Central Nucleus Research Articles

Skeletal Muscle Involvement in Patients With Truncations of Titin and Familial Dilated Cardiomyopathy

BackgroundGenetic variants in titin (TTN) are associated with dilated cardiomyopathy (DCM) and skeletal myopathy. However, the skeletal muscle phenotype in individuals carrying heterozygous truncating TTN variants (TTNtv), the leading cause of DCM, is understudied. ObjectivesThis study aimed to assess the skeletal muscle phenotype associated with TTNtv. MethodsParticipants with TTNtv were included in a cross-sectional study. Skeletal muscle fat fraction was evaluated by magnetic resonance imaging (compared with healthy controls and controls with non-TTNtv DCM). Muscle strength was evaluated by dynamometry and muscle biopsy specimens were analyzed. ResultsTwenty-five TTNtv participants (11 women, mean age 51 ± 15 years, left ventricular ejection fraction 45% ± 10%) were included (19 had DCM). Compared to healthy controls (n = 25), fat fraction was higher in calf (12.5% vs 9.9%, P = 0.013), thigh (12.2% vs 9.3%, P = 0.004), and paraspinal muscles (18.8% vs 13.9%, P = 0.008) of TTNtv participants. Linear mixed effects modelling found higher fat fractions in TTNtv participants compared to healthy controls (2.5%; 95% CI: 1.4-3.7; P < 0.001) and controls with non-TTNtv genetic DCM (n = 7) (1.5%; 95% CI: 0.2-2.8; P = 0.025). Muscle strength was within 1 SD of normal values. Biopsy specimens from 21 participants found myopathic features in 13 (62%), including central nuclei. Electron microscopy showed well-ordered Z-lines and T-tubuli but uneven and discontinuous M-lines and excessive glycogen depositions flanked by autophagosomes, lysosomes, and abnormal mitochondria with mitophagy. ConclusionsMild skeletal muscle involvement was prevalent in patients with TTNtv. The phenotype was characterized by an increased muscle fat fraction and excessive accumulation of glycogen, possibly due to reduced autophagic flux. These findings indicate an impact of TTNtv beyond the heart.

Regeneration process of myotendinous junction injury induced by collagenase injection between Achilles tendon and soleus muscle in mice.

Recently, it has become clear that peri-muscular tissues play a significant role in the deterioration of muscle function. Understanding the function and regeneration of muscle, as well as its surrounding tissues, is crucial to determining the causes of muscular illnesses. However, the regeneration process of the myotendinous junction (MTJ), the most closely related peri-muscular tissue, is still unknown. Therefore, we generated a mouse model of MTJ injury by collagenase injection and searched for the process of regeneration of the MTJ and its adjacent regions. The MTJ region was damaged by collagenase injection, which greatly increased the tendon cross sectional area. Collagenase injections increased the proportion of myofibers with a central nucleus, which is a characteristic of regenerating muscle. The collagenase injection group had myofibers with central nuclei and expressing MTJ markers. Additionally, we measured the length of MTJs using serial cross sections of the soleus muscle and discovered that MTJs at 2 weeks after collagenase injection were shorter compared to the control group, with a propensity to progressively recover their length over time. The results showed that MTJs undergo morphological regeneration even when severely damaged, and that this regeneration occurs in conjunction with muscle regeneration. We anticipate that these findings will be valuable in upcoming research on motor unit regeneration.

Neuroplasticity of the extended amygdala in opioid withdrawal and prolonged opioid abstinence.

Opioid use disorder is characterized by excessive use of opioids, inability to control its use, a withdrawal syndrome upon discontinuation of opioids, and long-term likelihood of relapse. The behavioral stages of opioid addiction correspond with affective experiences that characterize the opponent process view of motivation. In this framework, active involvement is accompanied by positive affective experiences which gives rise to "reward craving," whereas the opponent process, abstinence, is associated with the negative affective experiences that produce "relief craving." Relief craving develops along with a hypersensitization to the negatively reinforcing aspects of withdrawal during abstinence from opioids. These negative affective experiences are hypothesized to stem from neuroadaptations to a network of affective processing called the "extended amygdala." This negative valence network includes the three core structures of the central nucleus of the amygdala (CeA), the bed nucleus of the stria terminalis (BNST), and the nucleus accumbens shell (NAc shell), in addition to major inputs from the basolateral amygdala (BLA). To better understand the major components of this system, we have reviewed their functions, inputs and outputs, along with the associated neural plasticity in animal models of opioid withdrawal. These models demonstrate the somatic, motivational, affective, and learning related models of opioid withdrawal and abstinence. Neuroadaptations in these stress and motivational systems are accompanied by negative affective and aversive experiences that commonly give rise to relapse. CeA neuroplasticity accounts for many of the aversive and fear-related effects of opioid withdrawal via glutamatergic plasticity and changes to corticotrophin-releasing factor (CRF)-containing neurons. Neuroadaptations in BNST pre-and post-synaptic GABA-containing neurons, as well as their noradrenergic modulation, may be responsible for a variety of aversive affective experiences and maladaptive behaviors. Opioid withdrawal yields a hypodopaminergic and amotivational state and results in neuroadaptive increases in excitability of the NAc shell, both of which are associated with increased vulnerability to relapse. Finally, BLA transmission to hippocampal and cortical regions impacts the perception of conditioned aversive effects of opioid withdrawal by higher executive systems. The prevention or reversal of these varied neuroadaptations in the extended amygdala during opioid withdrawal could lead to promising new interventions for this life-threatening condition.

Skeletal muscle involvement in patients with truncations of titin and familial dilated cardiomyopathy

Abstract Background Variants in TTN are associated with dilated cardiomyopathy (DCM) and skeletal myopathy with or without cardiac affection. However, the skeletal muscle phenotype has not been systematically evaluated in patients with predisposition to or manifest cardiac involvement due to heterozygous truncating TTN variants (TTNtv), the most common cause of DCM. Purpose Assess the skeletal muscle phenotype associated with TTNtv. Methods This cross-sectional study examined skeletal muscle involvement in individuals with TTNtv by quantifying and comparing fat fraction from muscle magnetic resonance imaging to controls (matched on body-size, sex, and age), and evaluating muscle strength by dynamometry and features from muscle biopsies. Results Twenty-five participants (11 women, age 51±15 years, left ventricular ejection fraction 45±10%) with TTNtv were included (19 had DCM). Compared to controls, participants with TTNtv had higher fat fraction in calf- (12.5% vs 9.9%, p=0.013), thigh- (12.2% vs 9.3%, p=0.004) and paraspinal muscles (18.8% vs 13.9%, p=0.008), see figure. Muscle strength was relatively intact (within 1 SD of normal values). Muscle biopsies in 21 participants showed that 13 (62%) displayed myopathic features, most notably an increased proportion of central nuclei. Electron microscopy showed well-ordered Z-lines and T-tubuli but uneven and discontinuous M-lines and excessive glycogen depositions flanked by large autophagosomes, lysosomes, and abnormal mitochondria with mitophagy. Conclusion Skeletal muscle involvement is prevalent in patients with cardiac involvement or predisposition to DCM due to TTNtv and is characterized by an increased muscle fat fraction, and excessive accumulation of glycogen, possibly due to reduced autophagic flux. This emphasizes the need for specialized diagnostic work-up in patients with TTNtv, especially if reporting symptoms or objective signs of muscle involvement.

Exploring the neural mechanisms underlying achalasia: A study of functional connectivity and regional brain activity

Background and AimsThe pathophysiology of achalasia, which involves central nuclei abnormalities, remains unknown. We investigated the resting-state functional MRI (rs-fMRI) features of patients with achalasia. MethodsWe applied resting-state functional MRI (rs-fMRI) to investigate the brain features in patients with achalasia (n = 27), compared to healthy controls (n = 29). Focusing on three regions of interest (ROIs): the dorsal motor nucleus of the vagus (DMV), the nucleus ambiguus (NA), and the nucleus of the solitary tract (NTS), we analyzed variations in resting-state functional connectivity (rs-FC), fractional amplitude of low-frequency fluctuations (fALFF), and regional homogeneity (ReHo). ResultsAchalasia patients demonstrated stronger functional connectivity between the NA and the right precentral gyrus, left postcentral gyrus, and left insula. No significant changes were found in the DMV or NTS. The fMRI analysis showed higher rs-FC values for NA-DMV and NA-NTS connections in achalasia patients. Achalasia patients exhibited decreased fALFF values in the NA, DMV, and NTS regions, as well as increased ReHo values in the NA and DMV regions. A positive correlation was observed between fALFF values in all six ROIs and the width of the barium meal. The NTS fALFF value and NA ReHo value displayed a positive correlation with integrated relaxation pressure (IRP), while the ReHo value in the right precentral gyrus showed an inverse correlation with the height of the barium meal. ConclusionsAbnormal rs-FC and regional brain activity was found in patients with achalasia. Our study provides new insights into the pathophysiology of achalasia and highlights the potential of rs-fMRI in improving the diagnosis and treatment of this condition.

Effects of Nandrolone Decanoate on Skeletal Muscle and Neuromuscular Junction of Sedentary and Exercised Rats.

Background and Objectives: Nandrolone decanoate (ND) is the most widely used among the anabolic androgenic steroids (AAS), synthetic substances derived from testosterone, to improve muscular and health gains associated with exercises. The AAS leads to physical performance enhancement and presents anti-aging properties, but its abuse is associated with several adverse effects. Supraphysiological doses of AAS with or without physical exercise can cause morphological and functional alterations in neuromuscular interactions. This study aims to investigate the effects of ND supraphysiological doses in neuromuscular interactions, focusing on the soleus muscle and its neuromuscular junctions (NMJs) in rats, associated or not with physical exercise. Materials and Methods: Forty male Sprague Dawley rats were divided into four groups: sedentary and exercised groups, with or without ND at the dose of 10 mg/kg/week. The animals were treated for eight weeks, with intramuscular injections, and the soleus muscle was collected for morphological analyses. Results: The supraphysiological doses of ND in the sedentary group caused muscle degeneration, evidenced by splitting fibers, clusters of small fibers, irregular myofibrils, altered sarcomeres, an increase in collagen deposition and in the number of type I muscle fibers (slow-twitch) and central nuclei, as well as a decrease in fibers with peripheral nuclei. On the other hand, in the ND exercise group, there was an increase in the NMJs diameter with scattering of its acetylcholine receptors, although no major morphological changes were found in the skeletal muscle. Thus, the alterations caused by ND in sedentary rats were partially reversed by physical exercise. Conclusions: The supraphysiological ND exposure in the sedentary rats promoted an increase in muscle oxidative pattern and adverse morphological alterations in skeletal muscle, resulting from damage or post-injury regeneration. In the ND-exercised rats, no major morphological changes were found. Thus, the physical exercise partially reversed the alterations caused by ND in sedentary rats.

Time-dependent photoionization spectroscopy of the Seyfert galaxy NGC 3783

We present an investigation into the spectroscopic properties of non-equilibrium photoionization processes operating in a time-evolving mode. Through a quantitative comparison between equilibrium and time-evolving models, we find that the time-evolving model exhibits a broader distribution of charge states, accompanied by a slight shift in the peak ionization state depending on the source variability and gas density. The time-evolving code tpho in SPEX was successfully employed to analyze the spectral properties of warm absorbers in the Seyfert galaxy NGC 3783. The incorporation of variability in the tpho model improves the fits of the time-integrated spectra, providing more accurate descriptions of the average charge states of several elements, in particular Fe, which is peaked around Fe XIX. The inferred densities and distances of the relevant X-ray absorber components are estimated to be approximately a few times 1011 m−3 and ≤1 pc, respectively. Furthermore, the updated fit suggests a potential scenario in which the observed absorbers are being expelled from the central active galactic nucleus at the escape velocities. This implies that these absorbers might not play a significant role in the active galactic nucleus feedback mechanism.

NEUN EXPRESSION IN SPINAL NEURONS ORGANIZING PROJECTIONS TO THE CEREBELLUM

We analyzed the peculiarities of the NeuN immunostaining of the cat spinal cord neurons located in four structures organizing projections to the cerebellum: the Clarke’s nucleus and border cells – in the L4 segment, the central cervical nucleus – in the C3 segment, and the Stilling’s nucleus – in the S2 segment. Morphometric and densitometric studies were carried out. It was shown that all neurons of interest have a striking feature: an extremely weak level of the cytoplasmic NeuN-staining, while maintaining a high level of the nuclear NeuN-staining. The soma size of neurons of interest was 1000–1850 mkm2, which is comparable to the size of another type of large neurons at slices – motoneurons (1140–1660 mkm2). Thus, we used a motoneuronal population of the corresponding segments to compare the values of optical density. The relative optical density of neurons of interest was several times lower than for the motoneurons (0.060 ± 0.030 vs 0.330 ± 0.127). There were no significant differences in optical density between different structures of interest. Given the morphological uniqueness and similarity of these four cell populations, we believe that the feature of NeuN protein expression can be used as a simple tool for the visualization of cells organizing projections to the cerebellum. It can be valuable both for targeted morphological examination and for histological control after a physiological experiment.

Large-scale Dynamics of Line-driven Winds with the Re-radiation Effect

Previous simulations studying winds only focus on the line force due to photons from central active galactic nuclei. What properties of the winds will be when including the re-radiation force due to the scattered and reprocessed photons (i.e., the re-radiation effect)? We perform simulations to study the large-scale dynamics of accretion disk winds driven by radiation line force and re-radiation force. For the fiducial run, we find that the re-radiation force drives stronger outflows during the early stages. When the flows get into the steadiness, the UV radiation due to spectral lines dominates total radiation and the re-radiation effect could be negligible. The opening angle of winds narrows as the initial gas density increases. The larger the gas density is, the stronger the re-radiation effect will be. For M BH = 106 M ⊙, ε = 0.3, the outflows do become much stronger with the re-radiation effect and the winds still cannot escape from gravitational potential. We find that the detection probability of ultra-fast outflows and the properties of the winds are both consistent with the observations.

Silk-hydrogel functionalized with human decellularized Wharton's jelly extracellular matrix as a minimally invasive injectable hydrogel system for potential nucleus pulposus tissue replacement therapy

Intervertebral disc degeneration is a primary cause for chronic low back pain, a common health problem with high incidence and the leading cause of disability globally. The early stages of disc degeneration in terms of functional and anatomical abnormalities start from the central nucleus pulposus tissue of the intervertebral disc; hence its regeneration has become a prime concern. A plethora of hydrogel systems have been investigated as nucleus pulposus tissue substitute over the years, with limited clinical translation. In the present study, we formulated a minimally invasive injectable cross-linker-free bioactive silk-based hybrid hydrogel system functionalized with decellularized human Wharton's jelly extracellular matrix as an ampule of bioactive cues. The centrifugation based decellularization method removed >92 % of cellular components and preserved >83 % of extracellular matrix composition. The hydrogels were investigated for secondary structure and surface properties through infrared spectroscopy and electron micrographs, respectively. Notably, the developed hydrogels were found to mimic the rheological and mechanical properties of native nucleus pulposus tissue when decellularized Wharton's jelly extracellular matrix content was 0.5 % (w/v) in the base silk hydrogel. Finally, the hydrogels were found to support cell viability, proliferation, and tissue maturation offering great potential for future applications related to nucleus pulposus tissue engineering.

Exposure to sublethal concentrations of imidacloprid, pyraclostrobin, and glyphosate harm the behavior and fat body cells of the stingless bee Scaptotrigona postica

Pesticide use in agriculture threatens non-target insects such as bees. Considering the ecological and economic relevance of native bees, such as Scaptotrigona postica, and the insufficient studies on the effects of pesticides on their behavior and physiology, improving the current knowledge on this issue is essential. Therefore, this study investigated the sublethal effects of imidacloprid, pyraclostrobin, and glyphosate on the behavior and fat body cells of S. postica. Pesticide ingestion decreased the walking distance and mean velocity of bees compared to the control and solvent control groups. The oenocytes of the control groups were spherical, with central nuclei containing decondensed chromatin, and the trophocytes presented irregular morphology, with cells varying in shape and the cytoplasm filled with vacuoles and granules. However, bees exposed to pesticides showed extensive cytoarchitectural disruption in the fat body, such as vacuolization and shape changes in oenocytes and altered nuclei morphology in trophocytes. Moreover, pesticide exposure increased the number of atypical oenocytes and altered trophocytes, except for the PYR group, which showed a lower number of atypical oenocytes. Caspase-positive labeling significantly increased in all exposed bee groups. Alternatively, TLR4 labeling was significantly decreased in the exposed groups compared to the control groups. There was a significant increase in HSP90 immunolabeling in all exposed groups compared to the control. These findings reinforce the importance of research on the sublethal effects of low pesticide concentrations on key neotropical pollinators and prove that these toxic substances can impair their detoxification and immune defense.

Turmeric Bioactive Compounds Alleviate Spinal Nerve Ligation-Induced Neuropathic Pain by Suppressing Glial Activation and Improving Mitochondrial Function in Spinal Cord and Amygdala.

This study examined the effects of turmeric bioactive compounds, curcumin C3 complex® (CUR) and bisdemethoxycurcumin (BDMC), on mechanical hypersensitivity and the gene expression of markers for glial activation, mitochondrial function, and oxidative stress in the spinal cord and amygdala of rats with neuropathic pain (NP). Twenty-four animals were randomly assigned to four groups: sham, spinal nerve ligation (SNL, an NP model), SNL+100 mg CUR/kg BW p.o., and SNL+50 mg BDMC/kg BW p.o. for 4 weeks. Mechanical hypersensitivity was assessed by the von Frey test (VFT) weekly. The lumbosacral section of the spinal cord and the right amygdala (central nucleus) were collected to determine the mRNA expression of genes (IBA-1, CD11b, GFAP, MFN1, DRP1, FIS1, PGC1α, PINK, Complex I, TLR4, and SOD1) utilizing qRT-PCR. Increased mechanical hypersensitivity and increased gene expression of markers for microglial activation (IBA-1 in the amygdala and CD11b in the spinal cord), astrocyte activation (GFAP in the spinal cord), mitochondrial dysfunction (PGC1α in the amygdala), and oxidative stress (TLR4 in the spinal cord and amygdala) were found in untreated SNL rats. Oral administration of CUR and BDMC significantly decreased mechanical hypersensitivity. CUR decreased CD11b and GFAP gene expression in the spinal cord. BDMC decreased IBA-1 in the spinal cord and amygdala as well as CD11b and GFAP in the spinal cord. Both CUR and BDMC reduced PGC1α gene expression in the amygdala, PINK1 gene expression in the spinal cord, and TLR4 in the spinal cord and amygdala, while they increased Complex I and SOD1 gene expression in the spinal cord. CUR and BDMC administration decreased mechanical hypersensitivity in NP by mitigating glial activation, oxidative stress, and mitochondrial dysfunction.

Central administered xenin induced Fos expression in nesfatin-1 neurons in rats

Xenin is a 25-amino acid peptide identified in human gastric mucosa, which is widely expressed in peripheral and central tissues. It is known that the central or peripheral administration of xenin decreases food intake in rodents. Nesfatin-1/NUCB2 (nesfatin-1) has been identified as an anorexic neuropeptide, it is often found co-localized with many peptides in the central nervous system. After the intracerebroventricular administration of xenin on nesfain-1-like immunoreactivity (LI) neurons, we examined its effects on food intake and water intake in rats. As a result, Fos-LI neurons were observed in the organum vasculosum of the laminae terminalis (OVLT), the median preoptic nucleus (MnPO), the subfornical organ (SFO), the supraoptic nucleus (SON), the paraventricular nucleus (PVN), the arcuate nucleus (Arc), the lateral hypothalamic area (LHA), the central amygdaloid nucleus (CAN), the dorsal raphe nucleus (DR), the locus coeruleus (LC), the area postrema (AP) and the nucleus of the solitary tract (NTS). After the administration, the number of Fos-LI neurons was significantly increased in the LC and the OVLT, the MnPO, the SFO, the SON, the PVN, the Arc, the LHA, the CAN, the DR, the AP and the NTS, compared with the control group. After the administration of xenin, we conducted double immunohistochemistry for Fos and nesfatin-1, and found that the number of nesfatin-1-LI neurons expressing Fos were significantly increased in the SON, the PVN, the Arc, the LHA, the CAN, the DR, the AP and the NTS, compared with the control group. The pretreatment of nesfatin-1 antisense significantly attenuated this xenin-induced feeding suppression, while that of nesfatin-1 missense showed no improvement. These results indicate that central administered xenin may have anorexia effects associated with activated central nesfatin-1 neurons.

THU646 Postmenopausal Hyperandrogenism Secondary To Ovarian Leydig Cell Tumor

Abstract Disclosure: J.T. Batch: None. G.Y. Gandhi: None. Introduction: Hirsutism is typically the initial presentation of virilization, including male pattern balding, deepening of the voice, and clitoromegaly. Postmenopausal hyperandrogenism can originate from adrenal or ovarian causes. This report describes marked hirsutism and scalp hair loss in a patient, leading to significant negative psychological and social impacts. Case Report: A 73-year-old female presented to the clinic complaining of scalp hair loss and increased facial hair in the upper lip and chin. She has hypertension (treated with amlodipine, losartan, metoprolol tartrate, and hydrochlorothiazide), dyslipidemia (treated with omega-3 fatty acids), hypothyroidism (treated with levothyroxine), and transvaginal hysterectomy without oophorectomy in 1994 for menorrhagia (no hormonal replacement therapy after surgery). The patient reported regular menstrual periods before the hysterectomy but developed menorrhagia during her early 50s. For the past five years, she noted bitemporal scalp hair loss that progressed significantly and created recession of the hairline and thinning of hair in her crown area. She developed dark pigmented hair on her upper lip and chin area, lower abdomen, and chest. Due to the significant impact of these physical changes, she became socially withdrawn and admitted to only leaving home to attend doctors’ appointments. She denied using supplements or physical contact with anyone using topical testosterone. She denied enlargement of her clitoris. She did note a deepening of her voice, although she is a chronic smoker. A hormonal work-up revealed a significantly high total testosterone of 511 ng/dL (normal range 2-45 ng/dL). DHEA-sulfate was normal at 62 mcg/dL (4-157 mcg/dL), and 17-hydroxyprogesterone was not significantly high at 192 ng/dL. MRI abdominal and pelvis with and without contrast revealed a 1.8 cm avidly enhancing left ovarian nodule. The patient underwent bilateral salpingo-oophorectomy. Pathology showed tumor cells with eosinophilic cytoplasm, central nucleus, and prominent nucleolus, consistent with a Leydig cell tumor measuring 1 cm and was confined to the left ovary. Four weeks after surgery, a repeat hormonal work-up revealed a normal total testosterone level of 23 ng/dL (normal range 2-45 ng/dL). Discussion: Hyperandrogenism with rapidly progressing hirsutism indicates a tumoral etiology. Leydig cell ovarian tumors are uncommon neoplasms arising from the gonadal stroma, accounting for &amp;lt;0.1% of all primary ovarian tumors. The diagnosis is based mainly on clinical and laboratory data since imaging studies may not show the small androgen-producing lesion. Bilateral oophorectomy should be recommended in postmenopausal women when an ovarian source is suspected. Most ovarian virilizing tumors are benign, and bilateral salpingo-oophorectomy results in a cure. Presentation: Thursday, June 15, 2023

OR01-05 Growth Hormone Action In Somatostatin Neurons Regulates Anxiety And Fear Memory

Abstract Disclosure: W.O. dos Santos: None. V.A. Juliano: None. H.R. Vieira: None. R. Frazao: None. C.D. Munhoz: None. J. Donato: None. Dysfunctions in growth hormone (GH) secretion increase the prevalence of anxiety and depression. Furthermore, GH receptor (GHR) signaling in the amygdala has been associated with fear memory, a key feature of post-traumatic stress disorder. However, it is currently unknown which neuronal population is targeted by GH action to influence neuropsychiatric diseases. Here we showed that approximately 60% of somatostatin (SST)-expressing neurons in the extended amygdala are directly responsive to GH. GHR ablation in SST-expressing cells (SSTΔGHR mice) led to increased anxiety in the light-dark box and elevated plus maze tests, whereas SSTΔGHR females showed no changes in anxiety, compared to control animals. Using auditory Pavlovian fear conditioning, both male and female SSTΔGHR mice exhibited a significant reduction in fear memory. In contrast, GHR ablation in SST neurons did not affect memory in the novel object recognition test. The gene expression was analyzed in a bilateral micropunch comprising the central nucleus of the amygdala and basolateral complex of male mice. Increased mRNA expression of Gabbr2 (GABAB2 receptor), Syp (synaptophysin), and Bdnf were observed in the amygdala of SSTΔGHR mice. In conclusion, GHR expression in SST neurons is necessary to regulate anxiety in males, but not in female mice. GHR ablation in SST neurons also decreases fear memory and affects the gene expression in the amygdala. Our findings identified for the first time a specific neuronal population responsible for mediating the effects of GH on behavioral aspects associated with neuropsychiatric diseases. Presentation: Thursday, June 15, 2023

SAT605 Growth Hormone Action In Somatostatin Neurons Regulates Anxiety And Fear Memory

Abstract Disclosure: W.O. dos Santos: None. V.A. Juliano: None. H.R. Vieira: None. R. Frazao: None. C.D. Munhoz: None. J. Donato: None. Dysfunctions in growth hormone (GH) secretion increase the prevalence of anxiety and depression. Furthermore, GH receptor (GHR) signaling in the amygdala has been associated with fear memory, a key feature of post-traumatic stress disorder. However, it is currently unknown which neuronal population is targeted by GH action to influence neuropsychiatric diseases. Here we showed that approximately 60% of somatostatin (SST)-expressing neurons in the extended amygdala are directly responsive to GH. GHR ablation in SST-expressing cells (SSTΔGHR mice) led to increased anxiety in the light-dark box and elevated plus maze tests, whereas SSTΔGHR females showed no changes in anxiety, compared to control animals. Using auditory Pavlovian fear conditioning, both male and female SSTΔGHR mice exhibited a significant reduction in fear memory. In contrast, GHR ablation in SST neurons did not affect memory in the novel object recognition test. The gene expression was analyzed in a bilateral micropunch comprising the central nucleus of the amygdala and basolateral complex of male mice. Increased mRNA expression of Gabbr2 (GABAB2 receptor), Syp (synaptophysin), and Bdnf were observed in the amygdala of SSTΔGHR mice. In conclusion, GHR expression in SST neurons is necessary to regulate anxiety in males, but not in female mice. GHR ablation in SST neurons also decreases fear memory and affects the gene expression in the amygdala. Our findings identified for the first time a specific neuronal population responsible for mediating the effects of GH on behavioral aspects associated with neuropsychiatric diseases. Presentation: Saturday, June 17, 2023

Msi2 enhances muscle dysfunction in a myotonic dystrophy type 1 mouse model

BackgroundMyotonic dystrophy type 1 (DM1) is a rare neuromuscular disease caused by a CTG repeat expansion in the 3′ untranslated region of the DM1 protein kinase gene. Characteristic degenerative muscle symptoms include myotonia, atrophy, and weakness. We previously proposed an Musashi homolog 2 (MSI2)>miR-7>autophagy axis whereby MSI2 overexpression repressed miR-7 biogenesis that subsequently de-repressed muscle catabolism through excessive autophagy. Because the DM1 HSALR mouse model expressing expanded CUG repeats shows weak muscle-wasting phenotypes, we hypothesized that MSI2 overexpression was sufficient to promote muscle dysfunction in vivo. MethodsBy means of recombinant AAV murine MSI2 was overexpressed in neonates HSALR mice skeletal muscle to induce DM1-like phenotypes. ResultsSustained overexpression of the murine MSI2 protein in HSALR neonates induced autophagic flux and expression of critical autophagy proteins, increased central nuclei and reduced myofibers area, and weakened muscle strength. Importantly, these changes were independent of MBNL1, MBNL2, and Celf1 protein levels, which remained unchanged upon Msi2 overexpression. ConclusionsGlobally, molecular, histological, and functional data from these experiments in the HSALR mouse model confirms the pathological role of MSI2 expression levels as an atrophy-associated component that impacts the characteristic muscle dysfunction symptoms in DM1 patients.

Alternative-Based Breeding Schemes for Designing Genetic Improvement of Indigenous Goats in the Western Lowlands of Ethiopia

Without well-designed national animal genetic improvement schemes, achieving and monitoring genetic gains is difficult. Therefore, the objective of the present study was to compare designs of alternative-based breeding schemes for genetic improvement of western lowland Arab goats. In the current study, four schemes for the village-based were designed and evaluated for sustainable and operationally feasible breeding programs. The results indicated that monetary genetic gains for the central nucleus scheme were higher than the village-based schemes. Among the central nucleus-based, scheme-5 gave the highest genetic progress in monetary terms (31.27/doe/year). Scheme-1 produced high genetic improvement and was the most efficient of all other village schemes. The trait of more significant genetic gain for the six-month weight (6MW) was predicted from central nucleus scheme-5, and scheme-1 was the highest among the village schemes. The results showed that the central nucleus-based plans were fairly superior to the village-based breeding scheme in terms of annual genetic response and profit. However, the central scheme was not appreciable under smallholder breeders’ management practices since it requires high investments. Given this limitation, a cooperative village scheme linked with a central nucleus scheme is the best option for fast genetic gains and profits. Nonetheless, to upgrade the entire Arab goat flocks which are kept under small-scale farmers’ conditions, scheme-1 could be used as an alternative option.

Clinical Effectiveness of Posterior Annular Targeted Ablative Decompression as an Alleviative Intervention for Lumbosacral Discogenic Pain: Systematic Review and Meta-analysis

BACKGROUND: Various percutaneous intradiscal procedures have been implemented to manage lumbosacral discogenic pain. But most of these procedures simply end up manipulating the central nucleus pulposus or the inner annulus, instead of accessing the posterior outer annulus where the actual, major pain generators exist. Thus, more localized percutaneous techniques, specifically derived to address the pathologic tissues creeped between the torn, posterior annulus and hyperplastic sinuvertebral nerve, have been devised. However, the clinical effectiveness of these “more” accurate procedures is still skeptical. OBJECTIVES: This study has investigated whether the posterior annular targeted decompression was a useful method to treat lumbosacral discogenic pain in terms of pain control or functional improvement. STUDY DESIGN: A systematic review and meta-analysis. SETTING: Primary clinic and tertiary referral center. PATIENTS: Published past references that have dealt with the issue of clinical effectiveness after the posterior annular targeted decompression as a treatment of discogenic pain in terms of pain control and functional improvement. METHODS: A literature search was performed using MEDLINE, EMBASE, Cochrane Review, and KoreaMed databases from the studies published until December 2022. After reviewing titles, abstracts, and full texts of 65 studies during the initial database search, 12 studies were included in a qualitative synthesis, and 9 trials from 8 studies were in quantitative meta-analysis. Data, including pain and functional scores, were extracted and were analyzed using a random effects model to obtain statistical significance of mean difference. Quality assessment and evidence level were established in accordance with the Grading of Recommendations Assessment, Development and Evaluation methodology. RESULTS: Finally, 12 single-arm studies without the control group were included. All studies showed significant pain reduction and functional improvement from a 1-month to 1-year follow-up period. A meta-analysis showed significant reduction in pain scores at 1 month, 3 months, 6 months, and 1 year and functional scores at 1 month, 6 months, and 1 year. The level of evidence was very low because of the nonrandomized study design and inconsistency and imprecision across studies. LIMITATIONS: Only single-arm studies comparing clinical results before and after treatment without the control group were analyzed. The statistical and clinical heterogeneity, due to different aspect of techniques across the studies and a relatively small number of patients, reduced the evidence level. CONCLUSIONS: Comprehensive reviews of selected articles revealed posterior annular targeted decompression could be recommended as treatment option in the patients with discogenic pain who have failed in attaining clinical improvement after the conservative managements under weak evidential strength support. KEY WORDS: Discogenic pain, minimal invasive technique, percutaneous targeted disc decompression, systematic review, meta-analysis

Effects of autoimmune abnormalities on skeletal muscle regeneration after needle puncture in mice.

Regeneration of injured skeletal muscles is supported by the activation of satellite cells, and excessive traumatic injuries may trigger abnormal processes, such as fibrosis. Because the participation of immune cells is crucial during skeletal muscle repair, systemic autoimmune diseases impair their regeneration. This study focused on a traumatic injury by injection and investigated the effect of autoimmune diseases on skeletal muscle regeneration. Male mice of MRL/MpJ-Faslpr/lpr and MRL/MpJ (6-7 months old) were used for autoimmune disease and healthy groups. The abdominal walls punctured by a needle were histologically analyzed at 1, 3, and 8 days postinjection. In both groups, injured skeletal muscle tissues showed necrosis and inflammatory cell infiltrations on day 1, increased cell density at 3 days, and regenerative myotubes with central nuclei without fibrosis at 8 days. Gr-1+ neutrophils at injured skeletal muscle were abundant at 1 day, and then substantially decreased starting from 3 days in both groups. The number of CD3+ T cells was remarkably higher in MRL/MpJ-Faslpr/lpr than that in MRL/MpJ at 1 day, and a similar tendency was observed in B220+ B cells. The numbers of IBA1+ macrophages and bromodeoxyuridine-incorporating cells tended to be higher at 3 days, and those of the latter, mainly proliferating paired-box-7+ satellite cells, showed significance at other time points and negatively correlated with the autoimmune disease indices, such as spleen weights or serum autoantibody level. Thus, this result suggested that injured skeletal muscle by minor trauma is normally regenerated regardless of the effects of autoimmune diseases, although lymphocyte infiltrations during these processes were more severe in MRL/MpJ-Faslpr/lpr.