Association between endometrial senescent cells and immune cells in women with repeated implantation failure.

PURPOSE: The aim of this study was to compare women with recurrent implantation failure (RIF) and control group in terms of the associations between p16-positive senescent cells and certain types of immune cells in human endometrium during the mid-luteal phase METHODS: Immunohistochemical staining was performed in 116 endometrial biopsies taken from 57 women presenting RIF, and control group of 59 women who became pregnant after the first intracytoplasmic sperm injection. Endometrial tissue sections were stained immunohistochemically for p16 (Senescent cells), CD4 (T-helpers), CD8 (T-killers), CD14 (Monocytes), CD68 (Macrophages), CD56 (Natural killers), and CD79α (B-cells). The percentage of positively stained cells for each marker was calculated by HALO image analysis software. The quantity and the relationship between senescent cells and immune cells were assessed and compared between the two groups. RESULTS: The correlation coefficient was highest between senescent cells and CD4+ cells and was lowest between senescent cells and CD14+ cells in RIF women, similarly to the control group. However, most of the observed correlations among senescent and immune cells weaken notably or disappear in the RIF group. When comparing senescent cell-to-immune cell quantitative ratios, only p16+/CD4+ cell ratio was significantly higher in RIF women as compared with patients from the control group. CONCLUSION: Our study indicates that the quantity of senescent cells in human endometrium during the mid-luteal phase has the strongest association with the amount of T helpers. Moreover, the specificity of this association might have an important impact on the occurrence of RIF.

A triglyceride-rich lipoprotein environment exacerbates renal injury in the accelerated nephrotoxic nephritis model.

Hyperlipidaemia accompanies chronic renal disease either as a consequence of the renal dysfunction or as part of generalized metabolic derangements. Under both situations, the lipid profile is characterized by accumulation of triglyceride-rich lipoproteins (TGRLs). This lipid profile is recognized as a risk factor for cardiovascular complications. Whether it may pose a risk for renal injury as well remains unclear. A hyper-TGRL state was generated in C57BL/6 mice using poloxamer-407 (P-407) and immune complex-mediated renal injury was triggered using the accelerated nephrotoxic nephritis (ANTN) model. The hyper-TGRL animals were hypersensitive to ANTN demonstrated by greater haematuria and glomerular cellularity. These changes were accompanied by increased glomerular accumulation of CD68+ macrophages. The hypersensitive response to ANTN was not seen in low-density lipoprotein receptor knock-out mice fed with a high fat diet, where triglyceride levels were lower but cholesterol levels comparable to those obtained using P-407. These data indicate that a hyper-TGRL state might be more detrimental to the kidneys than low-density lipoprotein-driven hypercholesterolaemia during immune complex-mediated nephritis. We speculate that the hyper-TGRL environment primes the kidney to exacerbated renal damage following an inflammatory insult with increased accumulation of macrophages that may play a key role in mediating the injurious effects.

C3 dysregulation due to factor H deficiency is mannan-binding lectin-associated serine proteases (MASP)-1 and MASP-3 independent in vivo.

Uncontrolled activation of the complement alternative pathway is associated with complement-mediated renal disease. Factor B and factor D are essential components of this pathway, while factor H (FH) is its major regulator. In complete FH deficiency, uncontrolled C3 activation through the alternative pathway results in plasma C3 depletion and complement-mediated renal disease. These are dependent on factor B. Mannan-binding lectin-associated serine proteases 1 and 3 (MASP-1, MASP-3) have been shown recently to contribute to alternative pathway activation by cleaving pro-factor D to its active form, factor D. We studied the contribution of MASP-1 and MASP-3 to uncontrolled alternative pathway activation in experimental complete FH deficiency. Co-deficiency of FH and MASP-1/MASP-3 did not ameliorate either the plasma C3 activation or glomerular C3 accumulation in FH-deficient mice. Our data indicate that MASP-1 and MASP-3 are not essential for alternative pathway activation in complete FH deficiency.

Complement, roles in renal disease and modulation for therapy.

The complement system, an essential part of the innate immune system, defends the host against invading pathogens, prevents immune complex disease and aids the acquired immune response. Under normal conditions the host is protected from complement attack by an array of complement regulatory proteins. However, in certain contexts inappropriate complement activation can occur associating the C system with a variety of disease pathologies. This review focuses upon the role complement plays in a number of renal pathologies as well as the role of complement in three examples of extrarenal diseases: paroxysmal nocturnal hemoglobinuria, age-related macular degeneration and liver fibrosis. From the evidence discussed it is clear that mutations or polymorphisms in the complement regulators resulting in reduced levels or inefficient action dramatically enhance susceptibility to certain diseases and in particular render the kidney more vulnerable to complement attack. Additionally, deficiency in the complement components can predispose to disease through reduced clearance of apoptotic cells and subsequent generation of complement activating autoantibodies or enhanced formation of convertases resulting in heightened complement activation. As complement has devastating effects, in such disease contexts it has become a therapeutic target. Therapeutic intervention strategies discussed here focus upon the use of recombinant agents, the most promising of which are the anti-C5 antibody-derived reagents. These agents have proved effective in the treatment of paroxysmal nocturnal hemoglobinuria, nephritis and ischemia-reperfusion injuries and will no doubt, along with other reagents currently being developed, prove invaluable in the treatment of renal pathologies.

Deficiency of mannan-binding lectin associated serine protease-2 due to missense polymorphisms.

Mannan-binding lectin (MBL) and ficolins distinguish between self, non-self and altered-self by recognizing patterns of ligands on the surface of microorganisms or aberrant cells. When this happens MBL-associated serine protease-2 (MASP-2) is activated and cleaves complement factors to start inflammatory actions. We examined human populations for MASP-2 levels, MASP-2 function and for the presence of mutations in coding exons of MASP2. The MASP-2 levels were lowest in Africans from Zambia (median, 196 ng/ml) followed by Hong Kong Chinese (262 ng/ml), Brazilian Amerindians (290 ng/ml) and Danish Caucasians (416 ng/ml). In the Chinese population, we uncovered a novel four amino-acid tandem duplication (p.156_159dupCHNH) associated with low levels of MASP-2. The frequency of this mutation as well as the SNPs p.R99C, p.R118C, p.D120G, p.P126L and p.V377A were analyzed. The p.156_159dupCHNH was only found in Chinese (gene frequency 0.26%) and p.D120G was found only in Caucasians and Inuits from West-Greenland. The p.P126L and p.R99Q were present in Africans and Amerindians only, except for p.R99Q in one Caucasian. The MASP-2 levels were reduced in individuals with p.V377A present. The MASP-2 present in individuals homozygous for p.377A or p.99Q had a normal enzyme activity whereas MASP-2 in individuals homozygous for p.126L was non-functional.

Mannan-binding lectin recognizes structures on ischaemic reperfused mouse kidneys and is implicated in tissue injury.

Organ damage as a consequence of ischaemia and reperfusion (I/R) is a major clinical problem in an acute renal failure and transplantation. Ligands on surfaces of endothelial cells that are exposed due to the ischaemia may be recognized by pattern recognition molecules such as mannan-binding lectin (MBL), inducing complement activation. We examined the contribution of the MBL complement pathway in a bilateral renal I/R model (45 min of ischaemia followed by 24 h of reperfusion), using transgenic mice deficient in MBL-A and MBL-C [MBL double knockout (MBL DKO)] and in wildtype (WT) mice. Kidney damages, which were evaluated by levels of blood urea nitrogen (BUN) and creatinine, showed that MBL DKO mice were significantly protected compared with WT mice. MBL DKO mice, reconstituted with recombinant human MBL, showed a dose-dependent severity of kidney injury increasing to a comparable level to WT mice. Acute tubular necrosis was evident in WT mice but not in MBL DKO mice after I/R, confirming renal damages in WT mice. MBL ligands in kidneys were observed to be present after I/R but not in sham-operated mice. C3a (desArg) levels in MBL DKO mice were decreased after I/R compared with that in WT mice, indicating less complement activation that was correlated with less C3 deposition in the kidneys of MBL DKO mice. Our data implicate a role of MBL in I/R-induced kidney injury.

Mannan-binding lectin modulates the response to HSV-2 infection.

Viruses have developed numerous strategies to escape recognition by the immune system. However, some viruses such as herpes simplex virus-2 (HSV-2) are recognized by initiators of the complement system, e.g. mannan-binding lectin (MBL). To study the effects of MBL deficiency during viral infection we have chosen a model of generalized HSV-2 infection. We infected MBL-A and MBL-C double knock-out mice (DKO) with HSV-2 via the intraperitoneal (i.p.) route. DKO mice cleared HSV-2 from the liver less efficiently than the comparable wild-type animals. The impairment to effectively neutralize HSV-2 correlated with compromised liver function as measured by increased plasma levels of alanine-amino transferase. No differences in the viral burden were found in other organs such as spleen or brain. Thus, MBL-mediated protection was limited to the effects of preservation of liver homeostasis. Reconstitution with recombinant human MBL before and during the HSV-2 infection dramatically lowered the viral titres in the liver. Taken together, the data show that MBL modulates the response to HSV-2 in mice by affecting neutralization of the virus. To analyse if MBL plays a role in establishment and progression of human HSV-2 infection we analysed MBL levels in the serum samples from asymptomatic (virus-exposed people who have never displayed symptoms of HSV-2 infection) and symptomatic HSV-2 patients (people with recurrent HSV-2 infections). We found that the frequency of the MBL deficiency (<100 ng/ml) was higher in the symptomatic group and significantly different from that in the asymptomatic group (P = 0.0369). This suggests that lack of MBL-mediated complement activation increases susceptibility to viral infection.

[Frequency of antiphospholipid antibodies and Leiden mutation of hemostasis Factor V in unexplained recurrent fetal and embryo loss]. / Chestota na antifosfolipidni antitela i Leidenova mutatsiia Faktor V na kr'vos'sirvaneto pri povtariashta se neobiasnima fetalna i embrionalna zaguba.

Object of the study are women with a history of unexplained recurrent embryo, fetal and early neonatal death, severe preeclampsia, fetal growth retardation, abruptio placentae, puerperal thromboses. Quite often placental insufficiency is linked to abnormal vascular system and hemostatic disturbancies. In about 65% of the women with a complicated and in 18% of the women with a normal pregnancy are observed different genetic anomalies that lead to a hypercoagulative state. A major place is taken by the Leiden mutation of hemostasis factor V, by protein C and protein S deficiency, etc. Another disease that leads to arterial and venous thromboses and is most often linked to recurrent miscarriage is the antiphospholipid syndrome. Many authors confirm the findings of large placental infarctions and thromboses in women who are positive for antophospholipid antibodies.

[Electron microscopic study of preserved skin]. / Elektronnomikroskopski izsledvaniia na konservirana kozha

The ultrastructure of normal and preserved skin of rabbits breed "chin-chill" has been investigated. The authors state that when the skin is preserved under given conditions for 20 days, the intracellular changes of the epithelium and connective tissue have a reversible character, but after 30 day preservation under the same conditions the connective tissue shows deep pathological changes. The authors conclude that the electronic microscopic investigations give a more complete characteristics for the fitness of the tissues for transplantation, as compared with other methods.