Rectifying METTL4-Mediated N6-Methyladenine Excess in Mitochondrial DNA Alleviates Heart Failure.

BACKGROUND: Myocardial mitochondrial dysfunction underpins the pathogenesis of heart failure (HF), yet therapeutic options to restore myocardial mitochondrial function are scarce. Epigenetic modifications of mitochondrial DNA (mtDNA), such as methylation, play a pivotal role in modulating mitochondrial homeostasis. However, their involvement in HF remains unclear. METHODS: Experimental HF models were established through continuous angiotensin II and phenylephrine (AngII/PE) infusion or prolonged myocardial ischemia/reperfusion injury. The landscape of N6-methyladenine (6mA) methylation within failing cardiomyocyte mtDNA was characterized using high-resolution mass spectrometry and methylated DNA immunoprecipitation sequencing. A tamoxifen-inducible cardiomyocyte-specific Mettl4 knockout mouse model and adeno-associated virus vectors designed for cardiomyocyte-targeted manipulation of METTL4 (methyltransferase-like protein 4) expression were used to ascertain the role of mtDNA 6mA and its methyltransferase METTL4 in HF. RESULTS: METTL4 was predominantly localized within adult cardiomyocyte mitochondria. 6mA modifications were significantly more abundant in mtDNA than in nuclear DNA. Postnatal cardiomyocyte maturation presented with a reduction in 6mA levels within mtDNA, coinciding with a decrease in METTL4 expression. However, an increase in both mtDNA 6mA level and METTL4 expression was observed in failing adult cardiomyocytes, suggesting a shift toward a neonatal-like state. METTL4 preferentially targeted mtDNA promoter regions, which resulted in interference with transcription initiation complex assembly, mtDNA transcriptional stalling, and ultimately mitochondrial dysfunction. Amplifying cardiomyocyte mtDNA 6mA through METTL4 overexpression led to spontaneous mitochondrial dysfunction and HF phenotypes. The transcription factor p53 was identified as a direct regulator of METTL4 transcription in response to HF-provoking stress, thereby revealing a stress-responsive mechanism that controls METTL4 expression and mtDNA 6mA. Cardiomyocyte-specific deletion of the Mettl4 gene eliminated mtDNA 6mA excess, preserved mitochondrial function, and mitigated the development of HF upon continuous infusion of AngII/PE. In addition, specific silencing of METTL4 in cardiomyocytes restored mitochondrial function and offered therapeutic relief in mice with preexisting HF, irrespective of whether the condition was induced by AngII/PE infusion or myocardial ischemia/reperfusion injury. CONCLUSIONS: Our findings identify a pivotal role of cardiomyocyte mtDNA 6mA and the corresponding methyltransferase, METTL4, in the pathogenesis of mitochondrial dysfunction and HF. Targeted suppression of METTL4 to rectify mtDNA 6mA excess emerges as a promising strategy for developing mitochondria-focused HF interventions.

A Wearable Fluorescence Imaging Device for Intraoperative Identification of Human Brain Tumors.

Malignant glioma (MG) is the most common type of primary malignant brain tumors. Surgical resection of MG remains the cornerstone of therapy and the extent of resection correlates with patient survival. A limiting factor for resection, however, is the difficulty in differentiating the tumor from normal tissue during surgery. Fluorescence imaging is an emerging technique for real-time intraoperative visualization of MGs and their boundaries. However, most clinical grade neurosurgical operative microscopes with fluorescence imaging ability are hampered by low adoption rates due to high cost, limited portability, limited operation flexibility, and lack of skilled professionals with technical knowledge. To overcome the limitations, we innovatively integrated miniaturized light sources, flippable filters, and a recording camera to the surgical eye loupes to generate a wearable fluorescence eye loupe (FLoupe) device for intraoperative imaging of fluorescent MGs. Two FLoupe prototypes were constructed for imaging of Fluorescein and 5-aminolevulinic acid (5-ALA), respectively. The wearable FLoupe devices were tested on tumor-simulating phantoms and patients with MGs. Comparable results were observed against the standard neurosurgical operative microscope (PENTERO® 900) with fluorescence kits. The affordable and wearable FLoupe devices enable visualization of both color and fluorescence images with the same quality as the large and expensive stationary operative microscopes. The wearable FLoupe device allows for a greater range of movement, less obstruction, and faster/easier operation. Thus, it reduces surgery time and is more easily adapted to the surgical environment than unwieldy neurosurgical operative microscopes. Clinical and Translational Impact Statement-The affordable and wearable fluorescence imaging device developed in this study enables neurosurgeons to observe brain tumors with the same clarity and greater flexibility compared to bulky and costly operative microscopes.

Stomatin-like protein 2 promotes cell proliferation and survival under 5-Fluorouracil stress in hepatocellular carcinoma.

BACKGROUND: The crucial role of STOML2 in tumor progression has been documented recently in various cancers. Previous studies have shown that STOML2 promoted cancer cell proliferation, but the underlying mechanism is not fully illustrated. METHODS AND RESULTS: The expression and clinical relevance of STOML2 in pan-cancer was analyzed by TIMER2 web platform in pan-cancer. The prognostic significance of STOML2 in HCC was evaluated utilizing KM curve and a nomogram model. Signaling pathways associated with STOML2 expression were discovered by GSEA. CCK-8 assay was performed to evaluate the proliferative capacity of HCC cells after manipulating STOML2 expression. Flow cytometry was utilized to analyze cell cycle progression. Results indicated that increased STOML2 expression in HCC linked to unfavorable clinical outcomes. Cell cycle and cell division related terms were enriched under conditions of elevated STOML2 expression via GSEA analysis. A notable decrease in cell proliferation was observed in MHCC97H with STOML2 knocked-down, accompanied by G1-phase arrest, up-regulation of p21, down-regulation of CyclinD1 and its regulatory factor MYC, while STOML2 overexpression in Huh7 showed the opposite results. These results indicated that STOML2 was responsible for HCC proliferation by regulating the expression level of MYC/cyclin D1 and p21. Furthermore, an inverse correlation was found between STOML2 expression and 5-FU sensitivity. CONCLUSIONS: STOML2 promotes cell cycle progression in HCC which is associated with activation of MYC/CyclinD1/p21 pathway, and modulates the response of HCC to 5-FU.

Predictive Factors for Seizures after Revascularization in Patients with Moyamoya Disease.

BACKGROUND: Moyamoya disease (MMD) is a rare and complex cerebrovascular disorder that is diagnosed through imaging studies, such as computed tomography or magnetic resonance imagin, which show progressive narrowing of the terminal portion of the internal carotid arteries and the development of compensatory capillary collaterals. The objective of our study was to identify and clarify the predictive factors for seizures in patients with MMD. METHODS: From January 2019 to March 2023, a total of 102 patients with MMD were enrolled in this study. Ten patients with seizures after surgery as the main presentation were included. Patients with epilepsy were compared to those without epilepsy in terms of their clinical characteristics. Multivariable analysis was applied to determine factors linked with postoperative seizures. RESULTS: Ten patients developed seizures after revascularization for MMD. Logistic regression analysis revealed that early seizure (odds ratio [OR], 0.068; 95% CI, 0.014-0.342; P = 0.001), cortical involvement (OR, 9.593; 95% CI, 2.256-40.783; P = 0.002), and postoperative hyperperfusion (OR, 7.417; 95% CI, 1.077-51.093; P = 0.042) were significantly associated with seizures. In a multivariate analysis, it was found that early seizures were significantly associated with a higher likelihood of experiencing seizures (OR, 5.88; 95% CI, 1.01-33.96; P = 0.048), while patients who had seizures were more likely to have cortical involvement (OR, 8.90; 95% CI, 1.55-50.96; P = 0.014) or postoperative hyperperfusion (OR, 12.44; 95% CI, 1.21-127.74; P = 0.034). CONCLUSIONS: Epilepsy in patients with MMD link with several clinical factors. In patients with MMD who undergo bypass surgery, early seizures, cortical involvement, and postoperative hyperperfusion are significant independent predictive factors for the development of epilepsy.

M2 macrophage-derived exosomes carry miR-142-3p to restore the differentiation balance of irradiated BMMSCs by targeting TGF-ß1.

Radiotherapy is essential to cancer treatment, while it inevitably injures surrounding normal tissues, and bone tissue is one of the most common sites prone to irradiation. Bone marrow mesenchymal stem cells (BMMSCs) are sensitive to irradiation and the irradiated dysfunction of BMMSCs may be closely related to irradiation-induced bone damage. Macropahges play important role in regulating stem cell function, bone metabolic balance and irradiation response, but the effects of macrophages on irradiated BMMSCs are still unclear. This study aimed to investigate the role of macrophages and macrophage-derived exosomes in restoring irradiated BMMSCs function. The effects of macrophage conditioned medium (CM) and macrophage-derived exosomes on osteogenic and fibrogenic differentiation capacities of irradiated BMMSCs were detected. The key microribonucleic acids (miRNAs) and targeted proteins in exosomes were also determined. The results showed that irradiation significantly inhibited the proliferation of BMMSCs, and caused differentiation imbalance of BMMSCs, with decreased osteogenic differentiation and increased fibrogenic differentiation. M2 macrophage-derived exosomes (M2D-exos) inhibited the fibrogenic differentiation and promoted the osteogenic differentiation of irradiated BMMSCs. We identified that miR-142-3p was significantly overexpressed in M2D-exos and irradiated BMMSCs treated with M2D-exos. After inhibition of miR-142-3p in M2 macrophage, the effects of M2D-exos on irradiated BMMSCs differentiation were eliminated. Furthermore, transforming growth factor beta 1 (TGF-ß1), as a direct target of miR-142-3p, was significantly decreased in irradiated BMMSCs treated with M2D-exos. This study indicated that M2D-exos could carry miR-142-3p to restore the differentiation balance of irradiated BMMSCs by targeting TGF-ß1. These findings pave a new way for promising and cell-free method to treat irradiation-induced bone damage.

First report on establishment and characterization of the extrahepatic cholangiocarcinoma sarcoma cell line CBC2T-2.

BACKGROUND: Extrahepatic cholangiocarcinoma sarcoma is extremely rare in clinical practice. These cells consist of both epithelial and mesenchymal cells. Patient-derived cell lines that maintain tumor characteristics are valuable tools for studying the molecular mechanisms associated with carcinosarcoma. However, cholangiocarcinoma sarcoma cell lines are not available in cell banks. AIM: To establish and characterize a new extrahepatic cholangiocarcinoma sarcoma cell line, namely CBC2T-2. METHODS: We conducted a short tandem repeat (STR) test to confirm the identity of the CBC2T-2 cell line. Furthermore, we assessed the migratory and invasive properties of the cells and performed clonogenicity assay to evaluate the ability of individual cells to form colonies. The tumorigenic potential of CBC2T-2 cells was tested in vivo using non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice. The cells were injected subcutaneously and tumor formation was observed. In addition, immunohistochemical analysis was carried out to examine the expression of epithelial marker CK19 and mesenchymal marker vimentin in both CBC2T-2 cells and xenografts. The CBC2T-2 cell line was used to screen the potential therapeutic effects of various clinical agents in patients with cholangiocarcinoma sarcoma. Lastly, whole-exome sequencing was performed to identify genetic alterations and screen for somatic mutations in the CBC2T-2 cell line. RESULTS: The STR test showed that there was no cross-contamination and the results were identical to those of the original tissue. The cells showed round or oval-shaped epithelioid cells and mesenchymal cells with spindle-shaped or elongated morphology. The cells exhibited a high proliferation ratio with a doubling time of 47.11 h. This cell line has migratory, invasive, and clonogenic abilities. The chromosomes in the CBC2T-2 cells were polyploidy, with numbers ranging from 69 to 79. The subcutaneous tumorigenic assay confirmed the in vivo tumorigenic ability of CBC2T-2 cells in NOD/SCID mice. CBC2T-2 cells and xenografts were positive for both the epithelial marker, CK19, and the mesenchymal marker, vimentin. These results suggest that CBC2T-2 cells may have both epithelial and mesenchymal characteristics. The cells were also used to screen clinical agents in patients with cholangiocarcinoma sarcoma, and a combination of paclitaxel and gemcitabine was found to be the most effective treatment option. CONCLUSION: We established the first human cholangiocarcinoma sarcoma cell line, CBC2T-2, with stable biogenetic traits. This cell line, as a research model, has a high clinical value and would facilitate the understanding of the pathogenesis of cholangiocarcinoma sarcoma.

Risk factors of Omicron variant associated acute encephalitis/encephalopathy in children.

BACKGROUND: Outbreak of Omicron BA.2 in Taiwan led to an increased number of acute encephalitis/encephalopathy cases in children and several fatal cases drew public attention. In pre-Omicron period, pediatric cases of COVID-19-associated acute encephalitis have been reported and during Omicron epidemic, febrile convulsions, encephalitis were mentioned more frequently. The outcome of patients with neurological complications was worse. However, few studies investigated the risk factors, pathophysiology and prognosis of COVID-19-associated encephalitis/encephalopathy. Here, we describe the presentation of pediatric cases of COVID-19-associated acute encephalitis/encephalopathy and explore the associated risk factors. METHODS: Pediatric patients with confirmed SARS-CoV-2 infections were prospectively enrolled at admission at Chang Gung Memorial Hospital between April and August 2022. Patients were categorized into groups of acute encephalitis/encephalopathy, febrile convulsions or mild disease. Demographic descriptions, clinical manifestations and laboratory data were collected. RESULTS: Of 288 acute COVID-19 patients, there were 38 (13.2%) acute encephalitis/encephalopathy, 40 (13.9%) febrile convulsions, and 210 (72.9%) mild disease. Among acute encephalitis/encephalopathy group, the mean age was 68.3 ± 45.0 months. The common neurological symptoms were lethargy (65.8%), seizures (52.6%), and impaired consciousness (34.2%). Over 3 years old (adjusted odds ratio [aOR]: 7.57, p < 0.001), absolute neutrophil count ≥3150/µL (aOR: 5.46, p = 0.008), and procalcitonin ≥0.5 ng/mL (aOR: 4.32, p = 0.021) were independent factors for acute encephalitis/encephalopathy. CONCLUSIONS: Most cases of COVID-19-associated acute encephalitis/encephalopathy showed no evidence of direct viral invasion but associations with older age, increased peripheral neutrophil, and serum procalcitonin. These findings may imply the neutrophil-mediated systemic inflammatory response plays an important role on central nerve system, leading to cerebral dysfunction.

Geochemical behaviors of uranium and thorium during weathering and pedogenesis of carbonate rock: constraint from their speciation.

During weathering and pedogenesis of carbonate rock with poor-uranium (U) and thorium (Th), U and Th present the characteristics of strong leaching (especially U) and significant residual enrichment, the cause of which is still unclear. In this paper, a weathering profile developed by dolomite in karst area of Guizhou province in southwest China was selected, which showed zonation characteristics of bedrock (Y), powdery rock (Yf), and soil layer (T1 to T12) from the bottom to up. Through the determination of the occurrence speciation of U and Th in Y and weathering profile, combined with mineralogical, geochemical characteristics, and element mass balance calculation, the constraints of U and Th speciation on the geochemical behavior of U and Th during the weathering of carbonate rock were revealed. The results proved that U and Th in Y preferentially existed in acid insoluble phase, for example, the contents of U and Th in Y were 0.90 mg·kg-1 and 0.28 mg·kg-1, respectively, while those in acid insoluble matter were 2.34 mg·kg-1 and 2.57 mg·kg-1, respectively, but because the mass percentage of acid insoluble matter was extremely low (0.95%), the mass percentages of U and Th in the acid soluble phase in the whole rock were absolutely superior (96% of U and 86% Th). The U and Th in the acid soluble phase of Y were mainly adsorbed on the crystal surface of carbonate minerals or existed in the cement, and the U and Th in the carbonate lattice only accounted for a small proportion. From Y to Yf with the initial dissolution, U and Th released from the surface of carbonate minerals and cements were in carbonate-rich alkaline environment, and these portions of U and Th were leached out, resulting in strong loss of U and Th in the Yf (the loss rates are 83% of U and 65% of Th, respectively). From the Yf to the overlying soil layer T1, the carbonate components were completely dissolved, and the U and Th released from the carbonate lattice showed different behaviors, where U was completely leached and Th tended to stay in the weathered residue. Thus, in the soil layer T1 formed by Y or Yf , the residual U was the inheritance of the U in the acid insoluble phase of Y; For Th, it not only inherited the Th of acid insoluble phase of Y, but also superimposed the Th from carbonate lattice in Y. On the other hand, during the evolution process from Y to Yf and to soil layer T1, with the dissolution of carbonate, the acid insoluble phase also showed a significant tendency of chemical weathering. However, the U and Th in the Y acid insoluble phase were not leached with the decomposition of the acid insoluble phase but were redistributed among the residual phases. For the geochemical behaviors of U and Th in the evolution of soil profile (T1~T12), they were subjected to the occurrence speciation of U and Th in T1 and the change of U and Th occurrence speciation with the upward direction of soil profile. The U and Th released from the carrier minerals were mainly redistributed among the residual solid phases, which weakened the intensity of their further loss. This study deepens the understanding of the geochemical behavior of radionuclides in karst environment and provides reference for the treatment of radioactive pollution in karst areas.

Development and validation of a mutation-annotated prognostic score for intrahepatic cholangiocarcinoma after resection: a retrospective cohort study.

BACKGROUND: The value of existing prognostic models for intrahepatic cholangiocarcinoma is limited. The inclusion of prognostic gene mutations would enhance the predictive efficacy. METHODS: In the screening cohorts, univariable Cox regression analysis was applied to investigate the effect of individual mutant genes on overall survival (OS). In the training set, multivariable analysis was performed to evaluate the independent prognostic roles of the clinicopathological and mutational parameters, and a prognostic model was constructed. Internal and external validations were conducted to evaluate the performance of this model. RESULTS: Among the recurrent mutations, only TP53 and KRASG12 were significantly associated with OS across all three screening cohorts. In the training cohort, TP53 and KRASG12 mutations in combination with seven other clinical parameters (tumor size, tumor number, vascular invasion, lymph node metastasis, adjacent invasion, CA19-9, and CEA), were independent prognostic factors for OS. A mutation-annotated prognostic score (MAPS) was established based on the nine prognosticators. The C-indices of MAPS (0.782 and 0.731 in the internal and external validation cohorts, respectively) were statistically higher than those of other existing models ( P <0.05). Furthermore, the MAPS model also demonstrated significant value in predicting the possible benefits of upfront surgery and adjuvant therapy. CONCLUSIONS: The MAPS model demonstrated good performance in predicting the OS of intrahepatic cholangiocarcinoma patients. It may also help predict the possible benefits of upfront surgery and adjuvant therapy.

Lanatoside C decelerates proliferation and induces apoptosis through inhibition of STAT3 and ROS-mediated mitochondrial membrane potential transformation in cholangiocarcinoma.

Introduction: The incidence of cholangiocarcinoma (CCA) has increased worldwide in recent years. Given the poor prognosis associated with the current management approach of CCA, new therapeutic agents are warranted to improve the prognosis of this patient population. Methods: In this study, we extracted five cardiac glycosides (CGs) from natural plants: digoxin, lanatoside A, lanatoside C, lanatoside B, and gitoxin. Follow-up experiments were performed to assess the effect of these five extracts on cholangiocarcinoma cells and compounds with the best efficacy were selected. Lanatoside C (Lan C) was selected as the most potent natural extract for subsequent experiments. We explored the potential mechanism underlying the anticancer activity of Lan C on cholangiocarcinoma cells by flow cytometry, western blot, immunofluorescence, transcriptomics sequencing, network pharmacology and in vivo experiments. Results: We found that Lan C time-dependently inhibited the growth and induced apoptosis of HuCCT-1 and TFK-1 cholangiocarcinoma cells. Besides Lan C increased the reactive oxygen species (ROS) content in cholangiocarcinoma cells, decreased the mitochondrial membrane potential (MMP) and resulted in apoptosis. Besides, Lan C downregulated the protein expression of STAT3, leading to decreased expression of Bcl-2 and Bcl-xl, increased expression of Bax, activation of caspase-3, and initiation of apoptosis. N-acetyl-L-cysteine (NAC) pretreatment reversed the effect of Lan C. In vivo, we found that Lan C inhibited the growth of cholangiocarcinoma xenografts without toxic effects on normal cells. Tumor immunohistochemistry showed that nude mice transplanted with human cholangiocarcinoma cells treated with Lan C exhibited decreased STAT3 expression and increased caspase-9 and caspase-3 expression in tumors, consistent with the in vitro results. Conclusion: In summary, our results substantiates that cardiac glycosides have strong anti-CCA effects. Interestingly the biological activity of Lan C provides a new anticancer candidate for the treatment of cholangiocarcinoma.

Novel biomarkers identifying hypertrophic cardiomyopathy and its obstructive variant based on targeted amino acid metabolomics.

BACKGROUND: Hypertrophic cardiomyopathy (HCM) is an underdiagnosed genetic heart disease worldwide. The management and prognosis of obstructive HCM (HOCM) and non-obstructive HCM (HNCM) are quite different, but it also remains challenging to discriminate these two subtypes. HCM is characterized by dysmetabolism, and myocardial amino acid (AA) metabolism is robustly changed. The present study aimed to delineate plasma AA and derivatives profiles, and identify potential biomarkers for HCM. METHODS: Plasma samples from 166 participants, including 57 cases of HOCM, 52 cases of HNCM, and 57 normal controls (NCs), who first visited the International Cooperation Center for HCM, Xijing Hospital between December 2019 and September 2020, were collected and analyzed by high-performance liquid chromatography-mass spectrometry based on targeted AA metabolomics. Three separate classification algorithms, including random forest, support vector machine, and logistic regression, were applied for the identification of specific AA and derivatives compositions for HCM and the development of screening models to discriminate HCM from NC as well as HOCM from HNCM. RESULTS: The univariate analysis showed that the serine, glycine, proline, citrulline, glutamine, cystine, creatinine, cysteine, choline, and aminoadipic acid levels in the HCM group were significantly different from those in the NC group. Four AAs and derivatives (Panel A; proline, glycine, cysteine, and choline) were screened out by multiple feature selection algorithms for discriminating HCM patients from NCs. The receiver operating characteristic (ROC) analysis in Panel A yielded an area under the ROC curve (AUC) of 0.83 (0.75-0.91) in the training set and 0.79 (0.65-0.94) in the validation set. Moreover, among 10 AAs and derivatives (arginine, phenylalanine, tyrosine, proline, alanine, asparagine, creatine, tryptophan, ornithine, and choline) with statistical significance between HOCM and HNCM, 3 AAs (Panel B; arginine, proline, and ornithine) were selected to differentiate the two subgroups. The AUC values in the training and validation sets for Panel B were 0.83 (0.74-0.93) and 0.82 (0.66-0.98), respectively. CONCLUSIONS: The plasma AA and derivatives profiles were distinct between the HCM and NC groups. Based on the differential profiles, the two established screening models have potential value in assisting HCM screening and identifying whether it is obstructive.

Sex differences in hepatocellular carcinoma indicated BEX4 as a potential target to improve efficacy of lenvatinib plus immune checkpoint inhibitors.

Background: Hepatocellular carcinoma (HCC) is the most common form of liver cancer, and significant sex disparities have been observed in HCC. We aim to explore the potential sex-biased mechanisms involved in hepatocarcinogenesis. Methods: Based on TCGA data, we compared clinical features, genetic alterations, and immune cell infiltrations between male and female HCC patients. In addition, we performed sex-based differential expression analysis and functional enrichment analysis. Finally, GSE64041 dataset and another HCC cohort were engaged to validate our findings. Results: Significant differences of genetic alterations and TME were observed between male and female HCC patients. Enhanced metabolism of lipids was associated with hepatocarcinogenesis in men, while ECM-organization-related pathways were correlated to HCC development in women. BEX4 was upregulated in female but downregulated in male HCC patients, and was positively correlated with immune checkpoint molecules and infiltrated immune cell. These findings were further validated in dataset GSE64041 and our HCC cohort. More importantly, a negative correlation was found between BEX4 expression and lenvatinib sensitivity. Conclusion: Distinct biological processes were involved in sex-biased tumorigenesis of HCC. BEX4 can be targeted to improve the efficacy of lenvatinib plus immune checkpoint inhibitors.

Intraoperative Optical and Fluorescence Imaging of Blood Flow Distributions in Mastectomy Skin Flaps for Identifying Ischemic Tissues.

SUMMARY: Insufficient blood flow causes mastectomy skin flap necrosis in 5 to 30 percent of cases. Fluorescence angiography with the injection of indocyanine green dye has shown high sensitivities (90 to 100 percent) but moderate specificities (72 to 50 percent) in predicting mastectomy skin flap necrosis. However, a number of challenging issues limit its wide acceptance in clinical settings, including allergic reaction, short time-window for observation, and high cost for equipment and supplies. An emerging inexpensive speckle contrast diffuse correlation tomography technology enables noninvasive, noncontact, and continuous three-dimensional imaging of blood flow distributions in deep tissues. This preliminary study tested the hypothesis that speckle contrast diffuse correlation tomography and indocyanine green-fluorescence angiography measurements of blood flow distributions in mastectomy skin flaps are consistent. Eleven female patients undergoing skin-sparing or nipple-sparing mastectomies were imaged sequentially by the dye-free speckle contrast diffuse correlation tomography and dye-based commercial fluorescence angiography (SPY-PHI). Resulting images from these two imaging modalities were co-registered based on the ischemic areas with the lowest blood flow values. Because the ischemic areas have irregular shapes, a novel contour-based algorithm was used to compare three-dimensional images of blood flow distribution and two-dimensional maps of indocyanine green perfusion. Significant correlations were observed between the two measurements in all contours from a selected area of 10 × 10 mm 2 with the lowest blood flow ( r ≥ 0.78; p < 0.004), suggesting that speckle contrast diffuse correlation tomography provides the information for identifying ischemic tissues in mastectomy skin flaps. With further optimization and validation in large populations, speckle contrast diffuse correlation tomography may ultimately be used as a noninvasive and inexpensive imaging tool for intraoperative assessment of skin flap viability to predict mastectomy skin flap necrosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, II.

Isolation and Culture of Bone Marrow Mesenchymal Stem Cells from the Human Mandible.

Human mesenchymal stem cells (hMSCs) have shown great potential in bone regeneration, immune modulation, and treating refractory chronic diseases. Various origins have been found to obtain hMSCs recently, while bone marrow was still considered the main source. Bone marrow-derived MSCs (BMSCs) from different donor bone sites have distinct characteristics due to microenvironmental factors. Studies have shown that BMSCs from maxillofacial bone may have greater proliferative and osteogenic capacities than BMSCs from long bones or the iliac crest. And maxillofacial BMSCs were considered more suitable for stem cell therapy in the maxillofacial tissues. The mandible, especially the ascending ramal area with sufficient marrow, was a feasible donor site for harvesting BMSCs. This study described a protocol for harvesting, isolating, and culturing human mandibular bone marrow-derived MSCs (hmBMSCs). Furthermore, immunophenotyping of hmBMSCs, proliferation assays, and in vitro induction of osteogenic, adipogenic, and chondrogenic differentiation was performed to identify the cultured cells. Applying this protocol can help the researchers successfully obtain enough high-quality hmBMSCs, which is necessary for further studies of the biological function, microenvironmental effects, and clinical applications.

Small Extracellular Vesicles From Brown Adipose Tissue Mediate Exercise Cardioprotection.

RATIONALE: Long-term exercise provides reliable cardioprotection via mechanisms still incompletely understood. Although traditionally considered a thermogenic tissue, brown adipose tissue (BAT) communicates with remote organs (eg, the heart) through its endocrine function. BAT expands in response to exercise, but its involvement in exercise cardioprotection remains undefined. OBJECTIVE: This study investigated whether small extracellular vesicles (sEVs) secreted by BAT and their contained microRNAs (miRNAs) regulate cardiomyocyte survival and participate in exercise cardioprotection in the context of myocardial ischemia/reperfusion (MI/R) injury. METHODS AND RESULTS: Four weeks of exercise resulted in a significant BAT expansion in mice. Surgical BAT ablation before MI/R weakened the salutary effects of exercise. Adeno-associated virus 9 vectors carrying short hairpin RNA targeting Rab27a (a GTPase required for sEV secretion) or control viruses were injected in situ into the interscapular BAT. Exercise-mediated protection against MI/R injury was greatly attenuated in mice whose BAT sEV secretion was suppressed by Rab27a silencing. Intramyocardial injection of the BAT sEVs ameliorated MI/R injury, revealing the cardioprotective potential of BAT sEVs. Discovery-driven experiments identified miR-125b-5p, miR-128-3p, and miR-30d-5p (referred to as the BAT miRNAs) as essential BAT sEV components for mediating cardioprotection. BAT-specific inhibition of the BAT miRNAs prevented their upregulation in plasma sEVs and hearts of exercised mice and attenuated exercise cardioprotection. Mechanistically, the BAT miRNAs cooperatively suppressed the proapoptotic MAPK (mitogen-associated protein kinase) pathway by targeting a series of molecules (eg, Map3k5, Map2k7, and Map2k4) in the signaling cascade. Delivery of BAT sEVs into hearts or cardiomyocytes suppressed MI/R-related MAPK pathway activation, an effect that disappeared with the combined use of the BAT miRNA inhibitors. CONCLUSIONS: The sEVs secreted by BAT participate in exercise cardioprotection via delivering the cardioprotective miRNAs into the heart. These results provide novel insights into the mechanisms underlying the BAT-cardiomyocyte interaction and highlight BAT sEVs and their contained miRNAs as alternative candidates for exercise cardioprotection.

Discovery of 3,4-Dihydrobenzo[f][1,4]oxazepin-5(2H)-one Derivatives as a New Class of Selective TNIK Inhibitors and Evaluation of Their Anti-Colorectal Cancer Effects.

The Traf2- and Nck-interacting protein kinase (TNIK) is a downstream signal protein of the Wnt/ß-catenin pathway and has been thought of as a potential target for the treatment of colorectal cancer (CRC) that is often associated with dysregulation of Wnt/ß-catenin signaling pathway. Herein, we report the discovery of a series of 3,4-dihydrobenzo[f][1,4]oxazepin-5(2H)-one derivatives as a new class of TNIK inhibitors. Structure-activity relationship (SAR) analyses led to the identification of a number of potent TNIK inhibitors with compound 21k being the most active one (IC50: 0.026 ± 0.008 µM). This compound also displayed excellent selectivity for TNIK against 406 other kinases. Compound 21k could efficiently suppress CRC cell proliferation and migration in in vitro assays and exhibited considerable antitumor activity in the HCT116 xenograft mouse model. It also showed favorable pharmacokinetic properties. Overall, 21k could be a promising lead compound for drug discovery targeting TNIK and deserves further studies.

Gradient Microstructure Design in Stainless Steel: A Strategy for Uniting Strength-Ductility Synergy and Corrosion Resistance.

Martensite transformation and grain refinement can make austenitic stainless steel stronger, but this comes at a dramatic loss of both ductility and corrosion resistance. Here we report a novel gradient structure in 301 stainless steel sheets, which enables an unprecedented combination of high strength, improved ductility and good corrosion resistance. After producing inter-layer microstructure gradient by surface mechanical attrition treatment, the sheet was annealed at high temperature for a short duration, during which partial reverse transformation occurred to form recrystallized austenitic nano-grains in the surface layer, i.e., introducing extra intra-layer heterogeneity. Such 3D microstructure heterogeneity activates inter-layer and inter-phase interactions during deformation, thereby producing back stress for high yield strength and hetero-deformation induced (HDI) hardening for high ductility. Importantly, the recrystallized austenitic nano-grains significantly ameliorates the corrosion resistance. These findings suggest an effective route for evading the strength-ductility and strength-corrosion tradeoffs in stainless steels simultaneously.

Integrated bioinformatics analysis revealed the regulation of angiogenesis by tumor cells in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer mortality, metastasis accounts for most of the cases. Angiogenesis plays an important role in cancer metastasis, but how tumor cells affect the function of endothelial cells by dictating their microRNA (miRNA) expression remains largely unknown. Differentially expressed miRNAs (DEMs) were identified through dataset downloaded from the Gene Expression Omnibus (GEO) database and analyzed by GEO2R. We then used online tools to obtain potential targets of candidate miRNAs and functional enrichment analysis, as well as the protein-protein interaction (PPI). Finally, the function of miR-302c-3p was validated through in vitro assay. In the current study, we found that HCC cells altered miRNA expression profiles of human umbilical vein endothelial cells (HUVECs) and miR-302c-3p was the most down-regulated miRNA in HUVECs when they were co-cultured with HCC-LM3 cells. Functional enrichment analysis of the candidate targets revealed that these genes were involved in epigenetic regulation of gene expression, in particular, cytosine methylation. In addition, PPI network demonstrated distinct roles of genes targeted by miR-302c-3p. Importantly, inhibition of angiogenesis, migration and permeability by the most down-regulated miR-302c-3p in HUVECs was confirmed in vitro. These findings brought us novel insight into the regulation of angiogenesis by HCC cells and provided potential targets for the development of therapeutic strategies.

Integration of Metabolomics and Transcriptomicsto Comprehensively Evaluate the Metabolic Effects of Gelsemium elegans on Pigs.

Some naturalphytogenic feed additives, which contain several active compounds, have been shown to be effective alternatives to traditional antibiotics. Gelsemium elegans (G. elegans) is a whole grass in the family Loganiaceae. It is a known toxic plant widely distributed in China and has been used as a traditional Chinese herbal medicine for many years to treat neuropathic pain, rheumatoid pain, inflammation, skin ulcers, and cancer. However, G. elegans not only is nontoxic to animals such as pigs and sheep but also has an obvious growth-promoting effect. To our knowledge, the internal mechanism of the influence of G. elegans on the animal body is still unclear. The goal of this work is to evaluate the metabolic consequences of feeding piglets G. elegans for 45 days based on the combination of transcriptomics and metabolomics. According to growth measurement and evaluation, compared with piglets fed a complete diet, adding 20 g/kg G. elegans powder to the basal diet of piglets significantly reduced the feed conversion ratio. Results of the liver transcriptome suggest that glycine and cysteine-related regulatory pathways, including the MAPK signaling pathway and the mTOR signaling pathway, were extensively altered in G. elegans-induced piglets. Plasma metabolomics identified 21 and 18 differential metabolites (p < 0.05) in the plasma of piglets in the positive and negative ion modes, respectively, between G. elegans exposure and complete diet groups. The concentrations of glycine and its derivatives and N-acetylcysteine were higher in the G. elegans exposure group than in the complete diet group.This study demonstrated that G. elegans could be an alternative to antibiotics that improves the immune function of piglets, and the latent mechanism of G. elegans may be related to various signaling pathways, including the MAPK signaling pathway and the PPAR signaling pathway.