Changes in neuromuscular structure and functions of human colon during ageing are region-dependent

ObjectiveTo determine if human colonic neuromuscular functions decline with increasing age.DesignLooking for non-specific changes in neuromuscular function, a standard burst of electrical field stimulation (EFS) was used to evoke neuronally mediated (cholinergic/nitrergic) contractions/relaxations in ex vivomuscle strips of human ascending and descending colon, aged 35–91 years (macroscopically normal tissue; 239 patients undergoing cancer resection). Then, to understand mechanisms of change, numbers and phenotype of myenteric neurons (30 306 neurons stained with different markers), densities of intramuscular nerve fibres (51 patients in total) and pathways involved in functional changes were systematically investigated (by immunohistochemistry and use of pharmacological tools) in elderly (≥70 years) and adult (35–60 years) groups.ResultsWith increasing age, EFS was more likely to evoke muscle relaxation in ascending colon instead of contraction (linear regression: n=109, slope 0.49%±0.21%/year, 95% CI), generally uninfluenced by comorbidity or use of medications. Similar changes were absent in descending colon. In the elderly, overall numbers of myenteric and neuronal nitric oxide synthase-immunoreactive neurons and intramuscular nerve densities were unchanged in ascending and descending colon, compared with adults. In elderly ascending, not descending, colon numbers of cell bodies exhibiting choline acetyltransferase immunoreactivity increased compared with adults (5.0±0.6 vs 2.4±0.3 neurons/mm myenteric plexus, p=0.04). Cholinergically mediated contractions were smaller in elderly ascending colon compared with adults (2.1±0.4 and 4.1±1.1 g-tension/g-tissue during EFS; n=25/14; p=0.04); there were no changes in nitrergic function or in ability of the muscle to contract/relax. Similar changes were absent in descending colon.ConclusionIn ascending not descending colon, ageing impairs cholinergic function.

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Chronic rejection causes early destruction of the intrinsic nervous system in rat intestinal transplants

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1997.273.2.g413 ◽

1997 ◽

Vol 273 (2) ◽

pp. G413-G421 ◽

Cited By ~ 1

Author(s):

P. F. Heeckt ◽

W. Halfter ◽

W. H. Schraut ◽

A. J. Bauer

Keyword(s):

Nervous System ◽

Chronic Rejection ◽

Circular Muscle ◽

Electrical Field Stimulation ◽

Functional Changes ◽

Diaphorase Activity ◽

Enteric Nerves ◽

Mucosal Changes ◽

Oxide Synthase ◽

Muscularis Externa

Chronic rejection is the major cause of late intestinal allograft dysfunction. We have previously shown that chronic rejection alters the muscularis externa of the graft. This study determined structural and functional changes to the enteric nerves during chronic rejection. Chronic rejection was achieved in orthotopic intestinal transplants (ACI to Lewis) by limited immunosuppression. Syngeneic transplants (ACI to ACI) and unoperated ACI rats served as controls. Animals were clinically healthy and showed no significant alterations in the mucosal architecture on postoperative day 90. Staining for NADPH diaphorase activity (nitric oxide synthase-containing neurons) and with neurofilament antibody RT-97 revealed that chronic rejection decreased the number of jejunal myenteric ganglia by approximately 50%. Inhibitory junction potentials (IJPs) to circular muscle cells were determined by electrical field stimulation (EFS). In controls and syngeneic grafts, EFS caused a stimulus-dependent increase in IJP amplitude, with a maximal amplitude of 9 +/- 0.4 and 10 +/- 0.8 mV, respectively. Chronic rejection in allografts markedly increased the threshold for IJP initiation and decreased the maximal IJP amplitude (5 +/- 0.8 mV). Our data indicate that chronic rejection severely damages the muscularis and the enteric nervous system before mucosal changes become evident.

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Differential protein abundance and function of UT-B urea transporters in human colon

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00405.2009 ◽

2010 ◽

Vol 298 (3) ◽

pp. G345-G351 ◽

Cited By ~ 21

Author(s):

D. Collins ◽

D. C. Winter ◽

A. M. Hogan ◽

L. Schirmer ◽

A. W. Baird ◽

...

Keyword(s):

Intestinal Bacteria ◽

Human Colon ◽

Immunoblot Analysis ◽

Cellular Level ◽

Gut Bacteria ◽

Protein Abundance ◽

Urea Transport ◽

Ascending Colon ◽

Differential Protein ◽

Descending Colon

Facilitative UT-B urea transporters enable the passage of urea across cell membranes. Gastrointestinal urea transporters are thought to play a significant role in the urea nitrogen salvaging process that occurs between mammalian hosts and their gut bacteria. This study investigated the expression of UT-B urea transporters in different segments of human colon. Immunoblot analysis showed that human colon expressed a 35-kDa glycosylated UT-B protein in the colonic mucosa. The 35-kDa UT-B transporter was predominantly located in plasma membrane-enriched samples ( P < 0.001; n = 6), and its expression was greater in the ascending colon compared with the descending colon ( P < 0.01; n = 3). At the cellular level, UT-B transporters were located throughout colonocytes situated in the upper portion of the colonic crypts. Bidirectional trans-epithelial urea transport was significantly greater in the ascending colon than the descending colon ( P < 0.05; n = 6). In addition, the facilitative urea transporter inhibitor 1,3,dimethylurea significantly reduced urea transport in the ascending colon ( P < 0.05; n = 6) but had no effect in the descending colon (NS; n = 6). These results illustrate differential protein abundance of functional UT-B protein in different sections of the human colon, strongly correlating to regions that contain the largest populations of intestinal bacteria. This study suggests an important role for UT-B urea transporters in maintaining the symbiotic relationship between humans and their gut bacteria.

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Hyperactivation of RAP1 and JAK/STAT Signaling Pathways Contributes to Fibrosis during the Formation of Nasal Capsular Contraction

European Surgical Research ◽

10.1159/000513780 ◽

2021 ◽

pp. 1-12

Author(s):

Meng Wu ◽

Ming Li ◽

Hong-Ju Xie ◽

Hong-Wei Liu

Keyword(s):

Signaling Pathways ◽

Type I Collagen ◽

Ex Vivo ◽

Capsular Contracture ◽

Silicone Implant ◽

Type I ◽

Loss Of Function ◽

Sequencing Data ◽

Functional Changes ◽

Stat Signaling

Silicone implant-based augmentation rhinoplasty or mammoplasty induces capsular contracture, which has been acknowledged as a process that develops an abnormal fibrotic capsule associated with the immune response to allogeneic materials. However, the signaling pathways leading to the nasal fibrosis remain poorly investigated. We aimed to explore the molecular mechanism underlying the pathogenesis of nasal capsular contracture, with a specific research interest in the signaling pathways involved in fibrotic development at the advanced stage of contracture. By examining our recently obtained RNA sequencing data and global gene expression profiling between grade II and grade IV nasal capsular tissues, we found that both the RAP1 and JAK/STAT signaling pathways were hyperactive in the contracted capsules. This was verified on quantitative real-time PCR which demonstrated upregulation of most of the representative component signatures in these pathways. Loss-of-function assays through siRNA-mediated Rap1 silencing and/or small molecule-directed inhibition of JAK/STAT pathway in ex vivo primary nasal fibroblasts caused a series of dramatic behavioral and functional changes, including decreased cell viability, increased apoptosis, reduced secretion of proinflammatory cytokines, and synthesis of type I collagen, compared to control cells, and indicating the essential role of the RAP1 and JAK/STAT signaling pathways in nasal capsular fibrosis. Our results sheds light on targeting downstream signaling pathways for the prevention and therapy of silicone implant-induced nasal capsular contracture.

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Restoring Perivascular Adipose Tissue Function in Obesity Using Exercise

Cardiovascular Drugs and Therapy ◽

10.1007/s10557-020-07136-0 ◽

2021 ◽

Author(s):

Sophie N Saxton ◽

Lauren K Toms ◽

Robert G Aldous ◽

Sarah B Withers ◽

Jacqueline Ohanian ◽

...

Keyword(s):

Adipose Tissue ◽

Contractile Function ◽

Ex Vivo ◽

Vascular Complications ◽

Electrical Field Stimulation ◽

Organic Cation Transporter ◽

Nervous Stimulation ◽

Perivascular Adipose Tissue ◽

Contractile Effect ◽

Organic Cation Transporter 3

AbstractPurposePerivascular adipose tissue (PVAT) exerts an anti-contractile effect which is vital in regulating vascular tone. This effect is mediated via sympathetic nervous stimulation of PVAT by a mechanism which involves noradrenaline uptake through organic cation transporter 3 (OCT3) and β3-adrenoceptor-mediated adiponectin release. In obesity, autonomic dysfunction occurs, which may result in a loss of PVAT function and subsequent vascular disease. Accordingly, we have investigated abnormalities in obese PVAT, and the potential for exercise in restoring function.MethodsVascular contractility to electrical field stimulation (EFS) was assessed ex vivo in the presence of pharmacological tools in ±PVAT vessels from obese and exercised obese mice. Immunohistochemistry was used to detect changes in expression of β3-adrenoceptors, OCT3 and tumour necrosis factor-α (TNFα) in PVAT.ResultsHigh fat feeding induced hypertension, hyperglycaemia, and hyperinsulinaemia, which was reversed using exercise, independent of weight loss. Obesity induced a loss of the PVAT anti-contractile effect, which could not be restored via β3-adrenoceptor activation. Moreover, adiponectin no longer exerts vasodilation. Additionally, exercise reversed PVAT dysfunction in obesity by reducing inflammation of PVAT and increasing β3-adrenoceptor and OCT3 expression, which were downregulated in obesity. Furthermore, the vasodilator effects of adiponectin were restored.ConclusionLoss of neutrally mediated PVAT anti-contractile function in obesity will contribute to the development of hypertension and type II diabetes. Exercise training will restore function and treat the vascular complications of obesity.

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Fecal Calprotectin, CRP and Leucocytes in IBD Patients: Comparison of Biomarkers With Biopsy Results

Journal of the Canadian Association of Gastroenterology ◽

10.1093/jcag/gwaa009 ◽

2020 ◽

Author(s):

Barry D Kyle ◽

Terence A Agbor ◽

Shajib Sharif ◽

Usha Chauhan ◽

John Marshall ◽

...

Keyword(s):

Ulcerative Colitis ◽

Fecal Calprotectin ◽

Dependent Manner ◽

Ascending Colon ◽

C Reactive Protein ◽

Concentration Dependent Manner ◽

Reactive Protein ◽

Inflammatory Bowel ◽

Descending Colon ◽

Active Inflammation

Abstract Background This study aimed to compare fecal calprotectin (FC) levels with other commonly used parameters as part of patient care during evaluation for inflammatory bowel disease (IBD). Methods We recruited adult IBD patients with ulcerative colitis (UC) and Crohn’s disease (CD) and compared the results of the patient’s biopsy results (i.e., inflamed versus noninflamed) for six sites (i.e., ileum, ascending colon, transverse colon, descending colon, sigmoid colon, rectum) with concentrations of C-reactive protein (CRP), total leucocytes and fecal calprotectin (FC). Results We found that FC was significantly elevated in a concentration-dependent manner that correlated with the number of active inflammation sites reported in biopsy. Although CRP and leucocyte measurements trended upwards in line with inflammation reported from biopsy, the results were highly variable and highlighted poor reliability of these biomarkers for indicating IBD inflammation. Conclusions These results strongly suggest that FC correlates best with biopsy reports and is a superior marker than CRP and leucocytes.

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Novel role of endothelial BKCa channels in altered vasoreactivity following hypoxia

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00124.2010 ◽

2010 ◽

Vol 299 (5) ◽

pp. H1439-H1450 ◽

Cited By ~ 22

Author(s):

Jennifer M. Hughes ◽

Melissa A. Riddle ◽

Michael L. Paffett ◽

Laura V. Gonzalez Bosc ◽

Benjimen R. Walker

Keyword(s):

Ex Vivo ◽

Barometric Pressure ◽

Channel Blockers ◽

Channel Activity ◽

Resistance Arteries ◽

Bkca Channels ◽

Oxide Synthase ◽

Increased Activity ◽

Small Conductance

The systemic vasculature exhibits attenuated vasoconstriction following hypobaric chronic hypoxia (CH) that is associated with endothelium-dependent vascular smooth muscle (VSM) cell hyperpolarization. We hypothesized that increased activity of endothelial cell (EC) large-conductance, calcium-activated potassium (BKCa) channels contributes to this response. Gracilis resistance arteries from hypobaric CH (barometric pressure = 380 mmHg for 48 h) rats demonstrated reduced myogenic reactivity and hyperpolarized VSM membrane potential ( Em) compared with controls under normoxic ex vivo conditions. These differences were eliminated by endothelial disruption. In the presence of cyclooxygenase and nitric oxide synthase inhibition, combined intraluminal administration of the intermediate and small-conductance, calcium-activated K+ channel blockers TRAM-34 and apamin was without effect on myogenic responsiveness and VSM Em in both groups; however, these variables were normalized in CH arteries by intraluminal administration of the BKCa inhibitor iberiotoxin (IBTX). Basal EC Em was hyperpolarized in arteries from CH rats compared with controls and was restored by IBTX, but not by TRAM-34/apamin. K+ channel blockers were without effect on EC basal Em in controls. Similarly, IBTX blocked acetylcholine-induced dilation in arteries from CH rats, but was without effect in controls, whereas TRAM-34/apamin eliminated dilation in controls. Acetylcholine-induced EC hyperpolarization and calcium responses were inhibited by IBTX in CH arteries and by TRAM-34/apamin in controls. Patch-clamp experiments on freshly isolated ECs demonstrated greater K+ current in cells from CH rats that was normalized by IBTX. IBTX was without effect on K+ current in controls. We conclude that hypobaric CH induces increased endothelial BKCa channel activity that contributes to reduced myogenic responsiveness and EC and VSM cell hyperpolarization.

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DNA Methylation Changes duringIn VitroPropagation of Human Mesenchymal Stem Cells: Implications for Their Genomic Stability?

Stem Cells International ◽

10.1155/2013/192425 ◽

2013 ◽

Vol 2013 ◽

pp. 1-9 ◽

Cited By ~ 33

Author(s):

Angela Bentivegna ◽

Mariarosaria Miloso ◽

Gabriele Riva ◽

Dana Foudah ◽

Valentina Butta ◽

...

Keyword(s):

Stem Cells ◽

Mesenchymal Stem Cells ◽

Ex Vivo ◽

Genomic Stability ◽

Great Promise ◽

Human Mscs ◽

Low Oxygen ◽

Long Term Culture ◽

Functional Changes

Mesenchymal stem cells (MSCs) hold great promise for the treatment of numerous diseases. A major problem for MSC therapeutic use is represented by the very low amount of MSCs which can be isolated from different tissues; thusex vivoexpansion is indispensable. Long-term culture, however, is associated with extensive morphological and functional changes of MSCs. In addition, the concern that they may accumulate stochastic mutations which lead the risk of malignant transformation still remains. Overall, the genome of human MSCs (hMSCs) appears to be apparently stable throughout culture, though transient clonal aneuploidies have been detected. Particular attention should be given to the use of low-oxygen environment in order to increase the proliferative capacity of hMSCs, since data on the effect of hypoxic culture conditions on genomic stability are few and contradictory. Furthermore, specific and reproducible epigenetic changes were acquired by hMSCs duringex vivoexpansion, which may be connected and trigger all the biological changes observed. In this review we address current issues on long-term culture of hMSCs with a 360-degree view, starting from the genomic profiles and back, looking for an epigenetic interpretation of their genetic stability.

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Constipation in patients with comorbidity

Лечащий врач ◽

10.51793/os.2021.24.12.010 ◽

2021 ◽

Author(s):

Е.А. Лялюкова ◽

Е.Н. Логинова

Keyword(s):

Gastrointestinal Tract ◽

Neurological Diseases ◽

The Elderly ◽

Lifestyle Changes ◽

Secretory Cells ◽

Endocrine Disorders ◽

Silver Age ◽

Functional Changes ◽

Slowing Down ◽

Age Related

Пациенты пожилого и старческого возраста в силу физиологических причин и коморбидной патологии имеют высокий риск развития запора. Причиной запора чаще всего являются алиментарные факторы и возраст-ассоциированные заболевания и повреждения толстой кишки (дивертикулярная болезнь, ишемия толстой кишки, ректоцеле, геморрой и другие); метаболические, эндокринные расстройства и неврологические заболевания. Возрастные анатомические, структурные и функциональные изменения пищеварительной системы вносят свой вклад в развитие запоров у пожилых. У пациентов «серебряного возраста» отмечено увеличение длины желудочно-кишечного тракта, прогрессирование атрофических, склеротических изменений слизистой и подслизистой оболочки, снижение количества секреторных клеток, замещение мышечных волокон соединительной тканью и др. Все это способствует замедлению транзита по желудочно-кишечному тракту и нарушению акта дефекации. Образ жизни пожилых людей также может способствовать развитию запора. Низкое содержание в рационе клетчатки, употребление преимущественно термически обработанной пищи, нарушение ритма питания (прием пищи 1-2 раза в день) являются одной из причин возникновения запоров у пожилых, чему способствуют трудности при жевании вследствие стоматологических проблем. Колоноскопия показана всем пациентам пожилого и старческого возраста с запором, а выявление «симптомов тревоги» необходимо проводить при каждом визите пациента. Вне зависимости от причины вторичного запора, все пациенты должны осуществлять ряд мер немедикаментозного характера, включающих изменение образа жизни, диету с включением достаточного количества клетчатки и потребление жидкости. Физические методы лечения могут включать лечебную гимнастику, массаж толстой кишки для стимуляции моторной активности кишечника в определенное время. При неэффективности немедикаментозных мероприятий рекомендуется использование осмотических слабительных, а также средств, увеличивающих объем каловых масс. Высокая эффективность и безопасность псиллиума позволяет рекомендовать его в лечении хронического запора у пожилых пациентов. Elderly and senile patients, due to physiological reasons and comorbid pathology, have a high risk of constipation. The causes of constipation are more often nutritional factors and age-associated diseases and damage to the colon (diverticular disease, colon ischemia, rectocele, hemorrhoids, and others); metabolic, endocrine disorders and neurological diseases. Age-related anatomical, structural and functional changes in the digestive system contribute to the development of constipation in the elderly. In patients of «silver age», there was an increase in the length of the gastrointestinal tract, the progression of atrophic, sclerotic changes in the mucous and submucosa, a decrease in the number of secretory cells, replacement of muscle fibers with connective tissue, etc. All this contributes to the slowing down of transit through the gastrointestinal tract and the violation of the act of defecation. Elderly lifestyles can also contribute to constipation. The low fiber content in the diet, the use of mainly thermally processed food, the violation of the rhythm of the diet (eating 1-2 times a day) are one of the causes of constipation in the elderly, which is facilitated by difficulty in chewing due to dental problems. Colonoscopy is ordered for all elderly and senile patients with constipation, and the identification of «anxiety symptoms» should be carried out at each patient visit. Regardless of the cause of secondary constipation, all patients should take a number of non-pharmacological measures, including lifestyle changes, a diet with adequate fiber, and fluid intake. Physical therapies may include medical gymnastics, colon massage to stimulate bowel movement at specific times. If non-drug measures are ineffective, it is recommended to use osmotic laxatives, as well as agents that increase the volume of feces. Psyllium supplementation is recommended for treatment of chronic constipation in elderly patients due to its high efficacy and safety.

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Glucose uptake during contraction in isolated skeletal muscles from neuronal nitric oxide synthase μ knockout mice

Journal of Applied Physiology ◽

10.1152/japplphysiol.00056.2015 ◽

2015 ◽

Vol 118 (9) ◽

pp. 1113-1121 ◽

Cited By ~ 12

Author(s):

Yet Hoi Hong ◽

Tony Frugier ◽

Xinmei Zhang ◽

Robyn M. Murphy ◽

Gordon S. Lynch ◽

...

Keyword(s):

Nitric Oxide ◽

Skeletal Muscle ◽

Nitric Oxide Synthase ◽

Glucose Uptake ◽

Ex Vivo ◽

Organ Bath ◽

Skeletal Muscle Glucose Uptake ◽

Nos Inhibitor ◽

Amp Activated Protein Kinase ◽

Oxide Synthase

Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation is observed in individuals with Type 2 diabetes compared with healthy individuals. Therefore, NO appears to play an important role in mediating muscle glucose uptake during contraction. In this study, we investigated the involvement of neuronal NOSμ (nNOSμ), the main NOS isoform activated during contraction, on skeletal muscle glucose uptake during ex vivo contraction. Extensor digitorum longus muscles were isolated from nNOSμ−/−and nNOSμ+/+mice. Muscles were contracted ex vivo in a temperature-controlled (30°C) organ bath with or without the presence of the NOS inhibitor NG-monomethyl-l-arginine (L-NMMA) and the NOS substrate L-arginine. Glucose uptake was determined by radioactive tracers. Skeletal muscle glucose uptake increased approximately fourfold during contraction in muscles from both nNOSμ−/−and nNOSμ+/+mice. L-NMMA significantly attenuated the increase in muscle glucose uptake during contraction in both genotypes. This attenuation was reversed by L-arginine, suggesting that L-NMMA attenuated the increase in muscle glucose uptake during contraction by inhibiting NOS and not via a nonspecific effect of the inhibitor. Low levels of NOS activity (∼4%) were detected in muscles from nNOSμ−/−mice, and there was no evidence of compensation from other NOS isoform or AMP-activated protein kinase which is also involved in mediating muscle glucose uptake during contraction. These results indicate that NO regulates skeletal muscle glucose uptake during ex vivo contraction independently of nNOSμ.

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Uncoupled biological and chronological aging of neutrophils in cancer promotes tumor progression

Journal for ImmunoTherapy of Cancer ◽

10.1136/jitc-2021-003495 ◽

2021 ◽

Vol 9 (12) ◽

pp. e003495

Author(s):

Laura A Mittmann ◽

Florian Haring ◽

Johanna B Schaubächer ◽

Roman Hennel ◽

Bojan Smiljanov ◽

...

Keyword(s):

Tumor Growth ◽

Tumor Progression ◽

Immune Cells ◽

Malignant Tumors ◽

Ex Vivo ◽

Biological Aging ◽

Malignant Neoplasms ◽

Chronological Aging ◽

Functional Changes

BackgroundBeyond their fundamental role in homeostasis and host defense, neutrophilic granulocytes (neutrophils) are increasingly recognized to contribute to the pathogenesis of malignant tumors. Recently, aging of mature neutrophils in the systemic circulation has been identified to be critical for these immune cells to properly unfold their homeostatic and anti-infectious functional properties. The role of neutrophil aging in cancer remains largely obscure.MethodsEmploying advanced in vivo microscopy techniques in different animal models of cancer as well as utilizing pulse-labeling and cell transfer approaches, various ex vivo/in vitro assays, and human data, we sought to define the functional relevance of neutrophil aging in cancer.ResultsHere, we show that signals released during early tumor growth accelerate biological aging of circulating neutrophils, hence uncoupling biological from chronological aging of these immune cells. This facilitates the accumulation of highly reactive neutrophils in malignant lesions and endows them with potent protumorigenic functions, thus promoting tumor progression. Counteracting uncoupled biological aging of circulating neutrophils by blocking the chemokine receptor CXCR2 effectively suppressed tumor growth.ConclusionsOur data uncover a self-sustaining mechanism of malignant neoplasms in fostering protumorigenic phenotypic and functional changes in circulating neutrophils. Interference with this aberrant process might therefore provide a novel, already pharmacologically targetable strategy for cancer immunotherapy.

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