Deficiency of C3a receptor attenuates the development of diabetic nephropathy

ObjectiveDiabetic nephropathy (DN) is the leading cause of chronic kidney disease and end-stage renal disease. Emerging evidence suggests that complement activation is involved in the pathogenesis of DN. The aim of this study was to investigate the pathogenic role of C3a and C3a receptor (C3aR) in DN.Research design and methodsThe expression of C3aR was examined in the renal specimen of patients with DN. Using a C3aR gene knockout mice (C3aR−/−), we evaluated kidney injury in diabetic mice. The mouse gene expression microarray was performed to further explore the pathogenic role of C3aR. Then the underlying mechanism was investigated in vitro with macrophage treated with C3a.ResultsCompared with normal controls, the renal expression of C3aR was significantly increased in patients with DN. C3aR−/− diabetic mice developed less severe diabetic renal damage compared with wild-type (WT) diabetic mice, exhibiting significantly lower level of albuminuria and milder renal pathological injury. Microarray profiling uncovered significantly suppressed inflammatory responses and T-cell adaptive immunity in C3aR−/− diabetic mice compared with WT diabetic mice, and this result was further verified by immunohistochemical staining of renal CD4+, CD8+ T cells and macrophage infiltration. In vitro study demonstrated C3a can enhance macrophage-secreted cytokines which could induce inflammatory responses and differentiation of T-cell lineage.ConclusionsC3aR deficiency could attenuate diabetic renal damage through suppressing inflammatory responses and T-cell adaptive immunity, possibly by influencing macrophage-secreted cytokines. Thus, C3aR may be a promising therapeutic target for DN.

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CD8 Treg-Mediated Suppression of Naive CD4+ T Cell Differentiation into Follicular Helper T Cells

International Archives of Allergy and Immunology ◽

10.1159/000521427 ◽

2021 ◽

pp. 1-11

Author(s):

Taissa M. Kasahara ◽

Sudhir Gupta

Keyword(s):

T Cells ◽

Cell Differentiation ◽

T Cell ◽

Inflammatory Responses ◽

Treg Cells ◽

Follicular Helper ◽

And Function ◽

Proliferation In Vitro

Background: The regulatory CD8+ T (CD8+ Treg) cells play an important role in immune tolerance and have been implicated in several human autoimmune diseases. In this context, follicular helper T (TFH) cells contribute by controlling the antibody production. In mice, CD8+ Treg cells control the number and function of TFH cells however the role of human CD8+ Treg cells on the differentiation of naive CD4+ T cells into TFH cells has not been studied. Objectives: Here, we evaluated the ability of human CD183+ CD8+ Treg cells to suppress TFH cell differentiation in vitro. Methods: Activated CD183+CCR7+CD45RA−CD8+ Treg and CD183+CD25highICOS+CD8+ Treg cells were sorted and cocultured with naïve CD4+ T cells under TFH differentiation condition. The differentiation of TFH cells was evaluated by flow cytometry. Results: Our results showed that activated CD183+CD8+ Treg cells upregulated the expression of Forkhead box P3 transcription factor, inducible T-cell co-stimulator (ICOS), and CD25 compared to CD183−CD8+ T cells. The CD183+CD25highICOS+CD8+ Treg cells suppressed TFH cell differentiation and CD4+ T cell proliferation in vitro which was not observed when CD183+CCR7+CD45RA−CD8+ Treg were cocultured with naïve CD4+ T cells under TFH cell differentiation condition. Conclusion: These results suggest that CD25highICOS+CD183+CD8+ Treg cells may regulate autoimmune and inflammatory responses mediated by TFH cells.

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Involvement of HECTD1 in LPS-induced astrocyte activation via σ-1R-JNK/p38-FOXJ2 axis

Cell & Bioscience ◽

10.1186/s13578-021-00572-x ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ying Tang ◽

Mengchun Zhou ◽

Rongrong Huang ◽

Ling Shen ◽

Li Yang ◽

...

Keyword(s):

Inflammatory Responses ◽

Astrocyte Activation ◽

Hect Domain ◽

P38 Inhibitor ◽

Ubiquitin Protein Ligase ◽

Primary Mouse ◽

Lps Treatment

Abstract Background Astrocytes participate in innate inflammatory responses within the mammalian central nervous system (CNS). HECT domain E3 ubiquitin protein ligase 1 (HECTD1) functions during microglial activation, suggesting a connection with neuroinflammation. However, the potential role of HECTD1 in astrocytes remains largely unknown. Results Here, we demonstrated that HECTD1 was upregulated in primary mouse astrocytes after 100 ng/ml lipopolysaccharide (LPS) treatment. Genetic knockdown of HECTD1 in vitro or astrocyte-specific knockdown of HECTD1 in vivo suppressed LPS-induced astrocyte activation, whereas overexpression of HECTD1 in vitro facilitated LPS-induced astrocyte activation. Mechanistically, we established that LPS activated σ-1R-JNK/p38 pathway, and σ-1R antagonist BD1047, JNK inhibitor SP600125, or p38 inhibitor SB203580 reversed LPS-induced expression of HECTD1, thus restored LPS-induced astrocyte activation. In addition, FOXJ2 functioned as a transcription factor of HECTD1, and pretreatment of primary mouse astrocytes with BD1047, SB203580, and SP600125 significantly inhibited LPS-mediated translocation of FOXJ2 into the nucleus. Conclusions Overall, our present findings suggest that HECTD1 participates in LPS-induced astrocyte activation by activation of σ-1R-JNK/p38-FOXJ2 pathway and provide a potential therapeutic strategy for neuroinflammation induced by LPS or any other neuroinflammatory disorders.

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The Inflammatory Role of Pro-Resolving Mediators in Endometriosis: An Integrative Review

International Journal of Molecular Sciences ◽

10.3390/ijms22094370 ◽

2021 ◽

Vol 22 (9) ◽

pp. 4370

Author(s):

Cássia de Fáveri ◽

Paula M. Poeta Fermino ◽

Anna P. Piovezan ◽

Lia K. Volpato

Keyword(s):

Intracellular Signaling ◽

Inflammatory Responses ◽

Therapeutic Potential ◽

Critical Role ◽

Integrative Review ◽

Inflammatory Factors ◽

Resolvin D1 ◽

Endogenous Factors

The pathogenesis of endometriosis is still controversial, although it is known that the inflammatory immune response plays a critical role in this process. The resolution of inflammation is an active process where the activation of endogenous factors allows the host tissue to maintain homeostasis. The mechanisms by which pro-resolving mediators (PRM) act in endometriosis are still little explored. Thus, this integrative review aims to synthesize the available content regarding the role of PRM in endometriosis. Experimental and in vitro studies with Lipoxin A4 demonstrate a potential inhibitory effect on endometrial lesions’ progression, attenuating pro-inflammatory and angiogenic signals, inhibiting proliferative and invasive action suppressing intracellular signaling induced by cytokines and estradiol, mainly through the FPR2/ALX. Investigations with Resolvin D1 demonstrated the inhibition of endometrial lesions and decreased pro-inflammatory factors. Annexin A1 is expressed in the endometrium and is specifically present in women with endometriosis, although the available studies are still inconsistent. Thus, we believe there is a gap in knowledge regarding the PRM pathways in patients with endometriosis. It is important to note that these substances’ therapeutic potential is evident since the immune and abnormal inflammatory responses play an essential role in endometriosis development and progression.

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Role of the C5a-C5a receptor axis in the inflammatory responses of the lungs after experimental polytrauma and hemorrhagic shock

Scientific Reports ◽

10.1038/s41598-020-79607-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Shinjini Chakraborty ◽

Veronika Eva Winkelmann ◽

Sonja Braumüller ◽

Annette Palmer ◽

Anke Schultze ◽

...

Keyword(s):

Hemorrhagic Shock ◽

Inflammatory Responses ◽

Experimental Models ◽

Lung Damage ◽

C5a Receptor ◽

Cytokine Levels ◽

Vitro Model

AbstractSingular blockade of C5a in experimental models of sepsis is known to confer protection by rescuing lethality and decreasing pro-inflammatory responses. However, the role of inhibiting C5a has not been evaluated in the context of sterile systemic inflammatory responses, like polytrauma and hemorrhagic shock (PT + HS). In our presented study, a novel and highly specific C5a L-aptamer, NoxD21, was used to block C5a activity in an experimental murine model of PT + HS. The aim of the study was to assess early modulation of inflammatory responses and lung damage 4 h after PT + HS induction. NoxD21-treated PT + HS mice displayed greater polymorphonuclear cell recruitment in the lung, increased pro-inflammatory cytokine levels in the bronchoalveolar lavage fluids (BALF) and reduced myeloperoxidase levels within the lung tissue. An in vitro model of the alveolar-capillary barrier was established to confirm these in vivo observations. Treatment with a polytrauma cocktail induced barrier damage only after 16 h, and NoxD21 treatment in vitro did not rescue this effect. Furthermore, to test the exact role of both the cognate receptors of C5a (C5aR1 and C5aR2), experimental PT + HS was induced in C5aR1 knockout (C5aR1 KO) and C5aR2 KO mice. Following 4 h of PT + HS, C5aR2 KO mice had significantly reduced IL-6 and IL-17 levels in the BALF without significant lung damage, and both, C5aR1 KO and C5aR2 KO PT + HS animals displayed reduced MPO levels within the lungs. In conclusion, the C5aR2 could be a putative driver of early local inflammatory responses in the lung after PT + HS.

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LPS Primes Brain Responsiveness to High Mobility Group Box-1 Protein

Pharmaceuticals ◽

10.3390/ph14060558 ◽

2021 ◽

Vol 14 (6) ◽

pp. 558

Author(s):

Verena Peek ◽

Lois M. Harden ◽

Jelena Damm ◽

Ferial Aslani ◽

Stephan Leisengang ◽

...

Keyword(s):

Inflammatory Responses ◽

Area Postrema ◽

High Mobility ◽

High Mobility Group ◽

Direct Access ◽

Significant Release ◽

Factor Α ◽

Culture Supernatants

High mobility group box (HMGB)1 action contributes to late phases of sepsis, but the effects of increased endogenous plasma HMGB1 levels on brain cells during inflammation are unclear. Here, we aimed to further investigate the role of HMGB1 in the brain during septic-like lipopolysaccharide-induced inflammation in rats (LPS, 10 mg/kg, i.p.). HMGB-1 mRNA expression and release were measured in the periphery/brain by RT-PCR, immunohistochemistry and ELISA. In vitro experiments with disulfide-HMGB1 in primary neuro-glial cell cultures of the area postrema (AP), a circumventricular organ with a leaky blood–brain barrier and direct access to circulating mediators like HMGB1 and LPS, were performed to determine the direct influence of HMGB1 on this pivotal brain structure for immune-to-brain communication. Indeed, HMGB1 plasma levels stayed elevated after LPS injection. Immunohistochemistry of brains and AP cultures confirmed LPS-stimulated cytoplasmatic translocation of HMGB1 indicative of local HMGB1 release. Moreover, disulfide-HMGB1 stimulation induced nuclear factor (NF)-κB activation and a significant release of interleukin-6, but not tumor necrosis factor α, into AP culture supernatants. However, only a few AP cells directly responded to HMGB1 with increased intracellular calcium concentration. Interestingly, priming with LPS induced a seven-fold higher percentage of responsive cells to HMGB1. We conclude that, as a humoral and local mediator, HMGB1 enhances brain inflammatory responses, after LPS priming, linked to sustained sepsis symptoms.

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Abstract WMP31: Dedifferentiation of Smooth Muscle Cells and its Potential Contribution to Pathogenesis of Intracranial Aneurysms

Stroke ◽

10.1161/str.51.suppl_1.wmp31 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Mieko Oka ◽

Nobuhiko Ohno ◽

Takakazu Kawamata ◽

Tomohiro Aoki

Keyword(s):

Endothelial Cells ◽

Smooth Muscle ◽

Smooth Muscle Cells ◽

Inflammatory Responses ◽

Muscle Cells ◽

Inflammatory Factors ◽

Potential Contribution ◽

Electron Microscopic

Introduction: Intracranial aneurysm (IA) affects 1 to 5 % in general public and becomes the primary cause of subarachnoid hemorrhage, the most severe form of stroke. However, currently, no drug therapy is available for IAs to prevent progression and rupture of lesions. Elucidation of mechanisms underlying the disease is thus mandatory. Considering the important role of vascular smooth muscle cells (SMCs) in the maintenance of stiffness of arterial walls and also in the pathogenesis of atherosclerosis via mediating inflammatory responses, we in the present study analyzed morphological or phenotypical changes of SMCs during the disease development in the lesions. Methods: We subjected rats to an IA model in which lesions are induced by increase of hemodynamic force loading on intracranial arterial bifurcations and performed histopathological analyses of induced lesions including the electron microscopic examination. We then immunostained specimens from induced lesions to explore factors responsible for dedifferentiation or migration of SMCs. In vitro study was also done to examine effect of some candidate factors on dedifferentiation or migration of cultured SMCs. Results: We first found the accumulation of SMCs underneath the endothelial cell layer mainly at the neck portion of the lesion. These cells was positive for the embryonic form of myosin heavy chain, a marker for the dedifferentiated SMCs, and the expression of pro-inflammatory factors like TNF-α. In immunostaining to explore the potential factor regulating the dedifferentiation of SMCs, we found that Platelet-derived growth factor-BB (PDGF-BB) was expressed in endothelial cells at the neck portion of IA walls. Consistently, recombinant PDGF-BB could promote the dedifferentiate of SMCs and chemo-attracted them in in vitro. Finally, in the stenosis model of the carotid artery, PDGF-BB expression was induced in endothelial cells in which high wall shear stress was loaded and the dedifferentiation of SMCs occurred there. Conclusions: The findings from the present study imply the role of dedifferentiated SMCs partially recruited by PDGF-BB from endothelial cells in the formation of inflammatory microenvironment at the neck portion of IA walls, leading to the progression of the disease.

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Immunomodulations induced in rats by exercise on a treadmill

Journal of Applied Physiology ◽

10.1152/jappl.1990.69.5.1912 ◽

1990 ◽

Vol 69 (5) ◽

pp. 1912-1915 ◽

Cited By ~ 16

Author(s):

A. Ferry ◽

B. L. Weill ◽

M. Rieu

Keyword(s):

T Cell ◽

Treadmill Exercise ◽

Absolute Number ◽

Not Given ◽

Spleen Cells ◽

Immune Parameters ◽

Exercise Regimen ◽

Long Duration

Various regimens of treadmill exercise (0% slope) were used with rats: 60 min at 15 m/min (T-15), 180 min at 10 m/min (T-10), and 60 min/day at 15 m/min for 6 consecutive days (T-15-6). Exercise resulted in 1) decreases in the absolute number of mononuclear spleen cells in T-10 rats, 2) significant increases in in vitro splenic T-cell blastogenesis in response to phytohemagglutinin in T-10 rats, and 3) significant decreases in T-cell blastogenesis in T-15-6 rats. T-15-6 rats were given aminoglutethimide per os before exercise sessions to study the role of corticosteroids in the alteration of splenic T-cell blastogenesis. Aminoglutethimide significantly increased the T-cell blastogenesis in these T-15-6 rats compared with those not given aminoglutethimide, whereas it had no effect on immune parameters of sedentary rats. These results show that immunomodulations in the rat depend on the treadmill exercise regimen employed. If the mechanisms of the immunomodulation induced by isolated exercise of long duration are not elucidated, these data suggest that corticosteroids are involved in the alteration in T-cell blastogenesis induced by chronic muscular exercise.

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Assessment of CD4+ T Cell Responses to Glutamic Acid Decarboxylase 65 Using DQ8 Tetramers Reveals a Pathogenic Role of GAD65 121–140 and GAD65 250–266 in T1D Development

PLoS ONE ◽

10.1371/journal.pone.0112882 ◽

2014 ◽

Vol 9 (11) ◽

pp. e112882 ◽

Cited By ~ 21

Author(s):

I-Ting Chow ◽

Junbao Yang ◽

Theresa J. Gates ◽

Eddie A. James ◽

Duy T. Mai ◽

...

Keyword(s):

T Cell ◽

Glutamic Acid ◽

Glutamic Acid Decarboxylase ◽

T Cell Responses ◽

Cd4 T Cell ◽

Acid Decarboxylase ◽

Pathogenic Role ◽

Cell Responses ◽

Glutamic Acid Decarboxylase 65

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Study of Staphylococcus aureusPathogenic Genes by Transfer and Expression in the Less Virulent Organism Streptococcus gordonii

Infection and Immunity ◽

10.1128/iai.69.2.657-664.2001 ◽

2001 ◽

Vol 69 (2) ◽

pp. 657-664 ◽

Cited By ~ 32

Author(s):

P. Stutzmann Meier ◽

J. M. Entenza ◽

P. Vaudaux ◽

P. Francioli ◽

M. P. Glauser ◽

...

Keyword(s):

Single Gene ◽

Individual Factors ◽

Gene Products ◽

Streptococcus Gordonii ◽

Pathogenic Role ◽

Gain Of Function ◽

Function Strategy

ABSTRACT Because Staphylococcus aureus strains contain multiple virulence factors, studying their pathogenic role by single-gene inactivation generated equivocal results. To circumvent this problem, we have expressed specific S. aureus genes in the less virulent organism Streptococcus gordonii and tested the recombinants for a gain of function both in vitro and in vivo. Clumping factor A (ClfA) and coagulase were investigated. Both gene products were expressed functionally and with similar kinetics during growth by streptococci and staphylococci. ClfA-positive S. gordoniiwas more adherent to platelet-fibrin clots mimicking cardiac vegetations in vitro and more infective in rats with experimental endocarditis (P < 0.05). Moreover, deletingclfA from clfA-positive streptococcal transformants restored both the low in vitro adherence and the low in vivo infectivity of the parent. Coagulase-positive transformants, on the other hand, were neither more adherent nor more infective than the parent. Furthermore, coagulase did not increase the pathogenicity ofclfA-positive streptococci when both clfA andcoa genes were simultaneously expressed in an artificial minioperon in streptococci. These results definitively attribute a role for ClfA, but not coagulase, in S. aureus endovascular infections. This gain-of-function strategy might help solve the role of individual factors in the complex the S. aureus-host relationship.

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Redox imbalance of red blood cells impacts T lymphocyte homeostasis: implication in carotid atherosclerosis

Thrombosis and Haemostasis ◽

10.1160/th11-02-0110 ◽

2011 ◽

Vol 106 (12) ◽

pp. 1117-1126. ◽

Cited By ~ 13

Author(s):

Brigitta Buttari ◽

Linda Petrone ◽

Elisabetta Straface ◽

Lucrezia Gambardella ◽

Donatella Pietraforte ◽

...

Keyword(s):

T Cell ◽

T Lymphocytes ◽

Red Blood Cells ◽

Blood Cells ◽

Healthy Subjects ◽

Carotid Atherosclerosis ◽

Cell Function ◽

Inflammatory Responses ◽

Activated T Lymphocytes

SummaryOxidative stress and immune/inflammatory responses are key pathogenetic factors of atherosclerotic disease. In this contest, mechanisms that regulate survival and death of immune cells may be relevant. Previous studies have demonstrated that red blood cells (RBCs) are physiologically able to inhibit apoptosis and to promote proliferation of activated T lymphocytes from healthy subjects. The aim of the present study was to evaluate whether RBCs from patients with carotid atherosclerosis maintain their property to modulate T cell homeostasis. Peripheral blood lymphocytes (PBLs) obtained from healthy subjects were activated in vitro by phytohemagglutinin in the presence/absence of RBCs from patients with carotid atherosclerosis or of in vitro oxidised RBCs from healthy subjects. Levels of reactive oxygen species (ROS) and aging markers of RBCs as well as susceptibility to apoptosis of PBLs were evaluated by flow cytometry. PBL proliferation was evaluated by 3H-methyl-thymidine incorporation assay whereas secretion of cytokines, analysed in view of their key role in T cell function, was assessed by ELISA. Levels of ROS and phosphatidyl-serine externalisation, a sign of RBC aging, resulted significantly higher in RBCs from patients than in those from healthy subjects, whereas surface glycophorin A expression and reduced glutathione content did the opposite. Unlike RBCs obtained from healthy subjects, RBCs from patients and in vitro oxidised RBCs did not protect activated T lymphocytes from apoptosis. Hence, RBCs from patients with carotid atherosclerosis, probably due to their oxidative imbalance, impact T cell integrity and function. Our results suggest a new regulatory role for RBCs in atherosclerosis.

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