Male Animals Research Articles

A comparison of cognitive decline in aged mice and mice treated with aftin-4.

Dementia, especially Alzheimer's disease, presents a major clinical challenge, and researchers are still searching for an optimal animal model. To address this gap, we compared male and ovariectomized female C57BL/6 mice treated with 30mg/kg aftin-4, which induces neurodegeneration, with naturally aged (15-16 months old) mice not treated with aftin-4. We performed a series of behavioral tests; measured postmortem plasma β-amyloid levels (Aβ1-40 and Aβ1-42) and the levels of the oxidative stress indicators glutathione peroxidase (GPx), superoxide dismutase (SOD) and malondialdehyde (MDA); and evaluated astrocytic reactivity in the brain using glial fibrillary acid protein (GFAP) levels. Our results revealed no behavioral changes in the aged or aftin-4-treated mice compared with the control mice. Aftin-4 mice presented lower brain MDA levels and no detectable changes in plasma Aβ levels. In general, female mice had higher GPx and SOD levels and lower Aβ1-42 levels than male mice did. In contrast, aged and aftin-4-treated male mice presented elevated levels of GFAP, indicating astrocyte damage. Our results could not confirm that either aftin-4-treated or aged mice are reliable models for dementia. However, the observed molecular changes suggest that male animals may be more susceptible to oxidative stress and brain damage than females are. This study demonstrates the complexity of modeling dementia in animals and the importance of future studies in this area.

The Sexual Dimorphism of the Neuroimmune Response in the Brains of Taenia crassiceps-Infected Mice

Background: Helminth infections are associated with cognitive deficits, especially in school-age children. Deworming treatment in heavily infected children improves their short- and long-term memory recall. In mice, intraperitoneal helminth infection with Taenia crassiceps (T. crassiceps) shows sexual dimorphism in terms of the parasite load, immune response, hormone levels, and behavioral changes. We have previously shown poorer short-term memory performance and changes in the concentrations of cytokines and neurotransmitters in the hippocampus, which were replicated in this study. The molecular changes in other brain structures, such as those related to reproduction, are unknown. Methods: Male and female Balb/cAnN mice were chronically infected with T. crassiceps larvae. We determined the peritoneal parasite load and established the presence of cytokines and neurotransmitters in the hippocampus, olfactory bulb, and hypothalamus. Results: The parasite load was higher in female than male infected mice, as expected. In the hippocampus, the neurotransmitters norepinephrine and serotonin increased in males but decreased in females. In contrast, in the olfactory bulb and hypothalamus, the neurotransmitters assessed showed no statistical differences. The cytokine profiles were different in each brain structure. The TNF-α levels in the olfactory bulb and the IL-4 levels in the hippocampus of infected mice were dimorphic; IFN-γ was augmented in both male and female infected animals, although the increase was higher in infected males. Conclusions: The brain responds to peripheral infection with cytokine levels that vary from structure to structure. This could be a partial explanation for the dimorphic behavioral alterations associated with infection, it also demonstrates the synergic interaction between the immune, the endocrine, and the nervous systems.

Multifocal cutaneous neoplastic vascular proliferations in a rainbow boa (Epicrates cenchria) collection with boid inclusion body disease.

Reports on neoplastic processes in snakes are sparse regardless of their location, origin or behavior. Here, we describe the occurrence of multifocal cutaneous neoplastic processes consistent with hemangioma and hemangioendothelioma, with a differential diagnosis of angiomatosis, in a colony of native Brazilian rainbow boas (Epicrates cenchria) which also included animals affected by boid inclusion body disease (BIBD). Thirteen snakes were affected; seven of these had been introduced from other Brazilian sites years earlier, the others had been bred in house but were not offspring of knowingly affected animals. The breeding regime allowed contact between all female and male animals over the years. The cutaneous lesions were first observed over eight years ago, with additional cases detected during the three following years, but no new cases in the last five years. Two affected animals were subjected to a post mortem examination and were found to suffer from peliosis hepatis as one of the additional pathological changes. BIBD was confirmed in five of the eight examined animals, by histology, immunohistology for reptarenavirus nucleoprotein, and multiplex RT-PCR targeting the reptarenavirus S segment. Reptarenavirus infection was also detected in cells in the cutaneous neoplastic processes. PCRs for Bartonella henselae and B. quintana as well as bacterial DNA in general, performed on a pool of six skin lesions, yielded negative results, ruling out ongoing bacterial infection, like bacillary angiomatosis in humans, of the lesions. The results hint towards an association of reptarenavirus infection and BIBD with neoplastic processes which is worth further investigations.

Deafness due to loss of a TRPV channel eliminates mating behavior in Aedes aegypti males

Attraction and mating between male and female animals depend on effective communication between conspecifics. However, in mosquitoes, we have only a rudimentary understanding of the sensory cues and receptors critical for the communication that is essential for reproductive behavior. While it is known that male Aedes aegypti use sound to help them identify females, it is not unclear whether sound detection is absolutely required since other cues such as vision may also participate in mating behavior. To determine the effect of eliminating hearing on mating success, we knocked out the Ae. aegypti TRPVa channel, which is a protein expressed in chordotonal neurons in the Johnston's organ (JO) that respond to sound-induced movements in the antenna. Loss of trpVa eradicated sound-induced responses from the JO, thereby abolishing hearing. Strikingly, mutation of trpVa eliminated mating behavior in males. In contrast, trpVa-null females mated, although this behavior was slightly delayed relative to wild-type females. Males and females produce sounds as they beat their wings at distinct frequencies during flight. Sound mimicking the female wingbeat induced flight, attraction, and copulatory-like behavior in wild-type males without females present, but not in trpVa-null males. Males are known to modulate their wingbeat frequencies before mating in the air, which is a phenomenon referred to as rapid frequency modulation (RFM). We found that RFM was absent in mosquitoes lacking TRPVa. We conclude that the requirement for trpVa and hearing for male reproductive behavior in Aedes is absolute, as mating in the deaf males is eliminated.

Establishing a Female Animal Model of Prediabetes Using a High-Carbohydrate, High-Fat Diet

Prediabetes is a condition that often precedes the onset of type 2 diabetes and is characterized by moderate levels of insulin resistance. This condition is well established in male animal models for diabetes; however, few female models exist. There is accumulating evidence that sex variations affect the pathogenesis, treatment, and consequences of numerous diseases, such as type 2 diabetes. Therefore, we sought to develop a diet-induced prediabetic female animal model to better understand prediabetes development and its effects in females. Female Sprague Dawley rats were randomly allocated to one of two groups: the standard diet (SD) group fed a standard diet with normal drinking water, and the high-carbohydrate, high-fat (HCHF) group fed a high-carbohydrate and high-fat diet with drinking water supplemented with fructose. During induction, we measured food intake, body weight, body mass index (BMI), and oral glucose tolerance response (OGT). After the induction period, biochemical analyses were conducted to assess the levels of plasma leptin, ghrelin, insulin, and glycated hemoglobin (HbA1c). Glycogen concentrations were quantified in the liver and skeletal muscles. The HCHF diet-fed group presented higher body weight gain, food intake, and BMI levels, which were accompanied by elevated plasma insulin, ghrelin, and liver and skeletal muscle glycogen levels compared to the SD-fed group. In the HCHF diet-fed group, the HOMA-IR was above 1.9, suggesting the presence of moderate levels of insulin resistance. The OGT response was significantly higher in the HCHF-fed group versus the SD-fed group, suggesting impaired glucose tolerance, thus displaying the signs and symptoms of prediabetes. The HCHF diet with fructose led to the induction of prediabetes in female Sprague Dawley rats. This model could be used to investigate and outline the pathophysiological complications associated with prediabetes in females as a result of the prolonged ingestion of a high carbohydrate, high-fat diet with fructose. The development of this model could also serve as an effort to further bridge the gap regarding the inclusion of females in biomedical research, thus providing advancements in deriving better, specified treatment strategies for women.

Evaluating the Impact of Adjunctive Partial Cryoablation on Dual Checkpoint Inhibitor Immunotherapy Response in a Murine Model.

Purpose To evaluate the impact of adjunctive partial cryoablation on checkpoint inhibitor (CPI) immunotherapy response. Materials and Methods One hundred fifty-six mice (equal number of male and female animals) with dual-implanted tumor models were treated with dual CPI or a vehicle and randomized to treatment of a single tumor with partial cryoablation. Tumors were followed for 60 days following cryoablation for response assessment. In additional groups, the tumor microenvironment was characterized via flow cytometry, cytokine analysis, and immunohistochemistry. Statistical comparison was made between the different treatment groups regarding T-cell infiltration and activation characteristics within the noncryoablated tumor and cytokine levels within the partially ablated tumor. Additionally, qualitative assessment of T-cell activation within the cryoablated and noncryoablated tumors at immunofluorescence was carried out. Results At 60 days following treatment, CPI and adjunctive cryoablation-treated MC-38 mice had a significantly increased survival rate (79%) compared with mice treated with CPI alone (61%; P < .001). CT-26 mice also had an increased survival rate (57% vs 35%, respectively; P = .04). Following cryoablation, increases in inflammatory cytokines and chemokines within the treated tumors were observed. Flow cytometry of noncryoablated tumor showed increased CD8 T-cell activation. Immunofluorescence and histologic evaluation following cryoablation further demonstrated a robust CD8 T-cell and myeloid infiltrate. Conclusion Adjunctive cryoablation significantly increased the response to dual CPI in multiple cancer models at both partially ablated and distant (nonablated) tumor sites. Immune analysis suggests cryoablation promotes a vigorous immune response within the partially cryoablated tumor that increases activation of the adaptive immune system within distant tumor sites. Keywords: Cancer, Cryoablation, Checkpoint Inhibitor Immunotherapy, Tumor Response Supplemental material is available for this article. © RSNA, 2024.

Microsatellite Markers & Mitochondrial D-Loop Based Phylogenetic And Diversity Analysis In Gabrali Cattle.

The Gabrali cattle is a multipurpose breed, native to Khyber Pakhtunkhwa, Pakistan. Despite its economic importance, scientific data about its phylogeny and genetic diversity is scarce. To address this issue, the present study was conducted on thirty (30) unrelated Gabrali male and female animals, from which blood samples were collected and DNA was extracted. Twelve (12) microsatellite loci and 1159bp of D-loop region were amplified via PCR and visualized on a 2% agarose gel. Sanger sequencing technique was used to sequence the D-loop amplicons. The microsatellite loci revealed 83 alleles with MNA (mean no of alleles per locus) = 8.8, the Ho (observed heterozygosity) and He (expected heterozygosity) of all loci were 0.58 and 0.50 respectively, mean PIC (Polymorphic Information content) = 0.59 and FIS (Inbreeding coefficient) = 0.056 using GeneAlEx® software. Microsatellite analysis revealed a normal allelic distribution across the breed, consistent with Hardy-Weinberg equilibrium. D-loop sequencing revealed eight haplotypes with 30 SNPs using DNA SP 6.0 software. High AT content was observed than GC content i.e. 55.9% and 44.1% respectively, while the transition to transversion ratio was R = 10:1. The value of Haplotype and Nucleotides diversity was Hd = 0.8601 ± SD = 0.0895 and Π = 0.0136 ± SD = 0.00197 respectively. Phylogenetic analysis done using Neighbor-joining method with bootstraps value of 1000, revealed the monophyletic clade of both Gabrali and Bos indicus haplotypes. Furthermore, the introgression of genes from national cattle breeds into Gabrali cattle was observed. It is concluded that Gabrali cattle have common ancestry with Bos indicus having no threats of genetic bottleneck having substantial genetic diversity.

Study of acute and subacute toxicities and genotoxic and mutagenic potentials of the lyophilized extract of Campomanesia sessiliflora (O.Berg) mattos leaves in wistar rats

Campomanesia sessiliflora (O.Berg) Mattos is a Brazilian native plant species used in a popular medicinal tea for treating gastrointestinal, urinary, and dermatological pathologies. This study evaluated the toxicity of Campomanesia sessiliflora (O.Berg) Mattos via acute and subacute toxicity tests. It also analyzed mutagenic and genotoxic potentials by the micronucleus test, which detects genetic material damage indicating mutagenicity, and the comet assay, which assesses DNA damage levels as a genotoxicity indicator. The plant extract initially originated from the ultrasonic maceration of Campomanesia sessiliflora (O.Berg) Mattos leaves in a hydroethanolic solution. The involved animals were adult Wistar rats. Ten females were available to evaluate acute toxicity and estimate the LD50, receiving a dose of 2000 mg/kg. The subacute toxicity evaluation used 35 females and 35 males divided into seven groups: negative control (saline control – SC), positive control (cyclophosphamide control – CC), 125 mg/kg (125), 250 mg/kg (250), 500 mg/kg (500), 1000 mg/kg (1000), and the satellite group (ST). Genotoxicity and mutagenicity experiments applied bone marrow micronucleus and comet assays. Acute and subacute toxicity tests did not present behavioral, physical, and physiological changes (p≥0.05). Administering the Campomanesia sessiliflora (O.Berg) Mattos extract reduced spleen size in male and female animals, without histopathological changes. However, doses above 500 mg/kg showed significant genotoxic and mutagenic effects in the comet and micronucleus assays compared to the control group. The extract did not exhibit acute or subacute toxicity, but doses higher than 500 mg/kg indicated some level of genotoxicity and mutagenicity.

Role of Sex and Early Life Stress Experience on Porcine Cardiac and Brain Tissue Expression of the Oxytocin and H2S Systems

Early life stress (ELS) significantly increases the risk of chronic cardiovascular diseases and may cause neuroinflammation. This post hoc study, based on the material available from a previous study showing elevated “serum brain injury markers” in male control animals, examines the effect of sex and/or ELS on the cerebral and cardiac expression of the H2S and oxytocin systems. Following approval by the Regional Council of Tübingen, a randomized controlled study was conducted on 12 sexually mature, uncastrated German Large White swine of both sexes. The control animals were separated from their mothers at 28–35 days, while the ELS group was separated at day 21. At 20–24 weeks, animals underwent anesthesia, ventilation, and surgical instrumentation. An immunohistochemical analysis of oxytocin, its receptor, and the H2S-producing enzymes cystathionine-β-synthase and cystathionine-γ-lyase was performed on hypothalamic, prefrontal cortex, and myocardial tissue samples. Data are expressed as the % of positive tissue staining, and differences between groups were tested using a two-way ANOVA. The results showed no significant differences in the oxytocin and H2S systems between groups; however, sex influenced the oxytocin system, and ELS affected the oxytocin and H2S systems in a sex-specific manner. No immunohistochemical correlate to the elevated “serum brain injury markers” in male controls was identified.

Developmental nicotine exposure alters cardiovascular structure and function in neonatal and juvenile rats.

Here we test the hypothesis that continuous nicotine exposure throughout pre- and postnatal development (developmental nicotine exposure, DNE) alters cardiovascular structure and function in neonatal and juvenile rats. Echocardiography showed that DNE reduced left ventricular mass, left ventricular outflow tract (LVOT) diameter, and posterior wall thickness, but only in females. Both male and female DNE rats had a lower end-systolic volume, higher ejection fraction, and increased fractional shortening, with unchanged stroke volume and cardiac output. Left ventricular single cardiac myocytes from male and female DNE animals exhibited increased calcium-evoked maximal tension with no effect on EC50. Tail-cuff plethysmography in awake rats showed that DNE males had lower systolic blood pressure and higher heart rate than control males. No significant changes in preload, afterload, or the in vitro renal artery response to vasodilators was observed. The results suggest that DNE enhances myocyte tension-generating capacity, possibly compensating for an unknown developmental insult, which may differ in males and females. While this adaptation maintains normal resting cardiac function, it may lead to reduced cardiac reserve, increased energy demand, and elevated oxidative stress, potentially compromising both short-and-long-term cardiovascular health in developing neonates.

Clinical trials of intratesticular administration of nanostructured lipid carriers encapsulated alpha-mangostin: Safety and efficacy on feline reproductive health

Surgical castration is a primary method for controlling male fertility, but it is impractical for large-scale population control of stray animals. Developing nanoparticle-mediated sterilants that induce cell apoptosis rather than necrosis is a complex and promising area of research. This study aimed to investigate the impact of intratesticular administration of alpha-mangostin encapsulated in nanostructured lipid carriers (AM-NLC) on testicular changes and any associated adverse effects over a 168-day observation period. Thirty-two healthy mature tomcats were enrolled. None of the cats treated with either AM-NLC (n = 28) or blank NLC (n = 4) exhibited noticeable complications related to pain or stress throughout the study, as assessed by clinical examination, blood profiles, and serum amyloid A levels. Histopathological analysis of AM-NLC treated cats revealed seminiferous epithelium degeneration, leading to defective tubules. Key findings included germ cell depletion, disorganized spermatogenic cells without spermatids in certain areas, apoptotic bodies, and intracytoplasmic vacuolization. The intertubular compartment showed no signs of inflammation, hyalinization, fibrosis, or necrosis. Despite widespread degeneration, some normal tubules were present in focal areas. The severity score of seminiferous tubule degeneration significantly increased from day 56 onwards (P < 0.05), suggesting a gradual and progressive compromise of the seminiferous epithelium. In contrast, testes from the blank-NLC group exhibited normal spermatogenesis. Overall, there were no significant changes in the volume of dissected testes, serum testosterone levels, or apoptotic index in AM-NLC-treated cats (P > 0.05). In conclusion, this study represents the first in vivo investigation of apoptotic-inducing agents as a novel nanomedicine-based antifertility compound for non-surgical castration in male animals. While the AM-NLC formulation proved safe for intratesticular administration, it failed to induce infertility in cats, as epididymal spermatozoa persisted throughout the study. Further research into alternative apoptosis-inducing nanomedicine sterilants remains both essential and challenging.

Antioxidants in Male and Animal Reproduction: Applications and Critical Issues

The Special Issue “Antioxidants in Male Human and Animal Reproduction: In Vitro and In Vivo Studies”, published by Antioxidants and led by us (https://www [...]

Glutathione Modulates Hydrogen Sulfide Release and the Ocular Hypotensive Action of Diallyl Polysulfide Compounds.

Hydrogen sulfide (H2S) is an endogenous transmitter with the potential to regulate aqueous humor dynamics and protect retinal neurons from degeneration. The aim of the present study was two-fold: (a) to evaluate the release of H2S from two polysulfides, diallyl disulfide (DADS), and diallyl trisulfide (DATS); and (b) to investigate their ocular hypotensive actions in normotensive male and female rabbits in the presence and absence of GSH. H2S was quantified hourly for up to 6 h using a H2S-Biosensor (World Precision Instruments, Sarasota, Fl). Intraocular pressure (IOP) was assessed in normotensive New Zealand Albino rabbits using a pneumotonometer (model 30 classic; Reichert Ophthalmic Instruments, Depew, NY, USA). In the presence of GSH, there was an increase in the in vitro release of H2S produced by DADS and DATS. Both DADS and DATS also caused a dose-dependent reduction in IOP in male and female rabbits, in both treated and untreated eyes. For instance, in male animals, the presence of GSH (3% and 5%) significantly (p < 0.05, n = 5) enhanced the ocular hypotensive action of DADS (2%) and DATS (2%) from 14.02 ± 2.89% to 18.67 ± 5.6% and from 16.22 ± 3.48 to 23.62 ± 5.79%, respectively. GSH enhanced both H2S release and ocular hypotensive action of the polysulfides in a manner that was dependent on the number of sulfur atoms present in each polysulfide. Furthermore, female animals were less sensitive to the IOP-lowering action of the polysulfides, when compared to their male counterparts.

Renal protective potential of pentoxifylline, chlorpromazine, and lovastatin in ischemia-reperfusion injury: An experimental study.

This study aimed to evaluate the ability of pentoxifylline when compared to lovastatin and chlorpromazine as nephroprotective substances in cases of renal ischemia and reperfusion syndrome (IRI). A total of 36 adult male animals were randomly allocated into four groups (untreated control group, pentoxifylline group, lovastatin group, and chlorpromazine group), each consisting of nine animals. All groups were submitted to experimental ischemia and reperfusion procedures. The animals were evaluated 24, 72 and 120 hours after IRI, including physical examinations, serum urea and creatinine measurements, as well as histopathological, morphometric, and stereological analyses of the renal tissue. Results indicated that 24 hours after IRI, only chlorpromazine was effective in controlling azotemia. At the 72-hour mark, both chlorpromazine and pentoxifylline exhibited efficacy. After 120 hours, all three substances demonstrated renal protective qualities. Pentoxifylline was the most effective in preserving the structural integrity of kidney tissue, followed by chlorpromazine. In conclusion, all three treatments (pentoxifylline, chlorpromazine, and lovastatin) were effective. Pentoxifylline proved to be promising in the response against acute tubular necrosis, although chlorpromazine presented earlier renoprotective effects in terms of maintaining renal function.

Differences in Growth Performance and Meat Quality between Male and Female Juvenile Nile Tilapia (Oreochromis niloticus) during Separate Rearing.

This study compared the growth and flesh quality of juvenile male and female Nile tilapia grown in separate RAS tanks. The Genetic Sex Determination method yielded 40 males and 40 females. Males grew longer and heavier than females, and the results showed significant variation between the sexes in terms of weight gain rate (WGR), specific growth rate (SGR), and final body length and weight. In terms of the feed conversion ratio (FCR), Gonad Somatic Index (GSI), and Viscera Somatic Index (VSI), females presented better results than males. Male and female Hepatosomatic Index (HSI) values did not differ significantly-no difference in blood serum values. The meat's moisture and crude protein composition did not alter significantly from male to female; however, the crude fat and ash levels did differ significantly. Male and female animals were given the same seventeen distinct types of amino acids, and there was no distinct variation in the profiles of total amino acids (TAAs) and essential amino acids (EAAs) between the sexes. However, in the non-essential amino acid (NEAA) category, there were marginally significant differences, wherein females performed better than males. Males and females differed considerably in crude fat and ash levels but not in the moisture content or crude protein composition of the meat. Regarding fatty acids, males outperformed females in terms of total fatty acids (TFAs), polyunsaturated fatty acids (PUFAs), and saturated fatty acids (SFAs). However, no significant difference in the amount of monounsaturated fatty acids (MUFAs) in muscle was found between males and females.

Perirhinal cortex to the nucleus accumbens circuit in novelty salience following methamphetamine self-administration

Methamphetamine (meth) use disorder is part of an overarching use disorder that encompasses continued drug seeking and an increased risk of returning to drug use following periods of abstaining. Chronic meth use results in drug-induced cortical plasticity in the perirhinal cortex (PRC) that mediates responses to novelty. PRH projection targets are numerous and include the nucleus accumbens core (NAc). Whereas the PRH-prefrontal cortex is involved in object recognition; we propose that the PRHNAc is involved in novelty salience. Rats underwent short-access (ShA, 1 hr) or long-access (LgA, 6 hr) meth self-administration (SA). We then used a dual viral strategy to inhibit or activate PRHNAc during a novel cue test in which rats were presented with meth‑associated and novel levers. Response patterns on these levers differ depending on the meth access protocol: ShA meth SA results in equal responding on both novel- and meth‑associated levers, whereas LgA meth results in perseverative responding on the meth‑associated lever. Inactivation of the PRHNAc increased responding on the meth lever relative to the novel lever, resulting in a LgA behavioral phenotype. In contrast, activation in LgA rats was without a behavioral effect. We also report that male LgA sucrose SA animals perseverated on the novel lever rather than the meth‑associated lever, which contrast their meth SA counter parts and female specific patterns of behavior. These data open a new line of interest in the role of the PRHNAc circuit in novelty salience through identification of the behavioral relevance of this circuit.

Protective and Detoxifying Effects of Resveratrol on Zearalenone-Mediated Toxicity: A Review

Zearalenone (ZEA) is a mycotoxin produced by Fusarium spp. fungi and is widely found in moldy corn, wheat, barley, and other grains. ZEA is distributed to the whole body via blood circulation after metabolic transformation in animals. Through oxidative stress, immunosuppression, apoptosis, autophagy, and mitochondrial dysfunction, ZEA leads to hepatitis, neurodegenerative diseases, cancer, abortion, and stillbirth in female animals, and decreased sperm motility in male animals. In recent years, due to the influence of climate, storage facilities, and other factors, the problem of ZEA pollution in global food crops has become particularly prominent, resulting in serious problems for the animal husbandry and feed industries, and threatening human health. Resveratrol (RSV) is a natural product with therapeutic activities such as anti-inflammatory, antioxidant, and anticancer properties. RSV can alleviate ZEA-induced toxic effects by targeting signaling pathways such as NF-κB, Nrf2/Keap1, and PI3K/AKT/mTOR via attenuating oxidative damage, inflammatory response, and apoptosis, and regulating cellular autophagy. Therefore, this paper provides a review of the protective effect of RSV against ZEA-induced toxicity and its molecular mechanism, and discusses the safety and potential clinical applications of RSV in the search for natural mycotoxin detoxification agents.

Gasdermin D is activated but does not drive neurodegeneration in SOD1 G93A model of ALS: Implications for targeting pyroptosis.

Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron loss, microgliosis, and neuroinflammation. While pyroptosis, an inflammatory form of programmed cell death, has been implicated in ALS, the specific role of Gasdermin D (GSDMD) - the primary executioner of pyroptosis - remains unexplored. In this study, we examined the function of GSDMD in the well-established SOD1 G93A mouse model of ALS. Our results showed robust GSDMD activation in the spinal cords of SOD1 G93A animals across two strain backgrounds, with elevated expression in Iba1+ microglia. To explore its role in disease progression, we bred B6.SOD1 G93A mice onto a GSDMD - deficient background. In comparing SOD1 G93A ; Gsdmd +/+ and SOD1 G93A ; Gsdmd -/- mice, we found that Gsdmd loss did not affect disease onset, weight loss, or grip strength decline in either male or female animals. Notably, GSDMD deficiency resulted in a modest but statistically significant increase in mortality in SOD1 G93A mice. Moreover, GSDMD absence had minimal impact on astrogliosis, microgliosis and motor neuron loss. These findings show that while GSDMD is activated in the ALS mouse model, its loss does not mitigate key ALS behavioral phenotypes, gliosis or motor neuron loss. This study provides insights into the potential therapeutic relevance of targeting pyroptosis and inflammatory pathways in ALS.

Metabolic Side Effects from Antipsychotic Treatment with Clozapine Linked to Aryl Hydrocarbon Receptor (AhR) Activation.

Metabolic syndrome (MetS) is the most common adverse drug reaction from psychiatric pharmacotherapy. Neuroreceptor blockade by the antipsychotic drug clozapine induces MetS in about 30% of patients. Similar to insulin resistance, clozapine impedes Akt kinase activation, leading to intracellular glucose and glutathione depletion. Additional cystine shortage triggers tryptophan degradation to kynurenine, which is a well-known AhR ligand. Ligand-bound AhR downregulates the intracellular iron pool, thereby increasing the risk of mitochondrial dysfunction. Scavenging iron stabilizes the transcription factor HIF-1, which shifts the metabolism toward transient glycolysis. Furthermore, the AhR inhibits AMPK activation, leading to obesity and liver steatosis. Increasing glucose uptake by AMPK activation prevents dyslipidemia and liver damage and, therefore, reduces the risk of MetS. In line with the in vitro results, feeding experiments with rats revealed a disturbed glucose-/lipid-/iron-metabolism from clozapine treatment with hyperglycemia and hepatic iron deposits in female rats and steatosis and anemia in male animals. Decreased energy expenditure from clozapine treatment seems to be the cause of the fast weight gain in the first weeks of treatment. In patients, this weight gain due to neuroleptic treatment correlates with an improvement in psychotic syndromes and can even be used to anticipate the therapeutic effect of the treatment.

RNA m6A methyltransferase activator affects anxiety-related behaviours, monoamines and striatal gene expression in the rat.

Modification of mRNA by methylation is involved in post-transcriptional regulation of gene expression by affecting the splicing, transport, stability and translation of mRNA. Methylation of adenosine at N6 (m6A) is one of the most common and important cellular modification occurring in the mRNA of eukaryotes. Evidence that m6A mRNA methylation is involved in regulation of stress response and that its dysregulation may contribute to the pathogenesis of neuropsychiatric disorders is accumulating. We have examined the acute and subchronic (up to 18 days once per day intraperitoneally) effect of the first METTL3/METTL14 activator compound CHMA1004 (methyl-piperazine-2-carboxylate) at two doses (1 and 5 mg/kg) in male and female rats. CHMA1004 had a locomotor activating and anxiolytic-like profile in open field and elevated zero-maze tests. In female rats sucrose consumption and swimming in Porsolt's test were increased. Nevertheless, CHMA1004 did not exhibit strong psychostimulant-like properties: CHMA1004 had no effect on 50-kHz ultrasonic vocalizations except that it reduced the baseline difference between male and female animals, and acute drug treatment had no effect on extracellular dopamine levels in striatum. Subchronic CHMA1004 altered ex vivo catecholamine levels in several brain regions. RNA sequencing of female rat striata after subchronic CHMA1004 treatment revealed changes in the expression of a number of genes linked to dopamine neuron viability, neurodegeneration, depression, anxiety and stress response. Conclusively, the first-in-class METTL3/METTL14 activator compound CHMA1004 increased locomotor activity and elicited anxiolytic-like effects after systemic administration, demonstrating that pharmacological activation of RNA m6A methylation has potential for neuropsychiatric drug development.