Brain-derived neurotrophic factor/tyrosine kinase B signaling regulates human trophoblast growth in an in vivo animal model of ectopic pregnancy

Possible new mechanisms of primary drug resistance in NSCLC with EGFR mutation treated with Osimertinib

In this study, a patient with lung adenocarcinoma harboring an EGFR mutation exhibited primary resistance to the targeted EGFR inhibitor Osimertinib after 2 months of treatment. As the disease advanced, further genetic analysis revealed the emergence of additional mutations in ARID1A, NTRK1, and ZRSR2, alongside the existing EGFR mutation. Subsequent treatment with Pemetrexed resulted in a significant reduction in liver metastases. Protein mass spectrometry sequencing and immunohistochemical analysis collectively indicated that the PI3K/mTOR pathway mediates the mechanism through which these gene mutations confer primary drug resistance. Evidence demonstrates that the co-occurrence of EGFR and ARID1A mutations diminishes the efficacy of EGFR tyrosine kinase inhibitors (EGFR TKIs). Consequently, it is hypothesized that mutations in NTRK1 and ZRSR2, which are implicated in the PI3K/mTOR pathway, contribute to the primary resistance observed with Osimertinib treatment. In this case, the illness was effectively managed through prompt adjustments to the treatment regimen and the rapid administration of chemotherapy drugs. This finding also constitutes the first evidence that mutations in NTRK1 and ZRSR2 are pivotal in the development of primary resistance to Osimertinib. Consequently, it is imperative to conduct genetic testing at the earliest opportunity and modify the treatment plan accordingly.

Effect of affective temperament on illness characteristics of subjects with bipolar disorder and major depressive disorder

BACKGROUND

Affective temperaments represent the stable, biologically determined substrates of mood disorders. The relationship between affective temperaments and bipolar disorder (BD) or major depressive disorder (MDD) has been described. However, the strength of such relationship should be tested while considering other factors influencing the diagnosis of BD/MDD. Literature also lacks a comprehensive description of the interplay between affective temperament and characteristics of mood disorders. The aim of the present study is to address these issues.

METHODS

This is a multicentric observational study including 7 Italian university sites. Five-hundred-fifty-five euthymic subjects with BD/MDD were enrolled and further divided in those with hyperthymic (Hyper, N = 143), cyclothymic (Cyclo, N = 133), irritable (Irr, N = 49), dysthymic (Dysth, N = 155), and anxious (Anx N = 76) temperaments. Linear, binary, ordinal and logistic regressions were performed to assess the association between affective temperaments and i) diagnosis of BD/MDD; ii) characteristics of illness severity and course.

RESULTS

Hyper, Cyclo and Irr were more likely to be associated with BD, together with earlier age of onset and presence of a first-degree relative with BD. Anx and Dysth were more associated with MDD. Differences in association between affective temperaments and characteristics of BD/MDD were observed for hospital admissions, phase-related psychotic symptoms, length and type of depression, comorbidity and pharmacological intake.

LIMITATIONS

Small sample size, cross-sectional design, recall biases.

CONCLUSION

Specific affective temperaments were associated to certain characteristics of illness severity and course of BD or MDD. Evaluation of affective temperaments might help a deeper understanding of mood disorders.

Neurotrophins: are they involved in immune tolerance in pregnancy?

In this review, an attempt was made to substantiate the possibility for neurotrophins to be involved in the development of immune tolerance based on data accumulated on neurotrophin content and receptor expression in the trophoblast and immune cells, in particular, in natural killer cells. Numerous research results are reviewed to show that the expression and localization of neurotrophins along with their high-affinity tyrosine kinase receptors and low-affinity p75NTR receptor in the mother-placenta-fetus system indicate the important role of neurotrophins as binding molecules in regulating the crosstalk between the nervous, endocrine, and immune systems in pregnancy. An imbalance between these systems can occur with tumor growth and pathological processes observed in pregnancy complications and fetal development anomalies.

Imbalance of Angiogenic and Growth Factors in Placenta in Maternal Hyperhomocysteinemia

Numerous studies have shown that various adverse factors of different nature and action mechanisms have similar negative influence on placental angiogenesis, resulting in insufficiency of placental blood supply. One of the risk factors for pregnancy complications with placental etiology is an increased level of homocysteine in the blood of pregnant women. However, the effect of hyperhomocysteinemia (HHcy) on the development of the placenta and, in particular, on the formation of its vascular network is at present poorly understood. The aim of this work was to study the effect of maternal HHcy on the expression of angiogenic and growth factors (VEGF-A, MMP-2, VEGF-B, BDNF, NGF), as well as their receptors (VEGFR-2, TrkB, p75NTR), in the rat placenta. The effects of HHcy were studied in the morphologically and functionally different maternal and fetal parts of the placenta on the 14th and 20th day of pregnancy. The maternal HHcy caused increase in the levels of oxidative stress and apoptosis markers accompanied by an imbalance of the studied angiogenic and growth factors in the maternal and/or fetal part of the placenta. The influence of maternal HHcy in most cases manifested in a decrease in the protein content (VEGF-A), enzymatic activity (MMP-2), gene expression (VEGFB, NGF, TRKB), and accumulation of precursor form (proBDNF) of the investigated factors. In some cases, the effects of HHcy differed depending on the placental part and stage of development. The influence of maternal HHcy on signaling pathways and processes controlled by the studied angiogenic and growth factors could lead to incomplete development of the placental vasculature and decrease in the placental transport, resulting in fetal growth restriction and impaired fetal brain development.

How neuroactive factors mediates immune responses during pregnancy: An interdisciplinary view

Pregnancy, from insemination to parturition, is a highly complex but well-orchestrated process that requires various organs and systems to participate. Immune system and neuroendocrine system are important regulators in healthy pregnancy. Dozens of neuroactive factors have been detected in human placenta, whether they are locally secreted or circulated. Among them, some are vividly studied such as corticotropin-releasing hormone (CRH), human chorionic gonadotropin (hCG), transforming growth factor-β (TGF-β), progesterone and estrogens, while others are relatively lack of research. Though the neuroendocrine-immune interactions are demonstrated in some diseases for decades, the roles of neuroactive factors in immune system and lymphocytes during pregnancy are not fully elucidated. This review aims to provide an interdisciplinary view on how the neuroendocrine system mediate immune system during pregnancy process.

Perfluoroalkyl Substance Exposure and the BDNF Pathway in the Placental Trophoblast

BACKGROUND

Per- and polyfluoroalkyl substances (PFAS) are persistent organic pollutants that have become globally ubiquitous in humans and the environment. In utero PFAS exposure is associated with neurodevelopmental effects; however, the mechanism is poorly understood. Brain-derived neurotrophic factor (BDNF) signaling is critical to fetal neurodevelopment during pregnancy and maintains important regulatory roles later in life. This study aims to characterize placental BDNF signaling and investigate whether PFAS exposure disrupts the signaling pathway in placental trophoblast cells.

METHODS

The expression and localization of BDNF receptors-p75^NTR and TrkB-in first trimester and term human placentas and trophoblast cells were investigated by immunofluorescence staining. To assess the effects of PFAS exposure on the BDNF pathway, BeWo cells were treated with PFAS mixtures that mimicked blood levels in a highly exposed population and major PFAS compounds in the mixture at 0.01, 0.1, 1, and 10 µM concentrations. Changes in pro-BDNF levels and phosphorylation of TrkB receptors were examined by Western blot.

RESULTS

In first trimester human placentas, TrkB and p75^NTR receptors were primarily localized to syncytiotrophoblast and cytotrophoblast cells. At term, TrkB and p75^NTR receptors were primarily observed in the placental villous stroma. TrkB receptor staining in trophoblasts was reduced at term, while p75^NTR receptor staining was negative. TrkB receptors were confined to the nuclear and perinuclear spaces, and phosphorylation occurred at the Tyr816 residue in BeWo cells. Exposure to PFOS, PFOA, PFBS, and the six-PFAS mixture did not significantly affect BDNF levels or activation (phosphorylation) of TrkB. Treating cells with 1 μM and 10 μM of PFNA resulted in increased TrkB phosphorylation compared to unexposed controls, but BDNF levels were unchanged.

CONCLUSIONS

BDNF receptors are present in different regions of human placental villi, indicating diverse functions of BDNF signaling in placental development. Our findings suggest that the BDNF pathway in placental trophoblast cells is not disrupted by exposures to PFOS, PFOA, PFBS, and a PFAS mixture, but may be affected by PFNA exposures. Further investigation is needed on how PFAS affects other critical signaling pathways during fetal neurodevelopment.

Brain-derived neurotrophic factor (BDNF) expression and function in the mammalian reproductive Tract

BACKGROUND

Neurotrophins of the nerve growth factor family are soluble polypeptides that are best known for their role in nerve growth, survival and differentiation in the central nervous system. A growing body of literature shows that neurotrophins and their receptors are also expressed throughout the reproductive tract.

OBJECTIVE AND RATIONALE

Neurotrophins are key regulatory proteins in reproductive physiology during development and throughout adult life. Of the neurotrophins, the literature describing the expression and function of brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, neurotrophin receptor kinase-2 (NTRK2), has been expanding rapidly. We therefore conducted a systematic inductive qualitative review of the literature to better define the role of the BDNF in the reproductive tract. We postulate that BDNF and NTRK2 are central regulatory proteins throughout the reproductive system.

SEARCH METHODS

An electronic search of Medline (PubMed) and Web of Science for articles relating to BDNF and the reproductive system was carried out between January 2018 and February 2019.

OUTCOMES

In the ovary, BDNF expression and levels have been linked with follicle organisation during ovarian development, follicle recruitment and growth and oocyte maturation. In the endometrium, BDNF is involved in cell proliferation and neurogenesis. In contrast, literature describing the role of BDNF in other reproductive tissues is sparse and BDNF-NTRK2 signalling in the male reproductive tract has been largely overlooked. Whilst estradiol appears to be the primary regulator of BDNF expression, we also identified reports describing binding sites for glucocorticoid and myocyte enhancer factor-2, a calcium-response element through activation of an N-methyl-D-aspartate (NMDA) receptor, and aryl hydrocarbon receptor nuclear transporter protein-4 (ARNT) response elements in promoter regions of the BDNF gene. Expression is also regulated by multiple microRNAs and post-translational processing of precursor proteins and intracellular shuttling. BDNF-NTRK2 signalling is modulated through tissue specific receptor expression of either the full-length or truncated NTRK2 receptor; however, the functional importance remains to be elucidated. Dysregulation of BDNF expression and circulating concentrations have been implicated in several reproductive disorders including premature ovarian failure, endometriosis, pre-eclampsia, intra-uterine growth restriction (IUGR) and several reproductive cancers.

WIDER IMPLICATIONS

We conclude that BDNF and its receptors are key regulatory proteins central to gonadal development, ovarian regulation and uterine physiology, as well as embryo and placenta development. Furthermore, dysregulation of BDNF-NTRK2 in reproductive diseases suggests their potential role as candidate clinical markers of disease and potential therapeutic targets.

Molecular mechanisms underlying altered neurobehavioural development of female offspring of mothers with polycystic ovary syndrome: FOS-mediated regulation of neurotrophins in placenta

BACKGROUND

This study explored the mechanisms underlying altered neurobehavioural development of female offspring born to mothers with polycystic ovary syndrome (PCOS).

METHODS

In total, 20 women with PCOS and 32 healthy women who underwent caesarean deliveries with a single female foetus were recruited. Infants were assessed with Dubowitz scoring. Swan71 cell line with stable FOS overexpression was used to verify the regulatory effects of FOS on brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) expression. Learning and memory in female first-generation (F1) and second-generation (F2) offspring in a rat model of PCOS was tested using the Morris water maze at puberty and adulthood. Transcriptome analysis of pubertal hippocampi and hypothalami of female F1 offspring was conducted.

FINDINGS

Total score and behaviour subscales of Dubowitz scoring were significantly lower in female infants of women with PCOS. FOS and NGF protein levels were downregulated in placental villi of the PCOS group. FOS played a key role in BDNF inhibition and enhancing NGF in Swan71 cells. PCOS female F1 rats exhibited lower target crossing times during puberty when compared to controls. Transcriptome analysis revealed significant changes in hippocampal and hypothalamic neuronal pathways in female F1 rats at puberty.

INTERPRETATION

FOS regulation of neurotrophins in the placenta negatively affects neurobehavioural development of female offspring of PCOS mothers.

FUNDING

This study was funded by the National Key R&D Program of China (2018YFC1004900 to F.Q. and F.W.) and the National Natural Science Foundation of China (81874480 to F.Q.; 81873837 to F.W.).

Zika Induces Human Placental Damage and Inflammation

In Brazil, an epidemic of Zika virus (ZIKV) infections was declared in 2015 that coincided with alarming reports of microcephaly in newborns associated with mother infection. Although the virus has placental tropism, changes in the tissue morphology and immunity of infected patients have not yet been elucidated. Here, we investigated the histopathological and ultrastructural changes along with the immunological profile and the BDNF expression in rare placental material. Tissues were obtained in the 2015–2016 Brazilian epidemic, of ten ZIKV-infected patients during pregnancy, five resulting in cases of fetal microcephaly and five non-microcephaly, compared to five non-infected control placentae. Viral antigens were only detected in samples from the ZIKV infected patients. Infected placentae presented histopathological severe damage, while the ultrastructural evaluation showed abnormal organelles, such as clusters of virus-like particles consistent with the ZIKV dimensions. Increased infiltration of CD68⁺ and TCD8⁺ cells, expression of MMPs, cytokines (IFN-γ and TNF-α) and other immunological mediators (RANTES/CCL5 and VEGFR-2) confirmed excessive inflammation and vascular permeability dysfunction. An evaluation of BDNF showed a decrease that could modulate neuronal damage in the developing fetus. The placental changes caused by ZIKV are not pathognomonic, however, the data provide evidence that this infection leads to severe placental injury.

Role of neurotrophins in pregnancy, delivery and postpartum

Neurotrophins (NTs) are a family of polypeptides whose functions have been extensively studied in the past two decades. In particular, Nerve Growth Factor (NGF) and Brain-Derived Neurotrophic Factor (BDNF) play a major role in the development, nutrition and growth of the central and peripheral nervous system and in the pathogenesis of neurodegenerative, cardiometabolic and (auto)immune diseases. However, NGF and BDNF have subtle functions for follicular development, implantation, and placentation. This short narrative review summarizes the existing evidence, published between 2000 and 2019, about the role of NTs in many different conditions that might affect women during and after pregnancy such as preeclampsia, gestational diabetes, obesity, depression, anxiety, smoking and alcohol abuse. Literature suggests that the dysregulation of synthesis and release of NTs may lead to decisive effects on both maternal and fetal health. Some piece of evidences was found about a possible association between NGF/BDNF and breastfeeding. Additional studies on human models are necessary to further characterize the role of NTs in life-changing experiences like labor and delivery.

The Possible Involvement of miR-371a-5p Regulating XIAP in the Pathogenesis of Recurrent Pregnancy Loss

Apoptosis is an interactive and dynamic biological process involved in all phases of embryogenesis. If apoptosis dominates the trophoblast cell growth process, it will result in adverse pregnancy outcomes. X-linked inhibitor of apoptosis protein (XIAP) is a potent caspase inhibitor and an important barrier to apoptotic cell death. MicroRNAs involve in posttranscriptional gene expression regulation and apoptosis. Online sequence alignment analysis showed that there was a putative binding site of miR-371a-5p on the 3'-untranslated region (UTR) of XIAP. Thirty chorionic villi samples were collected to examine the expression of miR-371a-5p and XIAP. The dual-luciferase reporter assay was applied to determine the relationship between miR-371a-5p and XIAP by human placental choriocarcinoma cells (JEG-3) cells in vitro. After 48-hour transfection of mimics and inhibitor by JEG-3 cells in vitro, Western blotting was used to, respectively, detect the protein expression levels of XIAP and caspase-3. Flow cytometry was used to validate the apoptosis ratio of transfection. The expression of miR-371a-5p and XIAP in recurrent pregnancy loss was greatly decreased. The results from the luciferase reporter assay strongly suggested binding of the XIAP 3'-UTR by miR-371a-5p. Apoptosis percentage of miR-371a-5p mimic was significantly greater than that of normal control. However, apoptosis percentage of miR-371a-5p inhibitor was significantly lower than that of normal control. A significant decrease in luciferase activity was observed in miR-371a-5p mimics-transfected JEG-3 cells compared with controls. These findings provide the evidence that miR-371a-5p is one of the regulating factors according to apoptosis pathway of XIAP-caspase-3 and may be involved in the pathogenesis of recurrent pregnancy loss.

Murine trophoblast-derived and pregnancy-associated exosome-enriched extracellular vesicle microRNAs: Implications for placenta driven effects on maternal physiology

The role of extracellular vesicles (EVs), specifically exosomes, in intercellular communication likely plays a key role in placental orchestration of pregnancy and maternal immune sensing of the fetus. While murine models are powerful tools to study pregnancy and maternal-fetal immune interactions, in contrast to human placental exosomes, the content of murine placental and pregnancy exosomes remains largely understudied. Using a recently developed in vitro culture technique, murine trophoblast stem cells derived from B6 mice were differentiated into syncytial-like cells. EVs from the conditioned media, as well as from pregnant and non-pregnant sera, were enriched for exosomes. The RNA composition of these murine trophoblast-derived and pregnancy-associated exosome-enriched-EVs (ExoE-EVs) was determined using RNA-sequencing analysis and expression levels confirmed by qRT-PCR. Differentially abundant miRNAs were detected in syncytial differentiated ExoE-EVs, particularly from the X chromosome cluster (mmu-miR-322-3p, mmu-miR-322-5p, mmu-miR-503-5p, mmu-miR-542-3p, and mmu-miR-450a-5p). These were confirmed to be increased in pregnant mouse sera ExoE-EVs by qRT-PCR analysis. Interestingly, fifteen miRNAs were only present within the pregnancy-derived ExoE-EVs compared to non-pregnant controls. Mmu-miR-292-3p and mmu-miR-183-5p were noted to be some of the most abundant miRNAs in syncytial ExoE-EVs and were also present at higher levels in pregnant versus non-pregnant sera ExoE-EVs. The bioinformatics tool, MultiMir, was employed to query publicly available databases of predicted miRNA-target interactions. This analysis reveals that the X-chromosome miRNAs are predicted to target ubiquitin-mediated proteolysis and intracellular signaling pathways. Knowing the cargo of placental and pregnancy-specific ExoE-EVs as well as the predicted biological targets informs studies using murine models to examine not only maternal-fetal immune interactions but also the physiologic consequences of placental-maternal communication.

Analysis of NTRK Alterations in Pan-Cancer Adult and Pediatric Malignancies: Implications for NTRK-Targeted Therapeutics

Purpose

Fusions that involve neurotrophic-tropomyosin receptor kinase (NTRK) genes are known drivers of oncogenesis. Therapies that target these ultra-rare, constitutionally active NTRK fusions have been remarkably effective. Herein, we analyze the prevalence of the full array of NTRK alterations-fusions, mutations, copy number alterations, and increased transcript expression-in diverse adult and pediatric tumor types to understand the landscape of NTRK aberrations in cancer.

Methods

We assessed 13,467 samples available from The Cancer Genome Atlas (adult tumors) and the St Jude PeCan database (pediatric tumors) for the prevalence of NTRK fusions, as well as associated genomic and transcriptomic co-aberrations in different tumor types.

Results

NTRK fusions were observed in 0.31% of adult tumors and in 0.34% of pediatric tumors. The most common gene partners were NTRK3 (0.16% of adult tumors) followed by NTRK1 (0.14% of pediatric tumors). NTRK fusions were found more commonly in pediatric melanoma (11.1% of samples), pediatric glioma (3.97%), and adult thyroid cancers (2.34%). Additional genomic and transcriptomic NTRK alterations- mutation, amplification, and mRNA overexpression-occurred in 14.2% of samples, whereas the frequency of alterations that implicated NTRK ligands and the NTRK co-receptor (p75NTR) ranged from 3.8% to 5.4%. Among 31 adult samples carrying NTRK fusions, co-alterations occurred often and usually involved the downstream phosphoinositide-3-kinase signaling pathway, cell-cycle machinery, other tyrosine-kinase receptors, and mitogen-activated protein kinase signals.

Conclusion

Whereas NTRK fusions are exceedingly rare, other NTRK abnormalities affect 14% of patients with cancer. Affecting these alterations has not yet been achievable in cancer. Genomic co-alterations occur frequently with NTRK fusions, but it is not known if co-targeting them can attenuate primary or secondary resistance to NTRK inhibitors.

Depressive Temperament in Relatives of Patients with Schizophrenia Is Associated with Suicidality in Patients with Schizophrenia

Objective

Suicide is a major cause of death in patients with schizophrenia; thus, predicting and preventing suicide in patients with schizophrenia is examined in various studies. Affective temperaments which are accepted as precursors of mood disorders may be an important factor in predicting suicidality. This study investigated the relationship between affective temperaments of relatives of schizophrenia patients and suicidal thoughts and other clinical correlates of patients with schizophrenia.

Methods

Patients with schizophrenia and their first degree relatives are included to the study. All of the participants were evaluated with Structured Clinical Interview for DSM-IV axis I disorders and relatives with active psychiatric diagnosis were excluded. Positive and Negative Symptom Scale, Clinical Global Impression Scale, Turkish version of cognitive assessment interview were administered congruently to the patients. Relatives of the patients were evaluated with Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Auto-questionnaire.

Results

Depressive temperament scores of relatives of schizophrenic patients who had suicidal thoughts were higher than the scores of the relatives of the patients who did not have suicidal thoughts. Depressive temperament also predicted number of suicide attempts in regression analysis. Number of suicide attempts was also related with number of hospitalization and functionality of the patient.

Conclusion

Suicidality in schizophrenia is related with relatives’ affective temperaments and patients’ own positive symptom scores. The relationship between suicidal thoughts and depressive temperament is high lightened in this study

Efficient Promotion of Autophagy and Angiogenesis Using Mesenchymal Stem Cell Therapy Enhanced by the Low-Energy Shock Waves in the Treatment of Erectile Dysfunction

Background

Mesenchymal stem cell therapy (MSCT) and defocused low-energy shock wave therapy (ESWT) has been shown to ameliorate erectile dysfunction (ED). However, the interactions and effects of action between MSCT and ESWT remain poorly understood. In this study, we investigated the mechanisms of combination therapy with MSCT and ESWT in a rat model of diabetic ED.

Materials and Methods

Eight-week-old male Sprague-Dawley rats were randomly divided into 2 parts. Diabetic rats induced by streptozotocin (65 mg/kg) were randomly divided into 4 groups: (1) DM control group, (2) DM + ESWT group, (3) DM + MSCT group, and (4) DM + ESWT + MSCT group. The sham group was a normal control group (without streptozotocin). MSCT and (or) ESWT were, respectively, administered to each group according to the proposal for 8 weeks. Immediately after recording of intracavernous pressure (ICP), the penis was then harvested for histologic analysis, ELISA, and Western blotting.

Results

The ratio of ICP/MAP was significantly higher in the DM + ESWT + MSCT group than in ESWT or MSCT treated group (P < 0.05). Also, the treatment stimulated angiogenesis and vasodilatation in the corpus cavernosum (P < 0.05). ESWT increased the quantity of MSCs in the corpus cavernosum and also induced MSCs to express more VEGF in vitro and vivo (P < 0.05) which activated the PI3K/AKT/mTOR and NO/cGMP signaling pathways in the corpus cavernosum. The combination approach stimulated autophagy and decreased apoptosis in the corpus cavernosum. NGF and BDNF expressions were higher in the DM + ESWT + MSCT group than in the DM control group (P < 0.01). Furthermore, the treatment promoted the MSC recruitment by inducing penile tissues to express more PECAM and SDF-1.

Conclusions

Combination of LI-ESWT and MSCT can get a better result than a single treatment by expressing more VEGF which can take part in autophagy by triggering the PI3K/AKT/mTOR signaling pathway. This cooperative therapy would provide a new research direction in ED treatment for the future.

Emerging Targeted Therapy for Tumors with NTRK Fusion Proteins

The oncogenesis-promoting role of chromosomal rearrangements for several hematologic and solid malignancies is well recognized. However, identifying targetable, actionable, and druggable chromosomal rearrangements remains a challenge. Targeting gene fusions and chromosomal rearrangements is an effective strategy in treating gene rearrangement-driven tumors. The NTRK (Neurotrophic Tyrosine Receptor Kinase) gene family encodes three tropomyosin-related kinase (TRK) receptors that preserve central and peripheral nervous system development and function. NTRK genes, similar to other genes, are subject to alterations, including fusions. Preclinical studies have demonstrated that TRK fusion proteins promote oncogenesis by mediating constitutive cell proliferation and survival. Several clinical trials have estimated the safety and efficacy of TRK fusion kinase receptor inhibitors and have demonstrated encouraging antitumor activity in patients with NTRK-rearranged malignancies. Specifically, larotrectinib and entrectinib have emerged as potent, safe, and promising TRK inhibitors. Herein, we discuss the potential oncogenic characteristics of TRK fusion proteins in various malignancies and highlight ongoing clinical trials of kinase inhibitors targeting them.

Placenta-specific drug delivery by trophoblast-targeted nanoparticles in mice

Rationale: The availability of therapeutics to treat pregnancy complications is severely lacking, mainly due to the risk of harm to the fetus. In placental malaria, Plasmodium falciparum-infected erythrocytes (IEs) accumulate in the placenta by adhering to chondroitin sulfate A (CSA) on the surfaces of trophoblasts. Based on this principle, we have developed a method for targeted delivery of payloads to the placenta using a synthetic placental CSA-binding peptide (plCSA-BP) derived from VAR2CSA, a CSA-binding protein expressed on IEs.

Methods: A biotinylated plCSA-BP was used to examine the specificity of plCSA-BP binding to mouse and human placental tissue in tissue sections in vitro. Different nanoparticles, including plCSA-BP-conjugated nanoparticles loaded with indocyanine green (plCSA-INPs) or methotrexate (plCSA-MNPs), were administered intravenously to pregnant mice to test their efficiency at drug delivery to the placenta in vivo. The tissue distribution and localization of the plCSA-INPs were monitored in live animals using an IVIS imaging system. The effect of plCSA-MNPs on fetal and placental development and pregnancy outcome were examined using a small-animal high-frequency ultrasound (HFUS) imaging system, and the concentrations of methotrexate in fetal and placental tissues were measured using high-performance liquid chromatography (HPLC).

Results: plCSA-BP binds specifically to trophoblasts and not to other cell types in the placenta or to CSA-expressing cells in other tissues. Moreover, we found that intravenously administered plCSA-INPs accumulate in the mouse placenta, and ex vivo analysis of the fetuses and placentas confirmed placenta-specific delivery of these nanoparticles. We also demonstrate successful delivery of methotrexate specifically to placental cells by plCSA-BP-conjugated nanoparticles, resulting in dramatic impairment of placental and fetal development. Importantly, plCSA-MNPs treatment had no apparent adverse effects on maternal tissues.

Conclusion: These results demonstrate that plCSA-BP-guided nanoparticles could be used for the targeted delivery of payloads to the placenta and serve as a novel placenta-specific drug delivery option.

Affective temperaments during pregnancy and postpartum period: a click to hyperthymic temperament

BACKGROUND

Pregnancy and postpartum periods are the main reproductive periods during which women experience mood disorders. Affective temperaments are known antecedents of mood disorders and their importance is increasing in time for early diagnosis and determining risky groups. But data about affective temperaments during perinatal period is limited.

METHODS

Women during pregnancy and perinatal period and healthy controls who are not in perinatal period are included in the study. 83 pregnant women in 1st trimester, 94 pregnant women in 2nd trimester and 115 pregnant women in 3rd trimester; 32 women in 1st month postpartum and 89 women in 2nd month postpartum; and 88 healthy non-pregnant women with similar ages were evaluated regarding their temperament evaluation of Memphis, Pisa, Paris and San Diego auto-questionnaire (TEMPS-A) scores.

RESULTS

Women in perinatal period had higher scores of hyperthymic temperaments than the control group. Women in the 2nd month of postpartum period had also higher anxious temperament scores. And women in the second trimester had the highest hyperthymic temperament scores.

CONCLUSION

Pregnancy and postpartum periods correlate with hyperthymic temperament characteristics in women without active psychiatric diagnosis. Future studies will help to understand if this is a mental quietness or increased risk for bipolarity.

Perinatal hypoxia as a risk factor for psychopathology later in life: the role of dopamine and neurotrophins

Brain development is influenced by various prenatal, intrapartum, and postnatal events which may interact with genotype to affect the neural and psychophysiological systems related to emotions, specific cognitive functions (e.g., attention, memory), and language abilities and thereby heighten the risk for psychopathology later in life. Fetal hypoxia (intrapartum oxygen deprivation), hypoxia-related obstetric complications, and hypoxia during the early neonatal period are major environmental risk factors shown to be associated with an increased risk for later psychopathology. Experimental models of perinatal hypoxia/ischemia (PHI) showed that fetal hypoxia-a consequence common to many birth complications in humans-results in selective long-term disturbances of the dopaminergic systems that persist in adulthood. On the other hand, neurotrophic signaling is critical for pre- and postnatal brain development due to its impact on the process of neuronal development and its reaction to perinatal stress. The aim of this review is (a) to summarize epidemiological data confirming an association of PHI with an increased risk of a range of psychiatric disorders from childhood through adolescence to adulthood, (b) to present immunohistochemical findings on human autopsy material indicating vulnerability of the dopaminergic neurons of the human neonate to PHI that could predispose infant survivors of PHI to dopamine-related neurological and/or cognitive deficits in adulthood, and

BNDF methylation in mothers and newborns is associated with maternal exposure to war trauma

BACKGROUND

The BDNF gene codes for brain-derived neurotrophic factor, a growth factor involved in neural development, cell differentiation, and synaptic plasticity. Present in both the brain and periphery, BDNF plays critical roles throughout the body and is essential for placental and fetal development. Rodent studies show that early life stress, including prenatal stress, broadly alters BDNF methylation, with presumed changes in gene expression. No studies have assessed prenatal exposure to maternal traumatic stress and BDNF methylation in humans. This study examined associations of prenatal exposure to maternal stress and BDNF methylation at CpG sites across the BDNF gene.

RESULTS

Among 24 mothers and newborns in the eastern Democratic Republic of Congo, a region with extreme conflict and violence to women, maternal experiences of war trauma and chronic stress were associated with BDNF methylation in umbilical cord blood, placental tissue, and maternal venous blood. Associations of maternal stress and BDNF methylation showed high tissue specificity. The majority of significant associations were observed in putative transcription factor binding regions.

CONCLUSIONS

This is the first study in humans to examine BDNF methylation in relation to prenatal exposure to maternal stress in three tissues simultaneously and the first in any mammalian species to report associations of prenatal stress and BDNF methylation in placental tissue. The findings add to the growing body of evidence highlighting the importance of considering epigenetic effects when examining the impacts of trauma and stress, not only for adults but also for offspring exposed via effects transmitted before birth.

A role for maternally derived myokines to optimize placental function and fetal growth across gestation

Exercise during pregnancy is associated with improved health outcomes for both mother and baby, including a reduced risk of future obesity and susceptibility to chronic diseases. Overwhelming evidence demonstrates a protective effect of maternal exercise against fetal birth weight extremes, reducing the rates of both large- and small-for-gestational-age infants. It is speculated that this protective effect is mediated in part through exercise-induced regulation of maternal physiology and placental development and function. However, the specific mechanisms through which maternal exercise regulates these changes remain to be discovered. We hypothesize that myokines, a collection of peptides and cytokines secreted from contracting skeletal muscles during exercise, may be an important missing link in the story. Myokines are known to reduce inflammation, improve metabolism and enhance macronutrient transporter expression and activity in various tissues of nonpregnant individuals. Little research to date has focused on the specific roles of the myokine secretome in the context of pregnancy; however, it is likely that myokines secreted from exercising skeletal muscles may modulate the maternal milieu and directly impact the vital organ of pregnancy—the placenta. In the current review, data in strong support of this potential role of myokines will be presented, suggesting myokine secretion as a key mechanism through which maternal exercise optimizes fetal growth trajectories. It is clear that further research is warranted in this area, as knowledge of the biological roles of myokines in the context of pregnancy would better inform clinical recommendations for exercise during pregnancy and contribute to the development of important therapeutic interventions.

Novel mechanism of miRNA-365-regulated trophoblast apoptosis in recurrent miscarriage

Clinical pregnancies increasingly end in recurrent miscarriage (RM) during the first trimester, with genetic factors shouldering the main responsibility. MicroRNAs (miRNAs) regulate gene expression in a wide array of important biological processes. We examined the potential role of dysregulated miRNAs in RM pathogenesis and trophoblast development as an approach to elucidate the molecular mechanism behind RM. miRNA profiles from clinical specimens of RM and induced abortion (IA) were compared, and several miRNAs were found to be aberrantly expressed in RM samples. Among the miRNAs, miR-365 was significantly differentially expressed in RM decidual tissues. Furthermore, our results demonstrate that miR-365 functions as an upstream regulator of MDM2/p53 expression, cell cycle progression and apoptosis in trophoblasts. Bioinformatic prediction and experimental validation assays identified SGK1 as a direct target of miR-365; consistently, its protein levels were low in decidual tissues. Additionally, functional studies revealed that SGK1 silencing elicits cell cycle arrest and apoptosis in trophoblasts and that SGK1 overexpression attenuates the effects of miR-365 on apoptosis and MDM2/p53 expression. Collectively, our data provide evidence that the up-regulation of miR-365 may contribute to RM by decreasing SGK1 expression, which suggests its potential utility as a prognostic biomarker and therapeutic target for RM.

Maternal obesity alters brain derived neurotrophic factor (BDNF) signaling in the placenta in a sexually dimorphic manner

INTRODUCTION

Obesity is a major clinical problem in obstetrics being associated with adverse pregnancy outcomes and fetal programming. Brain derived neurotrophic factor (BDNF), a validated miR-210 target, is necessary for placental development, fetal growth, glucose metabolism, and energy homeostasis. Plasma BDNF levels are reduced in obese individuals; however, placental BDNF has yet to be studied in the context of maternal obesity. In this study, we investigated the effect of maternal obesity and sexual dimorphism on placental BDNF signaling.

METHODS

BDNF signaling was measured in placentas from lean (pre-pregnancy BMI < 25) and obese (pre-pregnancy BMI>30) women at term without medical complications that delivered via cesarean section without labor. MiRNA-210, BDNF mRNA, proBDNF, and mature BDNF were measured by RT - PCR, ELISA, and Western blot. Downstream signaling via TRKB (BDNF receptor) was measured using Western blot.

RESULTS

Maternal obesity was associated with increased miRNA-210 and decreased BDNF mRNA in placentas from female fetuses, and decreased proBDNF in placentas from male fetuses. We also identified decreased mature BDNF in placentas from male fetuses when compared to female fetuses. Mir-210 expression was negatively correlated with mature BDNF protein. TRKB phosphorylated at tyrosine 817, not tyrosine 515, was increased in placentas from obese women. Maternal obesity was associated with increased phosphorylation of MAPK p38 in placentas from male fetuses, but not phosphorylation of ERK p42/44.

DISCUSSION

BDNF regulation is complex and highly regulated. Pre-pregnancy/early maternal obesity adversely affects BDNF/TRKB signaling in the placenta in a sexually dimorphic manner. These data collectively suggest that induction of placental TRKB signaling could ameliorate the placental OB phenotype, thus improving perinatal outcome.

Long-term effects of early life stress exposure: Role of epigenetic mechanisms

Stress is an adaptive response to demands of the environment and thus essential for survival. Exposure to stress during the first years of life has been shown to have profound effects on the growth and development of an adult individual. There are evidences demonstrating that stressful experiences during gestation or in early life can lead to enhanced susceptibility to mental disorders. Early-life stress triggers hypothalamic-pituitary-adrenocortical (HPA) axis activation and the associated neurochemical reactions following glucocorticoid release are accompanied by a rapid physiological response. An excessive response may affect the developing brain resulting in neurobehavioral and neurochemical changes later in life. This article reviews the data from experimental studies aimed to investigate hormonal, functional, molecular and epigenetic mechanisms involved in the stress response during early-life programming. We think these studies might prove useful for the identification of novel pharmacological targets for more effective treatments of mental disorders.

Increased epigenetic alterations at the promoters of transcriptional regulators following inadequate maternal gestational weight gain

Epigenetic modifications are thought to serve as a memory of exposure to in utero environments. However, few human studies have investigated the associations between maternal nutritional conditions during pregnancy and epigenetic alterations in offspring. In this study, we report genome-wide methylation profiles for 33 postpartum placentas from pregnancies of normal and foetal growth restriction with various extents of maternal gestational weight gain. Epigenetic alterations accumulate in the placenta under adverse in utero environments, as shown by application of Smirnov-Grubbs’ outlier test. Moreover, hypermethylation occurs frequently at the promoter regions of transcriptional regulator genes, including polycomb targets and zinc-finger genes, as shown by annotations of the genomic and functional features of loci with altered DNA methylation. Aberrant epigenetic modifications at such developmental regulator loci, if occurring in foetuses as well, will elevate the risk of developing various diseases, including metabolic and mental disorders, later in life.

Impact of bacterial and viral challenge on multidrug resistance in first- and third-trimester human placenta

The ABC transporters P-glycoprotein (P-gp, official gene symbol ABCB1) and breast cancer resistance protein (BCRP, official gene symbol ABCG2) protect the conceptus from exposure to toxins and xenobiotics present in the maternal circulation. Viral or bacterial challenges alter expression of placental multidrug transporters in rodents. We hypothesized that exposure to lipopolysaccharide (LPS, bacterial antigen) and polyinosinic-polycytidylic acid (poly(I:C), viral antigen) would decrease P-gp and BCRP in the human placenta. Placental explants from first and third trimesters were challenged with 0.1 to 10 μg/mL LPS or 1 to 50 μg/mL poly(I:C) for 4 or 24 hours; mRNA levels, protein expression, and localization were assessed by quantitative real-time PCR, Western blot analysis, and immunohistochemistry, respectively. Toll-like receptor (TLR)-3 and TLR-4 mRNA expression increased from the first to third trimester (P < 0.01), and the receptors localized to cytotrophoblasts in the first trimester and to syncytiotrophoblasts in the third trimester. LPS exposure in first-trimester explants decreased (P < 0.001) ABCB1 and ABCG2 mRNA and protein levels. In contrast, poly(I:C) decreased (P < 0.05) ABCB1, TLR-3, and TLR-4 mRNA levels in the third trimester but not first trimester. LPS and poly(I:C) treatments increased (P < 0.01) IL-8 and chemokine ligand 2. Results suggest that bacterial infections likely alter exposure of the conceptus to toxins and drugs during early pregnancy, whereas viral infections may disrupt fetal protection in later stages of pregnancy.

Involvement of Nitric Oxide, Neurotrophins and HPA Axis in Neurobehavioural Alterations Induced by Prenatal Stress

Several studies suggest that negative emotions during pregnancy generate adverse effects on the cognitive, behavioural and emotional development of the descendants. The psychoneuroendocrine pathways involve the transplacentary passage of maternal glucocorticoids in order to influence directly on fetal growth and brain development.Nitric oxide is a gaseous neurotransmitter that plays an important role in the control of neural activity by diffusing into neurons and participates in learning and memory processes. It has been demonstrated that nitric oxide is involved in the regulation of corticosterone secretion. Thus, it has been found that the neuronal isoform of nitric oxide synthase (nNOS) is an endogenous inhibitor of glucocorticoid receptor (GR) in the hippocampus and that nNOS in the hippocampus may participate in the modulation of hypothalamic-pituitary-adrenal axis activity via GR.Neurotrophins are a family of secreted growth factors consisting of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin 3 (NT3) and NT4. Although initially described in the nervous system, they regulate processes such as cell survival, proliferation and differentiation in several other compartments. It has been demonstrated that the NO-citrulline cycle acts together with BDNF in maintaining the progress of neural differentiation.In the present chapter, we explore the interrelation between nitric oxide, glucocorticoids and neurotrophins in brain areas that are key structures in learning and memory processes. The participation of this interrelation in the behavioural and cognitive alterations induced in the offspring by maternal stress is also addressed.

The brain-uterus connection: brain derived neurotrophic factor (BDNF) and its receptor (Ntrk2) are conserved in the mammalian uterus

The neurotrophins are neuropeptides that are potent regulators of neurite growth and survival. Although mainly studied in the brain and nervous system, recent reports have shown that neurotrophins are expressed in multiple target tissues and cell types throughout the body. Additionally, dysregulation of neurotrophins has been linked to several disease conditions including Alzheimer's, Parkinson's, Huntington's, psychiatric disorders, and cancer. Brain derived neurotrophic factor (BDNF) is a member of the neurotrophin family that elicits its actions through the neurotrophic tyrosine receptor kinase type 2 (Ntrk2). Together BDNF and Ntrk2 are capable of activating the adhesion, angiogenesis, apoptosis, and proliferation pathways. These pathways are prominently involved in reproductive physiology, yet a cross-species examination of BDNF and Ntrk2 expression in the mammalian uterus is lacking. Herein we demonstrated the conserved nature of BDNF and Ntrk2 across several mammalian species by mRNA and protein sequence alignment, isolated BDNF and Ntrk2 transcripts in the uterus by Real-Time PCR, localized both proteins to the glandular and luminal epithelium, vascular smooth muscle, and myometrium of the uterus, determined that the major isoforms expressed in the human endometrium were pro-BDNF, and truncated Ntrk2, and finally demonstrated antibody specificity. Our findings suggest that BDNF and Ntrk2 are transcribed, translated, and conserved across mammalian species including human, mouse, rat, pig, horse, and the bat.

Suppression of choriocarcinoma invasion and metastasis following blockade of BDNF/TrkB signaling

Brain-derived neurotrophic factor (BDNF) acts through its cognate receptor tyrosine kinase-B (TrkB) to regulate diverse physiological functions in reproductive and other tissues. In normal and malignant trophoblastic cells, the BDNF/TrkB signaling promotes cell growth. Due to the highly malignant nature of choriocarcinoma, we investigated possible involvement of this system in choriocarcinoma cell invasion and metastasis. We demonstrated that treatment of cultured choriocarcinoma cells, known to express both BDNF and TrkB, with a soluble TrkB ectodomain or a Trk receptor inhibitor K252a suppressed cell invasion accompanied with decreased expression of matrix metalloproteinase-2, a cell invasion marker. In vivo studies using a tumor xenograft model in athymic nude mice further showed inhibition of cell invasion from tumors to surrounding tissues following the suppression of endogenous TrkB signaling. For an in vivo model of choriocarcinoma metastasis, we performed intravenous injections of JAR cells expressing firefly luciferase into severe combined immunodeficiency (SCID) mice. Treatment with K252a inhibited metastasis of tumors to distant organs. In vivo K252a treatment also suppressed metastatic tumor growth as reflected by decreased cell proliferation and increased apoptosis and caspases-3/7 activities, together with reduced tissue levels of a tumor marker, human chorionic gonadotropin-β. In vivo suppression of TrkB signaling also led to decreased expression of angiogenic markers in metastatic tumor, including cluster of differentiation 31 and vascular endothelial growth factor A. Our findings suggested essential autocrine/paracrine roles of the BDNF/TrkB signaling system in choriocarcinoma invasion and metastasis. Inhibition of this signaling could serve as the basis to develop a novel therapy for patients with choriocarcinoma.

Differential regulation of brain-derived neurotrophic factor in term and preterm preeclampsia

Our earlier studies in preeclampsia (PE) suggest a causal relationship between altered angiogenic factors and birth outcomes. Recent studies suggest that brain-derived neurotrophic factor (BDNF) can stimulate angiogenesis. The present study examines the levels of maternal and cord BDNF in women with PE (n = 106; full term [n = 60] and preterm [n = 46]) and normotensive women (n = 95; control) delivering at term. Maternal BDNF levels were lower (P < .05) in women with PE when compared to normotensive women. Cord BDNF levels were higher (P < .01) in women with PE delivering at term, while it was lower (P < .01) in women delivering preterm. Maternal BDNF levels were negatively associated with systolic and diastolic blood pressure (P < .01 for both). Our data for the first time suggest a possible role for BDNF in the pathophysiology of PE. Differential regulation of cord BDNF levels in preterm PE suggests a need to follow-up children to assess the neurodevelopmental effects in later life.

Higher levels of brain derived neurotrophic factor but similar nerve growth factor in human milk in women with preeclampsia

Children born to mothers with preeclampsia have consistently been suggested to be at risk for cognitive and behavioral disorders in later life. Breastfeeding is said to be associated with better neurodevelopment outcomes. Our earlier studies indicated higher levels of docosahexaenoic acid (DHA) in human milk in women with preeclampsia. DHA is known to regulate the expression of neurotrophins and together they play a vital role in neurodevelopment and cognitive performance. The present study examines the levels of maternal plasma and milk neurotrophins [(nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF)] in women with preeclampsia and compares them with normotensive women who served as controls. Singleton pregnant women diagnosed with preeclampsia (n=72) and controls (n=102) were recruited for this study from Bharati Hospital, Pune. Plasma and milk samples were analyzed for NGF and BDNF levels using the Emax Immuno Assay System using promega kits. Maternal plasma NGF and BDNF levels were lower (p<0.01 for both) in women with preeclampsia as compared to the control women. Milk NGF levels were similar while milk BDNF levels were higher (p<0.05) in the preeclampsia group as compared to controls. Plasma NGF levels were positively correlated with milk NGF levels in the control group. Our results indicate the differential regulation of milk NGF and BDNF levels in women with preeclampsia. The present study suggests a role for both NGF and BDNF in human milk for postnatal brain development. Further studies need to examine the associations of DHA and BDNF in human milk with cognition at later ages.

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Suppression of hydatidiform molar growth by inhibiting endogenous brain-derived neurotrophic factor/tyrosine kinase B signaling

Brain-derived neurotrophic factor (BDNF)/tyrosine kinase B (TrkB) receptor signaling promotes trophoblast growth in normal and abnormal pregnancy. It also regulates the growth of malignant trophoblastic, choriocarcinoma cells. However, possible involvement of this signaling system in hydatidiform mole, another major gestational trophoblastic disease, has not been determined. Here, we found the expression of BDNF in syncytiotrophoblasts and its receptor, TrkB, in cytotrophoblasts of hydatidiform mole using real-time RT-PCR and immunoassays. In molar explant cultures, treatment with soluble TrkB ectodomain or a Trk receptor inhibitor K252a inhibited trophoblast outgrowth as well as decreased cytotrophoblast proliferation and cellular viability based on histopathological analyses and glucose metabolism monitoring. These inhibitors also increased apoptosis and caspase-3/7 activities. In an in vivo model of hydatidiform molar growth based on xenotransplantation of molar tissues into kidney capsules of SCID mice, treatment with K252a suppressed molar growth as reflected by decreased trophoblast proliferation and their invasion into mouse kidney, reduced tissue levels of chorionic gonadotropin-β, and increased apoptosis. Based on PCR array analyses to identify changes in expression profiles of cell cycle- and apoptosis-related genes in cultured molar explants, suppression of endogenous TrkB signaling led to decreases in key cell cycle-stimulatory and checkpoint genes together with the down-regulation of different antiapoptotic genes. Our findings demonstrate the importance of paracrine signaling by the BDNF/TrkB system in the proliferation and survival of molar trophoblasts. Inhibition of BDNF/TrkB signaling could provide a novel medical treatment for hydatidiform mole.

Inhibition of uterine sarcoma cell growth through suppression of endogenous tyrosine kinase B signaling

Uterine leiomyosarcoma is an aggressive tumor typically found at advanced stages due to difficulties with early diagnosis. Because uterine leiomyosarcoma is resistant to conventional radiation and chemotherapy, the development of more potent medical therapeutics is anticipated. Using quantitative real-time RT-PCR and immunostaining, we found the expression of brain-derived neurotrophic factor (BDNF) and neurotropin-4/5, together with their receptor, tyrosine kinase B (TrkB), in different uterine sarcoma cell lines and primary tumor samples from uterine leiomyosarcoma patients. We noted that levels of BDNF were more abundant than those of neurotropin-4/5. Moreover, the expression of TrkB and its ligands was elevated in a multidrug-resistant cell line and samples obtained from patients with leiomyosarcoma. In cultured uterine sarcoma cells, inhibition of endogenous TrkB signaling by treatment with either the soluble TrkB ectodomain or the Trk receptor inhibitor, K252a, suppressed cell proliferation and increased apoptosis based on cell viability and proliferation, in situ terminal deoxynucleotidyl transferase-mediated 2′-deoxyuridine 5′-triphosphate nick end-labeling and caspase-3/7 assays, whereas an inactive plasma membrane nonpermeable K252b was ineffective. Correspondingly, treatment with exogenous BDNF increased cell proliferation. In in vivo studies in athymic nude mice bearing multidrug-resistant uterine sarcoma cell tumors, we demonstrate suppression of tumor growth by treatment with K252a, but not K252b, as reflected by decreased cell proliferation and increased levels of apoptosis and caspase-3/7 activities without obvious side effects. Our findings indicated that endogenous signaling of the TrkB pathway contributed to uterine sarcoma cell growth, and inhibition of TrkB signaling in these tumors could provide a novel medical therapy for patients with uterine sarcomas.

Gastrocnemius-derived BDNF promotes motor function recovery in spinal cord transected rats

This study evaluated the role of gastrocnemius-derived brain-derived neurotrophic factor (BDNF) and possible mechanism in motor improvement in T10 spinal cord transection (SCT) rats. There was complete paralysis in hindlimbs immediately after SCT, followed by partial functional restoration with time going. The level of BDNF but not its mRNA gradually increased in caudal stump after SCT, whereas a significant increase in both BDNF and its mRNA was simultaneously seen in gastrocnemius. Injection of BDNF antibody into the gastrocnemius significantly decreased hindlimb locomotor function, downregulated the level of BDNF and its mRNA together with extracellular signal-regulated kinase 1/2 (Erk1/2). Moreover, ventral root ligation led to decrease both BDNF and Erk in caudal stump, indicating BDNF transportation from gastrocnemius into the spinal cord. We concluded that gastrocnemius-derived BDNF reduced motor functional deficits in SCT rats through Erk signaling pathway. These novel findings suggested the usage of BDNF in muscle for the treatment of spinal cord injury in clinic.

Association of brain-derived neurotrophic factor and tyrosine kinase B receptor in pregnancy

Abnormal brain development in a compromised prenatal and/or early postnatal environment is thought to be a risk factor for several neurobehavioural disorders. However, the mechanisms underlying these are not well understood. We have earlier reported reduced placental docosahexaenoic acid (DHA) levels in preterm deliveries. We have hypothesized that increased oxidative stress and reduced DHA levels may lead to changes in the circulating levels of maternal and cord brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase B (TrkB) levels. A total number of 96 women delivering preterm and 95 women delivering at term were recruited. Plasma BDNF levels were measured in both mother and cord blood plasma using the BDNF Immuno Assay kit. Placental TrkB levels were analysed using sandwich enzyme-linked immunosorbent assay (ELISA). Maternal plasma BDNF levels and placental TrkB levels were higher (p<0.05) while cord plasma BDNF levels were lower (p<0.01) in women delivering preterm as compared to term. There was a negative association between levels of placental TrkB and DHA (p=0.034). A negative association between maternal plasma BDNF levels and placental weight (p=0.001) was observed while a positive association was seen between cord plasma BDNF levels and gestation (p=0.025). The reduction in cord BDNF levels may have implications for altered neurodevelopment in childhood and later life. Studies need to be undertaken to follow up children born preterm for risk of neurobehavioural disorders like attention deficit hyperactivity disorder (ADHD) to understand the effect of altered BDNF at birth on neurodevelopment.