Critical Role of E1623 Residue in S3-S4 Loop of Nav1.1 Channel and Correlation Between Nature of Substitution and Functional Alteration

Objective: An overwhelming majority of the genetic variants associated with genetic disorders are missense. The association between the nature of substitution and the functional alteration, which is critical in determining the pathogenicity of variants, remains largely unknown. With a novel missense variant (E1623A) identified from two epileptic cases, which occurs in the extracellular S3-S4 loop of Nav1.1, we studied functional changes of all latent mutations at residue E1623, aiming to understand the relationship between substitution nature and functional alteration.Methods: Six latent mutants with amino acid substitutions at E1623 were generated, followed by measurements of their electrophysiological alterations. Different computational analyses were used to parameterize the residue alterations.Results: Structural modeling indicated that the E1623 was located in the peripheral region far from the central pore, and contributed to the tight turn of the S3-S4 loop. The E1623 residue exhibited low functional tolerance to the substitutions with the most remarkable loss-of-function found in E1623A, including reduced current density, less steady-state availability of activation and inactivation, and slower recovery from fast inactivation. Correlation analysis between electrophysiological parameters and the parameterized physicochemical properties of different residues suggested that hydrophilicity of side-chain at E1623 might be a crucial contributor for voltage-dependent kinetics. However, none of the established algorithms on the physicochemical variations of residues could well predict changes in the channel conductance property indicated by peak current density.Significance: The results established the important role of the extracellular S3-S4 loop in Nav1.1 channel gating and proposed a possible effect of local conformational loop flexibility on channel conductance and kinetics. Site-specific knowledge of protein will be a fundamental task for future bioinformatics.

Revisiting the Immunological Aspects of Temozolomide Considering the Genetic Landscape and the Immune Microenvironment Composition of Glioblastoma

The microenvironment (ME) plays a critical role in causing glioblastoma (GBM) to be a moving and incurable target. The main features governing the interaction between cancer cells and the ME include dependency, promotion, and in rare cases, even competition. In the original Stupp protocol, the alkylating agent temozolomide (TMZ) is the first-line chemotherapy drug to treat GBM, and it is broadly used together or after radiotherapy. Some studies have described TMZ as an adjuvant to other therapeutic approaches including immunotherapy because of its ability to induce an immunogenic death of cancer cells. TMZ also exerts immunomodulatory effects on the tumor and immune ME. These findings support the coexistence of two circuits, i.e., one that subverts local immunosuppressive mechanisms and another that exerts a harmful influence on the peripheral immune response. A bias toward the latter can drive the failure of treatments based on the combination of chemotherapy and immunotherapy approaches. In this review, we will reanalyze how intrinsic and acquired resistance to TMZ impacts the immunomodulatory effects previously described by way of inducing a functional alteration of local immune cells and promoting immunosuppression and how different components of the immune ME, with particular attention to tumor-associated macrophages and microglia, can cause TMZ resistance to circumvent potential local immunogenic mechanisms.

Case Report: A Novel Missense Variant in the SIPA1L3 Gene Associated With Cataracts in a Chinese Family

The signal-induced proliferation-associated 1-like 3 (SIPA1L3) gene that encodes a putative Rap GTPase-activating protein (RapGAP) has been associated with congenital cataract and eye development abnormalities. However, our current understanding of the mutation spectrum of SIPA1L3 associated with eye defects is limited. By using whole-exome sequencing plus Sanger sequencing validation, we identified a novel heterozygous c.1871A > G (p.Lys624Arg) variation within the predicted RapGAP domain of SIPA1L3 in the proband with isolated juvenile-onset cataracts from a three-generation Chinese family. In this family, the proband's father and grandmother were also heterozygous for the c.1871A > G variation and affected by cataracts varying in morphology, severity, and age of onset. Sequence alignment shows that the Lys 624 residue of SIPA1L3 is conserved across the species. Based on the resolved structure of Rap1–Rap1GAP complex, homology modeling implies that the Lys 624 residue is structurally homologous to the Lys 194 of Rap1GAP, a highly conserved lysine residue that is involved in the interface between Rap1 and Rap1GAP and critical for the affinity to Rap·GTP. We reasoned that arginine substitution of lysine 624 might have an impact on the SIPA1L3-Rap·GTP interaction, thereby affecting the regulatory function of SIPA1L3 on Rap signaling. Collectively, our finding expands the mutation spectrum of SIPA1L3 and provides new clues to the molecular mechanisms of SIPA1L3-related cataracts. Further investigations are warranted to validate the functional alteration of the p.Lys624Arg variant of SIPA1L3.

Thrombocytosis – a Valuable Parameter for Assessing Severity of Crohn Disease Patients

Background and aim: Capsule endoscopy is the most sensitive method for evaluating mucosal lesions in Crohn’s Disease and recent studies show that capsule endoscopy could be used for disease staging and for careful monitoring to evaluate endoscopic activity on a regular basis. Over time, many platelet changes have been described in IBD, including morphological and functional alteration and increased number. We determined whether platelets count correlates with the endoscopic activity measured using capsule endoscopy in Crohn’s disease patients from a single center. Methods: This is a retrospective observational study. There were enrolled patients with suspected or known Crohn’s disease that underwent evaluation with capsule endoscopy in our department, between 2011 and 2021. For the evaluation with capsule endoscopy, Pillcam SB3 or Pillcam Colon2 were used. For the evaluation of endoscopic activity, we used Lewis score calculated using RAPID 8 capsule reading software. Platelets level was measured and correlated with the Lewis score, inflammatory biomarkers (C-reactive protein and fecal calprotectin) and anemic syndrome. Results: A total of 62 patients were included in the study, of whom 37 (59.67%) were with suspected Crohn’s disease and 25 (40.32%) were with known Crohn’s disease. Thrombocytosis was present in the majority of patients with severe endoscopic activity (Lewis score more than 790), elevated CRP, fecal calprotectin more than 250microg/g and anemic syndrome. Conclusion: To our knowledge, this is the first study that assess the correlation between thrombocytosis and severity of Crohn’s disease, evaluated with capsule endoscopy. Our data suggests that platelet count is a valuable, non-invasive, easy to use biomarker that is a good predictor of severity of Crohn’s disease and could have a prognostic value. It correlates well with Lewis score, CRP, fecal calprotectin and anemia.

Rumen Microbial Community and Functions of Rumen Bacteria under Different Feeding Regime

The aim of the study was to evaluate the variations in the rumen ecosystem at genus level and predicted functions of rumen bacteria by using whole crop corn silage (WCS), whole crop rice silage (WRS) or rice straw (RS) as forage sources in beef cattle ration. Ruminal digesta samples from 10 bulls per treatment were collected at day 60 of experimental period. The PCoA plots based on the Bray-Curtis distance matrix (BDM) expressed separation between WRS and WCS , WRS and RS using PC1 (P<0.05, 45.56%). The PCoA plots based on BDM also expressed separation among WRS, WCS and RS group using PC2 (P<0.05, 11.95%). Microbiota composition resutls at genus level showed that the most abundant genera were Prevotella (13.37%) and Ruminococcus (4.00%). Comparison of treatments represented that Prevotella, Treponema and Anaerostipes were higher in bulls fed WCS forage. Clostridium, Anaeroplasma and RFN20 were higher in bulls fed RS forage than animals fed WCS and WRS. Butyrivibrio was higher in WRS and RS treatments than WCS treatment group. Pseudobutyrivibrio was higher in bulls fed WRS forage than animals fed RS and WCS forage. Fibrobacter was higher in RS and WCS as compared to WRS. The results of functional alteration of rumen microbiota in different experimental groups represented that the leading modified function of the microbiome was the transporter. Based on findings of current study, it is concluded that microbial community at genus level in the rumen of bulls was highly altered by forage type.

Coping With Oral Tongue Cancer and COVID-19 Infection

To date, April 19, 2021, the coronavirus disease 2019 (COVID-19) caused about 140,886,773 confirmed cases and more than 3,000,000 deaths worldwide since the beginning of the pandemic. Oncology patients are usually frail due to the fear of prognosis, recurrence, and outcomes of treatments. Thus, coping with cancer is a complicated process that is necessary to overcome oncological challenge, even more in case of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) disease. This is a brief case report on a middle-aged man affected by advanced oral tongue cancer and COVID-19, describing his experience of cancer diagnosis, surgical treatment, and rehabilitation during the hospital quarantine for COVID-19. Besides the traumatic experience due to the functional alteration in breathing, eating, and speaking caused by major surgery and the concurrent facial disfigurement, our patient had to face a COVID-19 diagnosis, which implied hospital and social isolation. The aim of this perspective work is to focus on the role of the psychological support in the management of hospital distress related to COVID-19 psychophysical loneliness or alienation. In our experience, such support should anticipate patients' oncological surgery or treatment and should be implemented through telemedicine in case of isolation or after hospital discharge.

Circ_0040039 May Aggravate Intervertebral Disk Degeneration by Regulating the MiR-874-3p-ESR1 Pathway

The functional alteration of nucleus pulposus cells (NPCs) exerts a crucial role in the occurrence and progression of intervertebral disk degeneration (IDD). Circular RNAs and microRNAs (miRs) are critical regulators of NPC metabolic processes such as growth and apoptosis. In this study, bioinformatics tools, encompassing Gene Ontology pathway and Venn diagrams analysis, and protein–protein interaction (PPI) network construction were used to identify functional molecules related to IDD. PPI network unveiled that ESR1 was one of the most critical genes in IDD. Then, a key IDD-related circ_0040039-miR-874-3p-ESR1 interaction network was predicted and constructed. Circ_0040039 promoted miR-874-3p and repressed ESR1 expression, and miR-874-3p repressed ESR1 expression in NPCs, suggesting ESR1 might be a direct target of miR-874-3p. Functionally, circ_0040039 could enhance NPC apoptosis and inhibit NPC growth, revealing that circ_0040039 might aggravate IDD by stabilizing miR-874-3p and further upregulating the miR-874-3p-ESR1 pathway. This signaling pathway might provide a novel therapeutic strategy and targets for the diagnosis and therapy of IDD-related diseases.

Comprehensive profiling of novel epithelial–mesenchymal transition mediators and their clinical significance in colorectal cancer

Epithelial–mesenchymal transition (EMT) is a drastic phenotypic change during cancer metastasis and is one of the most important hallmarks of aggressive cancer. Although the overexpression of some specific transcription factors explains the functional alteration of EMT-induced cells, a complete picture of this biological process is yet to be elucidated. To comprehensively profile EMT-related genes in colorectal cancer, we quantified the EMT induction ability of each gene according to its similarity to the cancer stromal gene signature and termed it “mesenchymal score.” This bioinformatic approach successfully identified 90 candidate EMT mediators, which are strongly predictive of survival in clinical samples. Among these candidates, we discovered that the neuronal gene ARC, possibly originating from the retrotransposon, unexpectedly plays a crucial role in EMT induction. Profiling of novel EMT mediators we demonstrated here may help understand the complexity of the EMT program and open up new avenues for therapeutic intervention in colorectal cancer.

Craniofacial and neurological manifestations in patients with Guillain-Barré Syndrome.

Introducción: Among the broad range of symptoms of the Guillain-Barré Syndrome (GBS), patients can present craniofacial manifestations. Consequently, the participation of the dental surgeon in the evaluation of the stomatognathic system using a multidisciplinary approach model is very important. Objective: To identify the craniofacial and neurological manifestations of the Guillain-Barré Syndrome in patients from three hospitals in the district of Lambayeque, Peru, in 2019. Material and Methods: A descriptive, prospective, and cross-sectional study was carried out in 59 patients diagnosed with GBS by means of a clinical evaluation carried out by previously calibrated neurologists (k=0.911). Additionally, an oral evaluation of the oral hygiene index, the periodontal status, and the oral pH was carried out. Data were processed using frequency distribution tables. Results: 44.07% of the patients presented at least one functional alteration, such as unilateral limitation for facial expressions (25.42%), dysphagia (18.64%), alteration in phonation (11.86%), and loss of the sense of taste (6.78%), showing involvement of the corresponding cranial nerves. In addition, unfavorable conditions oforal hygiene and acid pH were observed in some cases, which proved adverse for the periodontal structures of the patients. Conclusion: The study found craniofacial manifestations of GBS, such as cases of unilateral facial palsy, dysphagia, difficulty in phonation, and loss of the sense of taste, due to the alteration of the cranial nerves that command these functions. In addition, poor oral hygiene, and the presence of acidic pH in some patients created an adverse environment for the integrity of the periodontal structures.