Publications by authors named "Puliyur S Mohankumar"

This study examines the sex-specific effects of gestational exposure (days 6-21) to endocrine-disrupting chemicals such as bisphenol A (BPA), diethylhexyl phthalate (DEHP), or their combination on brain monoamine levels that play an important role in regulating behavior. Pregnant Sprague-Dawley rats were orally administered saline, low doses (5 µg/kg BW/day) of BPA or DEHP, and their combination or a high dose (7.5 mg/kg BW/day) of DEHP alone or in combination with BPA during pregnancy.

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  • The study investigates how prenatal exposure to endocrine disrupting chemicals (EDCs), specifically bisphenol A (BPA) and diethylhexyl phthalate (DEHP), affects the behavior of male and female rats.
  • Results show that female offspring exhibited reduced anxiety in certain behavioral tests, while males showed signs of feminization and maladaptive defensive behaviors, particularly with higher doses of DEHP.
  • The findings indicate that exposure to EDCs during pregnancy leads to sex-specific behavioral changes, altered corticosterone levels, and changes in adrenal gland weights, with varying effects based on dosage and chemical combinations.
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  • Aging significantly impacts the brain due to both external factors and changes in immune cells over time.
  • Immunosenescence and Inflammaging contribute to increased inflammation and oxidative stress in the brain, elevating cytokine levels.
  • This pro-inflammatory environment causes harmful alterations in brain structure and function, ultimately impairing central and neuroendocrine processes.
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Alzheimer's disease (AD) is an irreversible neurodegenerative disorder with a complex pathophysiology. Type 2 diabetes (T2D) is a strong risk factor for AD that shares similar abnormal features including metabolic dysregulation and brain pathology such as amyloid and/or Tau deposits. Emerging evidence suggests that circulating branched-chain amino acids (BCAAs) are associated with T2D.

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  • Type 1 diabetes (T1D) leads to symptoms like increased hunger and high blood sugar levels, along with a stressed hormonal response.
  • Researchers tested whether injecting a gene therapy vector for leptin (a hormone that helps regulate hunger and energy) could improve these issues in diabetic rats.
  • Results showed that leptin gene therapy reduced blood sugar and some neuroendocrine dysfunctions in diabetic rats, but higher doses are needed for it to be a practical treatment for T1D.
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The objective of this study was to evaluate the effects of gestational exposure to low doses of bisphenol A (BPA), bisphenol S (BPS), and bisphenol F (BPF) on pregnancy outcomes and offspring development. Pregnant Sprague-Dawley rats were orally dosed with vehicle, 5 μg/kg body weight (BW)/day of BPA, BPS and BPF, or 1 μg/kg BW/day of BPF on gestational days 6-21. Pregnancy and gestational outcomes, including number of abortions and stillbirths, were monitored.

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Bisphenol A (BPA) and Diethylhexyl Phthalate (DEHP) are well-studied endocrine disrupting chemicals (EDCs), however, the effects of mixtures of these EDCs are not. To assess the consequences of prenatal exposure to a mixture of these EDCs, dams were orally administered either saline (control), BPA (5 μg/kg BW/day), high dose DEHP (HD-D; 7.5 mg/kg BW/day), or a combination of BPA with HD-D in experiment 1; saline, BPA (5 μg/kg BW/day), low-dose DEHP (LD-D; 5 μg/kg BW/day) or a combination of BPA with LD-D in experiment 2.

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  • The HPA axis is disrupted in obesity, leading to leptin resistance in the brain and issues with noradrenergic function in DIO rats.
  • Metformin treatment in these rats resulted in decreased weight gain, fat mass, and improved HPA axis activity by normalizing its functions and reducing corticotropin-releasing hormone levels.
  • The study highlights metformin's potential to address HPA axis dysfunction in obesity, suggesting a new therapeutic role for the drug in managing weight.
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  • Diet-induced obese rats have altered stress (HPA) axis activity compared to diet-resistant rats, likely due to impaired leptin signaling.
  • Leptin injection increased serum leptin levels and reduced norepinephrine levels in both rat groups, suggesting that noradrenergic neurons respond to leptin, but responses in DIO rats' CRH and corticosterone varied with high-fat diet exposure.
  • DIO rats showed reduced leptin signaling in brainstem neurons and higher levels of free fatty acids and IL-1β, indicating neuroendocrine impairments that become more pronounced with prolonged high-fat diet exposure.
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Women are chronically exposed to estrogens through oral contraceptives, hormone replacement therapy or environmental estrogens. We hypothesized that chronic exposure to low levels of estradiol-17β (E2) can induce inflammatory and degenerative changes in the tuberoinfundibular dopaminergic (TIDA) system leading to reduced dopamine synthesis and hyperprolactinemia. Young (Y; 3–4 months) and middle-aged (MA; 10–12 months) Sprague-Dawley rats that were intact or ovariectomized (OVX) were either sham-implanted or implanted with a slow-release E2 pellet (20 ng E2/day for 90 days).

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Sudden acquired retinal degeneration syndrome (SARDS) is one of the leading causes of currently incurable canine vision loss diagnosed by veterinary ophthalmologists. The disease is characterized by acute onset of blindness due to loss of photoreceptor function, extinguished electroretinogram with an initially normal appearing ocular fundus, and mydriatic pupils which are slowly responsive to bright white light, unresponsive to red, but responsive to blue light stimulation. In addition to blindness, the majority of affected dogs also show systemic abnormalities suggestive of hyperadrenocorticism, such as polyphagia with resulting obesity, polyuria, polydipsia, and a subclinical hepatopathy.

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Estrogens are known to cause hyperprolactinemia, most probably by acting on the tuberoinfundibular dopaminergic (TIDA) system of the hypothalamus. Dopamine (DA) produced by TIDA neurons directly inhibits prolactin secretion and, therefore, to stimulate prolactin secretion, estrogens inhibit TIDA neurons to decrease DA production. However, the mechanism by which estrogen produces this effect is not clear.

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Prenatal testosterone excess in sheep leads to reproductive and metabolic disruptions that mimic those seen in women with polycystic ovary syndrome. Comparison of prenatal testosterone-treated sheep with prenatal dihydrotestosterone-treated sheep suggests facilitation of defects by androgenic as well as androgen-independent effects of testosterone. We hypothesized that the disruptive impact of prenatal testosterone on adult pathology may partially depend on its conversion to estrogen and consequent changes in maternal and fetal endocrine environments.

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Objective: Human adenovirus 36 (Ad-36) increases adiposity and reduces serum lipids in chicken, mouse, and non-human primate models, and it is linked to obesity in sero-epidemiological studies in humans. Involvement of the central nervous system (CNS) or adipose tissue in the mechanism of Ad-36-induced adiposity is unknown. The effects of Ad-36 on adiposity and on the neuroendocrine system were investigated in a rat model.

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Objective: Exposure to ambient particulate matter (PM) has been linked to respiratory diseases in people living in urban communities. The mechanism by which PM produces these diseases is not clear. We hypothesized that PM could act on the brain directly to stimulate the stress axis and predispose individuals to these diseases.

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Experimental elevation of maternal testosterone (T) from 30 to 90 days of gestation leads to intrauterine growth retardation (IUGR) and increased prepubertal growth rate in female lambs. This study tested the hypothesis that prenatal T treatment during mid-gestation alters the trajectory of the fetal insulin-like growth factor (IGF)-insulin-like growth factor binding protein (IGFBP) system to promote IUGR and subsequent postnatal catch-up growth in female lambs. Plasma IGF-I and IGFBPs were measured by radioimmunoassay and Western ligand blot, respectively, on 65, 90 and 140 days (d) of gestation, at birth, approximately 5 months (prepubertal, the catch-up growth period), and approximately 9.

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Perfluorooctane sulfonate (PFOS) is a degradation product of sulfonyl-based fluorochemicals that are used extensively in industrial and household applications. Humans and wildlife are exposed to this class of compounds from several sources. Toxicity tests in rodents have raised concerns about potential developmental, reproductive, and systemic effects of PFOS.

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The contribution of rabies virus (RV) glycoprotein (G) in viral distribution in the brain was examined by immunohistochemistry following stereotaxic inoculation into the rat hippocampus. Viruses used in this study include the highly neuroinvasive challenge virus standard strains (CVS-N2C and CVS-B2C) and the nonneuroinvasive attenuated SN-10 strain, as well as SN-10-derived recombinant viruses expressing the G gene from CVS-N2C (RN2C) or CVS-B2C (RB2C). The distribution of recombinant viruses in the brain was similar to those of the parental viruses from which the G was derived.

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Synopsis of recent research by authors named "Puliyur S Mohankumar"

  • - Puliyur S Mohankumar's research primarily focuses on the impact of endocrine-disrupting chemicals (EDCs) like bisphenol A and diethylhexyl phthalate on neurodevelopment and behavior, evident in recent studies examining sex-specific responses and monoamine level alterations in rat offspring following prenatal exposure.
  • - His investigations also delve into the broader implications of prenatal exposure on pregnancy outcomes, developmental trajectories, and stress responses in rodent models, highlighting the critical effects of EDCs across different dosages and combinations.
  • - Additionally, Mohankumar explores the mechanisms of aging and obesity in relation to neuroendocrine functions, linking cytokines, reactive oxygen species, and hormonal dysregulation to conditions such as Alzheimer's disease and diabetes in various animal models.