Higher baseline serum bilirubin levels are associated with increased risk of early neurological deterioration in women with acute ischemic stroke.

Background and objectives: Early neurological deterioration (END) occurs in up to one-third of patients with acute ischemic stroke (AIS) and associated with poor outcome. The role of serum bilirubin in END remains controversial. This study aims to investigate the association of total bilirubin (TBIL), direct bilirubin (DBIL) and indirect bilirubin (IBIL) with END. Methods: This study was a cross-sectional retrospective study with 344 AIS patients enrolled. We retrospectively reviewed consecutive AIS patients with END through a medical record retrieval system and enrolled patients as control randomly from the AIS patients without END at the same period. The bilirubin levels were compared between the END group and No END group. The correlations of bilirubin with END were assessed according to the bilirubin tertiles on the cohort of different genders. Results: In women, as the bilirubin level increased, the occurrence of END showed an increasing trend. The linear association was significant based on the tertiles of all bilirubin types (TBIL p = 0.003; DBIL p = 0.025; IBIL p = 0.025), while in men no similar trend was observed. After adjustment for confounders, higher TBIL (p for trend 0.009) and DBIL (p for trend 0.033) levels were associated with increased risk of END in women. The adjusted OR for T3 relative to T1 was 5.240 (95% CI 1.496-18.347) in TBIL and 3.549 (95% CI 1.089-11.566) in DBIL. Multivariate logistic regression showed that DBIL was independently associated with END in women (OR 1.717, 95% CI 1.106-2.666). The study also found that DBIL was superior to TBIL and IBIL in prediction of END occurrence in women, with greater predictive value. Discussion: There were gender differences in the relationship between bilirubin and END, and DBIL level was positively associated with END occurrence in women, not in men. DBIL had greater incremental predictive value for END than TBIL and IBIL.

Correlation between risk factors of cognitive dysfunction and blood pressure variability after acute ischemic stroke in northwest Shanghai.

Abstract：Objective: To explore the relationship between risk factors of cognitive dysfunction and blood pressure variability after acute ischemic stroke in northwest Shanghai to establish a model for early identification of high-risk groups of cognitive dysfunction and formulation of more targeted prevention and treatment measures. Methods: Spearman test was used to evaluate the correlation between blood pressure variability and Montreal Cognitive Assessment (MoCA) score in patients with acute ischemic stroke and the partial regression coefficient model was constructed based on the above independent risk factors, and the receiver operating characteristic (ROC) curve was described to analyze the relevant independent risk factors. Results: ROC curve analysis results showed that the clinical prediction model was significantly more effective than a single factor in predicting the risk of cognitive impairment after acute ischemic stroke in northwest Shanghai（P < 0.05）. Conclusion: Cognitive dysfunction after acute ischemic stroke was closely related to high Homocysteine (Hcy) levels, high standard deviation of systolic blood pressure, previous infarction history and infarction of cognitive function area in northwest Shanghai. The prediction model based on the above factors showed satisfactory value in predicting of cognitive dysfunction risk after acute ischemic stroke and there was also the correlation between cognitive function and blood pressure variability.

Preliminary findings on diagnostic performance of computed tomography perfusion images for intracranial arterial stenosis: a retrospective study.

OBJECTIVES: Computed tomographic perfusion (CTP) can play an auxiliary role in the selection of patients with acute ischemic stroke for endovascular treatment. However, data on CTP in non-stroke patients with intracranial arterial stenosis are scarce. We aimed to investigate images in patients with asymptomatic intracranial arterial stenosis to determine the detection accuracy and interpretation time of large/medium-artery stenosis or occlusion when combining computed tomographic angiography (CTA) and CTP images. METHODS: We retrospectively reviewed 39 patients with asymptomatic intracranial arterial stenosis from our hospital database from January 2021 to August 2023 who underwent head CTP, head CTA, and digital subtraction angiography (DSA). Head CTA images were generated from the CTP data, and the diagnostic performance for each artery was assessed. Two readers independently interpreted the CTA images before and after CTP, and the results were analyzed. RESULTS: After adding CTP maps, the accuracy (area under the curve) of diagnosing internal carotid artery (R1: 0.847 vs. 0.907, R2: 0.776 vs. 0.887), middle cerebral artery (R1: 0.934 vs. 0.933, R2: 0.927 vs. 0.981), anterior cerebral artery (R1: 0.625 vs. 0.750, R2: 0.609 vs. 0.750), vertebral artery (R1: 0.743 vs. 0.764, R2: 0.748 vs. 0.846), and posterior cerebral artery (R1: 0.390 vs. 0.575, R2: 0.390 vs. 0.585) occlusions increased for both readers (p < 0.05). Mean interpretation time (R1: 72.4 ± 6.1 s vs. 67.7 ± 6.4 s, R2: 77.7 ± 3.8 s vs. 72.6 ± 4.7 s) decreased when using a combination of both images both readers (p < 0.001). CONCLUSIONS: The addition of CTP images improved the accuracy of interpreting CTA images and reduced the interpretation time in asymptomatic intracranial arterial stenosis. These findings support the use of CTP imaging in patients with asymptomatic intracranial arterial stenosis.

Efficacy of antiplatelet drugs combined with Argatroban in treating acute ischemic stroke and its impact on patients' coagulation function and neurological function: a preliminary trial.

This retrospective study analyzed the efficacy of combined antiplatelet therapy with Argatroban in treating acute ischemic stroke (AIS) and its impact on patients' coagulation and neurological functions. Clinical data of 113 AIS patients admitted between January 2021 and January 2023 were retrospectively analyzed. Patients were divided into control (n = 56) and observation (n = 57) groups based on treatment interventions. The control group patients were treated with antiplatelet drugs, while the observation group patients received combination therapy with apatinib on the basis of the control group treatment. Compared to the control group, the observation group demonstrated higher clinical efficacy, improved coagulation parameters, reduced stroke severity (measured by NIHSS), enhanced daily living abilities (BI scores), and lowered inflammatory and neural injury markers post-treatment. Adverse reaction incidence was similar between groups. Combining Argatroban with antiplatelet drugs in AIS management showed superior efficacy without increasing adverse effects, suggesting its potential for clinical application.

Self-Powered Wide-Narrow Bandgap-Laminated Perovskite Photodetector with Bipolar Photoresponse for Secure Optical Communication.

Perovskite photodetectors with bipolar photoresponse characteristics are expected to be applied in the field of secure optical communication (SOC). However, how to realize the perovskite photodetector with bipolar response remains challenging. Herein, by introducing bismuth iodide (BiI3 ) into Sn-Pb mixed perovskite precursor solution, 2D perovskite FA3 Bi2 I9 is spontaneously formed at the bottom to realize a wide-narrow bandgap-laminated perovskite film. Wavelength-dependent bipolar response is realized based on the absorption difference of the photoactive region with different bandgap combined with the carrier competition of the homotypic transport layer adopted in the as-fabricated photodetector. Under the visible/near-infrared (NIR) light irradiation, the bottom/top of the film generates a higher carrier concentration, where electrons are easier to be separated and transported by the SnO2 /PC61 BM to the bottom/top electrodes, respectively, resulting in a negative and positive bipolar response. Finally, based on positive NIR signal as the effective signal and negative visible signal as the interference signal, the SOC system is realized, where the positive NIR signal is well hidden by the negative visible signal. This work provides a simple and feasible strategy for fabrication of laminated perovskite films to achieve bipolar response.

Analysis of risk factors for the efficacy of tirofiban in the treatment of acute ischemic stroke.

OBJECTIVE: To analyse the risk factors for tirofiban efficacy in the early treatment of acute ischemic stroke. METHODS: The clinical data of 204 patients with acute ischemic stroke treated with tirofiban were retrospectively analysed. The early efficacy of tirofiban was assessed by a ≥ 4-point decline in the National Institutes of Health Stroke Scale (NIHSS) score or via the complete disappearance of neurological deficits at the end of ischemic stroke treatment, and patients were divided into an effective groupand an ineffective group. Univariate and multivariate logistic regression analyses were used to compare the differences in clinical data between the two groups. RESULTS: Multivariate logistic regression analysis showed that heavy drinking (OR 0.477, 95% CI 0.249-0.899, P = 0.023), elevated total cholesterol (OR 0.331, 95% CI 0.141-0.734, P = 0.008), NIHSS score at initiation of treatment (OR 1.130, 95% CI 1.026-1.253, P = 0.016) and time from onset to treatment (OR 0.839, 95% CI 0.700-0.979, P = 0.038) were independent risk factors affecting the early efficacy of tirofiban. CONCLUSION: The early curative effect of tirofiban in acute ischemic stroke patients with a heavy drinking history and elevated total cholesterol was poor. In patients with acute ischemic stroke, the higher the NIHSS score was within a certain range (8 < NIHSS ≤15 and the Org 10,172 Trial in the Treatment of Acute Stroke (TOAST) belongs to small-artery occlusion lacunar) at the initiation of treatment and the shorter the time from onset to treatment, the better the early curative effect was.

What Is Happening in the Squares of China? Exploring the Experience of Participating in Square Sports and Sustainability Factors.

This phenomenological study explored the experience of participation in square sports in China and the social mechanisms by which they can be sustained. Ten study participants were selected through a purposeful sampling method. The findings indicate that their physical and mental health were either maintained or improved as they engaged in square sports. They also experienced reduced feelings of loneliness and an increase in their sense of belonging through exchanges with other members of their teams. They enjoyed the freedom from cost and spatial restrictions in pursuing leisure activities. However, conflicts also arose with other groups, mainly related to securing space in the squares. Additionally, the study found that conflicts between participants and non-participants in square sports emerged as a social problem. The social mechanisms by which square sports can be sustained were identified as people-led voluntary participation, pride in square sports, and the reproduction of economic capital using human resources.

Development of charybdotoxin Q18F variant as a selective peptide blocker of neuronal BK(α + ß4) channel for the treatment of epileptic seizures.

Epilepsy is the results from the imbalance between inhibition and excitation in neural circuits, which is mainly treated by some chemical drugs with side effects. Gain-of-function of BK channels or knockout of its ß4 subunit associates with spontaneous epilepsy. Currently, few reports were published about the efficacy of BK(α + ß4) channel modulators in epilepsy prevention. Charybdotoxin is a non-specific inhibitor of BK and other K+ channels. Here, by nuclear magnetic resonance (NMR) and other biochemical techniques, we found that charybdotoxin might interact with the extracellular loop of human ß4 subunit (i.e., hß4-loop) of BK(α + ß4) channel at a molar ratio 4:1 (hß4-loop vs. charybdotoxin). Charybdotoxin enhanced its ability to prevent K+ current of BK(α + ß4 H101Y) channel. The charybdotoxin Q18F variant selectively reduced the neuronal spiking frequency and increased interspike intervals of BK(α + ß4) channel by π-π stacking interactions between its residue Phe18 and residue His101 of hß4-loop. Moreover, intrahippocampal infusion of charybdotoxin Q18F variant significantly increased latency time of seizure, reduced seizure duration and seizure numbers on pentylenetetrazole-induced pre-sensitized rats, inhibited hippocampal hyperexcitability and c-Fos expression, and displayed neuroprotective effects on hippocampal neurons. These results implied that charybdotoxin Q18F variant could be potentially used for intractable epilepsy treatment by therapeutically targeting BK(α + ß4) channel.

Higher maternal thyroid resistance indices were associated with increased neonatal thyroid-stimulating hormone- analyses based on the Huizhou mother-infant cohort.

Objectives: This study aimed to explore the relationship of maternal thyroid function and thyroid resistance parameters with neonatal thyroid-stimulating hormone (TSH). Methods: This work was a longitudinal study. Singleton pregnant women without a history of thyroid disorders were recruited in their first prenatal visit from October 2018 to June 2020. Maternal thyroid markers including TSH, free triiodothyronine (FT3), free thyroxine (FT4), and neonatal TSH were tested in the clinical laboratory of the hospital by electrochemiluminescence immunoassay. Thyroid resistance indices including Thyroid Feedback Quantile-based Index (TFQI), TSH index (TSHI), and thyrotroph T4 resistance index (TT4RI) were estimated in accordance with maternal FT4 and TSH levels. Multivariable linear and logistic regression was applied to explore the associations of maternal thyroid indices with infantile TSH level. Results: A total of 3,210 mothers and 2,991 newborns with valid TSH data were included for analysis. Multivariable linear regression indicated that maternal thyroid variables were significantly and positively associated with neonatal TSH levels with standardized coefficients of 0.085 for TSH, 0.102 for FT3, 0.100 for FT4, 0.076 for TSHI, 0.087 for TFQI, and 0.089 for TT4RI (all P < 0.001). Compared with the lowest quartile, the highest quartile of TSHI [odds ratio (OR) = 1.590, 95% CI: 0.928-2.724; Ptrend = 0.025], TFQI (OR = 1.746, 95% CI: 1.005-3.034; Ptrend = 0.016), and TT4RI (OR = 1.730, 95% CI: 1.021-2.934; Ptrend = 0.030) were significantly associated with an increased risk of elevated neonatal TSH (>5 mIU/L) in a dose-response manner. Conclusion: The longitudinal data demonstrated that maternal thyroid resistance indices and thyroid hormones in the first half of gestation were positively associated with neonatal TSH levels. The findings offered an additionally practical recommendation to improve the current screening algorithms for congenital hypothyroidism.

Safety and efficacy of low-dose and long-course tirofiban in large hemispheric infarction.

Background: The clinical efficacy and safety of tirofiban in the treatment of large hemispheric infarction (LHI) remain controversial. Methods: This study prospectively enrolled patients with acute LHI who were admitted to Putuo Hospital affiliated with Shanghai University of Traditional Chinese Medicine from June 2021 to December 2021. The patients were randomly assigned to the tirofiban group [3-4 µg/(kg·h)] or control group (clopidogrel 75 mg/d). Results: A total of 71 patients with acute LHI were selected: 36 in the tirofiban group and 35 in the control group. The reduction of the NIHSS score in the tirofiban group was 2.92 ± 9.31 at discharge, and that of the control group was -3.23 ± 12.06 (p = 0.021, OR, 0.006; 95% CI, 0.004-0.008). Six patients (16.7%) in tirofiban group and 14 patients (40%) in control group died during hospitalization (p = 0.029, OR, 0.300; 95% CI, 0.099-0.908). There was significant difference in Modified Rankin Scale (mRS) 5-6 scores at 90 days between the two groups (p = 0.023, OR, 0.327; 95% CI, 0.124-0.867). However, there was no significant difference in mRS 0-1 (p = 0.321, OR, 0.972; 95% CI, 0.920-1.027), mRS 2 (p = 0.572, OR, 2.00; 95% CI, 0.173-23.109), mRS 3 (p = 0.225, OR, 2.214; 95% CI, 0.601-8.161), or mRS 4(p = 0.284, OR, 1.859; 95% CI, 0.593-5.825) scores between the two groups. There was no difference in symptomatic intracranial hemorrhage (p = 0.29, OR, 0.305; 95% CI, 0.030-3.081), asymptomatic intracranial hemorrhage (p = 0.123, OR, 0.284; 95% CI, 0.053-1.518). There was a significant difference in systemic bleeding events during hospitalization (p = 0.044, OR, 0.309; 95% CI, 0.096-1.000). Conclusions: Low-dose and long-course tirofiban treatment may significantly improve the early neurological function and reduce the in-hospital mortality in LHI patients. Meanwhile, tirofiban does not increase the risk of any type of bleeding events.

A clinical model and nomogram for early prediction of gestational diabetes based on common maternal demographics and routine clinical parameters.

AIM: We aimed to develop a risk prediction model for gestational diabetes mellitus (GDM) based on the common maternal demographics and routine clinical variables in Chinese population. METHODS: Individual information was collected from December 2018 to October 2019 by a pretested questionnaire on demographics, medical and family history, and lifestyle factors. Multivariable logistic regression was performed to establish a predictive model for GDM by variables in pre- and early pregnancy. The consistency and discriminative validity of the model were evaluated by Hosmer-Lemeshow goodness-of-fit testing and ROC curve analysis. Internal validation was appraised by fivefold cross-validation. Clinical utility was assessed by decision curve analysis. RESULTS: Total 3263 pregnant women were included with 17.2% prevalence of GDM. The model equation was: LogitP = -11.432 + 0.065 × maternal age (years) + 0.061 × pre-pregnancy BMI (kg/m2 ) + 0.055 × weight gain in early pregnancy (kg) + 0.872 × history of GDM + 0.336 × first-degree family history of diabetes +0.213 × sex hormone usages during pre- or early pregnancy + 1.089 × fasting glucose (mmol/L) + 0.409 × triglycerides (mmol/L) + 0.082 × white blood cell count (109/L) + 0.669 × positive urinary glucose. Homer-Lemeshow goodness-of-fit testing indicated a good consistency between predictive and actual data (p = 0.586). The area under the ROC curve (AUC) was 0.720 (95% CI: 0.697 ~ 0.744). Cross-validation suggested a good internal validity of the model. A nomogram has been made to establish an easy to use scoring system for clinical practice. CONCLUSIONS: The predictive model of GDM exhibited well acceptable predictive ability, discriminative performance, and clinical utilities. The project was registered in clinicaltrial.gov.com with identifier of NCT03922087.

Anti-epileptic/pro-epileptic effects of sodium channel modulators from Buthus martensii Karsch.

The East Asian scorpion Buthus martensii Karsch (BmK) is one of the classical traditional Chinese medicines for treating epilepsy for over a thousand years. Neurotoxins purified from BmK venom are considered as the main active ingredients, acting on membrane ion channels. Voltage-gated sodium channels (VGSCs) play a crucial role in the occurrence of epilepsy, which make them become important drug targets for epilepsy. Long chain toxins of BmK, composed of 60-70 amino acid residues, could specifically recognize VGSCs. Among them, α-like neurotoxins, binding to the receptor site-3 of VGSC, induce epilepsy in rodents and can be used to establish seizure models. The ß or ß-like neurotoxins, binding to the receptor site-4 of VGSC, have significant anticonvulsant effects in epileptic models. This review aims to illuminate the anticonvulsant/convulsant effects of BmK polypeptides by acting on VGSCs, and provide potential frameworks for the anti-epileptic drug-design.

Greater Consumption of Total and Individual Lignans and Dietary Fibers Were Significantly Associated with Lowered Risk of Hip Fracture-A 1:1 Matched Case-Control Study among Chinese Elderly Men and Women.

The study aims to examine the association of dietary intake of lignans with the risk of hip fractures in Chinese older adults. This was a 1:1 age- and gender- matched case−control study. Dietary survey was conducted by face-to-face interviews using a 79-item validated food frequency questionnaire. Habitual intake of total and individual lignans (matairesinol, secoisolariciresinol, pinoresinol, and lariciresinol) was estimated based on the available lignans databases. Conditional logistic regression was used to examine the relationship of dietary total and individual lignans, lignan-rich foods (vegetables, fruits, nuts, and cereals) and dietary fibers with the risk of hip fracture. A total of 1070 pairs of hip fracture incident cases and controls were recruited. Compared with the lowest quartile, the highest quartile group showed a reduced hip fracture risk by 76.3% (0.237, 95% CI: 0.103−0.544, Ptrend < 0.001) for total lignans, and 62.5% (0.375, 95% CI: 0.194−0.724, Ptrend = 0.001) for dietary fibers. Similar findings were observed for individual lignans, the estimated enterolactone level, as well as lignans from vegetables and nuts. We concluded that greater consumption of total and individual lignans, and lignan-rich foods were significantly associated with decreased risk of hip fracture.

Increased Central and Peripheral Thyroid Resistance Indices During the First Half of Gestation Were Associated With Lowered Risk of Gestational Diabetes-Analyses Based on Huizhou Birth Cohort in South China.

Objectives: The study aimed to explore the relationship of thyroid function and resistance indices with subsequent risk of gestational diabetes (GDM). Design: This was a longitudinal study embedded in the Huizhou Birth Cohort. Methods: A total of 2,927 women of singleton pregnancy were recruited from January to October of 2019. Thyroid central resistance indices were evaluated by Thyroid Feedback Quartile-Based index (TFQI), Thyrotrophy T4 Resistance Index (TT4RI), and TSH Index (TSHI) based on plasma-free thyroxine (FT4) and thyroid-stimulating hormone (TSH) levels during the first half of pregnancy. Thyroid peripheral sensitivity was assessed by free triiodothyronine (FT3) to FT4 ratio (FT3/FT4), a proxy of deiodinase activity. GDM was diagnosed between 24 and 28 weeks of gestation by a standardized 75 g oral glucose tolerance test. Multivariable linear and logistic regression was applied to examine the associations of thyroid markers with GDM risk. Results: FT3 and FT3/FT4 were positively associated with both fasting and post-load glucose levels, while TSH, TSHI, TT4RI, and TFQI were negatively associated with 1 and 2 h post-load glucose levels. Compared with the lowest quartile, GDM risk in the highest quartile increased by 44% [odds ratio (OR) = 1.44; 95%CI, 1.08-1.92; ptrend = 0.027] for FT3 and 81% (OR = 1.81; 95%CI, 1.33-2.46; ptrend < 0.001) for FT3/FT4, while it lowered by 37% (OR = 0.63; 95%CI, 0.47-0.86; ptrend = 0.002] for TSHI, 28% for TT4RI (OR = 0.72; 95%CI, 0.54-0.97; ptrend = 0.06), and 37% for TFQI (OR = 0.63; 95%CI, 0.46-0.85; ptrend < 0.001). Conclusions: This longitudinal study indicated that higher FT3 and FT3/FT4 and lower central thyroid resistance indices were associated with increased risk of GDM.

Free-Triiodothyronine to Free-Thyroxine Ratio Mediated the Effect of Prepregnancy Body Mass Index or Maternal Weight Gain During Early Pregnancy on Gestational Diabetes Mellitus.

OBJECTIVE: Maternal overweight or obesity during early pregnancy can increase the subsequent risk of gestational diabetes mellitus (GDM). However, whether these associations are mediated by thyroid hormones and their effect sizes is still unknown. This study aimed to identify the mediating effects of thyroid parameters between prepregnancy body mass index (BMI) or maternal weight gain during early pregnancy on the subsequent risk of GDM. METHODS: This prospective mother-infant cohort study was conducted from 2018 to 2019. A total of 2772 singleton pregnant women were included in the analysis. A questionnaire survey, anthropometric measures, and thyroid function testing were conducted during early pregnancy. Deiodinase activity was evaluated using the free-triiodothyronine-to-free-thyroxine ratio (FT3:FT4). The standard 75-g oral glucose tolerance test was performed during 24 to 28 weeks of gestation to diagnose GDM. A mediation analysis was performed using PROCESS 3.5 to examine the mediating effects of thyroid parameters between prepregnancy BMI or maternal weight gain during early pregnancy on the subsequent risk of GDM. RESULTS: The FT3:FT4 ratio was a significant mediator between prepregnancy BMI or maternal weight gain and GDM, accounting for 16.5% and 18.6% of total effects, respectively. FT3 also mediated the association of prepregnancy BMI with GDM, accounting for 3.3% of the total effects. Thyroid-stimulating hormone suppressed the effects of prepregnancy BMI and maternal weight gain on GDM risk, and the proportion of their total effects was 2.4% and 6.4%, respectively. CONCLUSION: Deiodinase activity, as indicated by the FT3:FT4 ratio, was the strongest mediator among thyroid parameters between prepregnancy BMI or maternal early weight gain and GDM.

The 6-month effect of whole soy and purified isoflavones daidzein on thyroid function-A double-blind, randomized, placebo controlled trial among Chinese equol-producing postmenopausal women.

The aim of this study was to examine the effect of whole soy and purified daidzein on markers of thyroid function in Chinese postmenopausal women who were equol-producers. Total 270 eligible women were randomized to either one of the three isocaloric supplements: 40 g soy flour (whole soy group), 40 g low-fat milk powder +63 mg daidzein (daidzein group) or 40 g low-fat milk powder (placebo) daily for 6 months. Serum thyroid markers were tested at baseline and 6 months for thyroid stimulating hormone, free triiodothyronine, reverse triiodothyronine and free thyroxine (FT4). There was no significant difference in the 6-month changes of thyroid markers among the three groups. Subgroup analysis among women with lowered thyroid function suggested a modest decrease of FT4. This randomized controlled trial among Chinese equol-producing postmenopausal women indicates the consumption of whole soy and purified daidzein at the provided dosages are safe and have no detrimental effect on thyroid function.

Glycosylation of ß1 subunit plays a pivotal role in the toxin sensitivity and activation of BK channels.

BACKGROUND: The accessory ß1 subunits, regulating the pharmacological and biophysical properties of BK channels, always undergo post-translational modifications, especially glycosylation. To date, it remains elusive whether the glycosylation contributes to the regulation of BK channels by ß1 subunits. METHODS: Herein, we combined the electrophysiological approach with molecular mutations and biochemical manipulation to investigate the function roles of N-glycosylation in ß1 subunits. RESULTS: The results show that deglycosylation of ß1 subunits through double-site mutations (ß1 N80A/N142A or ß1 N80Q/N142Q) could significantly increase the inhibitory potency of iberiotoxin, a specific BK channel blocker. The deglycosylated channels also have a different sensitivity to martentoxin, another BK channel modulator with some remarkable effects as reported before. On the contrary to enhancing effects of martentoxin on glycosylated BK channels under the presence of cytoplasmic Ca2+, deglycosylated channels were not affected by the toxin. However, the deglycosylated channels were surprisingly inhibited by martentoxin under the absence of cytoplasmic Ca2+, while the glycosylated channels were not inhibited under this same condition. In addition, wild type BK (α+ß1) channels treated with PNGase F also showed the same trend of pharmacological results to the mutants. Similar to this modulation of glycosylation on BK channel pharmacology, the deglycosylated forms of the channels were activated at a faster speed than the glycosylated ones. However, the V1/2 and slope were not changed by the glycosylation. CONCLUSION: The present study reveals that glycosylation is an indispensable determinant of the modulation of ß1-subunit on BK channel pharmacology and its activation. The loss of glycosylation of ß1 subunits could lead to the dysfunction of BK channel, resulting in a pathological state.

Molecular Mechanisms of Epileptic Encephalopathy Caused by KCNMA1 Loss-of-Function Mutations.

The gene kcnma1 encodes the α-subunit of high-conductance calcium- and voltage-dependent K+ (BK) potassium channel. With the development of generation gene sequencing technology, many KCNMA1 mutants have been identified and are more closely related to generalized epilepsy and paroxysmal dyskinesia. Here, we performed a genetic screen of 26 patients with febrile seizures and identified a novel mutation of KCNMA1 (E155Q). Electrophysiological characterization of different KCNMA1 mutants in HEK 293T cells, the previously-reported R458T and E884K variants (not yet determined), as well as the newly-found E155Q variant, revealed that the current density amplitude of all the above variants was significantly smaller than that of the wild-type (WT) channel. All the above variants caused a positive shift of the I-V curve and played a role through the loss-of-function (LOF) mechanism. Moreover, the ß4 subunit slowed down the activation of the E155Q mutant. Then, we used kcnma1 knockout (BK KO) mice as the overall animal model of LOF mutants. It was found that BK KO mice had spontaneous epilepsy, motor impairment, autophagic dysfunction, abnormal electroencephalogram (EEG) signals, as well as possible anxiety and cognitive impairment. In addition, we performed transcriptomic analysis on the hippocampus and cortex of BK KO and WT mice. We identified many differentially expressed genes (DEGs). Eight dysregulated genes [i.e., (Gfap and Grm3 associated with astrocyte activation) (Alpl and Nlrp10 associated with neuroinflammation) (Efna5 and Reln associated with epilepsy) (Cdkn1a and Nr4a1 associated with autophagy)] were validated by RT-PCR, which showed a high concordance with transcriptomic analysis. Calcium imaging results suggested that BK might regulate the autophagy pathway from TRPML1. In conclusion, our study indicated that newly-found point E155Q resulted in a novel loss-of-function variant and the dysregulation of gene expression, especially astrocyte activation, neuroinflammation and autophagy, might be the molecular mechanism of BK-LOF meditated epilepsy.

Glycosylation of ß1 subunit plays a pivotal role in the toxin sensitivity and activation of BK channels

The accessory ß1 subunits, regulating the pharmacological and biophysical properties of BK channels, always undergo post-translational modifications, especially glycosylation. To date, it remains elusive whether the glycosylation contributes to the regulation of BK channels by ß1 subunits. Methods: Herein, we combined the electrophysiological approach with molecular mutations and biochemical manipulation to investigate the function roles of N-glycosylation in ß1 subunits. Results: The results show that deglycosylation of ß1 subunits through double-site mutations (ß1 N80A/N142A or ß1 N80Q/N142Q) could significantly increase the inhibitory potency of iberiotoxin, a specific BK channel blocker. The deglycosylated channels also have a different sensitivity to martentoxin, another BK channel modulator with some remarkable effects as reported before. On the contrary to enhancing effects of martentoxin on glycosylated BK channels under the presence of cytoplasmic Ca2+, deglycosylated channels were not affected by the toxin. However, the deglycosylated channels were surprisingly inhibited by martentoxin under the absence of cytoplasmic Ca2+, while the glycosylated channels were not inhibited under this same condition. In addition, wild type BK (α+ß1) channels treated with PNGase F also showed the same trend of pharmacological results to the mutants. Similar to this modulation of glycosylation on BK channel pharmacology, the deglycosylated forms of the channels were activated at a faster speed than the glycosylated ones. However, the V1/2 and slope were not changed by the glycosylation. Conclusion: The present study reveals that glycosylation is an indispensable determinant of the modulation of ß1-subunit on BK channel pharmacology and its activation. The loss of glycosylation of ß1 subunits could lead to the dysfunction of BK channel, resulting in a pathological state.(AU)