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Bovine leukemia virus (BLV) main host cells are B lymphocytes. Infected animals can be classified into high or low proviral load (HPL or LPL respectively), regarding the number of proviral copies infected lymphocytes they carry. After infection, there is an overexpression of several cytokines, particularly TNF-α, which has a delicate regulation mediated by receptors TNFRI and TNFRII; the first one involved with apoptosis, while the other stimulates cell proliferation. The study aimed to quantify TNF-α and its receptors mRNA expression, and in which extent in vitro proliferation was affected, in peripheral blood mononuclear cells (PBMC) from BLV-infected animals with different proviral loads, after the addition or not of synthetic TNF-α (rTNF-α) for 48 h. PBMC from BLV-infected animals showed spontaneous proliferation after 48 h in culture but did not show changes in proliferation rates after 48 h incubation in the presence of the rTNF-α. TNF-α mRNA expression after 48 h culture without exogenous stimulation was significantly lower, regardless of the proviral load of the donor, compared to non-infected animals. In the LPL animals, the expression of TNF-α mRNA was significantly lower with respect to the control group while the expression of TNFRI mRNA was significantly increased. The HPL animals showed a significant decrease in the expression of TNF-α and TNFRII mRNA respect to the control group. After 48 h incubation with rTNF-α, PBMC from infected animals had different responses: TNF-α and TNFRI mRNA expression was reduced in PBMC from the LPL group compared to the BLV negative group, but no differences were observed in PBMC from the HPL group. TNFRII mRNA expression showed no differences between HPL, LPL, and BLV negative groups, though HPL animals expressed 10.35 times more TNFRI mRNA than LPL. These results support the hypothesis that LPL animals, when faced with viral reactivation, present a pro-apoptotic and anti-proliferative state. However, complementary studies are needed to explain the influence of TNFRII on the development of the HLP profile. On the other hand, exogenous stimulation studies reinforce the hypothesis that BLV infection compromises the immune response of the animals. [ABSTRACT FROM AUTHOR]

In hypertension induced by angiotensin II (AngII) administration with high salt (HS) intake, intrarenal angiotensinogen (AGT) and tumor necrosis factor‐alpha (TNF‐α) levels increase. However, TNF‐α has been shown to suppress AGT formation in cultured renal proximal tubular cells. We examined the hypothesis that elevated AngII levels during HS intake reduces TNF‐α receptor type 1 (TNFR1) activity in the kidneys, thus facilitating increased intrarenal AGT formation. The responses to HS diet (4% NaCl) with chronic infusion of AngII (25 ng/min) via implanted minipump for 4 weeks were assessed in wild‐type (WT) and knockout (KO) mice lacking TNFR1 or TNFR2 receptors. Blood pressure was measured by tail‐cuff plethysmography, and 24‐h urine samples were collected using metabolic cages prior to start (0 day) and at the end of 2nd and 4th week periods. The urinary excretion rate of AGT (uAGT; marker for intrarenal AGT) was measured using ELISA. HS +AngII treatment for 4 weeks increased mean arterial pressure (MAP) in all strains of mice. However, the increase in MAP in TNFR1KO (77 ± 2 to 115 ± 3 mmHg; n = 7) was significantly greater (p < 0.01) than in WT (76 ± 1 to 102 ± 2 mmHg; n = 7) or in TNFR2KO (78 ± 2 to 99 ± 5 mmHg; n = 6). The increase in uAGT at 4th week was also greater (p < 0.05) in TNFR1KO mice (6 ± 2 to 167 ± 75 ng/24 h) than that in WT (6 ± 3 to 46 ± 16 ng/24 h) or in TNFR2KO mice (8 ± 7 to 65 ± 44 ng/24 h). The results indicate that TNFR1 exerts a protective role by mitigating intrarenal AGT formation induced by elevated AngII and HS intake. [ABSTRACT FROM AUTHOR]

Intravenous infusion of relatively higher doses of angiotensin II (AngII) elicits natriuresis as opposed to its usual anti‐natruretic response. As AngII can induce tumor necrosis factor‐α (TNFα) production which elicits natriuresis via its action on TNFα receptor type 1 (TNFR1), we hypothesize that the concomitant release of TNFα contributes to the natriuretic response to AngII. Responses to AngII infusion (1 ng min−1 g−1 for 75 min, iv) were evaluated in anesthetized knockout (KO) mice lacking TNFR1 (n = 6) and TNFR2 (TNFα receptor type 2; n = 6) and compared these responses with those in wild type (WT; n = 6) mice. Arterial pressure (AP) was recorded from a cannula placed in the carotid artery. Renal blood flow (RBF) and glomerular filtration rate (GFR) were measured by PAH and inulin clearances, respectively. Urine was collected from a catheter placed in the bladder. AngII caused similar increases (p < 0.05 vs basal values) in AP (WT, 37 ± 5%; TNFR1KO, 35 ± 4%; TNFR2KO, 30 ± 4%) and decreases (p < 0.05) in RBF (WT, −39 ± 5%; TNFR1KO, −28 ± 6%; TNFR2KO, −31 ± 4%) without significant changes in GFR (WT, −17 ± 7%; TNFR1KO, −18 ± 7%; TNFR2KO, −12 ± 7%). However, despite similar changes in AP and renal hemodynamics, AngII induced increases (p < 0.05) in urinary sodium excretion in WT (3916 ± 942%) were less in the KO strains, more or less in TNFR1KO (473 ± 170%) than in TNFR2KO (1176 ± 168%). These data indicate that TNF‐α receptors, particularly TNFR1 are involved in the natriuretic response that occur during acute infusion of AngII and thus, plays a protective role in preventing excessive salt retention at clinical conditions associated with elevated AngII level. [ABSTRACT FROM AUTHOR]

To evaluate the concentration of tumor necrosis factor α (TNF‐α) and its soluble receptors (sTNFR I and II) in serum and follicular fluid (FF) at the time of oocyte retrieval and to detect expression of TNF‐α and its receptors by luteinized granulosa cells (GCs). In a cross‐sectional study and through an in vitro fertilization–intracytoplasmic sperm injection (IVF–ICSI) program, 81 women undergoing oocyte retrieval were recruited. Serum and FF were obtained from 81 women. GCs were pooled from 20 patients (from six different days of oocyte retrievals, 5–16 follicles per patient). TNF‐α and its soluble receptors concentration were determined by enzyme‐linked immunosorbent assay and also their expression by immune cytochemistry and reverse‐transcription polymerase chain reaction analysis. The median TNF‐α concentration in serum was 4.06 pg/ml (interquartile range [IQR], 3.71–6.14) and significantly higher than that in FF with 3.50 pg/ml (IQR, 3.05–5.01), p < 0.001. The sTNFR I and II levels in serum were lower and higher than FF, respectively. The TNF‐α levels in serum and FF of good responders were higher than low responders (p = 0.017 and 0.021, respectively). TNF‐α cut‐off level for low responders versus good responders was 4.174 pg/ml in serum with a pregnancy rate of 25.8% and 40% for below and above of this level, respectively (p = 0.19). For FF, the cut‐off value was 3.89 pg/ml. TNF‐α and its receptors were expressed by GCs. The presence of TNF‐α and its soluble receptors in serum and FF and their expression by GCs suggest an important role for this cytokine in ovarian function. [ABSTRACT FROM AUTHOR]

Background The pathogenesis of fat redistribution syndromes (FRS) observed in the setting of highly active antiretroviral therapy (HAART) for the treatment of HIV-1-infection remains elusive. A dysregulation of the tumour necrosis factor alpha (TNF-α) system occurs in HIV-infected patients with FRS. Materials and methods The study looked at both the in vivo and in vitro relationship between TNF-α and the degree of subcutaneous adipocyte apoptosis in 60 HIV-1-infected patients on HAART with FRS, another 60 HIV-1-infected patients on HAART without FRS and 60 uninfected control patients. Apoptosis was assessed by the terminal deoxynucleotidyl transferase dUTP (deoxyuridine 5′-triphosphate)-digoxigenin Nick End Labelling (TUNEL) method. Soluble receptors of TNF-α were determined by the sandwich enzyme immunoassay technique. The in vitro viability was assessed by staining with 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and apoptosis by TUNEL. Results HIV-1-infected patients with FRS had significantly higher degrees of subcutaneous adipocyte apoptosis than those without FRS ( P = 0·0001) and uninfected controls ( P < 0·0001). There was a statistically significant association between serum levels of soluble TNF-α receptors #1 and #2 and the degree of subcutaneous adipocyte apoptosis in patients with and without FRS ( P < 0·0001 for both receptors). In vitro, the addition of TNF-α (10 ng mL−1) to an adipocyte culture embedded with indinavir, either alone or in clinically relevant combinations with stavudine (d4T) and lamivudine (3TC), significantly decreased adipocyte viability ( P = 0·0001) and increased adipocyte apoptosis ( P < 0·0001) with respect to that observed with the addition of antiretrovirals alone. Conclusions TNF-α plays a significant role in subcutaneous adipocyte apoptosis, which occurs in the setting of FRS in HIV-1-infected patients on highly active antiretroviral therapy. [ABSTRACT FROM AUTHOR]

Summary The in vitro regulation of tumour necrosis factor (TNF)-α receptors during Toxoplasma gondii infection of human MRC5 fibroblasts and human myelomonocytic THP-1 cells was investigated. Cells were infected with the virulent RH of T. gondii. TNFR membrane receptors were analysed by flow cytometry with biotinylated TNF-α. Shedding of the soluble form of TNFR1 and TNFR2 in cell culture supernatants was measured by enzyme-linked immunosorbent assay, and expression of mRNA production of TNFR1 and TNFR2 was analysed by quantitative real-time ploymerase chain reaction, 1 h after infection. In the MRC5 cell line, T. gondii infection did not induce any up- or down-regulation of membrane TNFRs, soluble TNFRs or mRNA of TNFRs. However, THP-1 cell infection with living parasites induced a significant soluble TNFR1 release by THP-1 cells after 1 h. We detected an approximately 50% up-regulation (P < 0·01) of soluble TNFR1 in infected THP-1 cells compared to controls. No change in soluble TNFR2 levels was observed in the same conditions. Moreover, infection decreased the level of TNF membrane receptors, but had no effect on TNFR1 and TNFR2 mRNA levels. TNFR modulation by T. gondii infection, in vitro, depends on the cell type. Furthermore, our data suggest that living parasites control the shedding of the soluble form of TNFR1. This mechanism may influence the role of TNF-α in toxoplasmosis. [ABSTRACT FROM AUTHOR]

Soluble tumor necrosis factor alpha (TNF-α) receptors contain two receptors: soluble tumor necrosis factor receptor (sTNFR) 1 and 2, and the aim of our study was to discover their concentration and diagnostic value for idiopathic membranous nephropathy (IMN). In total, 58 patients with IMN, 51 patients with chronic kidney disease (CKD), and 30 healthy volunteers were enrolled in this study. Levels of serum sTNFR1 and sTNFR2 were determined by enzyme-linked immunosorbent assay (ELISA). Serum cystatin C (CysC), urea, creatinine (CREA), uric acid (UA), total protein (TP), albumin (ALB), and 24-h urinary protein (proteinuria, PRO) were examined by automatic biochemical analyzer. Levels of sTNFR1 and sTNFR2 were significantly higher in IMN group than CKD and control group (P < 0.05). In IMN group, there were significant correlation between sTNFR1 and sTNFR2 (P < 0.01). Both sTNFR1 and sTNFR2 were positively related to serum urea, CREA, CysC, UA, 24-h PRO (P < 0.05) and negatively related to ALB (P < 0.01). Receiver operating characteristic (ROC) analysis showed that the area under the curve (AUC) of sTNFR1 and sTNFR2 were 0.997 and 0.993, respectively, when control was healthy volunteers. When sTNFR1 cut-off was 959.15 pg/mL, the sensitivity and specificity were 96.6% and 100%, respectively. When sTNFR2 cut-off was 2449.43 pg/mL, the sensitivity and specificity were 93.1% and 100%, respectively. While the control was CKD group, AUC of sTNFR1 and sTNFR2 were 0.647 and 0.626, respectively. When sTNFR1 cut-off was 3356.57 pg/mL, the sensitivity and specificity were 72.4% and 60.8%, respectively. When sTNFR2 cut-off was 6497.34 pg/mL, the sensitivity and specificity were 72.4% and 58.8%, respectively. This is the first study to show that both levels of sTNFR1 and sTNFR2 increased and correlated with serum urea, CREA, CysC, UA, ALB, 24-h PRO and could be usable for IMN diagnosis and differential diagnosis between IMN and CKD. [ABSTRACT FROM AUTHOR]