The effect of glucocorticoids on Thrombospondin-1, Osteocalcin and the Thrombospondin-1:Osteocalcin ratio in humans

Serum proteome profiles in cats with chronic enteropathies

BACKGROUND

Serum protein biomarkers are used to diagnose, monitor treatment response, and to differentiate various forms of chronic enteropathies (CE) in humans. The utility of liquid biopsy proteomic approaches has not been examined in cats.

HYPOTHESIS/OBJECTIVES

To explore the serum proteome in cats to identify markers differentiating healthy cats from cats with CE.

ANIMALS

Ten cats with CE with signs of gastrointestinal disease of at least 3 weeks duration, and biopsy-confirmed diagnoses, with or without treatment and 19 healthy cats were included.

METHODS

Cross-sectional, multicenter, exploratory study with cases recruited from 3 veterinary hospitals between May 2019 and November 2020. Serum samples were analyzed and evaluated using mass spectrometry-based proteomic techniques.

RESULTS

Twenty-six proteins were significantly (P < .02, ≥5-fold change in abundance) differentially expressed between cats with CE and controls. Thrombospondin-1 (THBS1) was identified with >50-fold increase in abundance in cats with CE (P < 0.001) compared to healthy cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

Damage to the gut lining released marker proteins of chronic inflammation that were detectable in serum samples of cats. This early-stage exploratory study strongly supports THBS1 as a candidate biomarker for chronic inflammatory enteropathy in cats.

Osteoporosis in Patients With Respiratory Diseases

Climate change, environmental pollution, and virus epidemics have sharply increased the number of patients suffering from respiratory diseases in recent years. Prolonged periods of illness and drug use increase the occurrence of complications in these patients. Osteoporosis is the common bone metabolism disease with respiratory disturbance, which affects prognosis and increases mortality of patients. The problem of osteoporosis in patients with respiratory diseases needs more attention. In this review, we concluded the characteristics of osteoporosis in some respiratory diseases including COPD, asthma, COVID-19, tuberculosis, and lung cancer. We revealed that hypoxia was the common pathogenesis of osteoporosis secondary to respiratory diseases, with malnutrition and corticosteroid abuse driving the progression of osteoporosis. Hypoxia-induced ROS accumulation and activated HIF-1α lead to attenuated osteogenesis and enhanced osteoclastogenesis in patients with respiratory diseases. Tuberculosis and cancer also invaded bone tissue and reduced bone strength by direct infiltration. For the treatment of osteoporosis in respiratory patients, oral-optimized bisphosphonates were the best treatment modality. Vitamin D was a necessary supplement, both for calcium absorption in osteogenesis and for improvement of respiratory lesions. Reasonable adjustment of the dose and course of corticosteroids according to the etiology and condition of patients is beneficial to prevent the occurrence and development of osteoporosis. Additionally, HIF-1α was a potential target for the treatment of osteoporosis in respiratory patients, which could be activated under hypoxia condition and involved in the process of bone remodeling.

Ex vivo glucocorticoid-induced secreted proteome approach for discovery of glucocorticoid-responsive proteins in human serum

PURPOSE

To identify glucocorticoid-responsive proteins measurable in human serum that may have clinical utility in therapeutic drug monitoring and the diagnosis of cortisol excess or deficiency.

EXPERIMENTAL DESIGN

A phased biomarker discovery strategy was conducted in two cohorts. Secretome from peripheral blood mononuclear cells (PBMC) isolated from six volunteers after ex vivo incubation ± dexamethasone (DEX) 100 ng/mL for 4 h and 24 h was used for candidate discovery and qualification using untargeted proteomics and a custom multiple reaction monitoring mass spectrometry (MRM-MS) assay, respectively. For validation, five candidates were measured by immunoassay in serum from an independent cohort (n = 20), sampled at 1200 h before and after 4 mg oral DEX.

RESULTS

The discovery secretome proteomics data generated a shortlist of 45 candidates, with 43 measured in the final MRM-MS assay. Differential analysis revealed 16 proteins that were significant in at least one of two time points. In the validation cohort, 3/5 serum proteins were DEX-responsive, two significantly decreased: lysozyme C (p < 0.0001) and nucleophosmin-1 (p < 0.01), while high mobility group box 2 significantly increased (p < 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

Using an ex vivo proteomic approach in PBMC, we have identified circulating glucocorticoid-responsive proteins which may have potential as serum biomarkers of glucocorticoid activity.