A modified orthotopic left lung transplantation model in rats.

To enhance the operability of the rat orthotopic left lung transplantation model, we implemented several improvements and meticulously detailed the procedure. One hundred and thirty-one healthy male Sprague Dawley rats, weighing between 250 and 300 g, were utilized, with 64 serving as donors, 64 as recipients, and 3 as sham controls. We employed a modified three-cuff technique for the orthotopic left lung transplantation. Notably, our modified perfusion method could prevent donor lung edema, while waist-shaped cuffs minimized suture slippage during anastomosis. Additionally, positioning the recipient rat in a slightly left-elevated supine position during anastomosis reduced tension on the lung hilum, thus mitigating the risk of vascular laceration. The introduction of a unique two-person anastomosis technique significantly reduced operation time and substantially improved success rates. Furthermore, maximizing inflation of donor lungs both during preservation and surgery minimized the occurrence of postoperative atelectasis. Various other procedural refinements contributed to the enhanced operability of our model. Sixty-four rat orthotopic left lung transplantations were performed with only one surgical failure observed. The acquisition time for donor lungs averaged (19 ± 4) minutes, while (11 ± 1) minutes were allocated for donor lung hilum anatomy and cuff installation. Recipient thoracotomy and left lung hilar anatomy before anastomosis required (24 ± 8) minutes, with anastomosis itself taking (31 ± 6) minutes. Remarkably, the survival rate at the 4-h postoperative mark stood at 96.7 %. Even six months post-operation, transplanted left rat lungs continued to exhibit proper inflation and contraction rhythms, displaying signs of chronic pathological changes. In summary, our modified rat model of orthotopic left lung transplantation demonstrates robust operability, significantly reducing surgical duration, improving operation success rates, and enhancing postoperative survival rates. Furthermore, its long-term survival capacity enables the simulation of acute and chronic disease processes following lung transplantation.

PARP-1 inhibitor alleviates cerebral ischemia/reperfusion injury by reducing PARylation of HK-1 and LDH in mice.

Poly (ADP-ribose) polymerase-1 (PARP-1) activity significantly increases during cerebral ischemia/reperfusion. PARP-1 is an NAD+-consumption enzyme. PARP-1 hyperactivity causes intracellular NAD+ deficiency and bioenergetic collapse, contributing to neuronal death. Besides, the powerful trigger of PARP-1 causes the catalyzation of poly (ADP-ribosyl)ation (PARylation), a posttranslational modification of proteins. Here, we found that PARP-1 was activated in the ischemic brain tissue during middle-cerebral-artery occlusion and reperfusion (MCAO/R) for 24 h, and PAR accumulated in the neurons in mice. Using immunoprecipitation, Western blotting, liquid chromatography-mass spectrometry, and 3D-modeling analysis, we revealed that the activation of PARP-1 caused PARylation of hexokinase-1 and lactate dehydrogenase-B, which, therefore, caused the inhibition of these enzyme activities and the resulting cell energy metabolism collapse. PARP-1 inhibition significantly reversed the activity of hexokinase and lactate dehydrogenase, decreased infarct volume, and improved neuronal deficiency. PARP-1 inhibitor combined with pyruvate further alleviated MCAO/R-induced ischemic brain injury in mice. As such, we conclude that PARP-1 inhibitor alleviates neuronal death partly by inhibiting the PARylation of metabolic-related enzymes and reversing metabolism reprogramming during cerebral ischemia/reperfusion injury in mice. PARP-1 inhibitor combined with pyruvate might be a promising therapeutic approach against brain ischemia/reperfusion injury.

Applications of upconversion nanoparticles in cellular optogenetics.

Upconversion-mediated optogenetics is an emerging powerful technique to remotely control and manipulate the deep-tissue protein functions and signaling pathway activation. This technique uses lanthanide upconversion nanoparticles (UCNPs) as light transducers and through near-infrared light to indirectly activate the traditional optogenetic proteins. With the merits of high spatiotemporal resolution and minimal invasiveness, this technique enables cell-type specific manipulation of cellular activities in deep tissues as well as in living animals. In this review, we introduce the latest development of optogenetic modules and UCNPs, with emphasis on the integration of UCNPs with cellular optogenetics and their biomedical applications on the control of neural/brain activity, cancer therapy and cardiac optogenetics in vivo. Furthermore, we analyze the current developed strategies to optimize and advance the upconversion-mediated optogenetics and discuss the remaining challenges of its further applications in biomedical study and clinical translational research. STATEMENT OF SIGNIFICANCE: Optogenetics harnesses photoactivatable proteins to optically stimulate and control intracellular activities. UCNPs-mediated NIR-activatable optogenetics uses lanthanide upconversion nanoparticles (UCNPs) as light transducers and utilizes near-infrared (NIR) light to indirectly activate the traditional optogenetic proteins. The integration of UCNPs with cellular optogenetics has showed great promise in biomedical applications in regulating neural/brain activity, cancer therapy and cardiac optogenetics in vivo. The evolution and optimization of functional UCNPs and the discovery and engineering of novel optogenetic modules would both contribute to the advance of such unique hybrid technology, which may lead to discoveries in biomedical research and provide new treatments for human diseases.

A survey on applications of deep learning in microscopy image analysis.

Advanced microscopy enables us to acquire quantities of time-lapse images to visualize the dynamic characteristics of tissues, cells or molecules. Microscopy images typically vary in signal-to-noise ratios and include a wealth of information which require multiple parameters and time-consuming iterative algorithms for processing. Precise analysis and statistical quantification are often needed for the understanding of the biological mechanisms underlying these dynamic image sequences, which has become a big challenge in the field. As deep learning technologies develop quickly, they have been applied in bioimage processing more and more frequently. Novel deep learning models based on convolution neural networks have been developed and illustrated to achieve inspiring outcomes. This review article introduces the applications of deep learning algorithms in microscopy image analysis, which include image classification, region segmentation, object tracking and super-resolution reconstruction. We also discuss the drawbacks of existing deep learning-based methods, especially on the challenges of training datasets acquisition and evaluation, and propose the potential solutions. Furthermore, the latest development of augmented intelligent microscopy that based on deep learning technology may lead to revolution in biomedical research.

Downregulated Long Noncoding RNA PART1 Inhibits Proliferation and Promotes Apoptosis in Bladder Cancer.

OBJECTIVE: In this study, we aimed to clarify the effects of long noncoding ribonucleic acid prostrate androgen-regulated transcript-1 on bladder cancer cell proliferation and apoptosis. METHODS: Microarrays were implemented to investigate the long noncoding ribonucleic acid expression profiles in bladder cancer tissue (N = 9) and in noncancer bladder tissue (N = 5). Relative prostrate androgen-regulated transcript-1 expression levels in tissue samples or cell lines were detected by real-time quantitative reverse transcription-polymerase chain reaction. Prostrate androgen-regulated transcript-1 expression was enhanced by the transfection of pcDNA3.1-prostrate androgen-regulated transcript-1 and downregulated by the infection with pcMV-sh prostrate androgen-regulated transcript-1. Additionally, cell proliferation and apoptosis were measured by the cell counting kit-8 assay and flow cytometry, respectively. Cell invasion was determined by a Transwell assay. RESULTS: Prostrate androgen-regulated transcript-1 expression was upregulated in bladder cancer tissues compared to adjacent nontumor tissues. Furthermore, prostrate androgen-regulated transcript-1 levels were successfully upregulated by pcDNA3.1-prostrate androgen-regulated transcript-1 and depleted by pCMV-sh prostrate androgen-regulated transcript-1 in bladder cancer cell lines (5637, T24). Enhanced prostrate androgen-regulated transcript-1 expression promoted cell proliferation and invasion and inhibited cell apoptosis. However, knockdown of prostrate androgen-regulated transcript-1 expression inhibited cell proliferation and invasion and induced cell apoptosis. CONCLUSION: In summary, these data suggest that the knockdown of prostrate androgen-regulated transcript-1 represents a tumor suppressor player in bladder cancer and contributes to the inhibition of tumor proliferation, the promotion of cell apoptosis, and the suppression of cell invasion. Prostrate androgen-regulated transcript-1 may function as a new prognostic biomarker and as a feasible therapeutic target for patients with bladder cancer.

Comparative studies on amphotericin B nanosuspensions prepared by a high pressure homogenization method and an antisolvent precipitation method.

Amphotericin B (AmB) is a widely used polyene antifungal agent; however, its poor solubility limits its clinical application. In this study, AmB nanosuspensions were prepared by a high pressure homogenization method (AmB-HPH) and an antisolvent precipitation method (AmB-AP) to improve the drug solubility. To reveal the distinct influences of these two different preparation methods, systematic comparisons of particle size, crystalline state, wettability, in vitro dissolution and in vivo pharmacokinetics on the properties of AmB-HPH and AmB-AP were performed. The results indicated that AmB-AP was in an amorphous state, exhibiting higher saturation solubility and dissolution rate than those of AmB-HPH in the crystalline state. However, the relative bioavailability of AmB-HPH was higher than that of AmB-AP in vivo, which was likely attributed to its better stability. In conclusion, both AmB-HPH and AmB-AP can enhance the solubility and bioavailability of AmB, but the stability of the nanosuspension prepared by the anti-solvent precipitation method should be carefully considered.

Hyaluronic-acid-modified lipid-polymer hybrid nanoparticles as an efficient ocular delivery platform for moxifloxacin hydrochloride.

To improve the ocular bioavailability of the strongly hydrophilic moxifloxacin hydrochloride, hyaluronic-acid-modified lipid-polymer hybrid nanoparticles (HA-LCS-NPs) were designed and characterized. An in vivo precorneal retention study in rabbits showed that the mean residence time (MRT) and area under the curve (AUC0-6h) of HA-LCS-NPs were up to 6.74-fold and 4.29-fold higher than those of the commercial product. An in vitro corneal penetration study in rabbits demonstrated that the apparent permeability coefficient (Papp) of HA-LCS-NPs was increased by 3.29-fold compared to the commercial product, which might be observed because the surface-modified hyaluronic acid could expedite the cellular uptake of HA-LCS-NPs by receptor-mediated endocytosis. Moreover, in contrast with other formulations, the results of ex vivo fluorescence imaging showed that the fluorescence intensity was higher in the cornea and conjunctiva after administration of HA-LCS-NPs. Finally, an ocular irritation study indicated that HA-LCS-NPs displayed excellent ocular tolerance. In summary, the hyaluronic-acid-modified lipid-polymer hybrid nanoparticles with multifunctional properties might be a promising ocular drug delivery system for prolonged precorneal retention, better corneal permeability and enhanced ocular bioavailability.