Subcutaneous adipose tissue composition and function are unaffected by liraglutide-induced weight loss in adults with type 1 diabetes.

Adipose tissue is the primary energy reservoir of the human body, which also possesses endocrine functions. The glucagon-like peptide agonist liraglutide produces weight loss, although the specific effects on adipose tissue are unknown. We aimed to characterize the white adipose tissue composition and pericellular fibrosis of subcutaneous adipose tissue in response to liraglutide treatment. Furthermore, we explored the level of circulating free fatty acids, cluster of differentiation 163 (CD163) macrophage marker, leptin and adiponectin. Thirty-nine adults with type 1 diabetes and polyneuropathy were randomly assigned to 26 weeks of liraglutide or placebo treatment. Biopsies of subcutaneous tissue were formalin-fixed stained with picrosirius red to visualize collagen or immunohistochemically stained for CD163. Serum concentrations of free fatty acids, CD163, leptin and adiponectin were assessed with immunoassays or multiplex panels. In comparison with placebo, liraglutide induced weight loss (3.38 kg, 95% CI -5.29; -1.48, P < 0.001), but did not cause any differences in cell size, distribution of CD163-positive cells, pericellular fibrosis and serum levels of free fatty acids, CD163, leptin or adiponectin (all P < 0.1). Additionally, no associations between weight loss, cell size and serum markers were found (all P > 0.08). In conclusion, despite liraglutide's effect on weight loss, sustained alterations in subcutaneous adipose tissue did not seem to appear.

Diabetic Neuropathy Influences Control of Spinal Mechanisms.

PURPOSE: Comprehensive evaluation of the upstream sensory processing in diabetic symmetrical polyneuropathy (DSPN) is sparse. The authors investigated the spinal nociceptive withdrawal reflex and the related elicited somatosensory evoked cortical potentials. They hypothesized that DSPN induces alterations in spinal and supraspinal sensory-motor processing compared with age- and gender-matched healthy controls. METHODS: In this study, 48 patients with type 1 diabetes and DSPN were compared with 21 healthy controls. Perception and reflex thresholds were determined and subjects received electrical stimulations on the plantar site of the foot at three stimulation intensities to evoke a nociceptive withdrawal reflex. Electromyogram and EEG were recorded for analysis. RESULTS: Patients with DSPN had higher perception (P < 0.001) and reflex (P = 0.012) thresholds. Fewer patients completed the recording session compared with healthy controls (34/48 vs. 21/21; P = 0.004). Diabetic symmetrical polyneuropathy reduced the odds ratio of a successful elicited nociceptive withdrawal reflex (odds ratio = 0.045; P = 0.014). Diabetic symmetrical polyneuropathy changed the evoked potentials (F = 2.86; P = 0.025), and post hoc test revealed reduction of amplitude (-3.72 mV; P = 0.021) and prolonged latencies (15.1 ms; P = 0.013) of the N1 peak. CONCLUSIONS: The study revealed that patients with type 1 diabetes and DSPN have significantly changed spinal and supraspinal processing of the somatosensory input. This implies that DSPN induces widespread differences in the central nervous system processing of afferent A-δ and A-ß fiber input. These differences in processing may potentially lead to identification of subgroups with different stages of small fiber neuropathy and ultimately differentiated treatments.

Peripheral, synaptic and central neuronal transmission is affected in type 1 diabetes.

AIMS: We hypothesized that adults with type 1 diabetes and severe polyneuropathy have alterations in neuronal transmission at different anatomical levels. The aims were to investigate upstream sensory neuronal activation in terms of peripheral, spinal, precortical, and cortical transmission. METHODS: 48 participants with type-1 diabetes and polyneuropathy, and 21 age-matched healthy participants were included. Electrophysiological median nerve recordings were used to analyze peripheral transmission at Erb's point (P9-N11); spinal evoked potentials at Cv7 (P11-N14); subcortical evoked potentials at Oz (N14-P18); early cortical evoked potentials at CP5 (N20-P22); late cortical evoked potentials at C1 (N60-P80) and estimated cortical inter-peak latencies as measures of central conduction time. RESULTS: In comparison to healthy, the presence of diabetes prolonged peripheral transmission at P9 and N11 (+0.49 ms, p = .000; +0.47 ms, p = .04, respectively), early cortical evoked potentials at CP5: N20 (+2.41 ms, p = .003) and P22 (+5.88 ms, p = .001) and cortical potentials at C1: N60 (+39.08 ms, p = .001) and P80 (+54.55 ms, p = .000) and central conduction time. Decreased amplitudes were shown peripherally (-2.13 µV, p = .000), spinally (-0.57 µV, p = .005) and pre-cortically (-0.22 µV, p = .004). In both healthy and people with diabetes increased central conduction time were associated with decreased parasympathetic tone (ρ = -0.52, p = .027; ρ = -0.35, p = .047, respectively). CONCLUSION: Neuronal afferent transmission and brain responses were significantly impaired in diabetes and the presence of prolonged central conduction time is indicative of severe extensive neuronal damage. Trial registry number: EUDRA CT: 2013-004375-12; clinicaltrials.gov: NCT02138045.

Pathophysiology and management of diabetic gastroenteropathy.

Polyneuropathy is a common complication to diabetes. Neuropathies within the enteric nervous system are associated with gastroenteropathy and marked symptoms that severely reduce quality of life. Symptoms are pleomorphic but include nausea, vomiting, dysphagia, dyspepsia, pain, bloating, diarrhoea, constipation and faecal incontinence. The aims of this review are fourfold. First, to provide a summary of the pathophysiology underlying diabetic gastroenteropathy. Secondly to give an overview of the diagnostic methods. Thirdly, to provide clinicians with a focussed overview of current and future methods for pharmacological and nonpharmacological treatment modalities. Pharmacological management is categorised according to symptoms arising from the upper or lower gut as well as sensory dysfunctions. Dietary management is central to improvement of symptoms and is discussed in detail, and neuromodulatory treatment modalities and other emerging management strategies for diabetic gastroenteropathy are discussed. Finally, we propose a diagnostic/investigation algorithm that can be used to support multidisciplinary management.

Quantities of comorbidities affects physical, but not mental health related quality of life in type 1 diabetes with confirmed polyneuropathy.

BACKGROUND: A large number of adults with long-term type 1 diabetes are affected by symmetrical peripheral neuropathy. These complications increase socioeconomic expenses and diminish the individual quality of life. The 36-Item Short Form Health Survey (SF-36) is a generic patient reported questionnaire, measuring mental and physical health related quality of life. We hypothesized that diabetic neuropathy would decrease physical and mental quality of life measured with SF-36, and that clinical appearance may be associated with the decline. AIM: To investigate if diabetic neuropathy would decrease physical and mental quality of life measured with SF-36, and if clinical appearance may be associated with the decline. METHODS: Forty-eight adults [age 50 ± 9 years, 10 females, disease duration 32 (14-51) years] with verified diabetic symmetrical peripheral neuropathy and 21 healthy participants (age 51 ± 6 years, 6 females) underwent standardised nerve conduction testing and completed the SF-36 questionnaire. Furthermore, disease duration, number of comorbidities, both diabetes related and nondiabetes related, vibration perception threshold, number of hypoglycaemic events, HbA1c and administration way of insulin was notified. RESULTS: In comparison to healthy subjects, patients' mental composite score was not significantly diminished (51.9 ± 8.9 vs 53.1 ± 5.5, P = 0.558), while the physical composite score was (46.3 ± 11.7 vs 54.6 ± 3.3, P = 0.002). As expected, the overall physical health related symptoms in patients were associated to total number of comorbidities (P < 0.0001), comorbidities relation to diabetes (P = 0.0002) and HbA1c (P = 0.005) as well as comorbidities not related to diabetes (P = 0.0006). CONCLUSION: The finding of this study emphasises the importance of focusing on quality of life in adults with diabetes and especially in those with multiple comorbidities as well as the possibility of HbA1c as a biomarker for severe complication.

Diabetic Enteropathy: From Molecule to Mechanism-Based Treatment.

The incidence of the micro- and macrovascular complications of diabetes is rising, mirroring the increase in the worldwide prevalence. Arguably, the most common microvascular complication is neuropathy, leading to deleterious changes in both the structure and function of neurons. Amongst the various neuropathies with the highest symptom burden are those associated with alterations in the enteric nervous system, referred to as diabetic enteropathy. The primary aim of this review is to provide a contemporaneous summary of pathophysiology of diabetic enteropathy thereby allowing a "molecule to mechanism" approach to treatment, which will include 4 distinct aspects. Firstly, the aim is to provide an overview of the diabetes-induced structural remodelling, biochemical dysfunction, immune-mediated alterations, and inflammatory properties of the enteric nervous system and associated structures. Secondly, the aim is to provide a synopsis of the clinical relevance of diabetic enteropathy. Thirdly, the aim is to discuss the various patient-reported outcome measures and the objective modalities for evaluating dysmotility, and finally, the aim is to outline the clinical management and different treatment options that are available. Given the burden of disease that diabetic enteropathy causes, earlier recognition is needed allowing prompt investigation and intervention, which may lead to improvements in quality of life for sufferers.

Upregulation of Mrps18a in breast cancer identified by selecting phage antibody libraries on breast tissue sections.

BACKGROUND: One of the hallmarks of cancer is an altered energy metabolism, and here, mitochondria play a central role. Previous studies have indicated that some mitochondrial ribosomal proteins change their expression patterns upon transformation. METHOD: In this study, we have used the selection of recombinant antibody libraries displayed on the surface of filamentous bacteriophage as a proteomics discovery tool for the identification of breast cancer biomarkers. A small subpopulation of breast cells expressing both cytokeratin 19 and cytokeratin 14 was targeted using a novel selection procedure. RESULTS: We identified the mitochondrial ribosomal protein s18a (Mrps18a) as a protein which is upregulated in breast cancer. However, Mrps18a was not homogeneously upregulated in all cancer cells, suggesting the existence of sub-populations within the tumor. The upregulation was not confined to cytokeratin 19 and cytokeratin 14 double positive cells. CONCLUSION: This study illustrates how phage display can be applied towards the discovery of proteins which exhibit changes in their expression patterns. We identified the mitochondrial protein Mrps18a as being upregulated in human breast cancer cells compared to normal breast cells.

Raising an Antibody Specific to Breast Cancer Subpopulations Using Phage Display on Tissue Sections.

BACKGROUND/AIM: Primary tumors display a great level of intra-tumor heterogeneity in breast cancer. The current lack of prognostic and predictive biomarkers limits accurate stratification and the ability to predict response to therapy. The aim of the present study was to select recombinant antibody fragments specific against breast cancer subpopulations, aiding the discovery of novel biomarkers. MATERIALS AND METHODS: Recombinant antibody fragments were selected by phage display. A novel shadowstick technology enabled the direct selection using tissue sections of antibody fragments specific against small subpopulations of breast cancer cells. Selections were performed against a subpopulation of breast cancer cells expressing CD271+, as these previously have been indicated to be potential breast cancer stem cells. The selected antibody fragments were screened by phage ELISA on both breast cancer and myoepithelial cells. The antibody fragments were validated and evaluated by immunohistochemistry experiments. RESULTS: Our study revealed an antibody fragment, LH8, specific for breast cancer cells. Immunohistochemistry results indicate that this particular antibody fragment binds an antigen that exhibits differential expression in different breast cancer subpopulations. CONCLUSION: Further studies characterizing this antibody fragment, the subpopulation it binds and the cognate antigen may unearth novel biomarkers of clinical relevance.

Selection of a breast cancer subpopulation-specific antibody using phage display on tissue sections.

Breast cancer tumors are composed of heterogeneous cell populations. These populations display a high variance in morphology, growth and metastatic propensity. They respond differently to therapeutic interventions, and some may be more prone to cause recurrence. Studying individual subpopulations of breast cancer may provide crucial knowledge for the development of individualized therapy. However, this process is challenged by the availability of biomarkers able to identify subpopulations specifically. Here, we demonstrate an approach for phage display selection of recombinant antibody fragments on cryostat sections of human breast cancer tissue. This method allows for selection of recombinant antibodies binding to antigens specifically expressed in a small part of the tissue section. In this case, a CD271(+) subpopulation of breast cancer cells was targeted, and these may be potential breast cancer stem cells. We isolated an antibody fragment LH 7, which in immunohistochemistry experiments demonstrates specific binding to breast cancer subpopulations. The selection of antibody fragments directly on small defined areas within a larger section of malignant tissue is a novel approach by which it is possible to better target cellular heterogeneity in proteomic studies. The identification of novel biomarkers is relevant for our understanding and intervention in human diseases. The selection of the breast cancer-specific antibody fragment LH 7 may reveal novel subpopulation-specific biomarkers, which has the potential to provide new insight and treatment strategies for breast cancer.

Selection of cell-type specific antibodies on tissue-sections using phage display.

With the advent of modern technologies enabling single cell analysis, it has become clear that small sub-populations of cells or even single cells can drive the phenotypic appearance of tissue, both diseased and normal. Nucleic acid based technologies allowing single cell analysis has been faster to mature, while technologies aimed at analysing the proteome at a single cell level is still lacking behind, especially technologies which allow single cell analysis in tissue. Introducing methods, that allows such analysis, will pave the way for discovering new biomarkers with more clinical relevance, as these may be unique for microenvironments only present in tissue and will avoid artifacts introduced by in vitro studies. Here, we introduce a technology enabling biomarker identification on small sub-populations of cells within a tissue section. Phage antibody libraries are applied to the tissue sections, followed by washing to remove non-bound phage particles. To eliminate phage antibodies binding to antigens ubiquitously expressed and retrieve phage antibodies binding specifically to antigens expressed by the sub-population of cells, the area of interest is protected by a 'shadow stick'. The phage antibodies on the remaining areas on the slide are exposed to UV light, which introduces cross-links in the phage genome, thus rendering them non-replicable. In this work we applied the technology, guided by CD31 expressing endothelial cells, to isolate recombinant antibodies specifically binding biomarkers expressed either by the cell or in the microenvironment surrounding the endothelial cell.