Loss Of Protein Research Articles

Convergent evolution has led to the loss of claw proteins in snakes and worm lizards.

The evolution of cornified skin appendages, such as hair, feathers and claws, is closely linked to the evolution of proteins that establish the unique mechanical stability of these epithelial structures. We hypothesized that the evolution of the limbless body anatomy of the Florida worm lizard (Rhineura floridana) and the concomitant loss of claws had led to the degeneration of genes with claw-associated functions. To test this hypothesis, we investigated the evolution of three gene families implicated in epithelial cell architecture, namely type I keratins, type II keratins and genes of the epidermal differentiation complex (EDC) in R. floridana in comparison to other squamates. We report that the orthologs of mammalian hair and nail keratins have undergone pseudogenization in R. floridana. Likewise, the EDC genes tentatively named EDYM1 and EDCCs have been lost in R. floridana. The aforementioned genes are conserved in various lizards with claws, but not in snakes. Proteomic analysis of the cornified claws of the bearded dragon (Pogona vitticeps) confirmed that type I and type II hair keratin homologs, EDYM1 and EDCCs are protein components of claws in squamates. We conclude that the convergent evolution of a limbless body was associated with the convergent loss of claw keratins and differentiation genes in squamates.

Giant axonal neuropathy (GAN): cross-sectional data on phenotypes, genotypes, and proteomic signature from a German cohort

Giant axonal neuropathy (GAN) is a progressive neurodegenerative disease affecting the peripheral and central nervous system and is caused by bi-allelic variants in the GAN gene, leading to loss of functional gigaxonin protein. A treatment does not exist, but a first clinical trial using a gene therapy approach has recently been completed. Here, we conducted the first systematic study of GAN patients treated by German-speaking child neurologists. We collected clinical, genetic, and epidemiological data from a total of 15 patients representing one of the largest cohorts described thus far. Average age of patients was 11.7 years at inclusion. The most frequently reported symptoms (HPO coded) were gait disturbance and muscle weakness, abnormality of muscle size, and abnormal reflexes. In line with the frequency of homozygous variants, in five families, parents reported being at least distantly related. In 14 patients, diagnosis was confirmed by molecular genetic testing, revealing eight different GAN variants, four being reported as pathogenic in the literature. Proteomics of white blood cells derived from four patients was conducted to obtain unbiased insights into the underlying pathophysiology and revealed dysregulation of 111 proteins implicated in diverse biological processes. Of note, diverse of these proteins is known to be crucial for proper synaptic function and transmission and affection of intermediate filament organisation and proteolysis, which is in line with the known functions of gigaxonin.

Ankyrin-B is required for the establishment and maintenance of lens cytoarchitecture, mechanics and clarity.

The transparent ocular lens is essential for vision because it focuses light onto the retina. Despite recognition of the importance of its unique cellular architecture and mechanical properties, the molecular mechanisms governing these attributes remain elusive. This study aims to elucidate the role of ankyrin-B (AnkB, encoded by ANK2), a membrane scaffolding protein, in lens cytoarchitecture, growth and function using a conditional knockout (cKO) mouse model. The AnkB cKO mouse has no defects in lens morphogenesis but exhibited changes that supported a global role for AnkB in maintenance of lens clarity, size, cytoarchitecture, membrane organization and stiffness. Notably, absence of AnkB led to nuclear cataract formation, which was evident from postnatal day 16. AnkB cKO lens fibers exhibit progressive disruption in membrane organization of the spectrin-actin cytoskeleton, cell adhesion proteins and channel proteins; loss and degradation of several membrane proteins [such as NrCAM. N-cadherin (CDH2) and aquaporin-0 (also known as MIP)]; along with a disorganized plasma membrane and impaired membrane interdigitations. Furthermore, absence of AnkB led to decreased lens stiffness. Collectively, these results illustrate the essential role for AnkB in lens architecture, growth and function through its involvement in membrane skeletal and protein organization and stability.

Apocynin and Hyperbaric Oxygen Therapy Improve Renal Function and Structure in an Animal Model of CKD

Background/Objectives: Chronic kidney disease (CKD) is a progressive pathological condition which results in the severe fibrosis of the kidneys. However, the mechanisms of CKD progression and fibrogenesis remain unclear. We wanted to examine the effects that apocynin and hyperbaric oxygen therapy (HBOT) have on renal function and structure in animals with CKD induced through 5/6 nephrectomy (5/6 Nx-L). Methods: Male Wistar rats were divided in 5 groups (n = 8/group) as follows: control—sham-operated rats; Nx-L—rats with 5/6 Nx-L; APO—5/6 Nx-L + apocynin treatment; HBOT—5/6 Nx-L + hyperbaric oxygen treatment, and APO+HBOT—5/6 Nx-L, treated with both treatments. All treatments started 4 weeks after the final step of CKD induction and lasted for 4 weeks. At the end of the experiment, urine samples were collected for the proteinuria assessment and the mean arterial pressure (MAP) was measured. Kidneys were collected for histopathological, Western blot, and immunohistochemical analyses. Results: All treatments significantly decreased MAP compared to the Nx-L group (p < 0.001). In the APO and APO+HBOT groups, the level of proteinuria was decreased compared to the Nx-L group (p < 0.05 and p < 0.01, respectively). All examined treatments significantly decreased the intensity of lesions in the kidney compared to those observed in the Nx-L group (p < 0.001). Isolated treatments with apocynin and HBOT induced a significant decrease in desmin expression compared to the Nx-L group (p < 0.05); meanwhile, they did not affect the levels of fibronectin (FN) and hypoxia-inducible factor-1α (HIF-1α). Combined treatment did not affect desmin expression levels; however, it induced a significant increase in fibronectin expression compared to Nx-L (p < 0.001). Conclusions: Apocynin treatment decreased BP and protein loss, and it improved renal morphology at least partly through the downregulation of desmin expression without changing FN and HIF-1α. Hyperbaric oxygen therapy improved hypertension but failed to significantly affect the level of proteinuria. Combined treatment (apocynin and HBOT) normalized blood pressure (BP) values, renal function, and improved kidney structure by modulating FN and HIF-1α, without affecting desmin protein expression. Further studies are needed to elucidate the mechanisms of slowing down the progression of CKD in this experimental model.

. Diagnostic value of HMGB-1 and Acetylcholinesterase in Assessing the Prognosis of Patients with Acute Pancreatitis

Aim: Acute pancreatitis (AP) is a disorder of tissue digestion caused by abnormal activation of pancreatic enzymes, which may lead to multi-organ failure and ultimately death as the disease progresses. How to quickly and accurately evaluate the progression of AP has always been a hotspot and difficulty in clinical research. Methods: Sixty-four AP patients admitted to our hospital from August 2022 to June 2023 and 60 concurrent healthy people were selected as the research subjects, with AP patients as the observation group and healthy people as the control group. Using kits from Wuhan Fine Biotechnology Co., Ltd., an enzyme-linked immunosorbent assay (ELISA) was carried out to measure HMGB-1 and AChE levels. In addition, an automatic biochemical analyzer was utilized to quantify the levels of nutritional proteins albumin (ALB), transferrin (TRF), and total protein (TP) in the observation group. Results: Compared with the control group, the HMGB-1 in the observation group was higher while the AChE was lower (P<0.05). ROC curve analysis showed that when HMGB-1 was less than 7.25 mg/L, the sensitivity and specificity for diagnosing AP were 89.06% and 51.67%, respectively (P<0.05); when AChE was less than 6.18 U/L, the sensitivity for diagnosing AP was 43.75% and the specificity was 90.00% (P<0.05). Using the joint detection Log(P)=-1.736+(0.645×HMGB-1)+(-0.454×AChE), it was found that HMGB-1+AChE had a sensitivity of 48.44% and a specificity of 88.33% for the diagnosis of AP (P<0.05, cut-off>0.639,) Conclusion: In this study, we found elevated HMGB-1 expression in AP and reduced acetylcholinesterase (AChE), suggesting that both of them may be involved in the occurrence and development of AP. Meanwhile, the two demonstrated excellent diagnostic efficacy in the onset and poor prognosis of AP, and were closely related to AP progression, confirming their potential as new clinical indicators for AP. Due to the self-digestion by pancreatic enzymes, the nutritional metabolism of AP patients is disrupted, so protein loss is also a focus of attention. In this study, we also found a negative correlation of nutritional protein levels with HMGB-1 in AP patients and a positive correlation between them with AChE, further supporting the relationship between the two and AP progression. The findings can lay a reliable foundation for future research on the diagnosis and treatment of AP based on HMGB-1 and AChE.

Behenic acid protects the testosterone cycle and prevents the sperm apoptosis and protein loss in phthalate exposure by inhibiting oxidative stress and stimulating ATPase activity

BackgroundPlastic products use phthalate to enhance their flexibility, transparency, and stability, while behenic acid is a carboxylic acid with antioxidant activity. ObjectivesThis study evaluates whether behenic acid can protect the testosterone cycle and prevent the sperm apoptosis and protein loss in phthalate-treated male rats. MethodsThere were 36 male albino rats in all, divided into six equal sets of six rats each: control, behenic acid (13g/kg), behenic acid (26g/kg), diethyl phthalate (10mg/kg), behenic acid (13g/kg) + diethyl phthalate (10mg/kg), and behenic acid (26g/kg) + diethyl phthalate (10mg/kg)-treated groups. Measurements were made of serum male hormones, sex hormone-binding globulin, sodium/potassium ATPase, superoxide dismutase, glutathione, glucose-6-phosphate dehydrogenase, 3β-hydroxysteroid dehydrogenase, protein, and cholesterol in the testis, as well as malondialdehyde in the sperm, testis, and hypothalamus. Sperm monoclonal proliferating antibody Ki-67, sperm counts, motility, and abnormalities were measured. ResultsOral administration of diethyl phthalate increased malondialdehyde, serum follicle stimulating hormone, sex hormone binding globulin, luteinizing hormone, glucose-6-phosphate dehydrogenase, 3β-hydroxysteroid dehydrogenase, cholesterol, total protein, sperm abnormality, and the percentage of spermatogonia, first spermatocyte, second spermatocyte, and spermatid in the testis. Superoxide dismutase, glutathione, serum testosterone and dehydroepiandrosterone sulphate, sperm count and motility, and sodium/potassium-ATPase activity were all reduced. Additionally, all of the previously described parameters reverted to near control values after receiving two doses of behenic acid in phthalate-treated rats; a higher dose of behenic acid had a more effective effect than a lower dose. Conclusionbehenic acid can protect the testosterone cycle and prevent the sperm apoptosis and protein loss in phthalate-treated male rats by inhibiting oxidative stress and stimulating ATPase activity.

Genetic validation of a TSC2 immunohistochemistry assay in TSC/mTOR-pathway altered renal tumors.

Pathogenic mutations in the genes associated with tuberous sclerosis complex (TSC)/mTOR pathway are linked to histologically diverse renal cell neoplasms, including eosinophilic solid and cystic renal cell carcinoma (ESC RCC), low grade oncocytic tumor (LOT), eosinophilic vacuolated tumor (EVT), and xanthomatous giant cell renal cell carcinoma (XGC RCC). Here, we validate a TSC2 immunohistochemistry (IHC) assay by comparison to genomic data in these neoplasms. Automated TSC2 IHC was performed on formalin-fixed paraffin embedded (FFPE) tissues from 38 genetically-confirmed TSC/mTOR-associated renal tumors (6ESCs, 16 EVTs, 13 LOTs, 2 XGC and 1 clear cell RCC) and visually scored in a semi-dichotomous fashion compared to internal control tissue. The positive predictive value (PPV) of TSC2 protein loss for underlying pathogenic mutation in TSC2 was 92% (11/12), while the negative predictive value (NPV) of intact TSC2 by IHC for lack of underlying pathogenic mutation in TSC2 was 81% (21/26). Intact TSC2 by IHC was 95% (21/22) specific for absence of underlying pathogenic TSC2 mutation. All the cases lacking TSC2 mutation with intact TSC2 protein had an underlying mutation in TSC1, MTOR or PIK3CA. Loss of TSC2 was 77% (10/13) sensitive for underlying TSC2 truncation mutations and 33% (1/3) sensitive for underlying TSC2 missense mutations. Overall, 73% (8/11) tumors with TSC2 IHC loss and underlying pathogenic alterations in TSC2 showed heterogeneous protein loss, with rare interspersed positively staining tumor cells. These data support TSC2 IHC as a potentially useful assay for the diagnostic workup of renal tumors suspected to belong to the TSC/mTOR-associated subgroups.

Clinical features of 50 patients with primary intestinal lymphangiectasia

Objective: To investigate the clinical features of primary intestinal lymphangiectasia (PIL). Methods: This study was a retrospective case series study. Fifty consecutive patients diagnosed with PIL in Department of Lymphatic Surgery, Beijing Shijitan Hospital, Capital Medical University from March 2019 to March 2021 were included and their clinical data was retrospectively reviewed. There were 20 males and 30 females included, with an age of (M(IQR)) 14 (40) years (range:0 to 67 years). No patient had the family history. There were 26 children, including 9 males and 17 females, aged 0 (7) years (range:0 to 14 years). There were 24 adults, including 11 males and 13 females, aged 40 (26) years (range:20 to 67 years). The clinical manifestations and the results of laboratory examinations, gastrointestinal endoscopy, 99Tcm-labeled human albumin (99Tcm-HSA) scintigraphy, 99Tcm-DX scintigraphy, direct lymphangiography (DLG), histopathology, diet treatment, surgical intervention, and clinical symptom remission at discharge were collected. Comparisons between groups were performed using independent samples t-test, Mann-Whitney U test, or χ 2 test. Results: Among the 50 cases of PIL, the main manifestations were edema (86.0%), diarrhea (76.0%), and abdominal effusion (48.0%). Lymphedema (36.0%) and chylous ascites (18.0%) were not rare in PIL patients. In 99Tcm-HAS scintigraphy, 95.9% (47/49) cases showed signs of intestinal protein loss, and 91.7% (44/48) ceses showed positive findings in 99Tcm-DX scintigraphy. In DLG, 97.8% (45/46) cases showed signs of thoracic duct obstruction, 82.6% (38/46) cases showed retroperitoneal lymphatic hyperplasia, and 23.9% (11/46) cases showed backflow of contrast agent into intestine. No significant difference was seen in gender, course of disease, clinical manifestation, serum level of albumin or globulin, lymphocyte count, positive rate of fecal occult blood and prevalence of lymphedema between adults and children (all P>0.05). Conclusions: The clinical presentations of PIL between children and adults had no significant difference. The diagnosis of PIL should be made according to clinical manifestation, 99Tcm-HAS scintigraphy, 99Tcm-DX scintigraphy, DLG, gastrointestinal endoscopy and pathological findings.

In situ metal silos grains storage performance: Maize and pearl millet for improved food security in an arid environment

Grains are commonly stored for improved food security. Among the grains storage facilities are metal silos. However, there is limited data on the performance of maize and pearl millet grains when stored in metal silos in real life (in situ) operations. To fill this gap, this study evaluated maize and pearl millet grains qualitative (nutritional) and quantitative (weight) losses during a 6-month storage period in metal silos in a semi-arid environment. Ash, protein, fat and carbohydrates & fiber contents were evaluated to indicate qualitative losses and moisture content was evaluated to indicate quantitative apparent weight loss of the stored grains. Percentage changes were calculated for moisture, ash, fat, protein and carbohydrates & fiber contents of the grains. In Katima Mulilo silo 1 based on % changes, fat contributed 5.76%, ash contributed 9.89% and carbohydrates & fiber contributed 1.61 % to the nutritional loss. There was no statistically significant protein loss in stored grains in all the studied silos. Pearl millet grains that were stored in Okongo silo had a % change of 30.38%, suggesting an apparent weight loss. The cause of ash, fat and carbohydrates & fiber loss of grains could be attributed to increased pest infestation at 6-month storage while moisture loss in pearl millet grains stored in Okongo silo could be attributed to increased temperature during the 6-month storage period. Maintenance of grains at appropriate relative humidity and temperature levels can mitigate grain weight loss.

Molecular Aspects of Loss of Y-linked Proteins and Their Potential Applications in Cell Biology

Loss of proteins linked to Y chromosome (LOY) is a biomarker in human that is typically found in male blood samples. In healthy males, its frequency often rises with age. Additionally, it has lately been linked to numerous illnesses, including cancer with significantly high prevalence. A healthy male development depends on the Y chromosome and associated proteins. The deletion of this chromosome’s proteins or even its LOY variant may have effects on the male body. These proteins serve purposes beyond those of the male reproductive system. Paternity testing, ancestry research, and sexual assault investigations are just a few of the forensic situations where Y-linked protein analyses are frequently used. Due to its connection to the aging process, LOY detection has the benefit of being a biological age biomarker. The possibility of using LOY as a biomarker brings to light the need to define the molecular process underlying its occurrence and its potential applications in both health and forensic studies. Humans frequently experience LOY, a non-physiological post-zygotic molecular change that mostly affects male blood cells[Forsberg, 2017; Forsberg et al., 2017]. It is a natural part of aging and has been related to a number of illnesses, including as Alzheimer’s, Autoimmune disorders, Schizophrenia, Cardiovascular problems, and different malignancies[Holmes et al., 1985;Persanietal., 2012; Dumanskiet al., 2016; Forsberg, 2017; Forsberg et al., 2017; Haitjemaet al., 2017;]. It is possible to think about LOY as a biological age marker and a biomarker that predicts male age-related disorders [Dumanskiet al., 2016].However, LOY analysis might obstruct the forensic examination of male samples while also being helpful in forensic investigations by offering important details.

Intranasal dantrolene nanoparticles inhibit inflammatory pyroptosis in 5XFAD mice brains.

This study investigates the effects of intranasal dantrolene nanoparticles on inflammation and programmed cell death by pyroptosis in 5XFAD Alzheimer's Disease (AD) mice. 5XFAD and wild type (WT) B6SJLF1/J mice were treated with intranasal dantrolene nanoparticles (5 mg/kg), daily, Monday to Friday, for 12 weeks continuously, starting at 9 months of age. Blood and brain were harvested at 13 months of age, one month after completion of 12 weeks intranasal dantrolene nanoparticle treatment. Blood biomarkers function of liver (Alanine transaminase, ALT), kidney (Creatinine), and thyroid (TSH: Thyroid-stimulating hormone) were measured using ELISA. The changes of whole brain tissue proteins on Ca 2+ release channels on membrane of endoplasmic reticulum (type 2 ryanodine and type 1 InsP3 receptors, RyR-2 and InsP3R-1), lipid peroxidation byproduct malondialdehyde (MDA)-modified proteins, 4-HNE, pyroptosis regulatory proteins (NLR family pyrin domain containing 3 (NLRP3), cleaved caspase-1, full length or N-terminal of Gasdermin D (GSDMD), cytotoxic (IL-1, IL-18, IL-6, TNF-a) and cytoprotective (IL-10) cytokines, astrogliosis (GFAP), microgliosis (IBA-1) and synapse proteins (PSD-95, Synapsin-1) were determined using immunoblotting. Body weights were monitored regularly. Intranasal dantrolene nanoparticles significantly inhibited the increase of RyR-2 and InsP3R-1 proteins, MDA-modified proteins, 4-NHE, pyroptosis regulatory proteins (NLRP3, cleaved caspase-1, N-terminal GSDMD), cytotoxic cytokine (IL-1β, IL-18, IL-6, TNF-α), biomarkers for astrogliosis (GFAP) and microgliosis (IBA-1), and the decrease of cytoprotective cytokine (IL-10) and synaptic proteins (PSD-95, synpasin-1). Intranasal dantrolene nanoparticles for 12 weeks did not affect blood biomarkers for function of liver, kidney, and thyroid, not did it change body weight significantly. Intranasal dantrolene nanoparticles significantly inhibit the increase of RyR-2 and InsP 3 R-1 Ca 2+ channel receptor proteins, ameliorate activation of the pyroptosis pathway and pathological inflammation, and the associated loss of synapse proteins. Intranasal dantrolene nanoparticles for three months did not affect liver, kidney and thyroid functions or cause other side effects.

Gut-on-a-Chip Reveals Enhanced Peristalsis Reduces Nanoplastic-Induced Inflammation.

Nanoplastics (NPs) pollution is a global issue posing potential threats to human health, particularly the digestive system. NPs may exacerbate intestinal inflammation, increasing the risk of inflammatory bowel disease. However, the impact of intestinal peristalsis on NP-induced inflammation remains unknown. Here, a biomimetic gut-on-a-chip (GOC) with integrated online sensing is presented to investigate NPs' impact on intestinal inflammation and propose enhanced peristalsis as a potential intervention. The GOC simulates intestinal peristalsis through periodic stretching and the optimized sensors dynamically detect inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) over 12 d with low detection limits (0.0095 and 0.0020 pg mL-1). Exposure to NPs led to vacuolization, apoptosis, and loss of tight junction proteins in intestinal cells, with IL-6 and TNF-α secretion peaking at 24 h (1341.55 ± 64.91 and 862.03 ± 66.45 pg mL-1). Notably, increasing periodic strain alleviates inflammatory cytokines secretion induced by NPs. With strain increased from 5% to 6.5%, IL-6 and TNF-α secretion decrease by 2.73-fold and 3.34-fold, respectively. This highlights the protective role of intestinal peristalsis in reducing NP-induced inflammation.

Dedifferentiated endometrial carcinoma/undifferentiated endometrial carcinoma with loss of expression of SMARCA4: clinicopathological features analysis

Objective: To investigate the clinicopathological characteristics of dedifferentiated endometrial carcinoma/undifferentiated endometrial carcinoma (DDEC/UDEC) with loss of expression of SMARCA4. Methods: A total of 10 cases with loss of expression of SMARCA4 were diagnosed at Fujian Cancer Hospital between January 2019 and December 2023. A retrospective analysis was conducted on the clinical characteristics, morphology, immunophenotype, molecular classification, and prognosis. Results: (1) Clinical characteristics: among 10 cases of DDEC/UDEC with loss of expression of SMARCA4, the patients' age ranged from 48 to 65 years, with a median age of 56 years.Five cases were classified as International Federation of Gynecology and Obstetrics (FIGO) stages Ⅰ-Ⅱ, while the remaining five were categorized as stages Ⅲ-Ⅳ. (2) Pathological features: tumor cells exhibited poor cell adhesion, with common intravascular tumor emboli (8/10), occasional vacuolated nuclei (6/10), rhabdoid cells (4/10), and starry sky phenomenon formed by tissue cell phagocytosis apoptosis bodies or fragments (4/10). Six cases (6/10) showed loss of mismatch repair (MMR) protein expression, two cases (2/10) exhibited p53 mutant expression, and five cases (5/10) tested positive for programmed cell death ligand 1 (PD-L1). (3) Molecular subtyping: molecular subtyping revealed POLEmut in 1 case (1/10), mismatch repair deficient (MMR-d) in 5 cases (5/10), p53 abn in 1 case (1/10), and no specific molecular profile (NSMP) in 3 cases (3/10). (4) Prognosis: the follow-up period ranged from 7 to 42 months, with a median of 20 months. Five patients succumbed to the tumor, whereas the remaining five exhibited no recurrence during subsequent postoperative evaluations. The 2-year progression-free survival rates and overall survival rates were 58.3% and 52.5%, respectively. Conclusions: Loss of expression of SMARCA4 occurs in approximately 1/5 of DDEC/UDEC, which presents with an aggressive clinical course and a poor prognosis. About half of them show MMR protein loss expression and PD-L1 positive expression, suggesting that there might be benefit from treatment with immune checkpoint inhibitors.

Severe traumatic brain injury temporally affects cerebral blood flow, endothelial cell phenotype, and cilia.

Previous clinical work suggested that altered cerebral blood flow (CBF) in severe traumatic brain injury (sTBI) correlates with poor executive function and clinical outcome. However, the molecular consequences of altered CBF on endothelial cells (ECs) and their blood flow-sensor organelle called cilia are not known. We performed laser speckle contrast imaging, single cell isolation, and single cell RNA sequencing (scRNAseq) after sTBI in a closed skull, linear impact mouse model. Validation of select ciliary target protein changes was performed using flow cytometry. Additionally, in vitro experiments modeled the post-injury hypoxic environment to evaluate the effect on cilia protein ARL13B in human brain microvascular ECs. We detected immediate reductions in CBF that were sustained for at least 100 minutes in both impacted and non-impacted sides of the brain. Our scRNAseq data detected heterogeneity in the brain cortex-derived EC cluster and demonstrated that two of five unique EC sub-clusters changed their relative proportions post-sTBI. Consistent with flow changes, we identified multiple genes associated with the fluid shear stress pathway that were significantly differentially expressed in brain ECs post-injury. Also, ECs displayed activation of ischemic pathway as early as day 1 post-injury, and enrichment of hypoxia pathway at day 7 and 28 post- injury. Arl13b ciliary gene expression was lost on day 1 in ECs cluster and remained lost for the entire course of the injury. We validated the loss of cilia protein ARL13B specifically from brain ECs as early as day 1 post-injury and detected the protein in the peripheral blood of the injured mice. We also determined that hypoxia could induce loss of ARL13B protein from cultured ECs. In severe TBI, blood flow is disrupted in both impacted and non-impacted regions of the brain, creating a hypoxic environment that may influence ciliary gene and protein expression on ECs.

Introducing a novel TRAPPC10 gene variant as a potential cause of developmental delay and intellectual disability in an Iranian family.

TRAPP complexes are crucial components for intracellular transport and cellular organization. Their role in vesicle trafficking, particularly through their involvement in the secretory pathway, make them more important in neurodevelopmental mechanisms. This study aims to identify a novel genetic variant, associated with developmental delay and intellectual disability by analyzing a consanguineous Iranian family. Here, we performed whole-exome sequencing on an Iranian family, originating from a small population. The patient presented with severe developmental delay, microcephaly, and behavioral abnormalities. Through our analysis, we discovered a new biallelic variant on a previously introduced gene: TRAPPC10 (NM_003274.5): c.3222C > A; p.(Cys1074Ter) that is a potential cause for these specific clinical characteristics. Previous functional analysis suggest that the mutation causes premature termination of protein translation, likely leading to nonsense-mediated decay because of biallelic loss of functional TRAPPC10 protein which leads to severe developmental delay, microcephaly, and behavioral abnormalities such as aggression and autistic traits. The aim of this research is to discover a novel variant in the TRAPPC10 gene that is responsible for a particular neurodevelopmental condition, dominantly characterized by developmental delay, intellectual disability, and microcephaly. These findings advance the comprehension of TRAPP-related diseases and emphasize the need for further exploration into the impact of TRAPPC10 on the development of the nervous system.

PINK1 controls RTN3L-mediated ER autophagy by regulating peripheral tubule junctions.

Here, we report that the RTN3L-SEC24C endoplasmic reticulum autophagy (ER-phagy) receptor complex, the CUL3KLHL12 E3 ligase that ubiquitinates RTN3L, and the FIP200 autophagy initiating protein, target mutant proinsulin (Akita) condensates for lysosomal delivery at ER tubule junctions. When delivery was blocked, Akita condensates accumulated in the ER. In exploring the role of tubulation in these events, we unexpectedly found that loss of the Parkinson's disease protein, PINK1, reduced peripheral tubule junctions and blocked ER-phagy. Overexpression of the PINK1 kinase substrate, DRP1, increased junctions, reduced Akita condensate accumulation, and restored lysosomal delivery in PINK1-depleted cells. DRP1 is a dual-functioning protein that promotes ER tubulation and severs mitochondria at ER-mitochondria contact sites. DRP1-dependent ER tubulating activity was sufficient for suppression. Supporting these findings, we observed PINK1 associating with ER tubules. Our findings show that PINK1 shapes the ER to target misfolded proinsulin for RTN3L-SEC24C-mediated macro-ER-phagy at defined ER sites called peripheral junctions. These observations may have important implications for understanding Parkinson's disease.

Elucidating the pathobiology of Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS) with its expanded RNA structure formation and proteinopathy

Numerous neurological disorders are linked to sequences rich in guanine repeats found in introns, exons, and regulatory regions of genes. These sequences have been observed to form stable G-quadruplex (GQ) structures both in vitro and in vitro. Cerebellar Ataxia with Neuropathy and Vestibular Areflexia Syndrome (CANVAS), a slowly progressive neurodegenerative disorder, is associated with the biallelic expansion of (AAGGG)n pathogenic repeats in the second intron of the RFC1 gene. Though these G-rich pathogenic repeats in other neurological diseases are associated with protein loss of function, RNA gain of function, and/or protein gain of function, not much is known about the pathological mechanism associated with CANVAS. Herein, we report the formation of stable GQ conformations in the CANVAS-associated repeats i.e., r(AAGGG)n, where ‘r’ stands for RNA. These GQs are critical regulators in neurological disorders leading to RNA foci formation and RNA binding protein sequestration. They also alter other causative processes like intron retention, which leads us to hypothesize a toxic Proteinopathy mechanism in CANVAS. Various biophysical and biomolecular assays characterized the interactions of three aggregation-prone RNA-binding proteins (RBPs): heterogeneous nuclear ribonucleoprotein H1/F (hnRNP H1/F), and DGCR8 with different pathogenic repeats [(AAGGG)9] in vitro, further affirming the hypothesis. The biophysical observations are further supported by molecular dynamics analysis and cell-based studies, putting us a step closer to elucidating the pathological mechanism(s) in CANVAS neuropathy, paving the way for the development of innovative therapeutic interventions.

Small bowel ulcers and hypoproteinemia, differential diagnosis beyond inflamatory bowel disease.

Protein-losing enteropathy is a relatively uncommon syndrome characterized by excessive loss of proteins into the intestinal lumen. It can be caused by various etiologies. Inflammatory bowel disease (IBD) is the first condition we think of when we meet a patient with intestinal ulcers and hypoproteinemia. However, there are many other complicated and relatively novel etiologies, which we must be aware of in order to perform an appropriate differential diagnosis, such as the one we present.

BIOM-47. SINGLE NUCLEOTIDE POLYMORPHISM IN SMARCB1 MUTATION FOR SCHWANNOMATOSIS

Abstract Schwannomatosis, a form of neurofibromatosis, involves critical roles for the SMARCB1 gene. Clinical diagnosis guidelines recommend considering pathogenic variants or suspecting schwannomatosis to exclude splicing-related intron mutations. However, some patients may initially present with non-significant mutations and lack clinical signs of schwannoma, leading to misdiagnosis, missed annual assessments, malignancy awareness, and genetic consultation opportunities during pregnancy. Here, we reported a patient with a sporadic synonymous mutation in the SMARCB1 gene (SNP c.1032 C>T (p.Gly344Gly(GGC>GGT)) in exon 8), not previously associated with schwannomatosis. This patient, a 55-year-old female with an 8-year history of schwannomatosis, presented to the neurosurgical department for recurrent tumor removal. Initially, the clinical impact of the SMARCB1 mutation was undetermined, and other genes tested were wild-type. Both schwannomas exhibited a mosaic loss of nuclear SMARCB1 protein, ranging from 10% to 60%. Protein assays confirmed low levels of SMARCB1 protein, with a significant loss in the distal thigh schwannoma. It highlights the tumorigenic potential of single nucleotide polymorphism in the SMARCB1 gene and aids clinicians in making more accurate diagnoses in patients with pathologically confirmed schwannoma. It underscores the importance of long-term follow-up, increased awareness of recurrence and malignancy, and timely surgical planning in such patients.

Human ITGAV variants are associated with immune dysregulation, brain abnormalities, and colitis.

Integrin heterodimers containing an Integrin alpha V subunit are essential for development and play critical roles in cell adhesion and signaling. We identified biallelic variants in the gene coding for Integrin alpha V (ITGAV) in three independent families (two patients and four fetuses) that either caused abnormal mRNA and the loss of functional protein or caused mistargeting of the integrin. This led to eye and brain abnormalities, inflammatory bowel disease, immune dysregulation, and other developmental issues. Mechanistically, the reduction of functional Integrin αV resulted in the dysregulation of several pathways including TGF-β-dependent signaling and αVβ3-regulated immune signaling. These effects were confirmed using immunostaining, RNA sequencing, and functional studies in patient-derived cells. The genetic deletion of itgav in zebrafish recapitulated patient phenotypes including retinal and brain defects and the loss of microglia in early development as well as colitis in juvenile zebrafish with reduced SMAD3 expression and transcriptional regulation. Taken together, the ITGAV variants identified in this report caused a previously unknown human disease characterized by brain and developmental defects in the case of complete loss-of-function and atopy, neurodevelopmental defects, and colitis in cases of incomplete loss-of-function.