ADENOSINE MONOPHOSPHATE-ACTIVATED PROTEIN KINASE PHOSPHORYLATION MEDIATED BY SIRTUIN 5 ALLEVIATES SEPTIC ACUTE KIDNEY INJURY.

ABSTRACT: Background : Our previous studies have shown that ameliorating mitochondrial damage in renal tubular epithelial cells (RTECs) can alleviate septic acute kidney injury (SAKI). It is reported that AMPK phosphorylation (p-AMPK) could ameliorate mitochondrial damage in renal tissue and Sirtuin 5 (SIRT5) overexpression significantly enhanced the level of p-AMPK in bovine preadipocytes. However, the role of SIRT5-mediated phosphorylation of AMPK in SAKI needs to be clarified. Methods : WT/SIRT5 gene knockout mouse model of cecal ligation and puncture-induced SAKI and a human kidney 2 cell model of LPS-induced SAKI were constructed. An AMPK chemical activator and SIRT5 overexpression plasmid were used. Indexes of mitochondrial structure and function, level of p-AMPK, and expression of SIRT5 protein in renal tissue and RTECs were measured. Results : After sepsis stimulation, the p-AMPK level was decreased, mitochondrial structure was disrupted, and ATP content was decreased. Notably, an AMPK activator alleviated SAKI. Sirtuin 5 gene knockout significantly aggravated SAKI, while SIRT5 overexpression alleviated mitochondrial dysfunction after LPS stimulation, as manifested by the increase of p-AMPK level, the alleviation of mitochondrial structure damage, the restoration of ATP content, the decrease of proapoptotic protein expression, as well as the reduction of reactive oxygen species generation. Conclusions : Upregulation of SIRT5 expression can attenuate mitochondrial dysfunction in RTECs and alleviate SAKI by enhancing the phosphorylation of AMPK.

Sintilimab combined with apatinib plus capecitabine in the treatment of unresectable hepatocellular carcinoma: A prospective, open-label, single-arm, phase II clinical study.

Objective: To evaluate the efficacy and safety of sintilimab combined with apatinib plus capecitabine in the treatment of unresectable hepatocellular carcinoma (HCC) to provide a more effective first-line treatment for patients with advanced HCC. Methods: This open-label, prospective, phase II study included patients with unresectable HCC who did not receive systematic treatment. The patients were treated with sintilimab (200 mg, intravenous drip, once every 3 weeks) combined with apatinib (250 mg, oral administration, once a day) plus capecitabine (1000 mg/m2, twice a day; after 2 weeks of oral administration, the drug was stopped for 1 week; course of treatment, 3 weeks). The primary endpoint was the objective response rate (ORR). The secondary endpoints included disease control rate (DCR), progression-free survival (PFS), duration of response (DoR), overall survival (OS), and safety. Results: Forty-seven patients (1 lost to follow-up) were enrolled in the study. As of March 1, 2022, the ORR and DCR were 50.0% (95% CI: 34.9-65.1%) and 91.3% (95% CI: 79.2-97.6%), respectively, after blind, independent imaging evaluation. The median follow-up time was 18.7 months (95% CI: 17.2-20.2 months). The median PFS was 9.0 months (95% CI: 7.1-10.9 months). The median DoR was 10.8 months (95% CI: 4.8-16.8 months). The median OS was not reached, and the 1-year OS rate was 71.7% (95% CI: 56.5-84.0%). Only 28.3% (13/46) of patients had grade 3/4 treatment-related adverse events. Conclusion: Sintilimab combined with apatinib plus capecitabine has good safety and anti-tumor activity as a first-line treatment for unresectable HCC. This is worthy of further multi-center, prospective, randomized, large-sample clinical studies. Clinical Trial Registration: https://ClinicalTrials.gov, identifier NCT04411706.

Peptide-Metal Organic Framework Swimmers that Direct the Motion toward Chemical Targets.

Highly efficient and robust chemical motors are expected for the application in microbots that can selectively swim toward targets and accomplish their tasks in sensing, labeling, and delivering. However, one of major issues for such development is that current artificial swimmers have difficulty controlling their directional motion toward targets like bacterial chemotaxis. To program synthetic motors with sensing capability for the target-directed motion, we need to develop swimmers whose motions are sensitive to chemical gradients in environments. Here we create a new intelligent biochemical swimmer by integrating metal organic frameworks (MOFs) and peptides that can sense toxic heavy metals in solution and swim toward the targets. With the aid of Pb-binding enzymes, the peptide-MOF motor can directionally swim toward PbSe quantum dots (QD) by sensing pH gradient and eventually complete the motion as the swimmer reaches the highest gradient point at the target position in solution. This type of technology could be evolved to miniaturize chemical robotic systems that sense target chemicals and swim toward target locations.

Screening of Oligopeptides that Recognize Inorganic Crystalline Facets of Metal Nanoparticles.

Peptides that possess specific affinity to distinct crystal facets have been reported previously. However, their adsorption behavior in terms of the crystal sizes and shapes is less exploited. Herein, we isolate several phage clones that show the strong affinity to {100} of Pd at a neutral pH from the M13 phage library, and among them the phages that have shape selectivity to the cubic structure are identified by eliminating ones that bind randomly shaped Pd nanoparticles (NPs). Since Pd nanocube-binding phages are eluted by lowering pH values in the biopanning process, the selected phages (and their binding peptides displayed on protein pIII) can be released from Pd surfaces through pH changes. We used this feature to modulate the capping density of selected peptides on NPs. For example, when less peptides are capped on Pd nanocubes by lowering the pH values, the shape of the nanocubes is deformed and some evolve into a concave shape, indicating that Pd atoms are released from the less protected {100} facet selectively due to the higher surface energy. This type of crystalline facet-recognizing peptides can be applied for smart capping agents that not only bind target crystalline planes, but also modify their coverage on the specific surfaces with pH changes. The peptide-capping agents could be useful to fabricate NPs with characteristic shapes through etching and adsorption of atoms on specific crystalline planes of seed nanocrystals.

Impedimetric detection of mutant p53 biomarker-driven metastatic breast cancers under hyposmotic pressure.

In cancer cells, the oncogenic mutant p53 (mtp53) protein is present at high levels and gain-of-function (GOF) activities with more expression of mtp53 proteins contribute to tumor growth and metastasis. Robust analytical approaches that probe the degree of metastasis of cancer cells in connection with the mtp53 activity will be extremely useful not only for establishing a better cancer prognosis but also understanding the fundamental mechanism of mtp53 oncogenic action. Here we assessed the influence of mtp53 in breast cancers to the mechanical property of breast cancer cells. Recently, ovarian and kidney cancer cell lines have been shown to have higher cellular elasticity as compared to normal cells assessed by monitoring the degree of deformation under hyposmotic pressure. To make fast detection in large scale, the impedance measurement was applied to monitor the swelling ratio of cells with time. The results showed that knockdown of mtp53 leads to decrease in cell swelling. In addition, by means of two types of impedimetric detection systems we consistently detected enhancement of impedance signal in mtp53-expressing breast cancer cells. Based on this observation we hypothesize that highly expressed mtp53 in metastatic mutant breast cancers can promote tumor progression by making cells more deformable and easier to spread out through extracellular matrix. The identification via the electric measurement can be accomplished within 10 minutes. All results in this report suggest that electric probing for the extent of the mtp53 expression of breast cancer cells may serve as a meaningful fingerprint for the cancer diagnostics, and this outcome will also have an important clinical implication for the development of mtp53-based targeting for tumor detection and treatment.

PbSe nanocrystal growth as nanocubes and nanorods on peptide nanotubes via different directed-assembly pathways.

Pb-binding TAR-1 peptides (Ile-Ser-Leu-Leu-His-Ser-Thr) were covalently conjugated on a bolaamphiphile peptide nanotube substrate and the precursors of PbSe were incubated at room temperature. This resulted in the growth of highly crystalline PbSe nanocubes on this biomimetic cylindrical substrate. The growth mechanism to generate nanocubes occurs via the directed self-assembly of nanoparticles and then nanoparticle fusion. The peptide conformation and the cylindrical peptide nanotube substrate play important roles in the mesoscopic crystallization of PbSe nanocubes. Changing the buffer for the peptide immobilization process from 2-(N-morpholino)ethanesulfonic acid to phosphate induces a transformation in the nanocrystal shape from nanocube to nanorods. The conformational change of the TAR-1 peptide on the nanotubes due to the change in the buffer seems to be responsible for aggregating intermediate nanoparticles in different directions for the directed fusion and mesoscopic crystallization of PbSe into the different shapes.