune cells either during or in response to localized inflammation in the colon and rectum are known to stimulate the complex interactions between the different cell types in the gut environment resulting in acute inflammation. Subsequently, chronic inflammation together with genetic and epigenetic changes has been shown to lead to the development and progression of CRC. Various cell types present in the colon such as enterocytes, Paneth cells, goblet cells and macrophages express receptors for inflammatory cytokines and respond to tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1β), IL-6 and other cytokines. Among the several cytokines produced, TNF-α and IL-1β are the key proinflammatory molecules that play critical roles in the development of CRC. The current review is intended to consolidate the published findings to focus on the role of proinflammatory cytokines, namely TNF-α and IL-1β, on inflammation (and the altered immune response) in the gut, to better understand the development of CRC in IBD, using various experimental model systems, preclinical and clinical studies. Moreover, this review also highlights the current therapeutic strategies available (monotherapy and combination therapy), to alleviate the symptoms or treat inflammationassociated CRC by using monoclonal antibodies or aptamers to block proinflammatory molecules, inhibitors of tyrosine kinases in inflammatory signaling cascade, competitive inhibitors of proinflammatory molecules, and the nucleic acid drugs like small activating RNAs (saRNAs) or microRNA (miRNA) mimics to activate tumor suppressor or repress oncogene/proinflammatory cytokine gene expression.


2021 ◽  
Vol 8 (3) ◽  
pp. 39
Author(s):  
Britani N. Blackstone ◽  
Summer C. Gallentine ◽  
Heather M. Powell

Collagen is a key component of the extracellular matrix (ECM) in organs and tissues throughout the body and is used for many tissue engineering applications. Electrospinning of collagen can produce scaffolds in a wide variety of shapes, fiber diameters and porosities to match that of the native ECM. This systematic review aims to pool data from available manuscripts on electrospun collagen and tissue engineering to provide insight into the connection between source material, solvent, crosslinking method and functional outcomes. D-banding was most often observed in electrospun collagen formed using collagen type I isolated from calfskin, often isolated within the laboratory, with short solution solubilization times. All physical and chemical methods of crosslinking utilized imparted resistance to degradation and increased strength. Cytotoxicity was observed at high concentrations of crosslinking agents and when abbreviated rinsing protocols were utilized. Collagen and collagen-based scaffolds were capable of forming engineered tissues in vitro and in vivo with high similarity to the native structures.


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