Advancements in Diabetic Kidney Disease Management: Integrating Innovative Therapies and Targeted Drug Development.

Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease and affects approximately 40% of diabetic individuals. Cases of DKD continue to rise globally as the prevalence of diabetes mellitus increases, with an estimated 415 million people living with diabetes in 2015 and a projected 642 million by 2040. DKD is associated with significant morbidity and mortality, representing 34% and 36% of all chronic kidney disease deaths in men and women, respectively. Common co-morbidities including hypertension and ageing-related nephron loss further complicate disease diagnosis and progression. The progression of DKD involves several mechanisms including glomerular endothelial cell dysfunction, inflammation, and fibrosis. Targeting these mechanisms has formed the basis of several therapeutic agents. Renin-angiotensin-aldosterone system (RAAS) blockers, specifically angiotensin receptor blockers (ARBs), demonstrate significant reductions in macroalbuminuria. SGLT-2 inhibitors demonstrate kidney protection independent of diabetes control while also decreasing the incidence of cardiovascular events. Emerging agents including GLP-1 agonists, anti-inflammatory agents like bardoxolone, and mineralocorticoid receptor antagonists show promise in mitigating DKD progression. Many novel therapies including monoclonal antibodies CSL346, Lixudebart, and tozorakimab, mesenchymal stem/stromal cell infusion, and cannabinoid-1 receptor inverse agonism via INV-202 are currently in clinical trials and present opportunities for further drug development.

Delayed Wound Healing in the Elderly and a New Therapeutic Target: CD271.

With the development of society, the global population is showing a trend of aging. It is well known that age is one of the factors affecting wound healing. Aging compromises the normal physiological process of wound healing, such as the change of skin structure, the decrease of growth factors, the deceleration of cell proliferation, and the weakening of migration ability, hence delaying wound healing. At present, research in adult stem cell-related technology and its derived regenerative medicine provides a novel idea for the treatment of senile wounds. Studies have confirmed that CD271 (P75 neurotropism receptor/P75NTR)-positive cells (CD271+ cells) are a kind of stem cells with a stronger ability of proliferation, differentiation, migration and secretion than CD271 negative (CD271- cells). Meanwhile, the total amount and distribution of CD271 positive cells in different ages of skin are also different, which may be related to the delayed wound healing of aging skin. Therefore, this article reviews the relationship between CD271+ cells and senile wounds and discusses a new scheme for the treatment of senile wounds.

Small-molecule modulators of tumor necrosis factor signaling.

Tumor necrosis factor (TNF) is a pleiotropic cytokine with a major role in immune system homeostasis and is involved in many inflammatory and autoimmune diseases, such as rheumatoid arthritis (RA), psoriasis, Alzheimer's disease (AD), and multiple sclerosis (MS). Thus, TNF and its receptors, TNFR1 and TNFR2, are relevant pharmacological targets. Biologics have been developed to block TNF-dependent signaling cascades, but they display serious side effects, and their pharmacological effectiveness decreases over time because of their immunogenicity. In this review, we present recent discoveries in small molecules targeting TNF and its receptors and discuss alternative strategies for modulating TNF signaling.

Effect of Hypericin-Mediated Photodynamic Therapy on the Secretion of Soluble TNF Receptors by Oral Cancer Cells.

Squamous cell carcinoma is the most common cancer of the head and neck region. In addition to the classic surgical treatment method, alternative therapy methods are sought. One such method is photodynamic therapy (PDT). In addition to the direct cytotoxic effect, it is essential to determine the effect of PDT on persistent tumor cells. The study used the SCC-25 oral squamous cell carcinoma (OSCC) cell line and the HGF-1 healthy gingival fibroblast line. A compound of natural origin-hypericin (HY)-was used as a photosensitizer (PS) at concentrations of 0-1 µM. After two hours of incubation with the PS, the cells were irradiated with light doses of 0-20 J/cm2. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test was used to determine sublethal doses of PDT. Cell supernatants subjected to sublethal PDT were assessed for soluble tumor necrosis alpha receptors (sTNF-R1, sTNF-R2). The phototoxic effect was observed starting with a light dose of 5 J/cm2 and amplified with the increase in HY concentration and light dose. A statistically significant increase in sTNF-R1 secretion by SCC-25 cells was demonstrated after the PDT with 0.5 µM HY and irradiation with 2 J/cm2 (sTNF-R1 concentration = 189.19 pg/mL ± 2.60) compared to the control without HY and irradiated with the same dose of light (sTNF-R1 concentration = 108.94 pg/mL ± 0.99). The baseline production of sTNF-R1 was lower for HGF-1 than for SCC-25, and secretion was not affected by the PDT. The PDT had no effect on the sTNF-R2 production in the SCC-25 or HGF-1 lines.

Nimesulide, a COX-2 inhibitor, sensitizes pancreatic cancer cells to TRAIL-induced apoptosis by promoting DR5 clustering †.

Nimesulide is a nonsteroidal anti-inflammatory drug and a COX-2 inhibitor with antitumor and antiproliferative activities that induces apoptosis in oral, esophagus, breast, and pancreatic cancer cells. Despite being removed from the market due to hepatotoxicity, nimesulide is still an important research tool being used to develop new anticancer drugs. Multiple studies have been done to modify the nimesulide skeleton to develop more potent anticancer agents and related compounds are promising scaffolds for future development. As such, establishing a mechanism of action for nimesulide remains an important part of realizing its potential. Here, we show that nimesulide enhances TRAIL-induced apoptosis in resistant pancreatic cancer cells by promoting clustering of DR5 in the plasma membrane. In this way, nimesulide acts like a related compound, DuP-697, which sensitizes TRAIL-resistant colon cancer cells in a similar manner. Our approach applies a time-resolved FRET-based biosensor that monitors DR5 clustering and conformational states in the plasma membrane. We show that this tool can be used for future high-throughput screens to identify novel, nontoxic small molecule scaffolds to overcome TRAIL resistance in cancer cells.

Sodium-Glucose Cotransporter-2 Inhibitors-Miracle Drugs for the Treatment of Chronic Kidney Disease Irrespective of the Diabetes Status: Lessons from the Dedicated Kidney Disease-Focused CREDENCE and DAPA-CKD Trials.

Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease (CKD) and end-stage kidney disease worldwide. In Japan, the proportion of new patients requiring dialysis due to DKD has remained unchanged over the past five years. Early diagnosis and treatment are extremely important for the prevention of DKD progression. Albuminuria is the most promising biomarker currently available for diagnosing DKD and predicting its prognosis at an early stage; however, it has relatively poor specificity and sensitivity for DKD. Measuring the serum levels of tumor necrosis factor receptors (TNFRs; TNFR1 and TNFR2) is an alternative for predicting the prognosis of patients with CKD, irrespective of their diabetes status. Cardiorenal risk factor management and renin-angiotensin system inhibitor usage are effective in slowing the DKD progression, although the residual risk remains high in patients with DKD. Recently, two classes of antihyperglycemic agents, sodium-glucose cotransporter 2 (SGLT2) inhibitors and glucagon-like peptide-1 receptor agonists, in addition to nonsteroidal selective mineralocorticoid receptor antagonists, which are less potent blood pressure-lowering and potassium-sparing agents, have emerged as cardiorenal disease-modifying therapies for preventing the DKD progression. This review focused on the SGLT2 inhibitor-based therapeutic strategies that have demonstrated cardiorenal benefits in patients with type 2 diabetes.

TNFR1 Contributes to Activation-Induced Cell Death of Pathological CD4+ T Lymphocytes During Ischemic Heart Failure.

CD4+ T cells turn pathological during heart failure (HF). We show that the expression of tumor necrosis factor (TNF)-α and tumor necrosis factor receptor (TNFR1) increases in HF-activated CD4+ T cells. However, the role of the TNF-α/TNFR1 axis in T-cell activation/proliferation is unknown. We show that TNFR1 neutralization during T-cell activation (ex vivo) or the loss of TNFR1 in adoptively transferred HF-activated CD4+ T cells (in vivo) augments their prosurvival and proliferative signaling. Importantly, TNFR1 neutralization does not affect CD69 expression or the pathological activity of HF-activated TNFR1-/- CD4+ T cells. These results show that during HF TNFR1 plays an important role in quelling prosurvival and proliferative signals in CD4+ T cells without altering their pathological activity.

Progranulin promotes bone fracture healing via TNFR pathways in mice with type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) significantly increases bone fragility and fracture risk. Progranulin (PGRN) promotes bone fracture healing in both physiological and type 1 diabetic conditions. The present study aimed to investigate the role of PGRN in T2DM bone fracture healing. MKR mice (with an FVB/N genetic background) were used as the T2DM model. Drill-hole and Bonnarens and Einhorn models were used to investigate the role of PGRN in T2DM fracture healing in vivo. Primary bone marrow cells were isolated for molecular and signaling studies, and reverse transcription-polymerase chain reaction, immunohistochemical staining, and western blotting were performed to assess PGRN effects in vitro. PGRN mRNA and protein expression were upregulated in the T2DM model. Local administration of recombinant PGRN effectively promoted T2DM bone fracture healing in vivo. Additionally, PGRN could induce anabolic metabolism during endochondral ossification through the TNFR2-Akt and Erk1/2 pathways. Furthermore, PGRN showed anti-inflammatory activity in the T2DM bone regeneration process. These findings suggest that local administration of exogenous PGRN may be an alternative strategy to support bone regeneration in patients with T2DM. Additionally, PGRN might hold therapeutic potential for other TNFR-related metabolic disorders.

The Human Milk Oligosaccharides 3-FL, Lacto-N-Neotetraose, and LDFT Attenuate Tumor Necrosis Factor-α Induced Inflammation in Fetal Intestinal Epithelial Cells In Vitro through Shedding or Interacting with Tumor Necrosis Factor Receptor 1.

SCOPE: Human milk oligosaccharides (hMOs) can attenuate inflammation by modulating intestinal epithelial cells, but the mechanisms of action are not well-understood. Here, the effects of hMOs on tumor necrosis factor-α (TNF-α) induced inflammatory events in gut epithelial cells are studied. METHODS AND RESULTS: The modulatory effects of 2'-fucosyllactose, 3-fucosyllactose (3-FL), 6'-sialyllactose, lacto-N-tetraose, lacto-N-neotetraose (LNnT), lactodifucotetraose (LDFT), and lacto-N-triaose (LNT2) on immature (FHs 74 Int) and adult (T84) intestinal epithelial cells with or without TNF-α are determined. Interleukin-8 (IL-8) secretion in FHs 74 Int and T84 are quantified to determine hMO induced attenuation of inflammatory events by ELISA. 3-FL, LNnT, and LDFT significantly attenuate TNF-α induced inflammation in FHs 74 Int, while LNT2 induces IL-8 secretion in T84. In addition, microscale thermophoresis assays and ELISA are used to study the possible mechanisms of interaction between effective hMOs and tumor necrosis factor receptor 1 (TNFR1). 3-FL, LNnT, and LDFT exert TNFR1 ectodomain shedding while LNnT also shows binding affinity to TNFR1 with a Kd of 900 ± 660 nM. CONCLUSION: The findings indicate that specific hMO types attenuate TNF-α induced inflammation in fetal gut epithelial cells through TNFR1 in a hMO structure-dependent fashion suggest possibilities to apply hMOs in management of TNF-α dependent diseases.

The association of tumor necrosis factor alpha, lymphotoxin alpha, tumor necrosis factor receptor 1 and tumor necrosis factor receptor 2 gene polymorphisms and serum levels with periodontitis and type 2 diabetes in Serbian population.

OBJECTIVES: Aiming to show that periodontitis (PD) and type 2 diabetes (T2D) are bidirectionally related and potentially linked by inflammatory cytokines, we searched for association between -308 G/A Tumor necrosis factor-alpha (TNFα), +252A/G Lymphotoxin-alpha (LTα), +36A/G Tumor necrosis factor receptor 1 (TNFR1) and +676 T/G tumor necrosis factor receptor 2 (TNFR2) single nucleotide polymorphisms (SNPs) and: risk of PD or PD + T2D; periodontitis parameters in PD and PD + T2D; serum levels of cytokines/their receptors. Relationship between periodontal inflammation and serum cytokine/receptor levels was also assessed. DESIGN: Subjects were stratified as: 57 healthy controls (HC); 58 PD; 65 PD + T2D. Sociodemographic, environmental, behavioral and periodontal clinical data were recorded. SNPs were genotyped using polymerase chain reaction-restriction fragment length polymorphism, while cytokines/receptors levels were quantified by enzyme-linked immunosorbent assay. Impact of periodontal inflammation was measured using periodontal inflamed surface area (PISA). RESULTS: TNFα AA genotype showed protective effect in T2D + PD compared to PD, even adjusted for behavioral/environmental factors (OR 0.18; 95 %CI 0.037-0.886; p = 0.035). LTα AG heterozygotes had increased risk of PD (OR 3.27; 95 %CI 1.35-7.96; p = 0.016), while TNFR2 TG genotype had protective effect (OR = 0.44; 95 %CI 0.954-0.9794; p = 0.043). TNFR1 AA was predictor of periodontal pocket depth and clinical attachment loss in PD. Correlation between TNFR2 concentration and PISA was negative in PD, positive in PD + T2D. CONCLUSIONS: None of the SNPs showed cross-susceptibility between PD and T2D. + 252A/G LTα and +676 T/G TNFR2 SNPs are associated with PD risk. Periodontal destruction in healthy individuals is influenced by TNFR1 genotype. Impact of periodontal on systemic inflammation is masked by T2D.

Molecular cloning, characterization, and expression of two TNFRs from the pearl oyster Pinctada fucata martensii.

Proteins in the tumor necrosis factor receptor (TNFR) superfamily play significant roles in many physiological and pathological events, such as inflammation, apoptosis, autoimmunity, and organogenesis. Here, two TNFR gene homologs (PmTNFR1 and PmTNFR5) were identified in the pearl oyster Pinctada fucata martensii. The predicted PmTNFR1 and PmTNFR5 protein sequences were 406 and 533 amino acids long, respectively, and both possessed motifs characteristic of the TNFR family, including a TNFR homology domain (CRD), a transmembrane domain (TM), and death domains. However, the predicted amino acid sequences of PmTNFR1 and PmTNFR5 had low identity (~16-23%) with sequences of vertebrate TNFR family proteins. Furthermore, PmTNFR5 had a death domain at the C-terminal, indicating that this protein may be a novel member of the TNFR superfamily. Constitutive PmTNFR1 and PmTNFR5 mRNA expression was detected in all six pearl oyster tissues tested, with comparatively greater transcript abundance in the hepatopancreas and gill. The gene expression levels of PmTNFR1 and PmTNFR5, as well as those of downstream signaling molecules related to the NF-κB pathway (RIP, TRAF2, TRAF3, IKK, and NF-κB), were quantified in the gill after LPS challenge and in the hemocytes after nucleus insertion surgery using real-time PCR (qRT-PCR). We found that all genes were significantly upregulated at 6 h and 12 h post-injection, as well as at 15 d post-insertion. We used RNAi to inhibit the expression of the PmTNFR1 and PmTNFR5 genes. We then quantified the expression levels of PmTNFR1 and PmTNFR5, as well as downstream genes, using qRT-PCR. We found that RNAi inhibition of PmTNFR1 and PmTNFR5 downregulated the downstream genes (RIP, TRAF2, TRAF3, IKK, and NF-κB). Therefore, our results suggested that PmTNFR1 and PmTNFR5 mediate the NF-κB signaling pathway, and are closely related to immune defense, particularly allograft immunity, in the pearl oyster P. fucata martensii.

Progranulin promotes osteogenic differentiation of human periodontal ligament stem cells via tumor necrosis factor receptors to inhibit TNF-α sensitized NF-kB and activate ERK/JNK signaling.

OBJECTIVE: To investigate the molecular mechanism of Progranulin (PGRN) in promoting osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) in inflammatory environment. BACKGROUND: Progranulin is an antagonist of tumor necrosis factor (TNF) receptors (TNFRs) and is known to promote inflammatory periodontal bone defect regeneration. METHODS: TNFR1- and TNFR2-silenced hPDLSCs designed as hPDLSCs-sh-TNFR1 and hPDLSCs-sh-TNFR2 were cultured with osteoinductive medium containing TNF-α and (or) PGRN. Immunofluorescence, quantitative real-time PCR, and western blot were used to, respectively, detect expressions of TNFR1\TNFR2 and osteogenic differentiation markers as well as phosphorylation level in NF-κB\MAPK-related pathways. RESULTS: Immunofluorescence and real-time PCR showed that TNFR1 and TNFR2 positively expressed in hPDLSCs. TNF-α stimulation could significantly decrease the expressions of ALP and RUNX2 in hPDLSCs, whereas PGRN treatment could significantly enhance their expressions, and reverse TNF-α-mediated expression suppression of ALP and RUNX2 in hPDLSCs. In hPDLSCs-sh-TNFR1, TNF-α mediated osteogenic inhibition decreased, but both TNF-α + PGRN and alone PGRN significantly promoted expression of ALP and RUNX2. PGRN significantly enhanced expression of P-ERK1/2 and P-JNK, while corresponding inhibitors eliminated PGRN-stimulated osteogenic differentiation. In hPDLSCs-sh-TNFR2, no significant difference existed in osteogenic markers and P-JNK expression between the PGRN group and the control group. However, PGRN still activated P-ERK1/2 expression. Besides, PGRN antagonized TNF-α-enhanced NF-κB P65 expression. CONCLUSION: Progranulin promotes osteogenic differentiation of hPDLSCs via TNFR1 to inhibit TNF-α-sensitized NF-κB and via TNFR2 to activate JNK signaling. The mechanism by which PGRN activates ERK signaling remains to be explored.

Plasma sTNFR1 and IL8 for prognostic enrichment in sepsis trials: a prospective cohort study.

BACKGROUND: Enrichment strategies improve therapeutic targeting and trial efficiency, but enrichment factors for sepsis trials are lacking. We determined whether concentrations of soluble tumor necrosis factor receptor-1 (sTNFR1), interleukin-8 (IL8), and angiopoietin-2 (Ang2) could identify sepsis patients at higher mortality risk and serve as prognostic enrichment factors. METHODS: In a multicenter prospective cohort study of 400 critically ill septic patients, we derived and validated thresholds for each marker and expressed prognostic enrichment using risk differences (RD) of 30-day mortality as predictive values. We then used decision curve analysis to simulate the prognostic enrichment of each marker and compare different prognostic enrichment strategies. MEASUREMENTS AND MAIN RESULTS: An admission sTNFR1 concentration > 8861 pg/ml identified patients with increased mortality in both the derivation (RD 21.6%) and validation (RD 17.8%) populations. Among immunocompetent patients, an IL8 concentration > 94 pg/ml identified patients with increased mortality in both the derivation (RD 17.7%) and validation (RD 27.0%) populations. An Ang2 level > 9761 pg/ml identified patients at 21.3% and 12.3% increased risk of mortality in the derivation and validation populations, respectively. Using sTNFR1 or IL8 to select high-risk patients improved clinical trial power and efficiency compared to selecting patients with septic shock. Ang2 did not outperform septic shock as an enrichment factor. CONCLUSIONS: Thresholds for sTNFR1 and IL8 consistently identified sepsis patients with higher mortality risk and may have utility for prognostic enrichment in sepsis trials.

Escherichia coli Pathobionts Associated with Inflammatory Bowel Disease.

Gut bacteria play a key role in initiating and maintaining the inflammatory process in the gut tissues of inflammatory bowel disease (IBD) patients, by supplying antigens or other stimulatory factors that trigger immune cell activation. Changes in the composition of the intestinal microbiota in IBD patients compared to that in healthy controls and a reduced diversity of intestinal microbial species are linked to the pathogenesis of IBD. Adherent invasive Escherichia coli (AIEC) has been linked to Crohn's disease (CD) patients, while diffusely adherent E. coli (DAEC) has been associated with ulcerative colitis (UC). Bacteriological analysis of intestinal biopsy specimens and fecal samples from IBD patients shows an increased number of E. coli strains belonging to the B2 phylogenetic group, which are typically known as extraintestinal pathogenic E. coli (ExPEC). Results from studies of both cell cultures and animal models reveal pathogenic features of these E. coli pathobionts, which may link them to IBD pathogenesis. This suggests that IBD-associated E. coli strains play a facilitative role during IBD flares. In this review, we explain IBD-associated E. coli and its role in IBD pathogenesis.

TRAPS, síndrome periódico asociado al receptor de necrosis tumoral: inmunopatogénesis y enfoque clínico / Understanding the immunopathogenic bases and the clinical approach of the periodic syndrome associated with the tumor necrosis receptor, TRAPS

RESUMEN El síndrome periódico asociado al receptor del factor de necrosis tumoral (TRAPS), se caracteriza por episodios de fiebre de más de 10 días de duración, mialgias migratorias, pseudocelulitis, dolor abdominal y edema bipalpebral. Su principal complicación es la amiloidosis y la falla renal producida por el estado inflamatorio crónico. Es una enfermedad autosómica dominante por mutación en el gen TNFRSF1A que codifica el receptor 1 del factor de necrosis tumoral (TNF). En las hipótesis elaboradas para explicar la enfermedad se describen la alteración en la liberación del receptor de TNF mutado, la activación del factor nuclear potenciador de las cadenas ligeras kappa de las células B activadas (NFkB) de forma independiente, las proteínas mal plegadas y alteraciones en el tráfico del receptor mutado, llevando a la acumulación de especies reactivas del oxígeno y defectos en la muerte celular por autofagia y apoptosis. Se han dirigido muchos esfuerzos en descubrir las bases inmunopatogénicas del TRAPS, dificultado por el elevado número de mutaciones encontradas, que se traducen en diferentes mecanismos y formas de presentación de la enfermedad. El tratamiento se basa en el bloqueo del TNF y de la interleuquina-1 (IL-1), la mejor comprensión de la inmunopatogénesis podría permitir un mejor seguimiento de los pacientes y el empleo de otras terapias.

SUMMARY Tumor necrosis factor receptor periodic syndrome (TRAPS) is characterized by episodes of fever of more than 10 days of duration, migratory myalgias, pseudocellulitis, abdominal pain and bipalpebral edema. It´s main complication is amyloidosis and renal failure caused by the chronic inflammatory state. It is an autosomal dominant disease, by mutation in the TNFRSF1A gene encoding tumor necrosis factor (TNF) receptor 1. Among the hypotheses to explain the disease have been proposed the alteration in the release of the mutated TNF receptor; the activation of nuclear factor enhancer of the kappa light chains of independently activated B cells (NFkB); poorly folded proteins, and alterations in the traffic of the mutated receptor. All of them, leading to the accumulation of reactive oxygen species and defects in cell death by autophagy and apoptosis. Many efforts have been directed to discover the immunopathogenic bases of TRAPS, which has been hampered by the high number of mutations found, which translate different mechanisms and forms of presentation of the disease. The treatment is based on the blockade of TNF and interleukin-1 (IL-1). The better understanding of immunopathogenesis could allow better monitoring of patients and the use of other therapies.

Tumor Necrosis Factor Receptor-Associated Factor Regulation of Nuclear Factor κB and Mitogen-Activated Protein Kinase Pathways.

Tumor necrosis factor receptor (TNFR)-associated factors (TRAFs) are a family of structurally related proteins that transduces signals from members of TNFR superfamily and various other immune receptors. Major downstream signaling events mediated by the TRAF molecules include activation of the transcription factor nuclear factor κB (NF-κB) and the mitogen-activated protein kinases (MAPKs). In addition, some TRAF family members, particularly TRAF2 and TRAF3, serve as negative regulators of specific signaling pathways, such as the noncanonical NF-κB and proinflammatory toll-like receptor pathways. Thus, TRAFs possess important and complex signaling functions in the immune system and play an important role in regulating immune and inflammatory responses. This review will focus on the role of TRAF proteins in the regulation of NF-κB and MAPK signaling pathways.

Correlation of serum level of tumor necrosis factor receptors with cervical cancer and cervical intraepithelial neoplasia / 中华老年医学杂志

Objective To investigate the correlation of cervical cancer and cervical intraepithelial neoplasia with expression level of serum soluble tumor necrosis factor receptor Ⅰ and Ⅱ.Methods A total of 915 recruited women in middle or advanced age were treated in our hospital from January 2015 to January 2017.Participants were assigned to one of five groups:group A (n=432) as control subjects;group B (n 89) diagnosed as cervical intraepithelial neoplasia Ⅰ;group C (n=94)as cervical intraepithelial neoplasia Ⅱ;group D (n=175) as cervical intraepithelial neoplasia Ⅲ;group E (n=125) as cervical cancer.The expression level of serum tumor necrosis factor receptor (sTNFR)was detected by enzyme linked immunosorbent assay.Results The level of sTNFR Ⅰ was much lower in the group A (0.869±0.243)μg/L than in the group B (1.127±0.435)μg/L,C (1.164±0.471)μg/L,D (1.206±0.693)μg/L,and E (1.836± 1.216)μg/L (t =7.782,8.741,8.860,and 15.523,all P＜0.001).The level of sTNFR Ⅰ in the group E was much higher than in the groups B,C,and D (t=5.263,5.077,and 5.684,all P＜0.001).No statistical significance was found in sTNFR Ⅰ level between B,C and D groups.The level of sTNFR Ⅱ was much lower in the group A (1.633±0.402)μg/L than in the group B (1.872±0.526)μg/L,C (1.895±0.402)μg/L,D (1.946±0.604)μg/L,and E (3.192±1.145)μg/L (t=4.824,5.254,7.446,and 23.731,all P＜0.001).The level of sTNFR Ⅱ was much higher in the group E than in the groups B,C,and D (t =10.136,10.501,and 12.216,all P＜0.001).There was no significant difference in sTNFR Ⅱ levels between the groups B,C,and D groups (all P ＞ 0.05).Conclusions Cervical cancer and cervical intraepithelial neoplasia are correlated with level of serum tumor necrosis factor receptors.

B Cell Requirement for Robust Regulatory T Cell Responses to Friend Retrovirus Infection.

Regulatory T cells (Tregs) are immunosuppressive cells of the immune system that control autoimmune reactivity. Tregs also respond during immune reactions to infectious agents in order to limit immunopathological damage from potent effectors such as CD8+ cytolytic T lymphocytes. We have used the Friend virus (FV) model of retroviral infection in mice to investigate how viral infections induce Tregs. During acute FV infection, there is significant activation and expansion of thymus-derived (natural) Tregs that suppress virus-specific CD8+ T cell responses. Unlike conventional T cells, the responding Tregs are not virus specific, so the mechanisms that induce their expansion are of great interest. We now show that B cells provide essential signals for Treg expansion during FV infection. Treg responses are greatly diminished in B cell-deficient mice but can be restored by adoptive transfers of B cells at the time of infection. The feeble Treg responses in B cell-deficient mice are associated with enhanced virus-specific CD8+ T cell responses and accelerated virus control during the first 2 weeks of infection. In vitro experiments demonstrated that B cells promote Treg activation and proliferation through a glucocorticoid-induced receptor superfamily member 18 (GITR) ligand-dependent mechanism. Thus, B cells play paradoxically opposing roles during FV infection. They provide proliferative signals to immunsosuppressive Tregs, which slows early virus control, and they also produce virus-specific antibodies, which are essential for long-term virus control.IMPORTANCE When infectious agents invade a host, numerous immunological mechanisms are deployed to limit their replication, neutralize their spread, and destroy the host cells harboring the infection. Since immune responses also have a strong capacity to damage host cells and tissues, their magnitude, potency, and duration are under regulatory control. Regulatory T cells are an important component of this control, and the mechanisms that induce them to respond and exert immunosuppressive regulation are of great interest. In the current report, we show that B cells, the cells responsible for making pathogen-specific antibodies, are also involved in promoting the expansion of regulatory T cells during a retroviral infection. In vitro studies demonstrated that they do so via stimulation of the Tregs through interactions between cell surface molecules: GITR interactions with its ligand (GITRL) on B cells and GITR on regulatory T cells. These findings point the way toward therapeutics to better treat infections and autoimmune diseases.

Soluble Extracellular Domain of Death Receptor 5 Inhibits TRAIL-Induced Apoptosis by Disrupting Receptor-Receptor Interactions.

Dysregulation of tumor necrosis factor (TNF) receptor signaling is a key feature of various inflammatory disorders. Current treatments for TNF-related diseases function either by sequestering ligand or blocking ligand-receptor interactions, which can cause dangerous side effects by inhibiting the receptors that are not involved in the disease condition. Thus, alternate strategies that target receptor-receptor interactions are needed. We hypothesized that the soluble extracellular domain (ECD) of long isoform of death receptor 5 (DR5) could block endogenous receptor assembly, mimicking the biological effect of decoy receptors that lack the death domain to trigger apoptosis. Using live-cell fluorescence resonance energy transfer studies, we demonstrated that soluble ECD disrupts endogenous DR5-DR5 interactions. Cell viability assays were used to demonstrate the complete inhibition of TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis by the ECD, although TRAIL is still able to bind to the receptor. Importantly, we used mutagenesis to prove that the inhibition of TRAIL-induced apoptosis by the ECD predominantly comes from the disruption of DR5 oligomerization and not ligand sequestration. Inhibition of death receptor activation should have important therapeutic applications in diseases such as nonalcoholic fatty liver disease. More generally, this approach should be generalized to enable the inhibition of other TNF receptor signaling mechanisms that are associated in a wide range of clinical conditions.

Piecing it together: Unraveling the elusive structure-function relationship in single-pass membrane receptors.

The challenge of crystallizing single-pass plasma membrane receptors has remained an obstacle to understanding the structural mechanisms that connect extracellular ligand binding to cytosolic activation. For example, the complex interplay between receptor oligomerization and conformational dynamics has been, historically, only inferred from static structures of isolated receptor domains. A fundamental challenge in the field of membrane receptor biology, then, has been to integrate experimentally observable dynamics of full-length receptors (e.g. diffusion and conformational flexibility) into static structural models of the disparate domains. In certain receptor families, e.g. the ErbB receptors, structures have led somewhat linearly to a putative model of activation. In other families, e.g. the tumor necrosis factor (TNF) receptors, structures have produced divergent hypothetical mechanisms of activation and transduction. Here, we discuss in detail these and other related receptors, with the goal of illuminating the current challenges and opportunities in building comprehensive models of single-pass receptor activation. The deepening understanding of these receptors has recently been accelerated by new experimental and computational tools that offer orthogonal perspectives on both structure and dynamics. As such, this review aims to contextualize those technological developments as we highlight the elegant and complex conformational communication between receptor domains. This article is part of a Special Issue entitled: Interactions between membrane receptors in cellular membranes edited by Kalina Hristova.