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Introduction: T-cadherin, a non-canonical member of the cadherin superfamily, was initially identified for its involvement in homophilic recognition within the nervous and vascular systems. Apart from its adhesive function, T-cadherin acts as a receptor for two ligands: LDL, contributing to atherogenic processes, and HMW adiponectin, a hormone with well-known cardiovascular protective properties. However, the precise role of T-cadherin in adipose tissue remains elusive. Previously, we generated Cdh13∆Exon3 mice lacking exon 3 in the Cdh13 gene, which encodes the T-cadherin protein, and characterized their phenotype. Methods: Using wild-type (WT) and T-cadherin-deficient mice (Cdh13ΔExon3), we isolated and cultured mesenchymal stem cells to explore the role of T-cadherin in adipogenic differentiation. The experimental approaches employed include culturing cells under standard or adipogenic conditions, performing Oil Red O and Nile Red staining followed by quantitative analysis, conducting rescue experiments to reintroduce T-cadherin using lentiviral constructs in T-cadherin-deficient cells combined with automated adipocyte differentiation quantification via a neural network. Additionally, Western blotting, ELISA assays, and statistical analysis were utilized to verify the results. Results: In this study, we demonstrate for the first time that T-cadherin influences the adipogenic differentiation of MSCs. The presence of T-cadherin dictates distinct morphological characteristics in MSCs. Lack of T-cadherin leads to spontaneous differentiation into adipocytes with the formation of large lipid droplets. T-cadherin-deficient cells (T−/− MSCs) exhibit an enhanced adipogenic potential upon induction with differentiating factors. Western Blot, ELISA assays, and rescue experiments collectively corroborate the conclusion that T−/− MSCs are predisposed toward adipogenic differentiation. We carried out an original comparative analysis to explore the effects of T-cadherin ligands on lipid droplet accumulation. LDL stimulate adipogenic differentiation, while T-cadherin expression mitigates the impact of LDL on lipid droplet accumulation. We also examined the effects of both low molecular weight (LMW) and high molecular weight (HMW) adiponectin on lipid droplet accumulation relative to T-cadherin. LMW adiponectin suppressed lipid droplet accumulation independently of T-cadherin, while the absence of T-cadherin enhanced susceptibility to the suppressive effects of HMW adiponectin on adipogenesis. Discussion: These findings shed light on the role of T-cadherin in adipogenic differentiation and suggest an interplay with other receptors, such as LDLR and AdipoRs, wherein downstream signaling may be modulated through lateral interactions with T-cadherin. [ABSTRACT FROM AUTHOR]

Background/Objectives: The changes in the level of small GTPase ARL4C are associated with the initiation and progression of many different cancers. The content of ARL4C varies greatly between different tissues, and the induction of ARL4C expression leads to changes in cell morphology and proliferation. Although ARL4C can bind alpha-tubulin and affect intracellular transport, the role of ARL4C in the functioning of the tubulin cytoskeleton remained unclear. The aim of the present work is to study this role; Methods: The cells of the following lines were used for the experiments: HeLa (human cervical carcinoma), MCF7 (human breast cancer), U2OS (human osteosarcoma), Vero, BS-C-1, and COS7 (African green monkey kidney). The receptor activation by agonists followed by the preparation of cell lysates, electrophoresis, and immunoblotting, as well as cell fixation and immunofluorescent staining, were used to assess endogenous ARL4C/ABCA1 levels and the microtubule network morphology. The microtubule regrowth technique was performed to estimate the rate of microtubule nucleation, and the overexpression of different ARL4C constructs was used to affect ARL4C activity in the cells; Results: We showed that the changes in the endogenous ARL4C level or the ARL4C activity alter the microtubule nucleation process in the cells; Conclusions: small GTPase ARL4C may serve as one of the regulators of the microtubule nucleation process both in normal and cancer cells. [ABSTRACT FROM AUTHOR]

The endoplasmic reticulum (ER) is involved in biogenesis, modification and transport of secreted and membrane proteins. The ER membranes are spread throughout the cell cytoplasm as well as the export domains known as ER exit sites (ERES). A subpopulation of ERES is centrally localized proximal to the Golgi apparatus. The significance of this subpopulation on ER‐to‐Golgi transport remains unclear. Transport carriers (TCs) form at the ERES via a COPII‐dependent mechanism and move to Golgi on microtubule (MT) tracks. It was shown previously that ERES are distributed along MTs and undergo chaotic short‐range movements and sporadic rapid long‐range movements. The long‐range movements of ERES are impaired by either depolymerization of MTs or inhibition of dynein, suggesting that ERES central concentration is mediated by dynein activity. We demonstrate that the processive movements of ERES are frequently coupled with the TC departure. Using the Sar1a[H79G]‐induced ERES clustering at the perinuclear region, we identified BicaudalD2 (BicD2) and Rab6 as components of the dynein adaptor complex which drives perinuclear ERES concentration at the cell center. BicD2 partially colocalized with ERES and with TC. Peri‐Golgi ERES localization was significantly affected by inhibition of BicD2 function with its N‐terminal fragment or inhibition of Rab6 function with its dominant‐negative mutant. Golgi accumulation of secretory protein was delayed by inhibition of Rab6 and BicD2. Thus, we conclude that a BicD2/Rab6 dynein adaptor is required for maintenance of Golgi‐associated ERES. We propose that Golgi‐associated ERES may enhance the efficiency of the ER‐to‐Golgi transport. [ABSTRACT FROM AUTHOR]

INTRODUCTION: Intravenous immunoglobulin (IVIG) has been widely used to treat various conditions, including inflammatory and autoimmune diseases. IVIG has been shown to have a direct influence on neutrophils, eosinophils and lymphocytes. However, many aspects IVIG's effect on neutrophils activation still remain unknown. OBJECTIVE: To evaluate the effect of IVIG on PMA-induced activation of neutrophils, with and without priming with TNF-a, in a series of in vitro experiments performed on whole blood. RESULTS: Our data coincided with well-known literature indicating that the effect of phorbol 12-myristate 13-acetate (PMA) on human leukocytes includes activation of neutrophils, monocytes and eosinophils, increase of chemiluminescence (CL) and induction of netosis, resulting in assembly of traps. In presence of IVIG (10 mg/mL), CL was reduced by 25% in response to PMA compared to PMA-induced leukocyte activation without IVIG. Decreasing IVIG concentration to 1 mg/mL and below did not inhibit PMA-induced activation of CL. PMA-induced activation after TNF-a priming resulted in approximately 50% increase of amplitude of CL response to PMA. Moreover, maximum CL was reached by minute 5, which was more rapid than in the absence of TNF-a-priming (in this case maximum CL was reached by minute 15). The IVIG concentrations did not affect morphological changes of leukocytes after sequential addition of TNF-a and PMA. IVIG had no effect on leukocyte content and on PMA-induced CL of primed leukocytes. Addition of IVIG under TNF-α priming significantly increased the number of traps in the smears in response to PMA activation. Of note, such an increase in the number of traps was depended on the IVIG concentration in plasma. CONCLUSION: In conclusion, we suggest that IVIG is able to reduce the degradation of traps under priming with TNF-α. Moreover, IVIG might switch the activation of primed leukocytes to netosis. [ABSTRACT FROM AUTHOR]

Sphingomyelin synthase 1 (SMS1) catalyses the biosynthesis of sphingomyelin in eukaryotic cells. We have previously determined the structure of the SGMS1 gene encoding this enzyme and a number of its alternative transcripts. Here, we describe a study of the expression of the full-length SMS1 protein and the sum of the alternative transcripts encoding this protein in human tissues. The SMS1 protein and mRNA levels in tissues differed significantly and were not correlated, implying the active post-transcriptional regulation of SMS1 protein expression. The putative truncated isoforms of the SMS1 protein, which are encoded by a number of alternative transcripts, were not detected by immunoblotting and thus may be absent or present in only small amounts. [ABSTRACT FROM AUTHOR]