Morphological Degeneration Research Articles

Analysis of the morphology of Sus scrofa domesticus oocyte-cumulus complexes exposed to low and ultra-low temperatures

Relevance. The priority task of reproductive technologies in animal husbandry is the development of effective storage protocols for female gametes. One way to preserve gametes is vitrification, which reduces damage to intracellular organelles by increasing viscosity upon cooling and minimizing crystallization.Methods. Various additives to cryoprotectants are used for optimization. In our work, titanium tetrapolyethylene glycolate was used in a 10-fold molar excess of polyethylene glycol (TTPEG*10PEG), the nature of the effect of which on cells was studied during short-term storage at low (5 °С) and ultra-low temperatures (-196 °С).The purpose of the study is a comprehensive analysis of the morphology of gametes and somatic cells (cumulus) of ovarian follicles of pigs after exposure to low and ultra-low temperatures (vitrification) when included in the TTPEG*10PEG low-temperature storage and vitrification protocol.Results. Exposure to TTPEG*10PEG at 5 °С caused an increase in the level of oocytes with subsequent morphological degenerations in points with control (from 13% to 5%, р = 0.005). After vitrification with TTPEG*10PEG: the level of gametes with low cumulus cells expansion increased to 35% in terms of the proportion of control gametes (23%); the proportion of denudated gametes was reduced to 50% compared to the control 65% (р < 0.05); the level of morphologically degenerated gametes corresponded to that of native oocytes (8% each) and was lower than in the control (17%), р < 0.005. The obtained data indicate the protective and cryoprotective effects of TTPEG*10PEG at a concentration of 2%, which suggests the possibility of its use in the technology of intraovarian vitrification of female reproductive cells.

Oral drug delivery vehicle for insulin and curcumin based on egg albumin-dextran conjugate: In vitro and in vivo studies

The increasing desire for oral delivery vehicle systems encouraged the development of micro and nano encapsulation technologies to protect drugs against gastric and enzymatic degradation. This study aimed to develop egg albumin-dextran conjugate as a delivery vehicle for oral administration. For this purpose, insulin was selected as a macromolecule drug and curcumin as a natural lipophilic polyphenol, both show negative absorption kinetics in gastrointestinal tract. Egg albumin-dextran conjugate was prepared by Maillard reaction under mild conditions and subsequently be used to encapsulate insulin and curcumin, respectively. The encapsulation efficiency reached to 97 % and 95.5 % at 300 mg/ml of insulin and curcumin, respectively. The profile of in vitro drug release for the insulin and curcumin indicates that approximately 60 % of the drugs were partially retained by the conjugate in gastric pH environment while a more extensive release was observed under intestinal pH conditions. Application of oral administration of insulin conjugate (IC) and/or curcumin conjugate (CC) to streptozotocin (STZ) induced diabetic rats was investigated for 6 weeks and compared with trade insulin drug. Fifty-four albino rats were separated into nine equivalent groups. Control, insulin conjugate (IC), curcumin conjugate (CC), and IC + CC. The remaining groups injected with STZ and subsequently received vehicle, IC, CC, IC + CC, and trade insulin drug; respectively.Interestingly, insulin conjugate and/or curcumin conjugate significantly reduced hyperglycemia, hyperlipidemia, decreased fructosamine level, decreased HOMA-IR, increased insulin level, increased HOMA-β, increased antioxidant defense molecules, along with modulating morphological pancreatic degeneration caused by STZ. In conclusion, oral insulin-conjugate is more effective than the trade insulin drug. Also, curcumin-conjugate has a promising role as antidiabetic agent as it may contribute in β-cells regeneration. Further, the combination between them may have synergetic antidiabetic effect. But, more detailed studies should be done to investigate the possible mechanisms of their antidiabetic effect.

Antibacterial activity and mechanism of luteolin isolated from Lophatherum gracile Brongn. against multidrug-resistant Escherichia coli.

Infections caused by multidrug-resistant (MDR) bacteria have become a major challenge for global healthcare systems. The search for antibacterial compounds from plants has received increasing attention in the fight against MDR bacteria. As a medicinal and edible plant, Lophatherum gracile Brongn. (L. gracile) has favorable antibacterial effect. However, the main antibacterial active compound and its antimicrobial mechanism are not clear. Here, our study first identified the key active compound from L. gracile as luteolin. Meanwhile, the antibacterial effect of luteolin was detected by using the broth microdilution method and time-kill curve analysis. Luteolin can also cause morphological structure degeneration and content leakage, cell wall/membrane damage, ATP synthesis reduction, and downregulation of mRNA expression levels of sulfonamide and quinolones resistance genes in multidrug-resistant Escherichia coli (MDR E. coli). Furthermore, untargeted UPLC/Q-TOF-MS-based metabolomics analysis of the bacterial metabolites revealed that luteolin significantly changed riboflavin energy metabolism, bacterial chemotaxis cell process and glycerophospholipid metabolism of MDR E. coli. This study suggests that luteolin could be a potential new food additive or preservative for controlling MDR E. coli infection and spread.

Zeaxanthin dipalmitate-enriched wolfberry extract improves vision in a mouse model of photoreceptor degeneration.

Zeaxanthin dipalmitate (ZD) is a chemical extracted from wolfberry that protects degenerated photoreceptors in mouse retina. However, the pure ZD is expensive and hard to produce. In this study, we developed a method to enrich ZD from wolfberry on a production line and examined whether it may also protect the degenerated mouse retina. The ZD-enriched wolfberry extract (ZDE) was extracted from wolfberry by organic solvent method, and the concentration of ZD was identified by HPLC. The adult C57BL/6 mice were treated with ZDE or solvent by daily gavage for 2 weeks, at the end of the first week the animals were intraperitoneally injected with N-methyl-N-nitrosourea to induce photoreceptor degeneration. Then optomotor, electroretinogram, and immunostaining were used to test the visual behavior, retinal light responses, and structure. The final ZDE product contained ~30mg/g ZD, which was over 9 times higher than that from the dry fruit of wolfberry. Feeding degenerated mice with ZDE significantly improved the survival of photoreceptors, enhanced the retinal light responses and the visual acuity. Therefore, our ZDE product successfully alleviated retinal morphological and functional degeneration in mouse retina, which may provide a basis for further animal studies for possible applying ZDE as a supplement to treat degenerated photoreceptor in the clinic.

The nephroprotective effect of Quercetin in Cyclophosphamide-induced renal toxicity might be associated with MAPK/ERK and NF-κB signal modulation activity

The present study aimed to examine the protective effect of quercetin (QUE) on cyclophosphamide (CTX)-induced nephrotoxicity. For that purpose, 24 mice were divided into four groups (Control, QUE, CTX, and CTX + QUE). The CTX and CTX + QUE groups received 200 mg/kg of cyclophosphamide on the 1st and 7th days. The QUE and CTX + QUE groups were treated with 50 mg/kg of quercetin daily for 14 days. At the end of the experiment, the animals were sacrificed, and kidney samples were analyzed. The results indicated that CTX leads to severe morphological degenerations and disruption in renal function. Serum BUN, Creatinine, Uric acid, tissue Bax, Caspase 3, TNF-α and IL-1β expression levels were upregulated in the CTX group compared to Control and QUE groups (p < 0.05). Although MAPK/ERK phosphorylation level is not affected in CTX group, there was a significant increase in CTX + QUE group (p < 0.05), but the NF-κB was significantly suppressed in this group (p < 0.01). The RT-qPCR results showed that the cyt-c and the Bax/Bcl-2 ratio mRNA expression folds were upregulated in the CTX group (p < 0.01), which was downregulated in the CTX + QUE group. However, there was a significant difference in the CTX + QUE group compared to the Control and QUE groups (p < 0.01). The findings showed that administering quercetin along with cyclophosphamide alleviated renal injury by regulating apoptotic and inflammatory expression. Moreover, the administration of quercetin and cyclophosphamide could synergistically improve renal function test results, and activate cellular responses, which upmodulate MAPK/ERK phosphorylation and suppression of NF-κB.

Generation and characterization of cerebellar granule neurons specific knockout mice of Golli-MBP

Golli–myelin basic proteins, encoded by the myelin basic protein gene, are widely expressed in neurons and oligodendrocytes in the central nervous system. Further, prior research has shown that Golli–myelin basic protein is necessary for myelination and neuronal maturation during central nervous system development. In this study, we established Golli–myelin basic protein-floxed mice to elucidate the cell-type-specific effects of Golli–myelin basic protein knockout through the generation of conditional knockout mice (Golli–myelin basic proteinsfl/fl; E3CreN), in which Golli–myelin basic proteins were specifically deleted in cerebellar granule neurons, where Golli–myelin basic proteins are expressed abundantly in wild-type mice. To investigate the role of Golli–myelin basic proteins in cerebellar granule neurons, we further performed histopathological analyses of these mice, with results indicating no morphological changes or degeneration of the major cellular components of the cerebellum. Furthermore, behavioral analysis showed that Golli–myelin basic proteinsfl/fl; E3CreN mice were healthy and did not display any abnormal behavior. These results suggest that the loss of Golli–myelin basic proteins in cerebellar granule neurons does not lead to cerebellar perturbations or behavioral abnormalities. This mouse model could therefore be employed to analyze the effect of Golli–myelin basic protein deletion in specific cell types of the central nervous system, such as other neuronal cells and oligodendrocytes, or in lymphocytes of the immune system.

Prevention of age-related neuromuscular junction degeneration in sarcopenia by low-magnitude high-frequency vibration.

Neuromuscular junction (NMJ) degeneration is one of pathological factors of sarcopenia. Low-magnitude high-frequency vibration (LMHFV) was reported effective in alleviating the sarcopenia progress. However, no previous study has investigated treatment effects of LMHFV targeting NMJ degeneration in sarcopenia. We first compared morphological differences of NMJ between sarcopenic and non-sarcopenic subjects, as well as young and old C57BL/6 mice. We then systematically characterized the age-related degeneration of NMJ in SAMP8 against its control strain, SAMR1 mice, from 3 to 12 months old. We also investigated effects of LMHFV in SAMP8 on the maintenance of NMJ during the onset of sarcopenia with respect to the Agrin-LRP4-MuSK-Dok7 pathway and investigated the mechanism related to ERK1/2 signaling. We observed sarcopenic/old NMJ presented increased acetylcholine receptors (AChRs) cluster fragmentation and discontinuity than non-sarcopenic/young NMJ. In SAMP8, NMJ degeneration (morphologically at 6 months and functionally at 8 months) was observed associated with the sarcopenia onset (10 months). SAMR1 showed improved NMJ morphology and function compared with SAMP8 at 10 months. Skeletal muscle performance was improved at Month 4 post-LMHFV treatment. Vibration group presented improved NMJ function at Months 2 and 6 posttreatment, accompanied with alleviated morphological degeneration at Month 4 posttreatment. LMHFV increased Dok7 expression at Month 4 posttreatment. Invitro, LMHFV could promote AChRs clustering in myotubes by increasing Dok7 expression through suppressing ERK1/2 phosphorylation. In conclusion, NMJ degeneration was observed associated with the sarcopenia onset in SAMP8. LMHFV may attenuate NMJ degeneration and sarcopenia progression by increasing Dok7 expression through suppressing ERK1/2 phosphorylation.

Patient-Specific Haemodynamic Analysis of Virtual Grafting Strategies in Type-B Aortic Dissection: Impact of Compliance Mismatch

IntroductionCompliance mismatch between the aortic wall and Dacron Grafts is a clinical problem concerning aortic haemodynamics and morphological degeneration. The aortic stiffness introduced by grafts can lead to an increased left ventricular (LV) afterload. This study quantifies the impact of compliance mismatch by virtually testing different Type-B aortic dissection (TBAD) surgical grafting strategies in patient-specific, compliant computational fluid dynamics (CFD) simulations.Materials and MethodsA post-operative case of TBAD was segmented from computed tomography angiography data. Three virtual surgeries were generated using different grafts; two additional cases with compliant grafts were assessed. Compliant CFD simulations were performed using a patient-specific inlet flow rate and three-element Windkessel outlet boundary conditions informed by 2D-Flow MRI data. The wall compliance was calibrated using Cine-MRI images. Pressure, wall shear stress (WSS) indices and energy loss (EL) were computed.ResultsIncreased aortic stiffness and longer grafts increased aortic pressure and EL. Implementing a compliant graft matching the aortic compliance of the patient reduced the pulse pressure by 11% and EL by 4%. The endothelial cell activation potential (ECAP) differed the most within the aneurysm, where the maximum percentage difference between the reference case and the mid (MDA) and complete (CDA) descending aorta replacements increased by 16% and 20%, respectively.ConclusionThis study suggests that by minimising graft length and matching its compliance to the native aorta whilst aligning with surgical requirements, the risk of LV hypertrophy may be reduced. This provides evidence that compliance-matching grafts may enhance patient outcomes.

Effect of pycnogenol on ischemia/reperfusion-induced oxidative and inflammatory damage in the ovaries of rats

Purpose: To investigate the protective effect of pycnogenol (PYC) against ischemia/reperfusion (I/R) ovarian damage induced by experimental ovarian torsion in rats using biochemical and histopathological methods.&#x0D; Methods: Four groups of rats (n = 6) were randomly assigned and designated as follows – SG: sham group, PCG: pycnogenol (40 mg/kg) group, IRG: ovarian ischemia-reperfusion group, and PIR: pycnogenol (40 mg/kg) + ovarian ischemia-reperfusion group. In IRG and PYC treatment groups, ischemia was induced in the right ovary for two hours with vascular clips. The ovary was reperfused for two hours after ischemia was induced. Then, the levels of malondialdehyde (MDA), total glutathione (tGSH), nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) in the ovarian tissues of rats were examined. Ovarian tissues were also examined histopathologically and follicle counts were performed.&#x0D; Results: Histopathological examination revealed that the developing follicles in ovary of I/R-induced group showed both morphological and cellular degeneration and vascular pathology. The PYC treatment group showed less ovarian damage, edema and vascular pathology than I/R-induced group (p &lt; 0.05). The MDA, NF-κB, TNF-α and IL-1β levels in I/R-induced group were significantly higher than in SG and tGSH levels were significantly reduced by I/R damage (p &lt; 0.05). Pycnogenol treatment reversed these biochemical indices as well as I/R-induced histopathological changes.&#x0D; Conclusion: Pycnogenol has a protective effect in rat ovaries by alleviating I/R-induced changes in biochemical parameters and histological disruptions. Further studies, including those in humans, to determine the effect of PYC on ovarian injuries would be required.

Modernization of the cryoprotective medium compoud for intraovarian vitrification of female gametes of Sus scrofa domesticus

Aim. Comprehensive analysis of the morphofunctional state of somatic (cumulus) and germ cells (oocytes) of Sus scrofa domesticus subjected to intraovarian vitrification using silicon dimethylglycerolate (SDMG) are presented.Materials and methods. Fragments of porcine ovaries (FsPO) 15×20 mm in size were gradually kept in cryoprotective agents (CPA) prepared in phosphate-buffered saline (PBS) with 20% fetal bovine serum (FBS): 25 min. in CPA-1 [7.5 % EG (ethylene glycol) with 7.5 % DMSO (dimethyl sulfoxide)] and 15 min. in CPA-2 (15 % EG with 15 % DMSO and 0.5 M sucrose). The composition of the CPA-2 in experimental groups was modified by addition of SDMG (at concentrations of 2 %, 6 %, or 10 %). FsPO were stored in liquid nitrogen. FsPO were devitrified by exposure 1 minute in solution 1 (80 % PBS, 20 % FBS, 0.5 mol/l sucrose) and 5 minutes in solution 2 (80 % PBS, 0.25 mol/l sucrose). The following indicators of cryoresistance of devitrified cumulus-oocyte complexes (COCs) were analyzed: degree of cumulus cells expansion; oocyte morphology and the functional status of lipidome in female gametes (fluorescence intensity of Nile red /lipid droplets complex - FILDs).Results. The addition of SDMG into cryoprotective media reduced the level of denuded oocytes after vitrification. The level of gamete with different degree of cumulus cells expansion (low, medium, high) in the experimental group with 10 % SDMG tended to indicators in the group of native cells. The level of native oocytes with the signs of morphological degeneration (7.7%) had no significant differences with the level of intraovarian vitrified gametes with 10 % SDMG (11 %). The proportion of native oocytes with low FILDs (38.9 %) exceeded the level of oocytes with the above indicator in vitrified oocytes of the control (16.5 %) group and in experimental groups of cells with the addition of 6 % SDMG (4.8 %) and 10 % SDMG (11.8 %, P&lt;0.001).Conclusion. In general, comprehensive monitoring of indicators cryoresistance of COCs in Sus scrofa domesticus subjected to intraovarian vitrification revealed the cryoprotective properties of SDMG. The effects were dose-dependent and were expressed in the stabilization of oocyte-cumulus communication, a decrease in the level of oocytes with the signs of morphological degeneration, and features of the lipidome functioning in intraovarian vitrified female gametes using SDMG at various concentrations.

Hyperoside alleviates photoreceptor degeneration by preventing cell senescence through AMPK-ULK1 signaling.

Vision loss and blindness are frequently caused by photoreceptor degeneration, for example in age-related macular degeneration and retinitis pigmentosa. However, there is no effective medicine to treat these photoreceptor degeneration-related diseases. Cell senescence is a common phenotype in many diseases; however, few studies have reported whether it occurs in photoreceptor degeneration diseases. Herein, we identified that cell senescence is associated with photoreceptor degeneration induced by N-methyl-N-nitrosourea (MNU, a commonly used photoreceptor degeneration model), presented as increased senescence-associated β-galactosidase activity, DNA damage, oxidative stress and inflammation-related cytokine Interleukin 6 (IL6), and upregulation of cyclin p21 or p16. These results suggested that visual function might be protected using anti-aging treatment. Furthermore, Hyperoside is reported to help prevent aging in various organs. In this study, we showed that Hyperoside, delivered intravitreally,alleviated photoreceptor cell senescence and ameliorated the functional and morphological degeneration of the retina in vivo and in vitro. Importantly, Hyperoside attenuated the MNU-induced injury and aging of photoreceptors via AMPK-ULK1 signaling inhibition. Taken together, our results demonstrated that Hyperoside can prevent MNU-induced photoreceptor degeneration by inhibiting cell senescence via the AMPK-ULK1 pathway.

A comparative analysis of gene and protein expression in chronic and acute models of photoreceptor degeneration in adult zebrafish.

Background: Adult zebrafish are capable of photoreceptor (PR) regeneration following acute phototoxic lesion (AL). We developed a chronic low light (CLL) exposure model that more accurately reflects chronic PR degeneration observed in many human retinal diseases. Methods: Here, we characterize the morphological and transcriptomic changes associated with acute and chronic models of PR degeneration at 8 time-points over a 28-day window using immunohistochemistry and 3'mRNA-seq. Results: We first observed a differential sensitivity of rod and cone PRs to CLL. Next, we found no evidence for Müller glia (MG) gliosis or regenerative cell-cycle re-entry in the CLL model, which is in contrast to the robust gliosis and proliferative response from resident MG in the AL model. Differential responses of microglia between the models was also observed. Transcriptomic comparisons between the models revealed gene-specific networks of PR regeneration and degeneration, including genes that are activated under conditions of chronic PR stress. Finally, we showed that CLL is at least partially reversible, allowing for rod and cone outer segment outgrowth and replacement of rod cell nuclei via an apparent upregulation of the existing rod neurogenesis mechanism. Discussion: Collectively, these data provide a direct comparison of the morphological and transcriptomic PR degeneration and regeneration models in zebrafish.

Hyperoside protects against oxidative stress-mediated photoreceptor degeneration: therapeutic potentials for photoreceptor degenerative diseases

BackgroundPhotoreceptor degeneration underpinned by oxidative stress-mediated mitochondrial dysfunction and cell death leads to progressive and irreversible vision impairment. Drug treatments that protect against photoreceptor degeneration are currently available in the clinical settings. It has been shown that hyperoside, a flavonol glycoside, protects against neuronal loss in part by suppressing oxidative stress and maintaining the functional integrity of mitochondria. However, whether hyperoside protects against photoreceptor degeneration remains unknown.MethodsTo address the pharmacological potentials of hyperoside against oxidative stress-mediated photoreceptor degeneration on molecular, cellular, structural and functional levels, multiple in vitro and in vivo methodologies were employed in the current study, including live-cell imaging, optical coherence tomography, electroretinography, histological/immunohistochemical examinations, transmission electron microscopy, RNA-sequencing and real-time qPCR.ResultsThe in vitro results demonstrate that hyperoside suppresses oxidative stress-mediated photoreceptor cell death in part by mitigating mitochondrial dysfunction. The in vivo results reveal that hyperoside protects against photooxidative stress-induced photoreceptor morphological, functional and ultrastructural degeneration. Meanwhile, hyperoside treatment offsets the deleterious impact of photooxidative stress on multiple molecular pathways implicated in the pathogenesis of photoreceptor degeneration. Lastly, hyperoside attenuates photoreceptor degeneration-associated microglial inflammatory activation and reactive Müller cell gliosis.ConclusionsAll things considered, the present study demonstrates for the first time that hyperoside attenuates oxidative stress-induced photoreceptor mitochondrial dysfunction and cell death. The photoreceptor-intrinsic protective effects of hyperoside are corroborated by hyperoside-conferred protection against photooxidative stress-mediated photoreceptor degeneration and perturbation in retinal homeostasis, warranting further evaluation of hyperoside as a photoreceptor protective agent for the treatment of related photoreceptor degenerative diseases.

Intrinsic and environmental basis of aging: A narrative review

Longevity has been a topic of interest since the beginnings of humanity, yet its aetiology and precise mechanisms remain to be elucidated. Aging is currently viewed as a physiological phenomenon characterized by the gradual degeneration of organic physiology and morphology due to the passage of time where both external and internal stimuli intervene. The influence of intrinsic factors, such as progressive telomere shortening, genome instability due to mutation buildup, the direct or indirect actions of age-related genes, and marked changes in epigenetic, metabolic, and mitochondrial patterns constitute a big part of its underlying endogenous mechanisms. On the other hand, several psychosocial and demographic factors, such as diet, physical activity, smoking, and drinking habits, may have an even more significant impact on shaping the aging process. Consequentially, implementing dietary and exercise patterns has been proposed as the most viable alternative strategy for attenuating the most typical degenerative aging changes, thus increasing the likelihood of prolonging lifespan and achieving successful aging.

The Aging Enteric Nervous System.

The gut and the brain communicate via the nervous system, hormones, microbiota-mediated substances, and the immune system. These intricate interactions have led to the term "gut-brain axis". Unlike the brain-which is somewhat protected-the gut is exposed to a variety of factors throughout life and, consequently, might be either more vulnerable or better adapted to respond to these challenges. Alterations in gut function are common in the elder population and associated with many human pathologies, including neurodegenerative diseases. Different studies suggest that changes in the nervous system of the gut, the enteric nervous system (ENS), during aging may result in gastrointestinal dysfunction and initiate human pathologies of the brain via its interconnection with the gut. This review aims at summarizing the contribution of normal cellular aging to the age-associated physiological changes of the ENS. Morphological alterations and degeneration of the aging ENS are observed in different animal models and humans, albeit with considerable variability. The aging phenotypes and pathophysiological mechanisms of the aging ENS have highlighted the involvement of enteric neurons in age-related diseases of the central nervous system such as Alzheimer's or Parkinson's disease. To further elucidate such mechanisms, the ENS constitutes a promising source of material for diagnosis and therapeutic predictions, as it is more accessible than the brain.

Motor neuron loss and neuromuscular transmission failure following chemogenetic inhibition of BDNF/TrkB signaling in adult rats

Brain derived neurotrophic factor (BDNF) signaling through its high-affinity tropomyosin receptor kinase B (TrkB) is known to have potent effects on motor neuron survival and morphology during development and in neurodegenerative diseases. However, the specific effects of reduced BDNF/TrkB signaling on neuromuscular structure and function in adult mammals are not as well known. In this study, we employed a novel 1NMPP1 sensitive TrkBF616 rat model to evaluate the effect of 14 days inhibition of BDNF/TrkB signaling on the number and morphology of phrenic motor neurons (PhMNs) and diaphragm muscle (DIAm) neurotransmission in adult animals. We hypothesized that reduced BDNF/TrkB signaling results in PhMN loss and impaired DIAm neuromuscular transmission. Adult female and male TrkBF616 rats were divided into 1NMPP1 or vehicle treated groups. Three days prior to treatment, PhMNs in both groups were labeled via intrapleural injection of Alexa-Fluor647 cholera toxin B (CTB). After 11 days of treatment, retrograde axonal transport was assessed by secondary labeling of PhMNs by intrapleural injection of Alexa-Fluor488 CTB. After 14 days of treatment, the spinal cord was excised and 100 μm thick spinal sections containing PhMNs were imaged in 3D using two-channel confocal microscopy. Phrenic nerve and DIAm was excised en bloc, and the extent of neuromuscular transmission failure (NMTF) was assessed by comparing DIAm isometric forces evoked by nerve (40 Hz in 330 ms duration trains repeated each s) compared to direct muscle stimulation (40 Hz 330 ms duration train) superimposed every 15 s. Presynaptic (synaptophysin immunoreactivity) and postsynaptic (α-Bungarotoxin) compartments of neuromuscular junctions (NMJs) were labeled and imaged in 3D by confocal microscopy and the extent of pre- and postsynaptic apposition assessed. 1NMPP1-induced BDNF/TrkB inhibition reduced the total number of PhMNs by ~16%, reduced the mean PhMN somal surface areas by ~25%, reduced PhMN dendritic surface area by ~38%, impaired secondary CTB uptake by 2.5-fold and impaired neuromuscular transmission by ~33%, with no overt evidence of NMJ derangement. We conclude that inhibition of BDNF/TrkB signaling in adult TrkBF616 rats is sufficient to lead to PhMN loss, morphological degeneration, deficits in retrograde axonal transport and impaired DIAm neurotransmission. Supported by NIH: R01-AG44615 and R01-HL146114 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Chemogenetic inhibition of TrkB signalling reduces phrenic motor neuron survival and size

Brain derived neurotrophic factor (BDNF) signalling through its high-affinity tropomyosin receptor kinase B (TrkB) is known to have potent effects on motor neuron survival and morphology during development and in neurodegenerative diseases. Here, we employed a novel 1NMPP1 sensitive TrkBF616 rat model to evaluate the effect of 14 days inhibition of TrkB signalling on phrenic motor neurons (PhMNs). Adult female and male TrkBF616 rats were divided into 1NMPP1 or vehicle treated groups. Three days prior to treatment, PhMNs in both groups were initially labeled via intrapleural injection of Alexa-Fluor-647 cholera toxin B (CTB). After 11 days of treatment, retrograde axonal uptake/transport was assessed by secondary labeling of PhMNs by intrapleural injection of Alexa-Fluor-488 CTB. After 14 days of treatment, the spinal cord was excised 100 μm thick spinal sections containing PhMNs were imaged using two-channel confocal microscopy. TrkB inhibition reduced the total number of PhMNs by ∼16 %, reduced the mean PhMN somal surface areas by ∼25 %, impaired CTB uptake 2.5-fold and reduced the estimated PhMN dendritic surface area by ∼38 %. We conclude that inhibition of TrkB signalling alone in adult TrkBF616 rats is sufficient to lead to PhMN loss, morphological degeneration and deficits in retrograde axonal uptake/transport.

Morphological and mechanical alterations in articular cartilage and subchondral bone during spontaneous hip osteoarthritis in guinea pigs.

Objectives: This study aimed to investigate the morphological and mechanical changes in articular cartilage and subchondral bone during spontaneous hip osteoarthritis in guinea pigs. Materials and methods: Hip joints of guinea pigs were investigated at 1, 3, 6, and 9 months of age (hereafter denoted as 1M, 3M, 6M, and 9M, respectively; n = 7 in each group). Morphological and mechanical alterations during spontaneous hip osteoarthritis in guinea pigs were investigated. The alterations included the micromechanical properties of articular cartilage (stiffness and creep deformation), microstructure of the subchondral bone (bone mineral density, bone volume fraction, trabecular thickness, trabecular number, and trabecular separation), micromorphology of the articular cartilage, and surface nanostructure (grain size and roughness) of the articular cartilage and subchondral bone. Results: Micromechanical properties of articular cartilage in 1M showed the lowest stiffness and highest creep deformation with no significant differences in stiffness or creep deformation amongst 3M, 6M, and 9M. Articular cartilage thickness decreased with age. The earliest degeneration of articular cartilage occurred at 6 months of age, characterised by surface unevenness and evident chondrocytes reduction in micromorphology, as well as increased grain size and decreased roughness in nanostructure. No degeneration at micro- or nanostructure of subchondral bone was observed before 9 months. Conclusion: Morphological degeneration of cartilage occurred before degeneration of mechanical properties. Meanwhile, degeneration of cartilage occurred before degeneration of subchondral bone during hip osteoarthritis. The current study provided novel insights into the structural and micromechanical interaction of hip osteoarthritis, which can serve as a theoretical basis for understanding the formation and progression of osteoarthritis.

Особенности функциональной активности липидома в ооцитах Sus scrofa domesticus при интраовариальной витрификации

Abstract. The creation of a cryobank of reproductive cells and tissues opens up the possibility of intensifying the introduction of innovative cellular reproductive technologies into the practice of husbandry, biomedicine, and veterinary medicine. The aim of the study was to evaluate the effects of silicon dimethylglycerolate (SDMG) on the morphology of gametes and lipidome of porcine oocytes after intraovarian vitrification (IOV). Methods. Fragments (15 × 20 mm) of porcine ovaries were subjected to vitrification, which were exposed to cryoprotective agents (CPA1 and CPA2) for 25 minutes and 15 minutes. Composition: CPA1: 7.5 % ethylene glycol (EG), 7.5 % dimethyl sulfoxide (DMSO), 65 % PBS, with 2M bovine serum albumin (BSA) and CPA2 – 2.0% EG, 20 % DMSO, 60 % PBS, 1M BSA, 0.5 mol/l sucrose. The effectiveness of using SDMG at the studied concentrations on the cryopreservation of bio objects was assessed by: the morphology of gametes and indicators of the functional activity of the lipidome (morphology, localization and fluorescence intensity of lipid droplets visualized with Nile Red vital dye) in oocytes. Results. 0.2 % SDMG does not induce apoptotic processes in granulosa cells, reduces the level of naked cells. Addition of 2 % SDMG into the composition of cryoprotective media, the proportion of gametes with signs of morphological degeneration decreases (from 31 % to 13 %, P &lt; 0.001). SDMG contributes to an increase in the level of gametes with positive indicators of the functioning of lipid droplets: the proportion of gametes with diffuse localization increases (from 58 % to 83 %, P &lt; 0.001); the level of cells with low fluorescence intensity of the Nile red/lipid droplets complex (from 16 % to 29 %, P &lt; 0.05) and the proportion of gametes with lipid granules (47 % vs. 68 %, P &lt; 0.005) increased. Scientific novelty. For the first time, the effects of SDMG on the morphology of female gametes, apoptotic processes in the chromatin of granulosa cells and the functional activity of the lipidome of porcine oocytes under the influence of ultralow temperatures at IOV were identified. The media for IOV of oocyte-cumulus complexes were modernized with the addition of 0.2 % or 2 % SDMG.

Ferulic acid mitigates diabetic cardiomyopathy via modulation of metabolic abnormalities in cardiac tissues of diabetic rats.

Cardiovascular abnormalities have been reported as a major contributor of diabetic mortality. The protective effect of ferulic acid on diabetic cardiomyopathy in fructose-streptozotocin induced type 2 diabetes (T2D) rat model was elucidated in this study. Type 2 diabetic rats were treated by oral administration of low (150 mg/kg b.w) and high (300 mg/kg b.w) doses of ferulic acid. Metformin was used as the antidiabetic drug. Rats were humanely euthanized after 5weeks of treatment, and their blood and hearts were collected. Induction of T2D depleted the levels of reduced glutathione, glycogen, and HDL-cholesterol and the activities of superoxide dismutase, catalase, ENTPDase, and 5'nucleotidase. It simultaneously triggered increase in the levels of malondialdehyde, total cholesterol, triglyceride, LDL-cholesterol, creatinine kinase-MB as well as activities of acetylcholinesterase, angiotensin converting enzyme (ACE), ATPase, glucose-6-phopsphatase, fructose-1,6-bisphophatase, glycogen phosphorylase, and lipase. T2D induction further revealed an obvious degeneration of cardiac muscle morphology. However, treatment with ferulic acid markedly reversed the levels and activities of these biomarkers with concomitant improvement in myocardium structural morphology, which had favorable comparison with the standard drug, metformin. Additionally, T2D induction led to the depletion of 40%, 75%, and 33% of fatty acids, fatty esters, and steroids, respectively, with concomitant generation of eicosenoic acid, gamolenic acid, and vitamin E. Ferulic acid treatment restored eicosanoic acid, 2-hydroxyethyl ester, with concomitant generation of 6-octadecenoic acid, (Z)-, cis-11-eicosenoic acid, tridecanedioic acid, octadecanoic acid, 2-hydroxyethyl ester, ethyl 3-hydroxytridecanoate, dipalmitin, cholesterol isocaproate, cholest-5-ene, 3-(1-oxobuthoxy)-, cholesta-3,5-diene. These results suggest the cardioprotective potential of ferulic acid against diabetic cardiomyopathy.