Exploring Unique Extracellular Vesicles Associated Signatures: Prognostic Insights, Immune Microenvironment Dynamics, and Therapeutic Responses in Pancreatic Adenocarcinoma.

Extracellular vesicles play an important role in the progression of pancreatic adenocarcinoma (PAAD) through the transfer of proteins, mRNAs, and long noncoding RNAs (lncRNAs). However, the intricate interplay between extracellular vesicles-related lncRNAs and the tumor microenvironment (TME) remains poorly elucidated. Consequently, our investigation aimed to delineate the association between extracellular vesicles-related lncRNAs and the PAAD microenvironment. Initially, we identified differentially expressed lncRNAs (DELs) from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) project datasets. Subsequently, we validated the expression of these DELs within extracellular vesicles and assessed their prognostic implications in PAAD using the GSE133684 and TCGA datasets. Multiomics data were analyzed comprehensively, including genomic landscape, functional annotation, immune profiles, and therapeutic responses. Differential expression of selected lncRNAs in both cellular and exosomal fractions of PAAD was further confirmed through quantitative polymerase chain reaction (qPCR). Eight DELs were identified from TCGA and GTEx datasets, and two exosomal lncRNAs exhibited a significant correlation with overall survival, warranting further investigation. Specifically, elevated expression of LINC00996 correlated positively with immune infiltration and enhanced response to immunotherapy. Conversely, heightened expression of TRHED-AS1 was associated with compromised immune cell infiltration and diminished responsiveness to immunotherapy. Our study establishes a compelling link between two extracellular vesicles-related gene signatures, prognosis, and immune infiltration in PAAD. Notably, these signatures serve as robust prognostic indicators for PAAD patients, offering valuable insights for the strategic selection of immunotherapeutic interventions.

The effectiveness of intravenous zoledronic acid in elderly patients with osteoporosis after rotator cuff repair: a retrospective study.

The aim of this study was to investigate the effect of zoledronic acid (ZA) on postoperative healing and functional rehabilitation in osteoporotic patients with rotator cuff (RC) injury. 96 Patients were divided into three groups according to bone mineral density and ZA use (Group A: normal BMD; Group B: osteoporosis and intravenous ZA use; Group C: osteoporosis, without ZA use). Radiologic, functional and Serological outcomes were evaluated 6 months after surgery. The functional scores in all groups exhibited significant improvement 6 months after surgery. Inter-group comparison showed that Constant Shoulder joint function Score (CSS) of group A not significantly differing from that of group B, the other indicators were significantly better than those of group B and C. There were no significant differences in shoulder forward flexion, abductive Range of Motion between group B and C. Other indicators of group B were significantly improved compared to group C. The retear rate in group C (30.3%, 10/33) was higher than group A (6.1%, 2/33) and group B (13.3%, 4/30). In conclusion, the application of ZA can significantly reduce the rate of RC retear in elderly patients with osteoporosis after surgery, which is significant for postoperative shoulder joint functional rehabilitation.

LARP7 overexpression alleviates aortic senescence and atherosclerosis.

Atherosclerosis, characterized by the accumulation of lipid plaques on the inner walls of arteries, is the leading cause of heart attack, stroke and severe ischemic injuries. Senescent cells have been found to accumulate within atherosclerotic lesions and contribute to the progression of atherosclerosis. In our previous study, we discovered that suppressing Larp7 accelerates senescence by inhibiting Sirt1 activity, resulting in increased atherosclerosis in high-fat diet (HFD) fed and ApoE deficient (ApoEKO) mice. However, there has been no direct evidence demonstrating Larp7 per se could attenuate atherosclerosis. To this end, we generated a tetO-controlled and Cre-activated Larp7 gain-of-function mouse. Through RT-PCR and western blotting, we confirmed Larp7 overexpression in the aortas of HFD-fed ApoEKO; Larp7tetO mice. Larp7 overexpression led to increased Sirt1 activity and decreased cellular senescence signals mediated by p53/p65 in the aortas. Additionally, Larp7 overexpression reduced the presence of p16-positive senescent cells in the aortic lesions. Furthermore, Larp7 overexpression resulted in a decrease in pro-inflammatory macrophages and SASP factors. Consequently, Larp7 overexpression led to a reduction in the area of atherosclerotic lesions in HFD-fed ApoEKO; Larp7tetO mice. In summary, our study provides evidence that Larp7 overexpression holds promise as an approach to inhibit cellular senescence and prevent atherosclerosis.

Allele-Specific Suppression of Variant MHC With High-Precision RNA Nuclease CRISPR-Cas13d Prevents Hypertrophic Cardiomyopathy.

BACKGROUND: Familial hypertrophic cardiomyopathy has severe clinical complications of heart failure, arrhythmia, and sudden cardiac death. Heterozygous single nucleotide variants (SNVs) of sarcomere genes such as MYH7 are the leading cause of this type of disease. CRISPR-Cas13 (clustered regularly interspaced short palindromic repeats and their associated protein 13) is an emerging gene therapy approach for treating genetic disorders, but its therapeutic potential in genetic cardiomyopathy remains unexplored. METHODS: We developed a sensitive allelic point mutation reporter system to screen the mutagenic variants of Cas13d. On the basis of Cas13d homology structure, we rationally designed a series of Cas13d variants and obtained a high-precision Cas13d variant (hpCas13d) that specifically cleaves the MYH7 variant RNAs containing 1 allelic SNV. We validated the high precision and low collateral cleavage activity of hpCas13d through various in vitro assays. We generated 2 HCM mouse models bearing distinct MYH7 SNVs and used adenovirus-associated virus serotype 9 to deliver hpCas13d specifically to the cardiomyocytes. We performed a large-scale library screening to assess the potency of hpCas13d in resolving 45 human MYH7 allelic pathogenic SNVs. RESULTS: Wild-type Cas13d cannot distinguish and specifically cleave the heterozygous MYH7 allele with SNV. hpCas13d, with 3 amino acid substitutions, had minimized collateral RNase activity and was able to resolve various human MYH7 pathological sequence variations that cause hypertrophic cardiomyopathy. In vivo application of hpCas13d to 2 hypertrophic cardiomyopathy models caused by distinct human MYH7 analogous sequence variations specifically suppressed the altered allele and prevented cardiac hypertrophy. CONCLUSIONS: Our study unveils the great potential of CRISPR-Cas nucleases with high precision in treating inheritable cardiomyopathy and opens a new avenue for therapeutic management of inherited cardiac diseases.

A novel injectable hydrogel prepared from phenylboronic acid modified gelatin and oxidized-dextran for bone tissue engineering.

Complicated fractures have always been challenging in orthopaedics. Designing a multifunctional biomaterial that can contribute to the treatment of fractures using a simple operation remains challenging. Here, we developed a trinity hydrogel system consisting of hydrogel prepared from phenylboronic acid modified gelatin and oxidized-dextran, lithium and cobalt co-doped mesoporous bioactive glass nanoparticles (MBGNs), and irisin. This hydrogel material exhibits considerable injectability, fat-to-shape, and self-healing characteristics. In addition, compared to hydrogel prepared from gelatin and oxidized-dextran, the hydrogel material presented a noticeable enhancement in compression stress and adhesion strength towards porcine bone fragments, which enables it more effectively splice bone fragments during surgery. Based on the various interactions between irisin and the hydrogel network, the system exhibited a clear sustained release of irisin. Based on the results of in vitro cell tests, the hydrogel material showed good cytocompatibility. And it also considerably enhanced the in vitro pro-osteogenic and pro-angiogenic capacities of bone marrow mesenchymal stromal cells (BMSCs) and human umbilical vein endothelial cells (HUVECs). In vivo experimental results indicated that this hydrogel considerably improved the repair of cranial defects in rats. The current study provides a feasible strategy for the treatment of bone fractures and stimulation of fracture healing.

Inhibition of Heat Shock-Induced H3K9ac Reduction Sensitizes Cancer Cells to Hyperthermia.

Heat stress, clinically known as hyperthermia, is a promising adjunctive modality in cancer treatment. However, the efficacy of hyperthermia as a monotherapy is limited and the underlying mechanism remains poorly understood. Targeting histone modifications is an emerging strategy for cancer therapy, but little is known regarding the role of heat stress in altering these modifications. Here, we report that heat shock inhibits H3K9 acetylation (H3K9ac) via histone deacetylase 6 (HDAC6) regulation. Heat shock inhibits the interaction between HDAC6 and heat shock protein 90 (HSP90), enhances nuclear localization of HDAC6, and promotes HDAC6 phosphorylation, which is regulated by protein phosphatase 2A (PP2A). Combining hyperthermia with HDAC inhibitors vorinostat or panobinostat leads to better anti-cancer effects compared to monotherapy. KEAP1 and DPP7 as genes affected by heat-induced inhibition of H3K9ac, and combining them with hyperthermia can better induce apoptosis in tumor cells. This study reveals previously unknown mechanisms of H3K9ac decreased by heat shock in cancer cells and highlights a potential combinational therapy involving hyperthermia and targeting of these new mechanisms.

Effect of different bone cement distributions in percutaneous kyphoplasty on clinical outcomes for osteoporotic vertebral compression fractures: A retrospective study.

Osteoporotic fractures and their complications are becoming increasingly harmful to the elderly. This study aimed to evaluate the clinical results of connected or unconnected bilateral cement after bilateral percutaneous kyphoplasty (PKP) in patients with osteoporotic vertebral compression fractures (OVCF). The clinical data of 217 patients with single-segment OVCF were retrospectively collected. Patients were allocated into 2 groups according to the bilateral bone cement in the vertebrae was connected or unconnected after surgery. The surgery-related indexes of the 2 groups were compared, including operation time; bone cement injection volume; contact situation between bone cement and the upper and lower endplates of the vertebral body; visual analogue scale (VAS) scores before surgery, 1 week and 1 year after surgery; Oswestry disability index (ODI) before surgery, 1 week and 1 year after surgery; local kyphosis angle (LKA) before surgery, 1 week and 1 year after surgery; postoperative vertebral body height at 1 week and 1 year after surgery; vertebral body height restoration rate (HRR) at 1 week and 1 year after surgery. The follow-up results of all patients were recorded. The postoperative VAS, ODI, vertebral body height, LKA and other indexes of the 2 groups were significantly improved compared with those before the operation (P < .05), and there was no significant difference between the 2 groups (P > .05). At the same time, there were no significant difference in vertebral body HRR and bone cement leakage rate between the 2 groups (P > .05). X-ray examination showed that 21 of 217 patients (21/217, 9.8%) had a refracture of the injured vertebral body, including 16 cases (16/121, 13.2%) in the unconnected group and 5 cases (5/96, 5.2%) in the connected group (P < .05). Adjacent vertebrae fractures occurred in 25 cases (25/217, 11.5%), while 19 cases (19/121, 15.7%) were in the unconnected group and 6 cases (6/96, 6.3%) were in the connected group (P < .05). PKP has a good therapeutic effect on OVCF no matter whether the bilateral bone cement is connected or not. However, if the bilateral cement inside the vertebra was connected, the risk of recollapse of the injured vertebrae and the new fracture of adjacent vertebrae could be reduced.

LARP7 ameliorates cellular senescence and aging by allosterically enhancing SIRT1 deacetylase activity.

Cellular senescence is associated with pleiotropic physiopathological processes, including aging and age-related diseases. The persistent DNA damage is a major stress leading to senescence, but the underlying molecular link remains elusive. Here, we identify La Ribonucleoprotein 7 (LARP7), a 7SK RNA binding protein, as an aging antagonist. DNA damage-mediated Ataxia Telangiectasia Mutated (ATM) activation triggers the extracellular shuttling and downregulation of LARP7, which dampens SIRT1 deacetylase activity, enhances p53 and NF-κB (p65) transcriptional activity by augmenting their acetylation, and thereby accelerates cellular senescence. Deletion of LARP7 leads to senescent cell accumulation and premature aging in rodent model. Furthermore, we show this ATM-LARP7-SIRT1-p53/p65 senescence axis is active in vascular senescence and atherogenesis, and preventing its activation substantially alleviates senescence and atherogenesis. Together, this study identifies LARP7 as a gatekeeper of senescence, and the altered ATM-LARP7-SIRT1-p53/p65 pathway plays an important role in DNA damage response (DDR)-mediated cellular senescence and atherosclerosis.

LARP7 Protects Against Heart Failure by Enhancing Mitochondrial Biogenesis.

BACKGROUND: Heart failure (HF) is among the leading causes of morbidity and mortality, and its prevalence continues to rise. LARP7 (La ribonucleoprotein domain family member 7) is a master regulator that governs the DNA damage response and RNAPII (RNA polymerase II) pausing pathway, but its role in HF pathogenesis is incompletely understood. METHODS: We assessed LARP7 expression in human HF and in nonhuman primate and mouse HF models. To study the function of LARP7 in heart, we generated global and cardiac-specific LARP7 knockout mice. We acutely abolished LARP7 in mature cardiomyocytes by Cas9-mediated LARP7 somatic knockout. We overexpressed LARP7 in cardiomyocytes using adeno-associated virus serotype 9 and ATM (ataxia telangiectasia mutated protein) inhibitor. The therapeutic potential of LARP7-regulated pathways in HF was tested in a mouse myocardial infarction model. RESULTS: LARP7 was profoundly downregulated in failing human hearts and in nonhuman primate and murine hearts after myocardial infarction. Low LARP7 levels in failing hearts were linked to elevated reactive oxygen species, which activated the ATM-mediated DNA damage response pathway and promoted LARP7 ubiquitination and degradation. Constitutive LARP7 knockout in mouse resulted in impaired mitochondrial biogenesis, myocardial hypoplasia, and midgestational lethality. Cardiac-specific inactivation resulted in defective mitochondrial biogenesis, impaired oxidative phosphorylation, elevated oxidative stress, and HF by 4 months of age. These abnormalities were accompanied by reduced SIRT1 (silent mating type information regulation 2 homolog 1) stability and deacetylase activity that impaired SIRT1-mediated transcription of genes for oxidative phosphorylation and energy metabolism and dampened cardiac function. Restoring LARP7 expression after myocardial infarction by either adeno-associated virus-mediated LARP7 expression or small molecule ATM inhibitor substantially improved the function of injured heart. CONCLUSIONS: LARP7 is essential for mitochondrial biogenesis, energy production, and cardiac function by modulating SIRT1 homeostasis and activity. Reduction of LARP7 in diseased hearts owing to activation of the ATM pathway contributes to HF pathogenesis and restoring LARP7 in the injured heart confers myocardial protection. These results identify the ATM-LARP7-SIRT1 pathway as a target for therapeutic intervention in HF.

Mitochondrial Pyruvate Carriers Prevent Cadmium Toxicity by Sustaining the TCA Cycle and Glutathione Synthesis.

Cadmium (Cd) is a major heavy metal pollutant, and Cd toxicity is a serious cause of abiotic stress in the environment. Plants protect themselves against Cd stress through a variety of pathways. In a recent study, we found that mitochondrial pyruvate carriers (MPCs) are involved in Cd tolerance in Arabidopsis (Arabidopsis thaliana). Following the identification of MPCs in yeast (Saccharomyces cerevisiae) in 2012, most studies have focused on the function of MPCs in animals, as a possible approach to reduce the risk of cancer developing. The results of this study show that AtMPC protein complexes are required for Cd tolerance and prevention of Cd accumulation in Arabidopsis. AtMPC complexes are composed of two elements, AtMPC1 and AtMPC2 (AtNRGA1 or AtMPC3). When the formation of AtMPCs was interrupted by the loss of AtMPC1, glutamate could supplement the synthesis of acetyl-coenzyme A and sustain the TCA cycle. With the up-regulation of glutathione synthesis following exposure to Cd stress, the supplementary pathway could not efficiently drive the tricarboxylic acid cycle without AtMPC. The ATP content decreased concomitantly with the deletion of tricarboxylic acid activity, which led to Cd accumulation in Arabidopsis. More importantly, ScMPCs were also required for Cd tolerance in yeast. Our results suggest that the mechanism of Cd tolerance may be similar in other species.