Impact of maternal iron deficiency anaemia on the expression of the newly discovered multi-copper ferroxidase, Zyklopen, in term placentas.

In the present study, we investigated the effect of maternal iron deficiency anaemia (IDA) on expression of the newly discovered iron transporter, Zyklopen in term placenta, in 200 pregnant women. Placental expression of Zyklopen was studied by mRNA analysis and immunohistochemistry for the protein. In addition neonatal anthropometric parameters were also analysed. 58.8% of 200 subjects were anaemic. Both Zyklopen mRNA as well as protein expression in the placenta showed a statistically significant increase with increasing severity of anaemia. Although all the neonatal anthropometric parameters were lower in newborns of anaemic mothers, none showed any statistical significance. Zp mRNA levels did not show any significant correlation with newborn and placental parameters (except newborn skinfold thickness and head circumference). Similar to mRNA expression, Zp IHC expression correlated positively, albiet non-significantly, with newborn length and Hb levels, the correlation was however negative with birth weight, head circumference, mid-arm circumference unlike the mRNA expression, where it positively correlated with the above parameters. Our study for the first time demonstrated a definite increase in expression of Zyklopen at both mRNA and protein levels in term placenta, in maternal IDA.IMPACT STATEMENTWhat is already known on this subject? Iron deficiency anaemia (IDA) in a pregnant mother can lead to anaemia in the developing foetus; which is frequently observed to be of lesser severity than that in the mother. Recently a copper-containing oxidase called Zyklopen was discovered which was involved in iron efflux in BeWo cells. The gene encoding Zyklopen has been identified with a putative C-terminal membrane-spanning sequence and high sequence identitical to hephaestin (Heph) and ceruloplasmin (Cp), the other known vertebrate multicopper ferroxidase (MCF). Protein expression of this new MCF was observed in multiple diverse mouse tissues, including placenta and mammary gland.What do the results of this study add? Zyklopen protein immunohistochemical expression showed a statistically significant increase with increasing severity of anaemia. Similarly, placental mRNA expression of the Zyklopen gene was observed to be higher in anaemic mothers when compared to non-anaemic mothers. Our study for the first time demonstrated a definite increase in expression of Zyklopen at both protein and mRNA levels in term placenta, in maternal IDA.What are the implications of these findings for clinical practice and/or further research? This study will help us to understand better, the increased potential for influx of iron from mother to foetus in the condition of maternal iron deficiency. This study will help to determine how placental iron transport proteins can be regulated in response to maternal and neonatal iron status and will further our existing knowledge on relationships between maternal and neonatal iron status and mechanisms by which placental iron transport is modified in relation to these parameters.

Effect of Maternal Iron Deficiency Anaemia on the Expression of Iron Transport Proteins in the Third Trimester Placenta.

BackgroundDuring pregnancy, iron is transferred from mother to fetus with placental iron transport proteins (Transferrin receptor, Divalent metal transporter/DMT1, ferroportin/FPN1 and Zyklopen). The aim of the study was to evaluate the effect of maternal iron deficiency anemia on placental iron transporters. Study Design: Two hundred pregnant women, in third trimester of pregnancy were divided into anemic (Hemoglobin/Hb < 11g/dl) and non-anemic groups (Hb ≥ 11 g/dl). After delivery, placental expression of iron transport proteins were studied by immunohistochemistry and by mRNA analysis. Results: Of the 200 subjects, 59% were anemic. All 3 placental proteins showed statistically significant increase in immunohistochemical expression, proportionate to the severity of maternal anemia. The mRNA expression of DMT-1 gene was only significantly elevated in placentas of anemic mothers. Conclusion: Although in our study mRNA expression of only the DMT-1 gene was significantly high, immunohistochemically however all the 3 proteins showed significantly higher expression in placentas of anemic mothers.

Transcriptional Regulation of Zinc Transporters in Human Osteogenic Sarcoma (Saos-2) Cells to Zinc Supplementation and Zinc Depletion.

Bone is a passive storage organ for zinc, which contains about 30% of the total body zinc. However, during extreme zinc deficiency, only a small fraction of zinc is released in contrast to other tissues where zinc is released like monocytes or conserved, e.g., skeletal muscle. Zinc plays an important role in bone tissue remodeling. Zinc homeostasis is regulated by several zinc transporters (ZnTs) and importers (ZIPs), but their expression dynamics concerning zinc status of bone cells is not well understood. The study aimed to elucidate the effects of zinc supplementation and depletion on the transcript levels of various zinc transporters. Saos-2, a human osteoblastic cell line, was used as representative bone tissue. Zinc sulfate was used for simulating sufficient zinc status whereas TPEN, a zinc chelator, was used to simulate zinc-deficient state. Expression of various transcripts was measured by qRT-PCR. Subcellular localization of ZnT-1 was carried out by immunofluorescent microscopy, and Western Blotting was carried out to measure the expression of ZnT-1 at the protein level. Among the export transporters the transcript levels of MT, ZnT-1 showed higher levels in zinc sufficient and lower levels in TPEN treated cells. Expression of ZnT-4 was decreased under both the conditions. ZIP-6 and ZIP-13 were downregulated in zinc sufficiency, and ZIP-10 upregulated probably to prevent an excess zinc accumulation in bone cells. Further, ZnT-1 was found to be localized in the nuclear region of SaOS-2 cells. ZnT-1, ZnT-4, ZIP-6, ZIP-11, ZIP-10, and ZIP-13 along with MT may be responsible for maintaining bone zinc homeostasis.

The PPE2 protein of Mycobacterium tuberculosis translocates to host nucleus and inhibits nitric oxide production.

Mycobacterium tuberculosis, the bacterium that causes tuberculosis, is one of the most successful pathogens of humans. It has evolved several adaptive skills and evasion mechanisms to hijack the immunologically educated host to suit its intracellular lifestyle. Here, we show that one of the unique PPE family member proteins of M. tuberculosis, PPE2, can limit nitric oxide (NO) production by inhibiting inos gene transcription. PPE2 protein has a leucine zipper DNA-binding motif and a functional nuclear localization signal. PPE2 was translocated into the macrophage nucleus via the classical importin α/ß pathway where it interacted with a GATA-binding site overlapping with the TATA box of inos promoter and inhibited NO production. PPE2 prolonged intracellular survival of a surrogate bacterium M. smegmatis in vitro as well as in vivo. This information are likely to improve our knowledge of host-pathogen interactions during M. tuberculosis infection which is crucial for designing effective anti-TB therapeutics.

PE11, a PE/PPE family protein of Mycobacterium tuberculosis is involved in cell wall remodeling and virulence.

The role of the unique proline-glutamic acid (PE)/proline-proline-glutamic acid (PPE) family of proteins in the pathophysiology and virulence of Mycobacterium tuberculosis is not clearly understood. One of the PE family proteins, PE11 (LipX or Rv1169c), specific to pathogenic mycobacteria is found to be over-expressed during infection of macrophages and in active TB patients. In this study, we report that M. smegmatis expressing PE11 (Msmeg-PE11) exhibited altered colony morphology and cell wall lipid composition leading to a marked increase in resistance against various environmental stressors and antibiotics. The cell envelope of Msmeg-PE11 also had greater amount of glycolipids and polar lipids. Msmeg-PE11 was found to have better survival rate in infected macrophages. Mice infected with Msmeg-PE11 had higher bacterial load, showed exacerbated organ pathology and mortality. The liver and lung of Msmeg-PE11-infected mice also had higher levels of IL-10, IL-4 and TNF-α cytokines, indicating a potential role of this protein in mycobacterial virulence.