Adhesion molecule expression precedes brain damages of lupus-prone mice and correlates with kidney pathology

To study the protective effect of Huangqi Baihe Granules on Radiation brain injury based on network pharmacology and experiment

ETHNOPHARMACOLOGICAL RELEVANCE

Huangqi baihe Granules (HQBHG), which is a key Chinese medical prescription, has a remarkable efficacy in oxidative stress and inflammation. Nevertheless, the therapeutic effect on Radiation brain injury (RBI) has rarely been studied.

AIM OF THE STUDY

The study aimed to verify the effect of HQBHG against RBI and explore its potential mechanism.

METHODS

The potential targets and mechanisms of HQBHG against RBI were predicted by network pharmacology and verified by established rat model of RBI Firstly, the therapeutic effect of HQBHG in RBI was confirmed by water maze test, HE staining and Enzyme-linked immunosorbent assay (ELISA). Secondly, the potential critical anti-RBI pathway of HQBHG was further explored by water maze, HE staining, immunofluorescence assays, ELISA and western blot.

RESULTS

A total of 43 HQBHG anti-RBI targets were obtained. Gene Ontology (Go) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional annotations showed that the treatment of HQBHG in RBI might be mainly related to oxidative stress, inflammation and PI3K/AKT pathway. Experimental studies have indicated that HQBHG can improve spatial learning and memory ability, alleviate pathological damage of brain tissue in RBI of rats. HQBHG also can down-regulate the levels of IL-1β, TNF-α, ROS and MDA, meanwhile, GSH was significantly up-regulated. In addition, the HQBHG can increase the protein expression phosphorylations PI3K (p-PI3K), phosphorylations AKT(p-AKT) and Nrf2 in the brain tissue of RBI.

CONCLUSION

HQBHG may alleviated RBI by regulated oxidative stress and inflammatory response through PI3K/AKT/Nrf2 pathway.

Insights into the role of neutrophils in neuropsychiatric systemic lupus erythematosus: Current understanding and future directions

Central nervous system (CNS) involvement of systemic lupus erythematosus (SLE), termed neuropsychiatric SLE (NPSLE), is a major and debilitating manifestation of the disease. While patients with SLE mostly complain of common neuropsychological symptoms such headache and mild mood disorders that may not even be technically attributed to SLE, many SLE patients present with life-threatening NPSLE syndromes such as cerebrovascular disease, seizures and psychosis that are equally challenging in terms of early diagnosis and therapy. While we are just beginning to unravel some mysteries behind the immunologic basis of NPSLE, advancements in the mechanistic understanding of the complex pathogenic processes of NPSLE have been emerging through recent murine and human studies. The pathogenic pathways implicated in NPSLE are multifarious and various immune effectors such as cell-mediated inflammation, autoantibodies and cytokines including type I interferons have been found to act in concert with the disruption of the blood-brain barrier (BBB) and other neurovascular interfaces. Beyond antimicrobial functions, neutrophils are emerging as decision-shapers during innate and adaptive immune responses. Activated neutrophils have been recognized to be involved in ischemic and infective processes in the CNS by releasing neutrophil extracellular traps (NETs), matrix metalloproteinase-9 and proinflammatory cytokines. In the context of NPSLE, these mechanisms contribute to BBB disruption, neuroinflammation and externalization of modified proteins on NETs that serve as autoantigens. Neutrophils that sediment within the peripheral blood mononuclear cell fraction after density centrifugation of blood are generally defined as low-density neutrophils (LDNs) or low-density granulocytes. LDNs are a proinflammatory subset of neutrophils that are increased with SLE disease activity and are primed to undergo NETosis and release cytokines such as interferon-α and tumor necrosis factor. This review discusses the immunopathogenesis of NPSLE with a focus on neutrophils as a core mediator of the disease and potential target for translational research in NPSLE.

Tissue resident cell processes determine organ damage in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that affects almost any organ. Multiple immunological abnormalities involving every domain of the immune system contribute to the expression of the disease. It is now recognized that elements of the immune system instigate processes in tissue resident cells which execute organ damage. Although correction of ongoing immune aberrations is important in the control of disease activity, targeting tissue specific injurious processes may prove desirable in limiting organ damage.

Hippocampal microglia CD40 mediates NPSLE cognitive dysfunction in mice

Neuropsychiatric systemic lupus erythematosus (NPSLE) is the most serious and complicated clinical manifestation of lupus erythematosus. Cognitive dysfunction is the most common symptom of NPSLE. A variety of potential mechanisms or mediators related to the pathogenesis of NPSLE cognitive dysfunction have been proposed. However, the involvement of microglia CD40 has not been reported yet. This study aimed to investigate whether hippocampal microglia CD40 of MRL/MpJ-Fas^lpr (MRL/lpr) mice was involved in NPSLE cognitive dysfunction. This study found, using quantitative polymerase chain reaction, western blotting and immunohistochemistry, that hippocampal CD40 was aberrantly overexpressed in the MRL/lpr lupus mice. It also determined using flow cytometry and immunofluorescence that the aberrantly overexpressed CD40 was mainly derived from hippocampal microglia. The adeno-associated virus was used to inhibit microglia CD40 expression, and the brain damage and cognitive dysfunction of MRL/lpr mice improved. Also, imiquimod (IMQ)-induced lupus mice had the same NPSLE cognitive dysfunction, brain damage, and overexpressed hippocampal microglia CD40 as MRL/lpr mice. Therefore, IMQ-induced lupus mouse was proposed as one of the mouse models for studying NPSLE cognitive dysfunction for the first time in this study. The findings indicated that hippocampal microglia CD40 was involved in the development of NPSLE cognitive dysfunction, thus providing a novel research direction for the study of the pathogenesis of NPSLE.

A Distinct T Follicular Helper Cell Subset Infiltrates the Brain in Murine Neuropsychiatric Lupus

Neuropsychiatric symptoms in systemic lupus erythematosus (SLE) are not uncommon, yet the mechanisms underlying disease initiation and progression in the brain are incompletely understood. Although the role of T cells in other lupus target organs such as the kidney is well defined, which T cells contribute to the pathogenesis of neuropsychiatric SLE is not known. The present study was aimed at characterizing the CD4 T cell populations that are present in the choroid plexus (CP) of MRL/MpJ-faslpr mice, the primary site of brain infiltration in this classic lupus mouse model which exhibits a prominent neurobehavioral phenotype. T cells infiltrating the CP of MRL/MpJ-faslpr mice were characterized and subset identification was done by multiparameter flow cytometry. We found that the infiltrating CD4 T cells are activated and have an effector phenotype. Importantly, CD4 T cells have a T follicular helper cell (T_FH) like phenotype, as evidenced by their surface markers and signature cytokine, IL-21. In addition, CD4 T_FH cells also secrete significant levels of IFN-γ and express Bcl-6, thereby conforming to a potentially pathogenic T helper population that can drive the disease progression. Interestingly, the regulatory axis comprising CD4 T regulatory cells is diminished. These results suggest that accumulation of CD4 T_FH in the brain of MRL/MpJ-faslpr mice may contribute to the neuropsychiatric manifestations of SLE, and point to this T cell subset as a possible novel therapeutic candidate.

Urine angiostatin and VCAM-1 surpass conventional metrics in predicting elevated renal pathology activity indices in lupus nephritis

AIM

The goal of this study is to investigate how urinary angiostatin, vascular cell adhesion molecule 1 (VCAM-1) and established measures of renal function relate to specific histologic findings in paired kidney biopsy samples from patients with lupus nephritis (LN).

METHOD

Urine samples were collected from 54 LN patients together with paired kidney biopsy samples and examined for urinary angiostatin and VCAM-1 protein levels. Nonparametric tests were used to examine the association of both urinary biomarkers and established traditional laboratory markers of renal function with nine specific renal histologic features seen in LN, including glomerular leukocyte infiltration, endocapillary proliferation, cellular crescents, fibrinoid necrosis, wire loops, interstitial inflammation, glomerulosclerosis, fibrous crescents, tubular atrophy and interstitial fibrosis.

RESULTS

Compared to traditional renal disease metrics, both urinary angiostatin and VCAM-1 exhibited outstanding potential (area under the curve 0.97, 0.98, respectively) to predict renal biopsy activity index score ≥ 7, which is associated with poor long-term prognosis. Whereas urine VCAM-1 was most significantly associated with fibrous crescents, urine angiostatin was most significantly associated with endocapillary proliferation, cellular crescents, fibrinoid necrosis and fibrous crescents in concurrent renal biopsies.

CONCLUSION

Urinary angiostatin and VCAM-1 are predictive of specific histological changes in concurrent LN renal biopsies. Both urinary biomarkers are good candidates for use as noninvasive measures of renal pathology activity changes in LN.

Neuropsychiatric SLE: from animal model to human

Animal models are a key element in disease research and treatment. In the field of neuropsychiatric lupus research, inbred, transgenic and disease-induced mice provide an opportunity to study the pathogenic routes of this multifactorial illness. In addition to achieving a better understanding of the immune mechanisms underlying the disease onset, supplementary metabolic and endocrine influences have been discovered and investigated. The ever-expanding knowledge about the pathologic events that occur at disease inception enables us to explore new drugs and therapeutic approaches further and to test them using the same animal models. Discovery of the molecular targets that constitute the pathogenic basis of the disease along with scientific advancements allow us to target these molecules with monoclonal antibodies and other specific approaches directly. This novel therapy, termed "targeted biological medication" is a promising endeavor towards producing drugs that are more effective and less toxic. Further work to discover additional molecular targets in lupus' pathogenic mechanism and to produce drugs that neutralize their activity is needed to provide patients with safe and efficient methods of controlling and treating the disease.

The blood brain barrier and neuropsychiatric lupus: new perspectives in light of advances in understanding the neuroimmune interface

Experts have previously postulated a linkage between lupus associated vascular pathology and abnormal brain barriers in the immunopathogenesis of neuropsychiatric lupus. Nevertheless, there are some discrepancies between the experimental evidence, or its interpretation, and the working hypotheses prevalent in this field; specifically, that a primary contributor to neuropsychiatric disease in lupus is permeabilization of the blood brain barrier. In this commonly held view, any contribution of the other known brain barriers, including the blood-cerebrospinal fluid and meningeal barriers, is mostly excluded from the discussion. In this review we will shed light on some of the blood brain barrier hypotheses and try to trace their roots. In addition, we will suggest new research directions to allow for confirmation of alternative interpretations of the experimental evidence linking the pathology of intra-cerebral vasculature to the pathogenesis of neuropsychiatric lupus.

Soluble Intracellular Adhesion Molecule-1 in Patients with Unipolar or Bipolar Affective Disorders: Results from a Pilot Trial

BACKGROUND

Immunological and vascular markers may play a role in the pathophysiology of mood disorders and mood changes.

AIM

To test whether the cell adhesion molecule soluble intracellular adhesion molecule-1 (sICAM-1) may serve as a biomarker for patients with unipolar or bipolar affective disorders when compared to a healthy control group, and whether sICAM-1 blood levels change during different mood states.

METHODS

sICAM-1 serum concentrations were compared between 20 healthy controls and 48 patients with affective disorders (unipolar, bipolar II and bipolar I disorder) during different mood states (euthymic mood state, depression or mania).

RESULTS

When compared to healthy controls, patients with affective disorders had significantly higher sICAM-1 levels during the euthymic state (p = 0.015). Differences became more pronounced during depression (p = 0.013). When unipolar and bipolar patients were analyzed separately, unipolar patients significantly differed from controls during the euthymic and depressive mood state, while bipolar II patients showed a trend towards higher sICAM-1 levels during depression. Patients with bipolar I disorders had significantly higher sICAM-1 levels during manic states when compared to controls (p = 0.007).

CONCLUSIONS

sICAM-1 elevation in unipolar and bipolar patients, independent of mood changes, might support the hypothesis of chronic immune activation and endothelial dysfunction in patients with affective disorders.

Pathophysiological Responses in Rat and Mouse Models of Radiation-Induced Brain Injury

The brain is the major dose-limiting organ in patients undergoing radiotherapy for assorted conditions. Radiation-induced brain injury is common and mainly occurs in patients receiving radiotherapy for malignant head and neck tumors, arteriovenous malformations, or lung cancer-derived brain metastases. Nevertheless, the underlying mechanisms of radiation-induced brain injury are largely unknown. Although many treatment strategies are employed for affected individuals, the effects remain suboptimal. Accordingly, animal models are extremely important for elucidating pathogenic radiation-associated mechanisms and for developing more efficacious therapies. So far, models employing various animal species with different radiation dosages and fractions have been introduced to investigate the prevention, mechanisms, early detection, and management of radiation-induced brain injury. However, these models all have limitations, and none are widely accepted. This review summarizes the animal models currently set forth for studies of radiation-induced brain injury, especially rat and mouse, as well as radiation dosages, dose fractionation, and secondary pathophysiological responses.

Neuropsychiatric Lupus, the Blood Brain Barrier, and the TWEAK/Fn14 Pathway

Patients with systemic lupus erythematosus (SLE) can experience acute neurological events such as seizures, cerebrovascular accidents, and delirium, psychiatric conditions including depression, anxiety, and psychosis, as well as memory loss and general cognitive decline. Neuropsychiatric SLE (NPSLE) occurs in between 30 and 40% of SLE patients, can constitute the initial patient presentation, and may occur outside the greater context of an SLE flare. Current efforts to elucidate the mechanistic underpinnings of NPSLE are focused on several different and potentially complementary pathways, including thrombosis, brain autoreactive antibodies, and complement deposition. Furthermore, significant effort is dedicated to understanding the contribution of neuroinflammation induced by TNF, IL-1, IL-6, and IFN-γ. More recent studies have pointed to a possible role for the TNF family ligand TWEAK in the pathogenesis of neuropsychiatric disease in human lupus patients, and in a murine model of this disease. The blood brain barrier (BBB) consists of tight junctions between endothelial cells (ECs) and astrocytic projections which regulate paracellular and transcellular flow into the central nervous system (CNS), respectively. Given the privileged environment of the CNS, an important question is whether and how the integrity of the BBB is compromised in NPSLE, and its potential pathogenic role. Evidence of BBB violation in NPSLE includes changes in the albumin quotient (Q_alb) between plasma and cerebrospinal fluid, activation of brain ECs, and magnetic resonance imaging. This review summarizes the evidence implicating BBB damage as an important component in NPSLE development, occurring via damage to barrier integrity by environmental triggers such as infection and stress; cerebrovascular ischemia as result of a generally prothrombotic state; and immune mediated EC activation, mediated by antibodies and/or inflammatory cytokines. Additionally, new evidence supporting the role of TWEAK/Fn14 signaling in compromising the integrity of the BBB in lupus will be presented.