Neuronal chemokines:new insights into neuronal communication after injury

Classically,chemokines were described as small proteins driving leukocyte migration.Nonetheless,more and more studies are showing the great variety of cell functions and tissues in which they participate,including neural cells.During the last years,research has highlighted the importance of chemokines in the nervous system,governing a wide range of processes (MesquidaVeny et al.,2021).This is evidenced for example by the crucial role played by CXCL12 during cortical development,or the homeostatic role of neuronal CX3CL1,preventing microglial activation.We are now certain that many chemokines and their receptors are widely expressed in neurons,and growing evidence has shown them as fundamental players in direct neuronal communication,both during homeostasis and after insult.

Chemokine Receptors CCR1, CCR3, CCR7 and Chemokines CX3CL1 and CCL5 are Significantly Up-Regulated and Very Reliable for Acute Rejection Diagnosis of Kidney Transplants

Background: The allo-immune response following organ transplantation constitutes one of the main determinants concerning both short- and long- term outcomes in renal graft recipients. Chemokines and their receptors play a diversified and important role, either homeostatic or inflammatory and direct different immune-competent cell types to the allograft. While deeply studied in the last two decades, controversy persists as a result of chemokines’ pleiotropic actions. We report our analysis of CCR1, CCR3, CCR7, CCL5 and CX3CL1 expression or synthesis by graft-infiltrating cells in human kidney transplants (KTx). At the same time, we tested their robustness in diagnosing acute rejection. Methods: Fine-needle aspiration biopsies (Fnab) were performed either on days 7 or 14 post-transplantation among stable KTx and on the day of acute rejection (AR) diagnosis. Fnab cytopreparations were studied by the enzymatic avidin-biotin complex staining for CCR1, CCR3, CCR7 and CX3CL1. From another subgroup of cases, Fnab samples were cultured for 48 hours and the supernatants were analysed for CCL5 by ELISA. Results: The group of AR cases showed a significantly up-regulated expression of CCR1, CCR3, CCR7 and CX3CL1 and a significantly higher synthesis of CCL5. The positive predictive values were respectively 92%, 97%, 85%, 76% and 78% and negative predictive values were by the same order, 100%, 73%, 100%, 98% and 83%. Conclusions: Our study permits us to advance that CCR1 and CCR3 play a significant and non-redundant role in acute rejection, and it is the first report of CCR3 association with rejection, probably related to CCL5. The presence inside the graft of significant up-regulation for CCR7 surmises that part of antigen presentation may be performed there without being restricted to secondary lymphoid sites. Our results with CX3CL1 confirm other reports.

C-X-C chemokine receptor type 7 antibody enhances neural plasticity after ischemic stroke

Stromal cell-derived factor-1 and its receptor C-X-C chemokine receptor 4(CXCR4) have been shown to regulate neural regeneration after stroke.Howeve r,whether stromal cell-derived factor-1 receptor CXCR7,which is widely distributed in the develo ping and adult central nervous system,participates in neural regeneration remains poorly unde rstood.In this study,we established rat models of focal cerebral ischemia by injecting endothelin-1 into the cerebral co rtex and striatum.Starting on day 7 after injury,CXCR7-neutralizing antibody was injected into the lateral ventricle using a micro drug delivery system for 6 consecutive days.Our results showed that CXCR7-neutralizing antibody increased the total length and number of sprouting co rticospinal tra ct fibers in rats with cerebral ischemia,increased the expression of vesicular glutamate transporter 1 and growth-related protein 43,marke rs of the denervated spinal cord synapses,and promoted the differentiation and maturation of oligodendrocyte progenitor cells in the striatum.In addition,CXCR7 antibody increased the expression of CXCR4 in the striatum,increased the protein expression of RAS and ERK1/2 associated with the RAS/ERK signaling pathway,and im proved rat motor function.These findings suggest that CXCR7 improved neural functional recovery after ischemic stroke by promoting axonal regeneration,synaptogenesis,and myelin regeneration,which may be achieved by activation of CXCR4 and the RAS/ERK1/2 signaling pathway.

Macrophage migration inhibitory factor facilitates astrocytic production of the CCL2 chemokine following spinal cord injury

Spinal cord injury causes accumulation of a large number of leukocytes at the lesion site where they contribute to excessive inflammation.Overproduced chemokines are responsible for the migratory process of the leukocytes,but the regulatory mechanism underlying the production of chemokines from resident cells of the spinal cord has not been fully elucidated.We examined the protein levels of macrophage migration inhibitory factor and chemokine C-C motif chemokine ligand 2 in a spinal cord contusion model at different time points following spinal cord injury.The elevation of macrophage migration inhibitory factor at the lesion site coincided with the increase of chemokine C-C motif chemokine ligand 2 abundance in astrocytes.Stimulation of primary cultured astrocytes with different concentrations of macrophage migration inhibitory factor recombinant protein induced chemokine C-C motif chemokine ligand 2 production from the cells,and the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine attenuated the stimulatory effect.Further investigation into the underlying mechanism on macrophage migration inhibitory factor-mediated astrocytic production of chemokine C-C motif chemokine ligand 2 revealed that macrophage migration inhibitory factor activated intracellular JNK signaling through binding with CD74 receptor.Administration of the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine following spinal cord injury resulted in the reduction of chemokine C-C motif chemokine ligand 2-recruited microglia/macrophages at the lesion site and remarkably improved the hindlimb locomotor function of rats.Our results have provided insights into the functions of astrocyte-activated chemokines in the recruitment of leukocytes and may be beneficial to develop interventions targeting chemokine C-C motif chemokine ligand 2 for neuroinflammation after spinal cord injury.

Blocking postsynaptic density-93 binding to C-X3-C motif chemokine ligand 1 promotes microglial phenotypic transformation during acute ischemic stroke

We previously reported that postsynaptic density-93 mediates neuron-microglia crosstalk by interacting with amino acids 357–395 of C-X3-C motif chemokine ligand 1(CX3 CL1) to induce microglia polarization. More importantly, the peptide Tat-CX3 CL1(comprising amino acids 357–395 of CX3 CL1) disrupts the interaction between postsynaptic density-93 and CX3 CL1, reducing neurological impairment and exerting a protective effect in the context of acute ischemic stroke. However, the mechanism underlying these effects remains unclear. In the current study, we found that the pro-inflammatory M1 phenotype increased and the anti-inflammatory M2 phenotype decreased at different time points. The M1 phenotype increased at 6 hours after stroke and peaked at 24 hours after perfusion, whereas the M2 phenotype decreased at 6 and 24 hours following reperfusion. We found that the peptide Tat-CX3 CL1(357–395 aa) facilitates microglial polarization from M1 to M2 by reducing the production of soluble CX3 CL1. Furthermore, the a disintegrin and metalloprotease domain 17(ADAM17) inhibitor GW280264 x, which inhibits metalloprotease activity and prevents CX3 CL1 from being sheared into its soluble form, facilitated microglial polarization from M1 to M2 by inhibiting soluble CX3 CL1 formation. Additionally, Tat-CX3 CL1(357–395 aa) attenuated long-term cognitive deficits and improved white matter integrity as determined by the Morris water maze test at 31–34 days following surgery and immunofluorescence staining at 35 days after stroke, respectively. In conclusion, Tat-CX3 CL1(357–395 aa) facilitates functional recovery after ischemic stroke by promoting microglial polarization from M1 to M2. Therefore, the Tat-CX3 CL1(357–395 aa) is a potential therapeutic agent for ischemic stroke.

CXC chemokines and chemokine receptors in gastric cancer: From basic findings towards therapeutic targeting

Gastric cancer is the fourth most common cancer,and the second-highest cause of cancer-related deaths worldwide.Despite extensive research to identify novel diagnostic and therapeutic agents,patients with advanced gastric cancer suffer from a poor quality of life and poor prognosis,and treatment is dependent mainly on conventional cytotoxic chemotherapy.To improve the quality of life and survival of gastric cancer patients,a better understanding of the underlying molecular pathologies,and their application towards the development of novel targeted therapies,is urgently needed.Chemokines are a group of small proteins associated with cytoskeletal rearrangements,the directional migration of several cell types during development and physiology,and the host immune response via interactions with G-protein coupled receptors.There is also growing evidence to suggest that chemokines not only play a role in the immune system,but are also involved in the development and progression of tumors.In gastric cancer,CXC chemokines and chemokine receptors regulate the trafficking of cells in and out of the tumor microenvironment.CXC chemokines and their receptors can also directly influence tumorigenesis by modulating tumor transformation,survival,growth,invasion and metastasis,as well as indirectly by regulating angiogenesis,and tumor-leukocyte interactions.In this review,we will focus on the roles of CXC chemokines and their receptors in the development,progression,and metastasis of gastric tumors,and discuss their therapeutic potential for gastric cancer.

CXC family of chemokines as prognostic or predictive biomarkers and possible drug targets in colorectal cancer

Colorectal cancer(CRC) is the third most common cancer in men and the second most common cancer in women,worldwide. In the early stages of the disease, biomarkers predicting early relapse would improve survival rates.In metastatic patients, the use of predictive biomarkers could potentially result in more personalized treatments and better outcomes. The CXC family of chemokines(CXCL1 to 17) are small(8 to 10 kDa) secreted proteins that attract neutrophils and lymphocytes. These chemokines signal through chemokine receptors(CXCR) 1 to 8.Several studies have reported that these chemokines and receptors have a role in either the promotion or inhibition of cancer, depending on their capacity to suppress or stimulate the action of the immune system, respectively.In general terms, activation of the CXCR1/CXCR2 pathway or the CXCR4/CXCR7 pathway is associated with tumor aggressiveness and poor prognosis; therefore,the specific inhibition of these receptors is a possible therapeutic strategy. On the other hand, the lesser known CXCR3 and CXCR5 axes are generally considered to be tumor suppressor signaling pathways, and their stimulation has been suggested as a way to fight cancer.These pathways have been studied in tumor tissues(using immunohistochemistry or measuring mRNA levels)or serum [using enzyme-linked immuno sorbent assay(ELISA) or multiplexing techniques], among other sample types. Common variants in genes encoding for the CXC chemokines have also been investigated as possible biomarkers of the disease. This review summarizes themost recent findings on the role of CXC chemokines and their receptors in CRC and discusses their possible value as prognostic or predictive biomarkers as well as the possibility of targeting them as a therapeutic strategy.

Chemokines play complex roles in cerebral ischemia

Ischemic stroke(IS) is a disease caused by deficiency of blood and oxygen in focal or complete brain,followed by inflammation cascade and other pathological reactions,which finally lead to irreversible damage to the cerebrum.For the inflammation is a key progress at the initiation of ischemia and poststroke,and chemokines work as vital cytokines in inflammation,we focus the roles of chemokines in IS.Studies have shown cerebral ischemia is associated with marked induction of both CXC and CC chemokines which resulting in extensive leukocyte infiltration in the ischemic brain,and neutrophil infiltration may increase cerebral edema inducing injury in the ischemic area.In addition,chemokines also shows other functions such as promote neuroblast migration,hematogenous cell recruitment and functional brain repair.Thus,a similar chemokine ligand/chemokine receptor pair can mediate both beneficial and detrimental effects depending on the window of observation and pathophysiological conditions.This manuscript reviews the studies about chemokine-mediated effects in cerebral ischemia/reperfusion and discusses the potential significance of these interactions in injury and repair of ischemic tissues.We also refer drug development based on the chemokines and clinical applications using chemokines as diagnostic or prognostic biomarkers in ischemic stroke.

Chemokines and their receptors play important roles in the development of hepatocellular carcinoma

The chemokine system consists of four different subclasses with over 50 chemokines and 19 receptors. Their functions in the immune system have been well elucidated and research during the last decades unveils their new roles in hepatocellular carcinoma(HCC). The chemokines and their receptors in the microenvironment influence the development of HCCby several aspects including:inflammation,effects on immune cells,angiogenesis,and direct effects on HCC cells. Regarding these aspects,pre-clinical research by targeting the chemokine system has yielded promising data,and these findings bring us new clues in the chemokine-based therapies for HCC.

Chemokines and hepatocellular carcinoma

Chemokines play a paramount role in tumor progres-sion. In hepatocellular carcinoma (HCC) progression, chemokines and their receptors play an intricate role. Currently, chemokines and their receptors such as the CXCL12-CXCR4 axis, CX3CL1-CX3CR1 axis and the CCL20-CCR6 axis have received much research attention. Although a large number of studies show that these axes are strongly associated with HCC, the exact mechanism by which these axes promote the growth and progression of HCC remains unknown. In this paper, several chemokines and their receptor interactions in HCC progression, growth and metastasis and immune response to HCC are reviewed.

Inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma

AIM:To study the inflammatory microenvironment and expression of chemokines in hepatocellular carcinoma(HCC) in nude mice.METHODS:CBRH-7919 HCC cells were injected into the subcutaneous region of nude mice.Beginning two weeks after the challenge,tumor growth was measured every week for six weeks.The stromal microenvironment and inflammatory cell infiltration was assessed by immunohistochemistry in paired tumor and adjacent peritumoral samples,and macrophage phenotype was assessed using double-stain immunohistochemistry incorporating expression of an intracellular enzyme.A chemokine PCR array,comprised of 98 genes,was used to screen differential gene expressions,which were validated by Western blotting.Additionally,expression of identified chemokines was knocked-down by RNA interference,and the effect on tumor growth was assessed.RESULTS:Inflammatory cell infiltrates are a key feature of adjacent peritumoral tissues with increased macrophage,neutrophil,and T cell(specifically helperand activated subsets)infiltration.Macrophages within adjacent peritumoral tissues express inducible nitric oxide synthase,suggestive of a proinflammatory phenotype.Fifty-one genes were identified in tumor tissues during the progression period,including 50that were overexpressed(including CXCL1,CXCL2 and CXCL3)and three that were underexpressed(CXCR1,Ifg and Actb).RNA interference of CXCL1 in the CBRH-7919 cells decreased the growth of tumors in nude mice and inhibited expression of CXCL2,CXCL3and interleukin-1βprotein.CONCLUSION:These findings suggest that CXCL1plays a critical role in tumor growth and may serve as a potential molecular target for use in HCC therapy.

Chemokines,chemokine receptors and the gastrointestinal system

The biological properties of tumor cells are known to be regulated by a multitude of cytokines and growth factors,which include epidermal growth factor receptor agonists and members of the transforming growth factor β family.Furthermore,the recent explosion of research in the field of chemokine function as mediators of tumor progression has led to the possibility that these small,immunomodulatory proteins also play key roles in carcinogenesis and may,therefore,be potential targets for novel therapeutic approaches.In this review,we will summarize recently reported findings in chemokine biology with a focus on the gastrointestinal tract.

Role of cytokines and chemokines in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) includes a variety of histological conditions (ranging from liver steatosis and steatohepatitis, to fibrosis and hepatocarcinoma) that are characterized by an increased fat content within the liver. The accumulation/deposition of fat within the liver is essential for diagnosis of NAFLD and might be associated with alterations in the hepatic and systemic inflammatory state. Although it is still unclear if each histological entity represents a different disease or rather steps of the same disease, inflammatory processes in NAFLD might influence its pathophysiology and prognosis. In particular, non-alcoholic steatohepatitis (the most inflamed condition in NAFLDs, which more frequently evolves towards chronic and serious liver diseases) is characterized by a marked activation of inflammatory cells and the upregulation of several soluble inflammatory mediators. Among several mediators, cytokines and chemokines might play a pivotal active role in NAFLD and are considered as potential therapeutic targets. In this review, we will update evidence from both basic research and clinical studies on the potential role of cytokines and chemokines in the pathophysiology of NAFLD.

Role of chemokines and their receptors in viral persistence and liver damage during chronic hepatitis C virus infection

Chemokines produced in the liver during hepatitis C virus(HCV) infection induce migration of activated T cells from the periphery to infected parenchyma.The milieu of chemokines secreted by infected hepatocytes is predominantly associated with the T-helper cell/Tc1 T cell(Th1/Tc1) response.These chemokines consist of CCL3(macrophage inflammatory protein-1α;MIP-1α),CCL4(MIP-1β),CCL5(regulated on activation normal T cell expressed and secreted;RANTES),CXCL10(interferon-γ-inducible protein-10;IP-10),CXCL11(interferon-inducible T-cell α chemoattractant;I-TAC),and CXCL9(monokine induced by interferon γ;Mig) and they recruit T cells expressing either CCR5 or CXCR3 chemokine receptors.Intrahepatic and peripheral blood levels of these chemokines are increased during chronic hepatitis C.The interaction between chemokines and their receptors is essential in recruiting HCV-specific T cells to control the infection.When the adaptive immune response fails in this task,non-specific T cells without the capacity to control the infection are also recruited to the liver,and these are ultimately responsible for the persistent hepatic damage.The modulation of chemokine receptor expression and chemokine secretion could be a viral escape mechanism to avoid specific T cell migration to the liver during the early phase of infection,and to maintain liver viability during the chronic phase,by impairing non-specific T cell migration.Some chemokines and their receptors correlate with liver damage,and CXCL10(IP-10) and CXCR3 levels have shown a clinical utility as predictors of treatment response outcome.The regulation of chemokines and their receptors could be a future potential therapeutic target to decrease liver inflammation and to increase specific T cell migration to the infected liver.

Indoleamine 2,3-dioxygenase (IDO) is essential for dendritic cell activation and chemotactic responsiveness to chemokines

Indoleamine 2, 3-dioxygenase (IDO) is a rate-limiting enzyme for the tryptophan catabolism. In human and murine cells, IDO inhibits antigen-specific T cell proliferation in vitro and suppresses T cell responses to fetal alloantigens during murine pregnancy. In mice, IDO expression is an inducible feature of specific subsets of dendritic cells (DCs), and is important for T cell regulatory properties. However, the effect of IDO and tryptophan deprivation on DC func- tions remains unknown. We report here that when tryptophan utilization was prevented by a pharmacological inhibitor of IDO, 1-methyl tryptophan (1MT), DC activation induced by pathogenic stimulus lipopolysaccharide (LPS) or inflam- matory cytokine TNF-α was inhibited both phenotypically and functionally. Such an effect was less remarkable when DC was stimulated by a physiological stimulus, CD40 ligand. Tryptophan deprivation during DC activation also regu- lated the expression of CCR5 and CXCR4, as well as DC responsiveness to chemokines. These results suggest that tryptophan usage in the microenvironment is essential for DC maturation, and may also play a role in the regulation of DC migratory behaviors.

Induction of CXC chemokines in human mesenchymal stem cells by stimulation with secreted frizzled-related proteins through non-canonical Wnt signaling

AIM: To investigate the effect of secreted frizzledrelated proteins(s FRPs) on CXC chemokine expression in human mesenchymal stem cells(h MSCs).METHODS: CXC chemokines such as CXCL5 and CXCL8 are induced in h MSCs during differentiation with osteogenic differentiation medium(OGM) and may be involved in angiogenic stimulation during bone repair. h MSCs were treated with conditioned medium(CM) from L-cells expressing non-canonical Wnt5 a protein, or with control CM from wild type L-cells, or directly with s FRPs for up to 10 d in culture. m RNA expression levels of both CXCL5 and CXCL8 were quantitated by real-time reverse transcriptase-polymerase chain reaction and secreted protein levels of these proteins determined by ELISA. Dose-(0-500 ng/m L) and time-response curves were generated for treatment with s FRP1. Signal transduction pathways were explored by western blot analysis with pan- or phosphorylation-specific antibodies, through use of specific pathway inhibitors, and through use of si RNAs targeting specific frizzled receptors(Fzd)-2 and 5 or thereceptor tyrosine kinase-like orphan receptor-2(Ro R2) prior to treatment with s FRPs. RESULTS: CM from L-cells expressing Wnt5 a, a noncanonical Wnt, stimulated an increase in CXCL5 m RNA expression and protein secretion in comparison to control L-cell CM. s FRP1, which should inhibit both canonical and non-canonical Wnt signaling, surprisingly enhanced the expression of CXCL5 at 7 and 10 d. Dickkopf1, an inhibitor of canonical Wnt signaling prevented the s FRPstimulated induction of CXCL5 and actually inhibited basal levels of CXCL5 expression at 7 but not at 10 d post treatment. In addition, all four s FRPs isoforms induced CXCL8 expression in a dose- and time-dependent manner with maximum expression at 7 d with treatment at 150 ng/m L. The largest increases in CXCL5 expression were seen from stimulation with s FRP1 or s FRP2. Analysis of mitogen-activated protein kinase signaling pathways in the presence of OGM showed s FRP1-induced phosphorylation of extracellular signal-regulated kinase(ERK)(p44/42) maximally at 5 min after s FRP1 addition, earlier than that found in OGM alone. Addition of a phospholipase C(PLC) inhibitor also prevented s FRPstimulated increases in CXCL8 m RNA. si RNA technology targeting the Fzd-2 and 5 and the non-canonical Fzd co-receptor Ro R2 also significantly decreased s FRP1/2-stimulated CXCL8 m RNA levels.CONCLUSION: CXC chemokine expression in h MSCs is controlled in part by s FRPs signaling through noncanonical Wnt involving Fzd2/5 and the ERK and PLC pathways.

Effects of cytokines and chemokines on migration of mesenchymal stem cells following spinal cord injury

We investigated the effects of cytokines and chemokines and their associated signaling pathways on mesenchymal stem cell migration after spinal cord injury, to determine their roles in the curative effects of mesenchymal stem cells. This study reviewed the effects of tumor necrosis factor-α, vascular endothelial growth factor, hepatocyte growth factor, platelet-derived growth factor, basic fibroblast growth factor, insulin like growth factor-I, stromal cell-derived factor and monocyte chemoattractant protein-1, 3 during mesenchymal stem cell migration to damaged sites, and analyzed the signal transduction pathways involved in their effects on mesenchymal stem cell migration. The results confirmed that phosphatidylinositol 3-kinase/serine/threonine protein kinases and nuclear factor-KB play crucial roles in the migration of mesenchymal stem cells induced by cytokines and chemokines.

Expression of Pref-1 and Related Chemokines during the Development of Rat Mesenteric Lymph Nodes

Objective The aim of this study was to investigate the ability of Pref-1~＋ adipocyte progenitor cells to mobilize into mesenteric lymph nodes（MLNs） and the dynamic expression of related chemokines during the development of rat MLNs. Methods Immunohistochemical analyses were used to detect the expression of Pref-1 and related chemokines. Transmission electron microscopy（TEM） was used to observe the changes in ultrastructure of MLNs. Results Cells containing lipid droplets were found in all rat MLNs at embryonic day（E） 18.5, 2 and 6 weeks（w） after birth, and they were similar to fibroblastic reticular cells（FRCs） or follicular dendritic cells（FDCs） under TEM. Pref-1~＋ adipocyte progenitor cells were found in all MLNs. The expression level of Pref-1 was significantly increased at 2 w after birth and decreased at 6 w after birth. The tendency of Cxcl12 expression was consistent with that of Pref-1 and was positively correlated with the expression of Pref-1（P 〈 0.01; r = 0.897）. At E18.5, Cxcl13, and Ccr7 were significantly expressed in the MLN anlage, but the expression level of Ccl21 was low. The expression level of Cxcl13, Ccr7, and Ccl21 in MLN were significantly increased at 2 w after birth（P 〈 0.05）, while the expression of Ccr7 and Ccl21 were significantly decreased at 6 w after birth（P 〈 0.05）. Conclusion Adipocyte progenitor cells are involved in the rat MLNs development through differentiation into FRC and FDC. The expression of the relevant chemokines during the development of MLNs is dynamic and may be related to the maintenance of lymph nodes self-balance state.

Involvement of CXCR3-associated Chemokines in MHV-3 Induced Fulminant Hepatic Failure

The role of chemokines in murine hepatitis virus strain 3 (MHV-3) induced fulminant hepatic failure (FHF) is not well defined. In this study, we investigated the role of the CXC chemokine receptor 3 (CXCR3)- associated chemokine [monokine induced by IFN-gamma (Mig/CXCL9) and interferon-gamma-inducible protein 10 (IP-10/CXCL10)] in the recruitment of intrahepatic lymphocytes and subsequent fulminant hepatic failure induced by MHV-3. Balb/cJ mice (6-8 weeks, female) were intraperitioneally injected with 100 PFU MHV-3.The proportions and numbers of T cells and NK cells as well as the expression of CXCR3 on T cells and NK cells in the liver, spleen and blood were analyzed by flow cytometry. The hepatic mRNA level of the CXCR3-associated chemokines (CXCL9 and CXCL10) was detected by realtime PCR. A transwell migration assay was used to assess the chemotactic effect of MHV-3-infected hepatocytes on the splenic lymphocytes. Following MHV-3 infection, the number of hepatic NK cells and T cells and the frequencies of hepatic NK cells and T cells expressing CXCR3 increased markedly; however, in the spleen and peripheral blood, they both decreased significantly. Moreover, the hepatic mRNAs levels of CXCL9 and CXCL10 were significantly elevated post infection. The transwell migration assay demonstrated that MHV-3-infected hepatocytes have the capacity to attract and recruit the splenic NK cells and T cells, and CXCL10 plays a key role in lymphocyte mobilization from the spleen. These results suggest that the CXCR3- associated chemokines (CXCL9 and CXCL10) may play animportant role in the recruitment of intrahepatic lymphocytes and subsequent necroinflammation and hepatic failure in MHV-3 infection.

Serum levels of chemokines in adolescents with major depression treated with fluoxetine

BACKGROUND Major depressive disorder(MDD)is a global health issue that affects 350 million people of all ages.Although between 2%and 5.6%of affected individuals are adolescents,research on young patients is limited.The inflammatory response contributes to the onset of depression,and in adult MDD patients,symptom severity has been linked to chemokine levels.AIM To determine the differences in circulatory levels of chemokines in healthy volunteers(HVs)and adolescents with MDD,and assess the changes induced by fluoxetine consume.METHODS The 22 adolescents with MDD were monitored during the first 8 wk of clinical follow-up and clinical psychiatric evaluation was done using the Hamilton depresión rating scale(HDRS).The serum levels of monocyte chemoattractant protein-1(MCP-1),macrophage inflammatory protein(MIP)-1α,MIP-1β,interleukin(IL)-8,interferon gamma-induced protein(IP)-10,and eotaxin were measured in patients and HVs.RESULTS In all cases,significant differences were detected in circulating chemokine levels between patients before treatment and HVs(P<0.0001).All chemokines decreased at 4 wk,but only MCP-1 and IL-8 significantly differed(P<0.05)between 0 wk and 4 wk.In the patients,all chemokines rose to their initial concentrations by 8 wk vs 0 wk,but only IP-10 did so significantly(P<0.05).All patients experienced a significant decrease in HDRS scores at 4 wk(P<0.0001)and 8 wk(P<0.0001)compared with 0 wk.CONCLUSION Despite the consumption of fluoxetine,patients had significantly higher chemokine levels,even after considering the improvement in HDRS score.The high levels of eotaxin,IP-10,and IL-8 partially explain certain aspects that are affected in MDD such as cognition,memory,and learning.