Parents’ adulthood stress induces behavioral and hormonal alterations in male rat offspring

Combined treatment of retinoic acid with olfactory ensheathing cells protect gentamicin-induced SGNs damage in the rat cochlea in vitro

Hearing is mainly dependent on the function of hair cells (HCs) and spiral ganglion neurons (SGNs) which damage or loss of them leads to irreversible hearing loss. Olfactory ensheathing cells (OECs) are specialized glia that forms the fascicles of the olfactory nerve by surrounding the olfactory sensory axons. The OECs, as a regenerating part of the nervous system, play a supporting function in axonal regeneration and express a wide range of growth factors. In addition, retinoic acid (RA) enhances the proliferation and differentiation of these cells into the nerve. In the present study, we co-cultured human OECs (hOECs) with cochlear SGNs in order to determine whether hOECs and RA co-treatment can protect the repair process in gentamycin-induced SGNs damage in vitro. For this purpose, cochlear cultures were prepared from P4 Wistar rats, which were randomly appointed to four groups: normal cultivated SGNs (Control), gentamicin-lesioned SGNs culture (Gent), gentamicin-lesioned SGNs culture treated with OECs (Gent + OECs) and gentamicin-lesioned SGNs culture co-treated with OECs and RA (Gent + OEC& RA). The expression of a specific protein in SGNs was examined using immunohistochemical and Western blotting technique. TUNEl staining was used to detect cell apoptosis. Here, we revealed that combined treatment of OECs and RA protect synapsin and Tuj-1 expression in the lesioned SGNs and attenuate cell apoptosis. These findings suggest that RA co-treatment can enhance efficiency of OECs in repair of SGNs damage induced by ototoxic drug.

Apelin-13 prevents apoptosis in the cochlear tissue of noise-exposed rat via Sirt-1 regulation

Noise-induced hearing loss (NIHL) is the second most common cause of acquired hearing loss. Acoustic trauma can cause oxidative damage in the cochlear hair cells (HCs) through apoptotic pathways. Apelin is a newly discovered neuropeptide with neuroprotective effects against the oxidative stress in neurodegenerative disorder. We investigated the preventive effects of apelin-13 on the cochlear HCs and spiral ganglion neurons (SGNs) against acoustic trauma via Sirtuin-1 (Sirt-1) regulation in rats. Animals were assigned to control, control + apelin-13 (50 or 100 μg/kg, ip), and noise exposure groups without any treatment or were administered apelin-13 (50 or 100 μg/kg, ip) and EX-527 (an inhibitor of Sirt-1) prior to each noise session. In the noise groups, 110 dB white noise was applied for 6 h per 5 days. Pre- and post-exposure distortion product otoacoustic emissions (DPOAE) and cochlear superoxide dismutase (SOD) activity were assessed. Western blot evaluated the cochlear protein expressions of Sirt-1, cleaved-caspase-3, Bax, and Bcl-2. Cell apoptosis was detected through TUNEL staining. Immunofluorescence was used to examine expression of HCs and SGNs specific protein. DPOAE level were significantly improved in the noise exposure group receiving 100 μg/kg apelin-13. At high doses, apelin augmented SOD levels in the rat cochlea subjected to noise. Apelin 100 markedly increased Sirt-1, and decreased cleaved- caspase-3 expression as well as Bax/Bcl-2 ratio in the cochlea tissue of noise-exposed rats. These findings suggest the promising therapeutic potential of apelin-13 for the prevention of noise-induced injury to cochlea and hearing loss.

Cohort profile: Understanding Pregnancy Signals and Infant Development (UPSIDE): a pregnancy cohort study on prenatal exposure mechanisms for child health

PURPOSE

Extensive research suggests that maternal prenatal distress is reliably related to perinatal and child health outcomes-which may persist into adulthood. However, basic questions remain regarding mechanisms involved. To better understand these mechanisms, we developed the Understanding Pregnancy Signals and Infant Development (UPSIDE) cohort study, which has several distinguishing features, including repeated assessments across trimesters, analysis of multiple biological pathways of interest, and incorporation of placental structure and function as mediators of child health outcomes.

PARTICIPANTS

Women with normal risk pregnancies were recruited at <14 weeks gestation. Study visits occurred in each trimester and included extensive psychological, sociodemographic, health behaviour and biospecimen collection. Placenta and cord blood were collected at birth. Child visits (ongoing) occur at birth and 1, 6, 12, 24, 36 and 48 months of age and use standard anthropometric, clinical, behavioural, biological and neuroimaging methods to assess child physical and neurodevelopment.

FINDINGS TO DATE

We recruited 326 pregnancies; 294 (90%) were retained through birth. Success rates for prenatal biospecimen collection were high across all trimesters (96%-99% for blood, 94%-97% for urine, 96%-99% for saliva, 96% of placentas, 88% for cord blood and 93% for buccal swab). Ninety-four per cent of eligible babies (n=277) participated in a birth examination; postnatal visits are ongoing.

FUTURE PLANS

The current phase of the study follows children through age 4 to examine child neurodevelopment and physical development. In addition, the cohort participates in the National Institutes of Health's Environmental influences on Child Health Outcomes programme, a national study of 50 000 families examining early environmental influences on perinatal outcomes, neurodevelopment, obesity and airway disease. Future research will leverage the rich repository of biological samples and clinical data to expand research on the mechanisms of child health outcomes in relation to environmental chemical exposures, genetics and the microbiome.

All-trans retinoic acid preconditioning enhances proliferation, angiogenesis and migration of mesenchymal stem cell in vitro and enhances wound repair in vivo

OBJECTIVES

Stem cell therapy is considered to be a suitable alternative in treatment of a number of diseases. However, there are challenges in their clinical application in cell therapy, such as to reduce survival and loss of transplanted stem cells. It seems that chemical and pharmacological preconditioning enhances their therapeutic efficacy. In this study, we investigated effects of all-trans retinoic acid (ATRA) on survival, angiogenesis and migration of mesenchymal stem cells (MSCs) in vitro and in a wound-healing model.

MATERIALS AND METHODS

MSCs were treated with a variety of concentrations of ATRA, and mRNA expression of cyclo-oxygenase-2 (COX-2), hypoxia-inducible factor-1 (HIF-1), C-X-C chemokine receptor type 4 (CXCR4), C-C chemokine receptor type 2 (CCR2), vascular endothelial growth factor (VEGF), angiopoietin-2 (Ang-2) and Ang-4 were examined by qRT-PCR. Prostaglandin E2 (PGE2) levels were measured using an ELISA kit and MSC angiogenic potential was evaluated using three-dimensional tube formation assay. Finally, benefit of ATRA-treated MSCs in wound healing was determined with a rat excisional wound model.

RESULTS

In ATRA-treated MSCs, expressions of COX-2, HIF-1, CXCR4, CCR2, VEGF, Ang-2 and Ang-4 increased compared to control groups. Overexpression of the related genes was reversed by celecoxib, a selective COX-2 inhibitor. Tube formation and in vivo wound healing of ATRA-treated MSCs were also significantly enhanced compared to untreated MSCs.

CONCLUSION

Pre-conditioning of MSCs with ATRA increased efficacy of cell therapy by activation of survival signalling pathways, trophic factors and release of pro-angiogenic molecules.

Paternal calorie restriction prior to conception alters anxiety-like behavior of the adult rat progeny

The maternal environment influences a broad range of phenotypic outcomes for offspring, with anxiety-like behavior being particularly susceptible to maternal environmental perturbations. Much less is known regarding paternal environmental influences. To investigate this, adult male rats were exposed to 25% calorie restriction (CR) or glucocorticoid elevation (CORT; 200 μg/ml of corticosterone in drinking water) for ∼ 6 weeks prior to breeding. Elevated plus maze (EPM), open field (OF), predator odor (cat urine), and acoustic startle/pre-pulse inhibition (AS/PPI) were characterised in the adult male offspring. Plasma concentrations of corticotrophin-releasing hormone (CRF), adrenocorticotropin hormone (ACTH), and serum leptin were characterised in both sires and offspring. Maternal care received by litters was additionally observed. Expectedly, CR and CORT treatment attenuated weight gain, whilst only CR induced anxiolytic behavior in the EPM. The adult offspring sired by CR males also demonstrated a reduction in weight gain, food intake and serum leptin levels when compared to controls. Moreover, CR offspring demonstrated an anxiolytic-like profile in the EPM and OF, enhanced habituation to the AS pulse, reduced PPI, but no alteration to predator odor induced defensiveness compared to control. CORT offspring failed to demonstrate any behavioral differences from controls, however, exhibited a trend towards reduced ACTH and leptin concentration. Collectively, the results indicate that a reduction in calories in males prior to conception can affect the behavior of adult offspring. The phenotypic transmission of CR experiences from fathers to the progeny could potentially be mediated epigenetically. The role of glucocorticoid elevation and maternal care are also discussed.

Magnesium sulfate prevents maternal inflammation-induced impairment of learning ability and memory in rat offspring

OBJECTIVE

Maternal chorioamnionitis is associated with newborn neurologic injury. Recent evidence suggests that maternal administration of magnesium sulphate (MG) may protect fetuses from white matter injury. Previously we demonstrated evidence by magnetic resonance imaging that MG may prevent maternal inflammation-induced gray matter injury of offspring. Thus, we sought to determine the potential of maternal inflammation to induce fetal neurological/behavioral deficits and assess whether maternal MG attenuates these effects.

STUDY DESIGN

Pregnant rats at day 18 received injections of intraperitoneal lipopolysaccharide (LPS) or saline. Dams were treated with subcutaneous saline/MG (270 mg/kg followed by 27 mg/kg every 20 minutes) for 2 hours before and following LPS/saline injections. Pups were delivered spontaneously. At 1 and 3 months of age, 11-12 offspring of each group (saline, LPS, MG, LPS-MG) underwent a 2-way shuttle box avoidance testing. The shuttle box is divided in half and the animal moves between compartments to avoid an electric shock in response to an auditory stimulus.

RESULTS

Control offspring demonstrated significantly improved learning and memory abilities from age 1 to 3 months. At 1 month, LPS-treated dams' offspring were similar to controls with no improvement in learning abilities at 3 months. MG treatment of LPS dams significantly improved offspring learning at 3 months, to equal or better than that of controls.

CONCLUSION

LPS-stimulated inflammation during pregnancy impairs offspring learning ability and memory, which is ameliorated by maternal MG treatment. These results suggest that maternal MG therapy may prevent white and gray matter injuries associated with maternal infection/inflammation.

Adult glucocorticoid exposure leads to transcriptional and DNA methylation changes in nuclear steroid receptors in the hippocampus and kidney of mouse male offspring

Synthetic glucocorticoids (sGCs) are commonly prescribed for the management of inflammatory and endocrine disorders. However, nothing is known regarding the effects of sGC on adult germline methylome and whether these effects can be transmitted to the next generation. We hypothesized that administration of sGC to adult male mice alters DNA methylation in mature sperm and modifies the transcription and methylation of steroid receptors in male F1 offspring. Adult C57BL/6 males (n = 10/group) were injected on five consecutive days with 1 mg/kg sGC (i.e., dexamethasone) or vehicle and euthanized 35 or 60 days after initial treatment or bred with control females (60 days postinitial treatment; n = 5/group). A significant increase in global non-CpG methylation was observed in F0 sperm 60 days following sGC treatment. In the hippocampus and kidney of Postnatal Day 50 (PND50) and PND240 male offspring derived from fathers exposed to sGC, significant differences in mineralocorticoid receptor (Nr3c2; Mr), estrogen alpha receptor (Nr3a1; Ers1), and glucocorticoid receptor (Nr3c1; Gr) expression were observed. Furthermore, significant demethylation in regulatory regions of Mr, Gr, and Esr1 was observed in the PND50 kidney derived from fathers exposed to sGC. This is the first demonstration that paternal pharmacological exposure to sGC can alter the expression and DNA methylation of nuclear steroid receptors in brain and somatic tissues of offspring. These findings provide proof of principle that adult male exposure to sGC can affect DNA methylation and gene expression in offspring, indicating the possibility that adult experiences that evoke increases in endogenous glucocorticoid (i.e., stress) might have similar effects.