Corosolic acid attenuates cardiac ischemia/reperfusion injury through the PHB2/PINK1/parkin/mitophagy pathway.

Despite advances in treatment, myocardial infarction remains the leading cause of heart failure and death worldwide, and the restoration of coronary blood flow can also cause heart damage. In this study, we found that corosolic acid (CA), also known as plant insulin, significantly protects the heart from ischemia-reperfusion (I/R) injury. In addition, CA can inhibit oxidative stress and improve mitochondrial structure and function in cardiomyocytes. Subsequently, our study demonstrated that CA improved the expression of the mitophagy-related proteins Prohibitin 2 (PHB2), PTEN-induced putative kinase protein-1 (PINK1), and Parkin. Meanwhile, through molecular docking, we found an excellent binding between CA and PHB2 protein. Finally, the knockdown of PHB2 eliminated the protective effect of CA on hypoxia-reoxygenation in cardiomyocytes. Taken together, our study reveals that CA increases mitophagy in cardiomyocytes via the PHB2/PINK1/Parkin signaling pathway, inhibits oxidative stress response, and maintains mitochondrial function, thereby improving cardiac function after I/R.

The genome of African manatee Trichechus senegalensis reveals secondary adaptation to the aquatic environment.

Sirenians exhibit unique aquatic adaptations, showcasing both convergent adaptive features shared with cetaceans and unique characteristics such as cold sensitivity and dense bones. Here, we report a chromosome-level genome of the African manatee (Trichechus senegalensis) with high continuity, completeness, and accuracy. We found that genes associated with osteopetrosis have undergone positive selection (CSF1R and LRRK1) or pseudogenized (FAM111A and IGSF23) in the African manatee, potentially contributing to the dense bone formation. The loss of KCNK18 may have increased their sensitivity to cold water temperatures. Moreover, we identified convergent evolutionary signatures in 392 genes among fully aquatic mammals, primarily enriched in skin or skeletal system development and circadian rhythm, which contributed to the transition from terrestrial to fully aquatic lifestyles. The African manatee currently possesses a small effective population size and low genome-wide heterozygosity. Overall, our study provides genetic resources for understanding the evolutionary characteristics and conservation efforts of this species.

TC-14, a cathelicidin-derived antimicrobial peptide with broad-spectrum antibacterial activity and high safety profile.

Cathelicidins, a major class of antimicrobial peptides (AMPs), hold considerable potential for antimicrobial drug development. In the present study, we identified a novel cathelicidin AMP (TC-33) derived from the Chinese tree shrew. Despite TC-33 demonstrating weak antimicrobial activity, the novel peptide TC-14, developed based on its active region, exhibited a 432-fold increase in antimicrobial activity over the parent peptide. Structural analysis revealed that TC-14 adopted an amphipathic α-helical conformation. The bactericidal mechanism of TC-14 involved targeting and disrupting the bacterial membrane, leading to rapid membrane permeabilization and rupture. Furthermore, TC-14 exhibited a high-safety profile, as evidenced by the absence of cytotoxic and hemolytic activities, as well as high biocompatibility and safety in vivo. Of note, its potent antimicrobial activity provided significant protection in a murine model of skin infection. Overall, this study presents TC-14 as a promising drug candidate for antimicrobial drug development.

Neurobiology and Treatment of Posttraumatic Stress Disorder.

The recent worldwide surge of warfare and hostilities exposes increasingly large numbers of individuals to traumatic events, placing them at risk of developing posttraumatic stress disorder (PTSD) and challenging both clinicians and service delivery systems. This overview summarizes and updates the core knowledge of the genetic, molecular, and neural circuit features of the neurobiology of PTSD and advances in evidence-based psychotherapy, pharmacotherapy, neuromodulation, and digital treatments. While the complexity of the neurobiology and the biological and clinical heterogeneity of PTSD have challenged clinicians and researchers, there is an emerging consensus concerning the underlying mechanisms and approaches to diagnosis, treatment, and prevention of PTSD. This update addresses PTSD diagnosis, prevalence, course, risk factors, neurobiological mechanisms, current standard of care, and innovations in next-generation treatment and prevention strategies. It provides a comprehensive summary and concludes with areas of research for integrating advances in the neurobiology of the disorder with novel treatment and prevention targets.

PATHOPHYSIOLOGY OF POSTTRAUMATIC ANKLE OSTEOARTHRITIS: A MULTICENTER PERSPECTIVE.

Besides the acute injury and trauma-induced macroscopic alterations, the evolution to posttraumatic ankle osteoarthritis (PTOA) is a complex process progressing at the tissue and molecular level. Furthermore, changes in the molecular pathways affect chondrocyte viability. Treatment modalities for PTOA focal or confined disease include innovative techniques. OBJECTIVE: Our purpose is to increase medical awareness based on scientific evidence of pathophysiology, molecular biology, and treatment of post-traumatic ankle osteoarthritis. METHODS: To support the perspectives of the experts, evidence from the scientific literature respected the PRISMA guidelines and the PICOS search strategy was used. We included case-control, cohort, experimental studies and case reports, written in English. RESULTS: The authors were homogeneously exposed to 282 selected abstracts and 114 full articles directly related to post-traumatic osteoarthritis after malleolar fractures. CONCLUSION: The pathophysiological factors involved in posttraumatic ankle osteoarthritis, such as biological, structural, mechanical, and molecular changes must be studied together, as the interaction between these factors determines the risk of progression of PTOA. Inhibition of a single catabolic molecule or cascade probably is not sufficient to alter the natural progression of the pathological process. Evidence level V, expert opinion.

A evolução para a osteoartrite pós-traumática do tornozelo (PTOA) a partir da lesão aguda e das alterações macroscópicas induzidas pelo trauma é um processo complexo, que progride em nível tecidual e molecular. Além disso, as alterações nas vias moleculares afetam a viabilidade dos condrócitos. As modalidades focais ou confinadas de tratamento para PTOA incluem técnicas inovadoras. Objetivo: Nosso objetivo é aumentar a conscientização médica, com base em evidências científicas de fisiopatologia, biologia molecular e tratamento da osteoartrite pós-traumática do tornozelo. Métodos: Para o embasamento das perspectivas dos autores experts, as evidências da literatura científica respeitaram as diretrizes Prisma e a estratégia de busca Picos foi empregada. Incluímos estudos de caso-controle, de coorte, experimentais e relatos de caso, escritos em inglês. Resultados: Os autores foram expostos de forma homogênea a 282 resumos e 114 artigos completos, diretamente relacionados à osteoartrite pós-traumática após fraturas maleolares. Conclusão: Os fatores fisiopatológicos envolvidos na osteoartrite pós-traumática do tornozelo, como alterações biológicas, estruturais, mecânicas e moleculares, devem ser estudados em conjunto, pois a interação entre esses fatores determina o risco de progressão da PTOA. A inibição de uma única molécula catabólica ou cascata provavelmente não é suficiente para alterar a progressão natural do processo patológico. Nível de evidência V, opinião do especialista.

TSPAN4 influences glioblastoma progression through regulating EGFR stability.

Glioblastoma (GBM) is characterized by high morbidity, mortality, and low cure rates. Recent studies suggest that TSPAN4 is recognized as a marker protein for migrasomes, a vesicular organelle associated with cell migration. However, the intrinsic role of TSPAN4 in cancers has not been clarified, especially in GBM. Here, we report that TSPAN4 promotes GBM progression by interacting with epidermal growth factor receptor (EGFR) and regulating its stability. Clinically, TSPAN4 is highly expressed in GBM and is significantly correlated with poor prognosis. Functionally, TSPAN4 knockdown dramatically inhibits GBM cell proliferation and invasion in vitro, as well as tumorigenicity in vivo. Conversely, overexpression of TSPAN4 facilitates GBM progression. Mechanistically, TSPAN4 knockdown disrupts interaction with EGFR, destabilizing its expression and inactivating EGFR and downstream signaling pathways, such as MEK/ERK, STAT3, and AKT. Our study reveals that TSPAN4 drives GBM progression through regulating EGFR stability and could be a potential target for cancer therapy.

Integrity assay for messenger RNA in mouse and human brain samples and synaptosomal preparations.

Traditionally, RNA integrity evaluation is based on ribosomal RNAs (rRNAs). Nevertheless, gene expression studies are usually focused on protein-coding messenger RNAs (mRNAs). Here, we present an RT-qPCR-based assay, which estimates mRNA integrity by comparing the abundance of 3' and 5' mRNA fragments. The assay was validated using plasmids with cloned 3'- and 5'-ends of the cDNA reflecting different ratios of 3' and 5' cDNA amplicons in partially degraded RNA samples. The accuracy of integrity value was ensured by including primer efficiency. We used 5':3' assay to quantify RNA degradation in heat- and enzyme-degraded mouse and human brain tissue RNA as well as in clinical human brain RNA samples. In addition, the 5':3' assay was suitable for assessing mRNA integrity in synaptosomal preparations that lack rRNAs. We concluded that the 5':3' assay can be used as a reliable method to evaluate mRNA integrity in tissue and subcellular preparations.

Decoding human bone marrow hematopoietic stem and progenitor cells from fetal to birth.

Bone marrow (BM) is the dominant site of hematopoiesis after 20 post-conception weeks (PCWs), but the intricacies of hematopoietic development in fetal BM up to birth and its involvement in malignancies remain unknown. Here, we compared the single-cell transcriptomic profile of BM hematopoietic stem and progenitor cells (HSPCs) at the early (12-14 PCW), middle (19-22 PCW) second trimester, and the neonatal stage. The stemness of hematopoietic stem cell and multipotent progenitor (HSC/MPP) is established at the middle second trimester, then maintained until birth. Furthermore, differentiation potentials toward three lineages are enhanced after the middle second trimester for birth, accompanied by the upregulation of aerobic metabolism. Notably, decreased stemness in HSCs/MPPs and higher interferon signals in progenitors at the early second trimester rendered the HSPCs more proximal to leukemogenesis. Collectively, our work elucidated the dynamics of fetal hematopoiesis in preparation for birth, offering valuable insights into the pathological processes underlying leukemia.

Structural insights into transcription activation of the Streptomyces antibiotic regulatory protein, AfsR.

The Streptomyces antibiotic regulatory proteins (SARPs) are ubiquitously distributed transcription activators in Streptomyces and control antibiotics biosynthesis and morphological differentiation. However, the molecular mechanism behind SARP-dependent transcription initiation remains elusive. We here solve the cryo-EM structure of an AfsR-loading RNA polymerase (RNAP)-promoter intermediate complex (AfsR-RPi) including the Streptomyces coelicolor RNAP, a large SARP member AfsR, and its target promoter DNA that retains the upstream portion straight. The structure reveals that one dimeric N-terminal AfsR-SARP domain (AfsR-SARP) specifically engages with the same face of the AfsR-binding sites by the conserved DNA-binding domains (DBDs), replacing σHrdBR4 to bind the suboptimal -35 element, and shortens the spacer between the -10 and -35 elements. Notably, the AfsR-SARPs also recruit RNAP through extensively interacting with its conserved domains (ß flap, σHrdBR4, and αCTD). Thus, these macromolecular snapshots support a general model and provide valuable clues for SARP-dependent transcription activation in Streptomyces.

Focal adhesion-mediated directional cell migration guided by gradient-stretched substrate.

Soft tissues experience strain under mechanical stresses, storing energy as residual stresses and strain energy. However, the specific impact of such strain on cell migration and its molecular mechanisms remains unclear. In this study, we investigated this by using polydimethylsiloxane (PDMS) membranes with varying prestrain levels but constant stiffness to mimic tissue-like conditions. Results showed that higher prestrain levels enhanced 3T3 fibroblast adhesion and reduced filopodia formation. Elevated prestrain also increased integrin and vinculin expression, which was associated with lower cell migration rates. Notably, both 3T3 fibroblasts and primary rat airway smooth muscle cells migrated faster toward higher prestrain areas on substrates with strain gradients. Knockdown of integrin or vinculin inhibited 3T3 cell migration directionality, highlighting their critical role. This research reveals a mechanobiological pathway where strain gradients direct cell migration, providing insight into a common mechanotransduction pathway influencing cellular responses to both stiffness and strain-related mechanical cues.

Astragalus polysaccharides sensitize ovarian cancer stem cells to PARPi by inhibiting mitophagy via PINK1/Parkin signaling.

Ovarian cancer (OC) remains the most lethal gynecological malignant tumor. PARP inhibitors (PARPi) have significantly improved survival, particularly in patients with OC with BRCA1/2 mutations. However, the majority of patients eventually develop resistance to PARPi. Cancer stem cells (CSCs) are considered the source of drug resistance in cancer. Our study found that the synergistic effect of astragalus polysaccharides (APSs) and PARPi was observed in ovarian cancer stem cells (OCSCs) by decreasing cell viability and self-renewal potential while inducing apoptosis. The present study also demonstrated that OCSCs had increased mitophagy. Furthermore, it was observed that APS in combination with PARPi inhibits mitophagy and downregulates the PINK1 protein level in OCSCs. The overexpression of PINK1 via the pEGFP(+)-PINK1 plasmid resulted in a partial reversal of the increased susceptibility of OCSCs when PARPi were administrated concurrently with APS. In conclusion, APS increases OCSC sensitivity to PARPi by inhibiting mitophagy via the PINK1/Parkin pathway regulation.

SPI1-KLF1/LYL1 axis regulates lineage commitment during endothelial-to-hematopoietic transition from human pluripotent stem cells.

PU.1 (SPI1) is pivotal in hematopoiesis, yet its role in human endothelial-to-hematopoietic transition (EHT) remains unclear. Comparing human in vivo and in vitro EHT transcriptomes revealed SPI1's regulatory role. Knocking down SPI1 during in vitro EHT led to a decrease in the generation of hematopoietic progenitor cells (HPCs) and their differentiation potential. Through multi-omic analysis, we identified KLF1 and LYL1 - transcription factors specific to erythroid/myeloid and lymphoid cells, respectively - as downstream targets of SPI1. Overexpressing KLF1 or LYL1 partially rescues the SPI1 knockdown-induced reduction in HPC formation. Specifically, KLF1 overexpression restores myeloid lineage potential, while LYL1 overexpression re-establishes lymphoid lineage potential. We also observed a SPI1-LYL1 axis in the regulatory network in in vivo EHT. Taken together, our findings shed new light on the role of SPI1 in regulating lineage commitment during EHT, potentially contributing to the heterogeneity of hematopoietic stem cells (HSCs).

SHP2 mutations promote glycolysis and inhibit apoptosis via PKM2/hnRNPK signaling in colorectal cancer.

Colorectal cancer (CRC) is one of the most common gastrointestinal tumors. Src homology-2 domain-containing protein tyrosine phosphatase-2 (SHP2) mutations occur in human solid tumors, including CRC. However, the function and underlying mechanism in CRC have not been well characterized. We demonstrated that the SHP2D61Y and SHP2E76K mutations occurred in CRC tissues, and these mutations promoted CRC cell proliferation, migration/invasion, and reduced CDDP-induced cell apoptosis in vitro and in vivo. Mechanistically, SHP2D61Y and SHP2E76K promote glycolysis by accelerating pyruvate kinase M2 (PKM2) nuclear translocation through mechanism beyond ERK activation. PKM2-IN-1 attenuates PKM2-dependent glycolysis and reduce glucose uptake, lactate production, and ATP levels promoted by SHP2D61Y and SHP2E76K in CRC cells. Furthermore, PKM2 upregulates heterogeneous nuclear ribonucleoprotein K (hnRNPK) expression and increases CRC cell proliferation and migration/invasion via regulating hnRNPK ubiquitination. These findings provide evidence that SHP2D61Y and SHP2E76K regulate CDDP-induced apoptosis, glucose metabolism, and CRC migration/invasion through PKM2 nuclear translocation and PKM2/hnRNPK signaling.

PIK3CA mutations enhance the adipogenesis of ADSCs in facial infiltrating lipomatosis through TRPV1.

Facial infiltrating lipomatosis (FIL) is a congenital disorder. The pathogenesis of FIL is associated with PIK3CA mutations, but the underlying mechanisms remain undetermined. We found that the adipose tissue in FIL demonstrated adipocytes hypertrophy and increased lipid accumulation. All adipose-derived mesenchymal stem cells from FIL (FIL-ADSCs) harbored PIK3CA mutations. Moreover, FIL-ADSCs exhibited a greater capacity for adipogenesis. Knockdown of PIK3CA resulted in a reduction in the adipogenic potential of FIL-ADSCs. Furthermore, WX390, a dual-target PI3K/mTOR inhibitor, was found to impede PIK3CA-mediated adipogenesis both in vivo and in vitro. RNA sequencing (RNA-seq) revealed that the expression of transient receptor potential vanilloid subtype 1 (TRPV1) was upregulated after PI3K pathway inhibition, and overexpression or activation of TRPV1 both inhibited adipogenesis. Our study showed that PIK3CA mutations promoted adipogenesis in FIL-ADSCs and this effect was achieved by suppressing TPRV1. Pathogenesis experiments suggested that WX390 may serve as an agent for the treatment of FIL.

Distinct effects of intravenous bone marrow-derived mesenchymal stem cell therapy on ischemic and non-ischemic lungs after ischemia-reperfusion injury.

BACKGROUND: The preclinical efficacy of mesenchymal stem cell (MSC) therapy after intravenous infusion has been promising, but clinical studies have yielded only modest results. Although most preclinical studies have focused solely on the ischemic lung, it is crucial to evaluate both lungs after ischemia-reperfusion injury, considering the various mechanisms involved. This study aimed to bridge this gap by assessing the acute effects of bone marrow MSC(BM) infusion before ischemic insult and evaluating both ischemic and non-ischemic lungs after reperfusion. METHODS: Eighteen male Wistar rats (403 ± 23 g) were anesthetized and mechanically ventilated using a protective strategy. After baseline data collection, the animals were randomized to 3 groups (n = 6/group): (1) SHAM; (2) ischemia-reperfusion (IR), and (3) intravenous MSC(BM) infusion followed by IR. Ischemia was induced by complete clamping of the left hilum, followed by 1 h of reperfusion after clamp removal. At the end of the experiment, the right and left lungs (non-ischemic and ischemic, respectively) were collected for immunohistochemistry and molecular biology analysis. RESULTS: MSC(BM)s reduced endothelial cell damage and apoptosis markers and improved markers associated with endothelial cell integrity in both lungs. In addition, gene expression of catalase and nuclear factor erythroid 2-related factor 2 increased after MSC(BM) therapy. In the ischemic lung, MSC(BM) therapy mitigated endothelial cell damage and apoptosis and increased gene expression associated with endothelial cell integrity. Conversely, in the non-ischemic lung, apoptosis gene expression increased in the IR group but not after MSC(BM) therapy. CONCLUSION: This study demonstrates distinct effects of MSC(BM) therapy on ischemic and non-ischemic lungs after ischemia-reperfusion injury. The findings underscore the importance of evaluating both lung types in ischemia-reperfusion studies, offering insights into the therapeutic potential of MSC(BM) therapy in the context of lung injury.

Application and evaluation of the hybrid "Problem-Based Learning" model based on "Rain Classroom" in experimental courses of medical molecular biology.

Background: With the advancement of society, the cultivation of medical professionals equipped with solid theoretical knowledge, a strong sense of innovation, and critical thinking has become a crucial goal in the reform of medical higher education. Over recent years, the hybrid Problem-Based Learning (hPBL) model, a blend of Problem-Based Learning (PBL) and Lecture-Based Learning (LBL), has emerged as a novel approach in the medical education reform landscape of China. The application and efficacy of the hPBL model in medical experimental courses have piqued the interest of medical educators. The aim of this study was to appraise the application and effectiveness of the hPBL model in the experimental course of Medical Molecular Biology at Beihua University. Methods: Utilizing the "Rain Classroom" platform, students from the Preventive Medicine and Medical Imaging programs were allocated to either the hPBL or LBL method for their Medical Molecular Biology experimental courses. The hPBL model's impact on students' performance was evaluated across four domains: experimental theory, experimental operation, experimental report, and practical application. Questionnaires were employed to gauge students' experiences and perceptions. Results: The results indicated that the final assessment scores of the hPBL group were significantly superior to those of the LBL group. Moreover, the hPBL model effectively amplified students' self-learning capability, practical application skills, and communication competencies. Students expressed a high degree of satisfaction with this blended learning model. Conclusion: The hPBL model, which amalgamates PBL and LBL, has demonstrated its effectiveness in medical education. Its implementation in the experimental course of Medical Molecular Biology at Beihua University yielded positive outcomes, enhancing students' performance and satisfaction levels. Consequently, it is recommended that the hPBL model be further promulgated in other medical experimental courses.

Affimer reagents enable targeted delivery of therapeutic agents and RNA via virus-like particles.

Monoclonal antibodies have revolutionized therapies, but non-immunoglobulin scaffolds are becoming compelling alternatives owing to their adaptability. Their ability to be labeled with imaging or cytotoxic compounds and to create multimeric proteins is an attractive strategy for therapeutics. Focusing on HER2, a frequently overexpressed receptor in breast cancer, this study addresses some limitations of conventional targeting moieties by harnessing the potential of these scaffolds. HER2-binding Affimers were isolated and characterized, demonstrating potency as binding reagents and efficient internalization by HER2-overexpressing cells. Affimers conjugated with cytotoxic agent achieved dose-dependent reductions in cell viability within HER2-overexpressing cell lines. Bispecific Affimers, targeting HER2 and virus-like particles, facilitated efficient internalization of virus-like particles carrying enhanced green fluorescent protein (eGFP)-encoding RNA, leading to protein expression. Anti-HER2 affibody or designed ankyrin repeat protein (DARPin) fusion constructs with the anti-VLP Affimer further underscore the adaptability of this approach. This study demonstrates the versatility of scaffolds for precise delivery of cargos into cells, advancing biotechnology and therapeutic research.

AnoPrimer: Primer Design in malaria vectors informed by range-wide genomic variation.

The major malaria mosquitoes, Anopheles gambiae s.l and Anopheles funestus, are some of the most studied organisms in medical research and also some of the most genetically diverse. When designing polymerase chain reaction (PCR) or hybridisation-based molecular assays, reliable primer and probe design is crucial. However, single nucleotide polymorphisms (SNPs) in primer binding sites can prevent primer binding, leading to null alleles, or bind suboptimally, leading to preferential amplification of specific alleles. Given the extreme genetic diversity of Anopheles mosquitoes, researchers need to consider this genetic variation when designing primers and probes to avoid amplification problems. In this note, we present a Python package, AnoPrimer, which exploits the Ag1000G and Af1000 datasets and allows users to rapidly design primers in An. gambiae or An. funestus, whilst summarising genetic variation in the primer binding sites and visualising the position of primer pairs. AnoPrimer allows the design of both genomic DNA and cDNA primers and hybridisation probes. By coupling this Python package with Google Colaboratory, AnoPrimer is an open and accessible platform for primer and probe design, hosted in the cloud for free. AnoPrimer is available here https://github.com/sanjaynagi/AnoPrimer and we hope it will be a useful resource for the community to design probe and primer sets that can be reliably deployed across the An. gambiae and funestus species ranges.

The majority of molecular biology applications require synthetic DNA sequences called primers, which bind to DNA and allow us to amplify specific stretches of DNA which we are interested in. Unfortunately, when mutations occur at primer binding sites, primers can fail to bind completely, or even worse, amplify differentially depending on the mutation present. Mutations can therefore bias molecular assays with often undetected effects. This is a particular problem in malaria mosquitoes, as they are some of the most genetically diverse species on earth. We present a user-friendly software tool, AnoPrimer, which allows users to design primers for molecular biology in malaria mosquitoes. AnoPrimer integrates high-quality whole-genome sequence data from the cloud, and creates clear, interactive visualisations, enabling users to avoid mutations that occur in wild malaria mosquitoes. By avoiding these mutations, we can ensure the design of reliable primers which result in robust molecular assays for research into malaria vectors.