A comprehensive review of Alport syndrome: definition, pathophysiology, clinical manifestations, and diagnostic considerations.

Alport syndrome, a rare genetic disorder affecting around 1 in 50,000 individuals, primarily presents as microscopic hematuria and chronic kidney disease (CKD) with associated extrarenal complications. The Alport syndrome results from mutations in COL4A3, COL4A4, and COL4A5 genes, disrupting the formation of the α3-α4-α5 chain in the collagen IV network. The etiology involves X chromosome-related, autosomal dominant, autosomal recessive, and digenic inheritance patterns. The disease primarily manifests as kidney involvement, featuring persistent hematuria, proteinuria, and a progressive decline in renal function. Hearing loss, ocular abnormalities, and extrarenal manifestations further contribute to its complexity. Genotype-phenotype correlations are relatively evident, with distinct presentations in X-linked, autosomal recessive, and autosomal dominant cases. Diagnosis relies on urinalysis, histologic examination, and genetic testing with advancements in next-generation sequencing aiding identification. Although no specific treatment exists, early diagnosis improves outcomes, emphasizing the importance of genetic testing for prognosis and familial screening. The purpose of this review is to advance knowledge and enhance understanding of Alport syndrome.

Kidney transplantation in the elderly.

Interest in kidney transplant studies in the elderly population is increasing as more research has been conducted on the immune system. With this review, we hope to encourage the need for research on kidney transplantation in the elderly.

Recent advancements in cGAS-STING activation, tumor immune evasion, and therapeutic implications.

The cGAS-STING signaling pathway is indeed a pivotal component of the immune system and serve as a crucial link between innate and adaptive immune responses. STING is involved in the cellular response to pathogen invasion and DNA damage, and which has important consequences for host defense mechanisms and cancer regulation. Ongoing research aiming to modulate the cGAS-STING pathway for improved clinical outcomes in cancer and autoimmune diseases is underway. Indeed, the interaction between the cGAS-STING pathway and immune evasion mechanisms is a complex and critical aspect of cancer biology. Pathogens and various host factors can exploit this pathway to reduce the effectiveness of cancer therapies, particularly immunotherapies. Thus, immunotherapies or combination therapies may assist in overcoming the immune suppression and improving clinical outcomes. This review explores recent advancements in understanding the cGAS-STING signaling pathway, with particular emphasis on its activation mechanisms and role in tumor immune evasion. The dual role of the pathway in boosting immune responses while simultaneously enabling tumors to evade the immune system makes it a crucial target for innovative cancer treatment approaches.Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 2 Given name: [Md Mazedul] Last name [Islam], Author 3 Given name: [Mst Rubaiat Nazneen] Last name [Akhand] and Author 5 Given name: [Md Rashedunnabi] Last name [Akanda]. Also, kindly confirm the details in the metadata are correct.AQ1: Here Author 4 given name: [Byung-Yong] Last name [Park] is missing. Metadata are correct.

Cordyceps militaris Grown on Germinated Rhynchosia nulubilis (GRC) Encapsulated in Chitosan Nanoparticle (GCN) Suppresses Particulate Matter (PM)-Induced Lung Inflammation in Mice.

Cordyceps militaris grown on germinated Rhynchosia nulubilis (GRC) exerts various biological effects, including anti-allergic, anti-inflammatory, and immune-regulatory effects. In this study, we investigated the anti-inflammatory effects of GRC encapsulated in chitosan nanoparticles (CN) against particulate matter (PM)-induced lung inflammation. Optimal CN (CN6) (CHI: TPP w/w ratio of 4:1; TPP pH 2) exhibited a zeta potential of +22.77 mV, suitable for GRC encapsulation. At different GRC concentrations, higher levels (60 and 120 mg/mL) led to increased negative zeta potential, enhancing stability. The optimal GRC concentration for maximum entrapment (31.4 ± 1.35%) and loading efficiency (7.6 ± 0.33%) of GRC encapsulated in CN (GCN) was 8 mg/mL with a diameter of 146.1 ± 54 nm and zeta potential of +30.68. In vivo studies revealed that administering 300 mg/kg of GCN significantly decreased the infiltration of macrophages and T cells in the lung tissues of PM-treated mice, as shown by immunohistochemical analysis of CD4 and F4/80 markers. Additionally, GCN ameliorated PM-induced lung tissue damage, inflammatory cell infiltration, and alveolar septal hypertrophy. GCN also decreased total cells and neutrophils, showing notable anti-inflammatory effects in the bronchoalveolar lavage fluid (BALF) from PM-exposed mice, compared to GRC. Next the anti-inflammatory properties of GCN were further explored in PM- and LPS-exposed RAW264.7 cells; it significantly reduced PM- and LPS-induced cell death, NO production, and levels of inflammatory cytokine mRNAs (IL-1ß, IL-6, and COX-2). GCN also suppressed NF-κB/MAPK signaling pathways by reducing levels of p-NF-κB, p-ERK, and p-c-Jun proteins, indicating its potential in managing PM-related inflammatory lung disease. Furthermore, GCN significantly reduced PM- and LPS-induced ROS production. The enhanced bioavailability of GRC components was demonstrated by an increase in fluorescence intensity in the intestinal absorption study using FITC-GCN. Our data indicated that GCN exhibited enhanced bioavailability and potent anti-inflammatory and antioxidant effects in cells and in vivo, making it a promising candidate for mitigating PM-induced lung inflammation and oxidative stress.

Vitamin C supplementation improves placental function and alters placental gene expression in smokers.

Maternal smoking during pregnancy (MSDP), driven by nicotine crossing the placenta, causes lifelong decreases in offspring pulmonary function and vitamin C supplementation during pregnancy prevents some of those changes. We have also shown in animal models of prenatal nicotine exposure that vitamin C supplementation during pregnancy improves placental function. In this study we examined whether vitamin C supplementation mitigates the effects of MSDP on placental structure, function, and gene expression in pregnant human smokers. Doppler ultrasound was performed in a subset of 55 pregnant smokers participating in the "Vitamin C to Decrease the Effects of Smoking in Pregnancy on Infant Lung Function" (VCSIP) randomized clinical trial (NCT01723696) and in 33 pregnant nonsmokers. Doppler ultrasound measurements showed decreased umbilical vein Doppler velocity (Vmax) in placebo-treated smokers that was significantly improved in smokers randomized to vitamin C, restoring to levels comparable to nonsmokers. RNA-sequencing demonstrated that vitamin C supplementation to pregnant smokers was associated with changes in mRNA expression in genes highly relevant to vascular and cardiac development, suggesting a potential mechanism for vitamin C supplementation in pregnant smokers to improve some aspects of offspring health.

Comparative study for fatigue prevalence in subjects with diseases: a systematic review and meta-analysis.

Fatigue is one of the common symptoms in individuals with diseases or disorders, significantly affecting quality of life (QoL) and the prognosis of diseases. This study aimed to comprehensively compare the features of fatigue across a wide range of diseases. We systematically searched the PubMed and Cochrane Library databases from inception to March 31st, 2021, and conducted a meta-analysis to generate precise estimates. The analyses were stratified by classification of diseases, gender, and severity of fatigue (moderate and severe), and study quality was assessed using the Newcastle-Ottawa Scale (NOS). In total, 214 articles (233 prevalence data) met our eligibility criteria, covering 102,024 participants (mean 438 ± 1,421) across 88 diseases. Among these, seventy-eight data sets (52,082 participants) and thirty-nine data sets (10,389 participants) reported gender- and severity-related fatigue prevalence. The overall prevalence among subjects with 88 diseases was 49.4% [95% CI 46.9-52.1]. According to the International Classification of Diseases-10 (ICD-10) classification, the highest prevalence of fatigue (65.9% [95% CI 54.9-79.6]) was observed in patients with mental/behavioral diseases, whereas the lowest prevalence (34.7% [95% CI 24.5-49.2]) was found among those with circulatory system diseases. A slight female dominance (43.5% vs. 49.8%) was observed in the total data, with the most notable female predominance (1.8-fold) seen in patients with low back pain. The top disease groups with a moderate to severe level of fatigue included gastroparesis (92.3%), pulmonary hypertension (90.0%), chronic obstructive pulmonary disease (COPD, 83.2%), and multiple sclerosis (80.0%). These results are the first to comprehensively show the comparative features of fatigue prevalence among subjects across 88 diseases. Our findings provide valuable reference data for future research on fatigue and for the management of patients with fatigue.Prospero registration number: CRD42021270494.

Outcomes of Hip Arthroplasty in Patients with Preoperative Thrombocytopenia.

Background: Thrombocytopenia is a condition where platelet counts are below the normal range (< 150 × 103/µL), resulting in a higher risk of bleeding and affecting the results of hip arthroplasty. We assessed the impact of preoperative platelet counts on the clinical results of patients who underwent hip arthroplasty. Methods: Between April 2003 and March 2023, 437 patients (451 hips), who had preoperative thrombocytopenia of less than 150 × 103/µL platelets, underwent hip arthroplasty. Preoperative platelet levels were categorized into severe thrombocytopenia (< 50 × 103/µL) and non-severe thrombocytopenia (50-149 × 103/µL). Total blood loss, operation time, requirement of transfusion, amount of transfusion, duration of surgical wound oozing, length of hospital stay, mortality rate at 1 year after surgery, and any complication were compared between the 2 groups. Results: No notable differences were observed in the surgery time or the total amount of blood loss between the groups. The requirement of transfusion and the amount of transfused blood were higher in the severe thrombocytopenia group. Prolonged oozing was found in around 18% in both groups, while periprosthetic joint infections occurred in 3 of the non-severe thrombocytopenia group. No significant difference was noted in the duration of hospital stay (25.6 ± 18.3 days vs. 19.4 ± 16.6 days, p = 0.067) and 1-year mortality (22.2% vs. 11.8%, p = 0.110). Conclusions: Hip arthroplasties are safe for patients with low platelet counts and do not lead to prolonged hospital stays. On the other hand, patients with severe thrombocytopenia tend to need blood transfusions more frequently than those with less severe thrombocytopenia.

Reliability of the 2018 Revised Version of AO/OTA Classification for Femoral Shaft Fractures.

Background: The Arbeitsgemeinschaft für Osteosynthesefragen (AO) and the Orthopaedic Trauma Association (OTA) classification system for diaphyseal fracture has been recently revised to refine and enhance the accuracy of fracture categorization. This study aimed to investigate the interobserver reliability of the new AO/OTA classification and to compare it with the older version in femoral shaft fractures. Methods: We retrospectively analyzed 139 patients (mean age, 43.8 ± 19.5 years; 92 men and 47 women) with femoral shaft fractures who were treated from 2003 to 2017. Four well-trained observers independently classified each fracture following the previous and revised AO/OTA classification system. We calculated the Fleiss kappa for the interobserver reliability. Results: The previous classification showed the kappa value of 0.580 (95% confidence interval [CI], 0.547-0.613), and the revised version showed 0.528 (95% CI, 0.504-0.552). Both the old and the revised versions showed moderate reliability. Conclusions: Our study highlights the moderate interobserver reliability of both the previous and new AO/OTA classification systems for diaphyseal femur fractures. These findings emphasize the importance of standardized systems in clinical decision-making and underscore the need for ongoing education and collaboration to enhance fracture classification.

Crosslinking reactions of a model aminated lignin compound as a platform for building thermosetting polymers for lignin-based bio adhesives.

As millions of tons of kraft lignin are being wasted, a potential application is to use its crosslinking reactions to build thermosetting bio adhesives. However, the crosslinking reactions between lignin molecules are not fully understood. The present study aims to elucidate the crosslinking reactions of the model lignin compound guaiacylglycerol-ß-guaiacyl ether (GGE) via one-step hydroxymethylation/ amination with formaldehyde and diethylenetriamine (DETAM), or one-step glyoxylation/ amination with glyoxal and DETAM via liquid NMR techniques such as 1H NMR, 13C NMR, 2D 1H-13C, and 1H-15N HSQC NMR. Specifically, the 2D 1H-13C HSQC NMR spectra confirm the presence of -CH2-NH- with a chemical shift of 1H 2.6-3.6/13C 40-60 ppm, and the formation of methylene linkages via the crosslinking reaction. Also, the 2D 1H-15N HSQC NMR spectra clearly detect the formation of amide and imine bonds at 1H 7.8/15N 110 and 1H 8.07/15N 121.5 ppm from the crosslinked GGE.

Effectiveness of meditation for fatigue management: Insight from a comprehensive systematic review and meta-analysis.

OBJECTIVE: This systematic review and meta-analysis revealed the effectiveness of meditation in addressing fatigue, given its widespread use as a remedy for sleep disturbances and fatigue. METHOD: We analyzed 29 randomized controlled trials from MEDLINE and the Cochrane Library, spanning from December 31, 2022. We conducted two metaanalyses using mean difference (MD) with normalized data and standardized mean difference (SMD) with original data. RESULTS: These trials included various populations, with baseline fatigue severity observed at 52.2 ± 16.0 points among 4104 participants. After an average meditation duration of 9.6 ± 4.7 weeks, fatigue scores decreased significantly by 6.4 points of MD [95% CI, 4.3-8.5] compared to controls. The most significant reduction occurred in the sub-healthy group (MD 8.2 [95% CI, 2.7 to 13.8]), followed by the general group (MD 6.9 [95% CI, 0.4 to 13.4]), and the disease group (MD 5.7 [95% CI, 3.4 to 8.0]). Notably, meditation-based anti-fatigue effects were particularly pronounced for mental fatigue (MD 10.0 [95% CI, 4.3 to 15.6]), especially with expert guidance and supplementary homework. CONCLUSION: These findings align with meta-analysis results using standardized mean difference (SMD), providing evidence for meditation as an effective nonpharmacological intervention for fatigue management, while also informing effective meditation approaches. REGISTRATION NUMBER: CRD42023395551 in PROSPERO.

HN1-mediated activation of lipogenesis through Akt-SREBP signaling promotes hepatocellular carcinoma cell proliferation and metastasis.

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related deaths worldwide, with more than 800,000 deaths each year, and its 5-year survival rate is less than 12%. The role of the HN1 gene in HCC has remained elusive, despite its upregulation in various cancer types. In our investigation, we identified HN1's heightened expression in HCC tissues, which, upon overexpression, fosters cell proliferation, migration, and invasion, unveiling its role as an oncogene in HCC. In addition, silencing HN1 diminished the viability and metastasis of HCC cells, whereas HN1 overexpression stimulated their growth and invasion. Gene expression profiling revealed HN1 silencing downregulated 379 genes and upregulated 130 genes, and suppressive proteins associated with the lipogenic signaling pathway networks. Notably, suppressing HN1 markedly decreased the expression levels of SREBP1 and SREBP2, whereas elevating HN1 had the converse effect. This dual modulation of HN1 affected lipid formation, hindering it upon HN1 silencing and promoting it upon HN1 overexpression. Moreover, HN1 triggers the Akt pathway, fostering tumorigenesis via SREBP1-mediated lipogenesis and silencing HN1 effectively curbed HCC tumor growth in mouse xenograft models by deactivating SREBP-1, emphasizing the potential of HN1 as a therapeutic target, impacting both external and internal factors, it holds promise as an effective therapeutic strategy for HCC.

Real-World Outcomes of First-Line Chemotherapy in Metastatic Pancreatic Cancer: A Nationwide Population-Based Study in Korea.

BACKGROUND/OBJECTIVES: This nationwide population-based study investigated the overall survival (OS) of patients with metastatic pancreatic cancer (mPC) receiving first-line chemotherapy. METHODS: Data from the National Health Insurance Service linked to the Korea Central Cancer Registry were used. Patients with mPC receiving first-line chemotherapy (2012-2019) were included and followed up until 2020. The gemcitabine plus nab-paclitaxel (GnP) and FOLFIRINOX groups were matched according to age, sex, and comorbidities. RESULTS: In total, 8652 patients with mPC were treated with chemotherapy. GnP and FOLFIRINOX have been administered since 2016 and 2017, respectively. The median OS increased annually from 6 months in 2012-2013 to 10 months in 2018-2019. The median OSs in the GnP and FOLFIRINOX groups were significantly longer than those in patients receiving gemcitabine ± erlotinib. A total of 1134 patients from both the GnP and FOLFIRINOX groups were selected using propensity score matching. Before matching, the median OS was longer in the FOLFIRINOX group than in the GnP group (p = 0.0029). After matching, however, there was no significant difference in the median OS between the two groups (11 vs. 11 months, respectively, p = 0.2438). CONCLUSIONS: Patients with mPC receiving chemotherapy have shown improved OS since the introduction of GnP and FOLFIRINOX. After matching, OS did not differ between the GnP and FOLFIRINOX groups.

Effects of Nutrient Manipulation during Peripartum and Suckling Period on Productivity of Hanwoo Cows and Offspring.

This study investigated the effects of nutrient manipulation during the peripartum and suckling periods on the productivity of Hanwoo cows and their offspring. A total of 183 pregnant cows and their 180 offspring were randomly assigned to either a control group, fed a formula feed with 13.5% crude protein (CP) and 70.5% total digestible nutrients (TDN), or a treatment group, fed nutrient-enriched formula feed with 18.0% CP and 72.5% TDN. Offspring were similarly divided and fed either 17.0% CP and 69.5% TDN (control) or 21.5% CP and 72.5% TDN (treatment). Results showed that body weight recovery was higher in the treatment group, although wither height, body length, and body condition scores were similar between groups. The treatment group exhibited increased chest girth, reduced intervals for first return to estrus, and shorter days open compared to the control group. Plasma non-esterified fatty acids, albumin, and progesterone concentrations of Hanwoo cows varied between groups at the 3 months before and after calving. Offspring in the treatment group had higher body weight and average daily gain at birth, three and six months of age, with higher dry matter intake. These findings suggest that nutrient-enriched formula feed positively influences the reproductive efficiency of Hanwoo cows and the growth performance of their offspring.

Role of subcutaneous closed suction drain in the prevention of incisional surgical site infection after loop ileostomy reversal with purse-string skin closure: a retrospective observational study.

BACKGROUND: Surgical site infection (SSI) is not rare after loop ileostomy reversal. This study assessed the effects of a subcutaneous closed suction drain on reducing SSIs after loop ileostomy reversal with purse-string skin closure. METHODS: This retrospective study included 229 patients who underwent loop ileostomy reversal with purse-string closure at the Pusan National University Yangsan Hospital between January 2017 and December 2021. We divided the patients into those with a subcutaneous drain (SD group) and those without it (ND group). We analyzed variables that affected SSI occurrence in both groups. RESULTS: The SD and ND groups included 109 and 120 patients, respectively. The number of incisional SSIs was significantly lower in the SD than in the ND group (0 vs. 7 events). An average of 35.7 mL of fluid was collected in the drainage bulb during hospitalization. The C-reactive protein level on postoperative day 4 was significantly lower in the SD group than in the ND group. The insertion of a subcutaneous drain was the only factor associated with a reduced incidence of SSIs (p = 0.015). CONCLUSIONS: Subcutaneous closed suction drain with purse-string skin closure in loop ileostomy reversal can reduce incisional SSI occurrence.

Glycogen Phosphorylase Inhibitor Promotes Hair Growth via Protecting from Oxidative-Stress and Regulating Glycogen Breakdown in Human Hair follicles.

Hair growth cycles are mainly regulated by human dermal papilla cells (hDPCs) and human outer root sheath cells (hORSCs). Protecting hDPCs from excessive oxidative stress and hORSCs from glycogen phosphorylase (PYGL) is crucial to maintaining the hair growth phase, anagen. In this study, we developed a new PYGL inhibitor, Hydroxytrimethylpyridinyl Methylindolecarboxamide (HTPI) and assessed its potential to prevent hair loss. HTPI reduced oxidative damage, preventing cell death and restored decreased level of anagen marker ALP and its related genes induced by hydrogen peroxide in hDPCs. Moreover, HTPI inhibited glycogen degradation and induced cell survival under glucose starvation in hORSCs. In ex-vivo culture, HTPI significantly enhanced hair growth compared to the control with minoxidil showing comparable results. Overall, these findings suggest that HTPI has significant potential as a therapeutic agent for the prevention and treatment of hair loss.

Characteristics of the epicardial adipose tissue measured by low-dose chest computed tomography according to the metabolic health/obesity status.

BACKGROUND: Epicardial adipose tissue (EAT) is associated with the development of cardiovascular disease and long-term survival. This study aimed to assess the characteristics of EAT according to the metabolic health and obesity status using low-dose chest computed tomography (CT). METHODS: A total of 1074 asymptomatic adults who underwent a medical health check-up were enrolled. Subjects were categorized into the following four groups according to the metabolic health and obesity status: metabolically healthy non-obese (MHNO); metabolically unhealthy non-obese (MUNO); metabolically healthy obese (MHO); and metabolically unhealthy obese (MUO). EAT on low-dose chest CT was measured by using automatic, quantitative measurement software. RESULTS: MUO showed the highest EAT volume and lowest EAT radiodensity in comparison with MHNO (p < 0.001). The MUNO (n = 70), MHO (n = 259), and MUO (n = 231) groups had increased EAT volume (ß [95 % CI], 37.65 [23.11,52.18], 56.79 [47.56,66.02], 84.85 [74.59,95.11] respectively, all p < 0.001), decreased EAT radiodensity (ß [95 % CI], - 3.22 [- 4.59,- 1.85], - 4.48 [- 5.30,- 3.66], - 6.03 [- 6.90,- 5.16] respectively, all p < 0.001) in comparison with the MHNO (n = 514) group by using multivariable linear regression models. CONCLUSIONS: Both metabolic abnormalities and obesity were closely associated with EAT characteristics. Characteristics of EAT are similar in MHO and MUNO. This finding suggests that MHO is not a favorable condition in terms of cardiac health, as assessed by the characteristics of EAT. The combination of obesity and metabolically unhealthy status has a synergistic adverse effect on EAT. Measurement of EAT could be a useful imaging biomarker for evaluation of an individual's metabolic health/obesity status.

The efficacy of adipose stem cell-derived exosomes in hair regeneration based on a preclinical and clinical study.

BACKGROUND: Androgenetic alopecia (AGA) is a prevalent hair loss disorder with psychological repercussions. Traditional treatments have limitations, leading to the exploration of regenerative therapies such as exosomes derived from adipose tissue stem cells (ASC-Exosomes). METHODS: First, using human hair follicle (HF) dermal papilla cells (hDPCs) treated with ASC-Exosomes, ALP, VCAN, ß-catenin, and LEF-1 levels with RT-PCR and p-GSK3ß, GSK3ß, ß-catenin, ALP, and ß-actin levels with western blot analysis were assessed. Hair shaft elongation test and assay for ALP, Ki-67, and ß-catenin were done using human HF organ culture. Patients with AGA had ASC-Exosomes treatment and were evaluated for hair counts, photographic assessments, subjective satisfaction, and safety profiles. RESULTS: ASC-Exosomes impact hDPCs, increasing proliferation and the upregulation of hair growth-related genes, including ALP, VCAN, ß-catenin, and LEF-1. The Wnt/ß-catenin pathway was activated, indicating their role in promoting hair growth. ASC-Exosomes also promoted hair shaft elongation and ALP activity, suggesting a potential for hair regeneration. Thirty participants with AGA enrolled and treated over 24 weeks. The subjects experienced a significant increase in total hair density, improved global photographic assessments, and reported higher subjective satisfaction without severe adverse reactions. CONCLUSION: This research contributes to the growing body of evidence supporting the use of exosomes in hair loss treatment, offering a safe and effective alternative for individuals with AGA.

Public Perception Towards Drug Abuse in South Korea: The Effects of Overconfidence and Affirmation.

OBJECTIVE: The abuse of prescription drugs and over-the-counter medicines has been a major issue addressed as a serious public health problem worldwide. This study explored factors contributing to substance abuse in Korea by examining the status of substance abuse among Korean adults and evaluating their knowledge, attitudes, and intentions toward substance abuse. METHODS: Data were collected online from a sample of participants 19 years old or older from May 20 to June 1, 2020 (n=1,020). The survey consisted of questions on demographics, perceptions of drug risk, motives for drug use, and attitudes toward drug addiction treatment. Principal component and multiple logistic regression analyses were used to explore the factors contributing to the perception of drug abuse. RESULTS: In the multivariate regression analysis, overconfidence in handling drug usage, acceptance of addictive substances, and affirmation of public support for drug abuse were associated with opioid abuse (Nagelkerke R2=0.486), and additionally affirmation of legal cannabis usage and motivation to use diet pills were associated with diet pill abuse (Nagelkerke R2=0.569). CONCLUSION: The findings of this study suggest that the actual situation of substance abuse among Korean adults increases awareness of and attitudes toward drug use related to substance abuse.

PAK4 phosphorylates and inhibits AMPKα to control glucose uptake.

Our recent studies have identified p21-activated kinase 4 (PAK4) as a key regulator of lipid catabolism in the liver and adipose tissue, but its role in glucose homeostasis in skeletal muscle remains to be explored. In this study, we find that PAK4 levels are highly upregulated in the skeletal muscles of diabetic humans and mice. Skeletal muscle-specific Pak4 ablation or administering the PAK4 inhibitor in diet-induced obese mice retains insulin sensitivity, accompanied by AMPK activation and GLUT4 upregulation. We demonstrate that PAK4 promotes insulin resistance by phosphorylating AMPKα2 at Ser491, thereby inhibiting AMPK activity. We additionally show that skeletal muscle-specific expression of a phospho-mimetic mutant AMPKα2S491D impairs glucose tolerance, while the phospho-inactive mutant AMPKα2S491A improves it. In summary, our findings suggest that targeting skeletal muscle PAK4 may offer a therapeutic avenue for type 2 diabetes.

Nonlinear sound-sheet microscopy: imaging opaque organs at the capillary and cellular scale.

Light-sheet fluorescence microscopy has revolutionized biology by visualizing dynamic cellular processes in three dimensions. However, light scattering in thick tissue and photobleaching of fluorescent reporters limit this method to studying thin or translucent specimens. Here we show that non-diffractive ultrasonic beams used in conjunction with a cross-amplitude modulation sequence and nonlinear acoustic reporters enable fast and volumetric imaging of targeted biological functions. We report volumetric imaging of tumor gene expression at the cm 3 scale using genetically encoded gas vesicles, and localization microscopy of currently uncharted cerebral capillary networks using intravascular microbubble contrast agents. Nonlinear sound-sheet microscopy provides a ∼64x acceleration in imaging speed, ∼35x increase in imaged volume and ∼4x increase in classical imaging resolution compared to the state-of-the-art in biomolecular ultrasound.