Microenvironment drives cell state, plasticity, and drug response in pancreatic cancer.

Prognostically relevant RNA expression states exist in pancreatic ductal adenocarcinoma (PDAC), but our understanding of their drivers, stability, and relationship to therapeutic response is limited. To examine these attributes systematically, we profiled metastatic biopsies and matched organoid models at single-cell resolution. In vivo, we identify a new intermediate PDAC transcriptional cell state and uncover distinct site- and state-specific tumor microenvironments (TMEs). Benchmarking models against this reference map, we reveal strong culture-specific biases in cancer cell transcriptional state representation driven by altered TME signals. We restore expression state heterogeneity by adding back in vivo-relevant factors and show plasticity in culture models. Further, we prove that non-genetic modulation of cell state can strongly influence drug responses, uncovering state-specific vulnerabilities. This work provides a broadly applicable framework for aligning cell states across in vivo and ex vivo settings, identifying drivers of transcriptional plasticity and manipulating cell state to target associated vulnerabilities.

Tumour-selective activity of RAS-GTP inhibition in pancreatic cancer.

Broad-spectrum RAS inhibition has the potential to benefit roughly a quarter of human patients with cancer whose tumours are driven by RAS mutations1,2. RMC-7977 is a highly selective inhibitor of the active GTP-bound forms of KRAS, HRAS and NRAS, with affinity for both mutant and wild-type variants3. More than 90% of cases of human pancreatic ductal adenocarcinoma (PDAC) are driven by activating mutations in KRAS4. Here we assessed the therapeutic potential of RMC-7977 in a comprehensive range of PDAC models. We observed broad and pronounced anti-tumour activity across models following direct RAS inhibition at exposures that were well-tolerated in vivo. Pharmacological analyses revealed divergent responses to RMC-7977 in tumour versus normal tissues. Treated tumours exhibited waves of apoptosis along with sustained proliferative arrest, whereas normal tissues underwent only transient decreases in proliferation, with no evidence of apoptosis. In the autochthonous KPC mouse model, RMC-7977 treatment resulted in a profound extension of survival followed by on-treatment relapse. Analysis of relapsed tumours identified Myc copy number gain as a prevalent candidate resistance mechanism, which could be overcome by combinatorial TEAD inhibition in vitro. Together, these data establish a strong preclinical rationale for the use of broad-spectrum RAS-GTP inhibition in the setting of PDAC and identify a promising candidate combination therapeutic regimen to overcome monotherapy resistance.

Sex differences in comorbidities and mortality risk among patients with chronic obstructive pulmonary disease: a study based on NHANES data.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) commonly have coexisting comorbidities that contribute to higher exacerbation frequency, poorer health status, and increased all-cause mortality; however, there are only a few studies available on the sex discrepancy in the comorbidity distribution and outcomes among COPD patients, and there is limited information about the discrepancy in all-cause mortality between men and women. METHODS: Based on data from the U.S. National Health and Nutrition Examination Survey conducted between 2007 and 2012, we compared participants aged 40-79 years with spirometry-defined COPD to compare the prevalence of comorbidities between men and women. The survival of the subjects was documented, and the sex discrepancy was determined using Kaplan-Meier analysis. Comorbidities and all-cause mortality were analyzed by using a Cox proportional hazards model to determine their strength of association in different sex groups. RESULTS: Compared to men, women had a significantly higher prevalence of asthma (OR 1.93, 95% CI 1.46 to 2.57, p < 0.001) and arthritis (OR 1.77, 95% CI 1.39 to 2.24, p < 0.001). Women had a significantly lower prevalence of coronary heart disease (OR 0.48, 95% CI 0.27 to 0.87, p = 0.015) and gout (OR 0.42, 95% CI 0.25 to 0.67, p = 0.001). Kaplan-Meier analysis revealed that compared with that of the female group, the survival rate of the male group was significantly lower (p < 0.001). Among men, the presence of anemia (HR 2.38, [95% CI 1.52-3.73], p < 0.001), gout (HR 1.55, [95% CI 1.04-2.30], p = 0.029) and congestive heart failure comorbidities (HR 1.85, [95% CI 1.12-3.04] p = 0.016) was associated with a higher risk of mortality; among women, the presence of anemia (HR 2.21, [95% CI 1.17-4.20], p = 0.015) and stroke (HR 2.04, [95% CI 1.07-3.88], p = 0.031) comorbidities was associated with a higher risk of mortality after adjusting for age, race/Hispanic status, BMI, smoking status, FEV1% predicted and prevalent comorbidities. CONCLUSIONS: COPD-related comorbidities and all-cause mortality were discrepant between men and women, and men had poorer survival than women in the nationally representative data that were analyzed.

Zr(IV)-based metal-organic framework nanocomposites with enhanced peroxidase-like activity as a colorimetric sensing platform for sensitive detection of hydrogen peroxide and phenol.

Recently, metal-organic frameworks (MOFs) have great potential as an emerging peroxide-mimicking enzyme, and the improvement of its enzyme-like activity is desired. There are few studies on improving the peroxidase-like activity of MOFs by using the strategy of size reduction. Moreover, it is challenging to enhance the activity of Zr-based MOFs with peroxidase-mimicking activity by size reduction strategy. In this work, the synthesis of Zr-based MOFs capped with polyvinylpyrrolidone (Zr-MOF-PVP) was firstly reported to reduce crystal size of peroxidase-mimicking enzyme for enhanced catalytic activity. Using the 3,3',5,5'-Tetramethylbenzidine (TMB) as substrate, the synthesized Zr-MOF-PVP nanocomposites with nanosize (about 45 nm) possessed obviously enhanced peroxidase-like activity compared with the pristine Zr-MOF. Based on the above, the Zr-MOF-PVP was also successfully applied in constructing colorimetric detection. By using hydrogen peroxide (H2O2) and phenol as the model analytes, the satisfactory detection performance was obtained, indicating that the proposed method had an attractive application prospect in the field of peroxidase-related detection. Besides, this work also provided a new perspective for improving the catalytic activity of nanozymes.

Synergetic integration of catalase and Fe3O4 magnetic nanoparticles with metal organic framework for colorimetric detection of phenol.

Toxic phenol pollutants pose a great threat to the environment, it is urgent to develop an efficient and recyclable method to monitor phenol. Herein, we reported the synthesis of catalase-Fe3O4@ZIF-8 (CAT-Fe3O4@ZIF-8) through a novel amino-acid-boosted one-pot embedding strategy that synergically integrated catalase and magnetic Fe3O4 nanoparticles with ZIF-8. As expected, CAT-Fe3O4@ZIF-8 exhibited enhanced catalytic activity compared with Fe3O4@ZIF-8, CAT@ZIF-8 and catalase. Depending on the satisfactory performance of CAT-Fe3O4@ZIF-8, a colorimetric detection platform for phenol based on CAT-Fe3O4@ZIF-8 was constructed. The corresponding detection limit was as low as 0.7 µM, and a wide linear range of 5-100 µM was obtained. Besides, CAT-Fe3O4@ZIF-8-based colorimetric detection platform has been verified to possess high stability and recyclability. The proposed method was proven to have potential practical applications in the field of water treatment, which would advance efficient, recyclable monitoring of water quality.

Vacuum Foam Drying Method Improved the Thermal Stability and Long-Term Shelf Life of a Live Attenuated Newcastle Disease Virus Vaccine.

Vaccines used for managing Newcastle disease virus (NDV) rely heavily on cold chain, and this results in major constraints in their successful application, shipping, and storage. This study was undertaken to improve the thermotolerance properties of live attenuated NDV vaccines using vacuum foam drying (VFD) technology. The live attenuated NDV vaccine formulated in 15% trehalose, 2.5% gelatin, 0.05% pluronic, and 25 mmol/L potassium phosphate buffer (T5) and dried using VFD showed improved heat tolerance in comparison to the vaccine formulated in T5 as well, but dried using freeze-drying (FD) method. The T5-formulated VFD vaccine was stored at 37°C for 120 days, 45°C for 7 days, and 60°C for 3 days; the virus titer loss decreased by no more than 1.0 Log10. In contrast, the FD vaccine prepared in T5 could only be stored at 37°C for 7-10 days. Furthermore, the T5-formulated NDV-VFD vaccine remained infectious when heated at 100°C for 30 min. Shelf-life studies confirmed the improved thermal tolerance of the T5-formulated NDV-VFD vaccine since it could be stably stored at 2-8°C for 42 months and 25°C for 15 months. Moreover, immunization of 1-month-old specific pathogen-free (SPF) chickens with the T5-formulated NDV-VFD vaccine stored at 25 and 37°C could produce hemagglutination inhibition (HI) antibody levels comparable to those of commercial NDV-FD vaccines, which require strict adherence to the cold chain. In conclusion, not only did the VFD technology improve the thermostability and long-term shelf life of the vaccine, it also maintained its immunogenicity.

Galectin-9 regulates follicular helper T cells to inhibit humoral autoimmunity-induced pulmonary fibrosis.

Interstitial pneumonia with autoimmune features (IPAF) is an unexplained disease state characterized by autoimmunity and pulmonary fibrosis. Exploring the pathogenesis of IPAF is helpful for the treatment of interstitial pneumonia and idiopathic pulmonary fibrosis. In this study, we observed that the lung Galectin-9 (Gal-9) of IPAF patients was significantly reduced, which was significantly related to lung dysfunction and abnormal humoral immunity. Moreover, an overreactive germinal center (GC) reaction in the lung lymph nodes (LNs) of Gal-9-deficient mice was found to be related to abnormally active follicular helper T cells (Tfh) cells. The lack of Gal-9 ligand in Tfh cells can lead to excessive transcriptional programming and differentiation and help GC B cells. Gal-9 deficiency caused an abnormal humoral immune response in mice, leading to excessive deposition of nonspecific autoantibodies in mice and chronic lung fibrosis. Our research reveals the important regulatory role of gal-9 in Tfh cells and a possible target for the treatment of IPAF.

A genome epidemiological study of mycobacterium tuberculosis in subpopulations with high and low incidence rate in Guangxi, South China.

BACKGROUND: Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis (Mtb). China is the third in top 8 high TB burden countries and Guangxi is one of the high incidence areas in South China. Determine bacterial factors that affected TB incidence rate is a step toward Ending the TB epidemic. RESULTS: Genomes of M. tuberculosis cultures from a relatively high and low incidence region in Guangxi have been sequenced. 347 of 358(96.9%) were identified as M. tuberculosis. All the strains belong to Lineage 2 and Lineage 4, except for one in Lineage 1. We found that the genetic structure of the M. tuberculosis population in each county varies enormously. Low incidence rate regions have a lower prevalence of Beijing genotypes than other regions. Four isolates which harbored mutT4-48 also had mutT2-58 mutations. It is suggested that strains from the ancestors of modern Beijing lineage is circulating in Guangxi. Strains of modern Beijing lineage (OR=2.04) were more likely to acquire drug resistances than Lineage 4. Most of the lineage differentiation SNPs are related to cell wall biosynthetic pathways. CONCLUSIONS: These results provided a higher resolution to better understand the history of transmission of M. tuberculosis from/to South China. And the incidence rate of tuberculosis might be affected by bacterial population structure shaped by demographic history. Our findings also support the hypothesis that Modern Beijing lineage originated in South China.

Vertebral bone marrow edema in magnetic resonance imaging correlates with bone healing histomorphometry in (sub)acute osteoporotic vertebral compression fracture.

BACKGROUND: BME on MRI has become the gold standard for the diagnosis of acute/subacute OVCF, but the correlation between the quantitative model of BME and histopathological manifestations of OVCF is rarely discussed in the literature. OBJECTIVES: This study aimed to retrospectively investigate the relationship between bone marrow edema (BME) in magnetic resonance imaging (MRI) and bone healing histomorphometry in (sub)acute osteoporotic vertebral compression fracture. METHODS: According to the period since fracture, 125 patients were divided into four stages: stage I (0 to 15 days), stage II (16 to 30 days), stage III (31 to 60 days) and stage IV (61 to 90 days). Bone marrow edema was evaluated by the signal changes and intensity patterns on MRI sagittal images. Decalcified biopsy specimens were obtained from the cancellous bone core in the fractured vertebral body. The histomorphometry study results were analyzed by light microscopy using grid analysis and defined using bone histomorphometry criteria. RESULTS: There were 70 (56%) patients in stage I, 29 (23.2%) in stage II, 12 (9.6%) in stage III and 14 (11.2%) in stage IV. BME and histomorphometry characteristics differentiated from each other stage: The BME percentage had a significantly negative correlation with the ratio of osteoid volume/bone volume (r = - 0.539, p = 0.001) and the ratio of woven bone volume/tissue volume (r = - 0.584, p = 0.001). There was also a positive correlation between the BME percentage and the ratio of fibrous tissue volume/tissue volume (r = 0.488, p = 0.001). CONCLUSIONS: Bone marrow edema significantly correlates with bone morphology parameters after vertebral fracture. The characteristics of histomorphological changes during fracture healing process can be preliminarily determined by observing the edema signal.

Colloidal-sized zirconium porphyrin metal-organic frameworks with improved peroxidase-mimicking catalytic activity, stability and dispersity.

Metal-organic frameworks (MOFs) have attracted great attention as enzyme mimic materials in colorimetric hydrogen peroxide (H2O2) detection. At present, it is highly desirable but remains challenging to prepare MOFs with high stability and dispersity to further improve their peroxidase-mimicking catalytic activity. In this work, we developed a new and facile method for the synthesis of a sub-100 nm peroxidase-mimicking zirconium porphyrin metal-organic framework (Zr-PorMOF) via a solvothermal method. The experimental results indicated that compared with the micron-sized crystals obtained using a classical synthesis method, the catalytic activity, stability and dispersity in water of the colloidal Zr-PorMOF were obviously enhanced. The as-synthesized colloidal Zr-PorMOF was further successfully applied in colorimetric H2O2 detection, and satisfactory detection performance was obtained. Furthermore, the colloidal Zr-PorMOF was also successfully employed in the construction of a peroxidase-based tandem catalysis system. Taking glucose oxidase as an example, this system was successfully applied for glucose sensing in real human serum samples, which proved its practical feasibility in diabetes diagnosis and indicates its high potential feasibility in peroxidase-related applications in complex biomatrix.

Genomic analysis provides insights into the transmission and pathogenicity of Talaromyces marneffei.

Talaromyces marneffei (T. marneffei) is a medically important opportunistic dimorphic fungus that infects both humans and bamboo rats. However, the mechanisms of transmission and pathogenicity of T. marneffei are poorly understood. In our study, we combined Illumina and PacBio sequencing technologies to sequence and assemble a complete genome of T. marneffei. To elucidate the transmission route and source, we sequenced three additional T. marneffei isolates using Illumina sequencing technology. Variations among isolates were used to develop a multilocus sequence typing (MLST) system comprising five housekeeping genes that can be used to discriminate between isolates derived from different sources. Our analysis revealed that human and bamboo rat share identical genotypes in these five loci. Thus, we hypothesized that T. marneffei is transmitted to humans through inhalation of spores in the surrounding environment into the lungs and that the bamboo rat can serve as an important natural reservoir for pathogens. Furthermore, we also identified temperature-dependent polyketide synthases, non-ribosomal peptide synthetases and secreted proteins as putative pathogenicity-related factors. In addition, we identified antifungal drug targets that can be investigated in future studies to elucidate the mechanisms underlying drug resistance. In summary, our study presents the basic features of the T. marneffei genome and provides insights into the transmission and pathogenicity of T. marneffei, which warrant fundamental experimental research.

Banana Transcription Factor MaERF11 Recruits Histone Deacetylase MaHDA1 and Represses the Expression of MaACO1 and Expansins during Fruit Ripening.

Phytohormone ethylene controls diverse developmental and physiological processes such as fruit ripening via modulation of ethylene signaling pathway. Our previous study identified that ETHYLENE RESPONSE FACTOR11 (MaERF11), a transcription factor in the ethylene signaling pathway, negatively regulates the ripening of banana, but the mechanism for the MaERF11-mediated transcriptional regulation remains largely unknown. Here we showed that MaERF11 has intrinsic transcriptional repression activity in planta. Electrophoretic mobility shift assay and chromatin immunoprecipitation analyses demonstrated that MaERF11 binds to promoters of three ripening-related Expansin genes, MaEXP2, MaEXP7 and MaEXP8, as well as an ethylene biosynthetic gene MaACO1, via the GCC-box motif. Furthermore, expression patterns of MaACO1, MaEXP2, MaEXP7, and MaEXP8 genes are correlated with the changes of histone H3 and H4 acetylation level during fruit ripening. Moreover, we found that MaERF11 physically interacts with a histone deacetylase, MaHDA1, which has histone deacetylase activity, and the interaction significantly strengthens the MaERF11-mediated transcriptional repression of MaACO1 and Expansins Taken together, these findings suggest that MaERF11 may recruit MaHDA1 to its target genes and repress their expression via histone deacetylation.

Solvent templates induced porous metal-organic materials: conformational isomerism and catalytic activity.

Solvent templates induced Co-based metal-organic materials; conformational isomers {[Co2(pdpa)(CH3CN)(H2O)3]·CH3OH·H2O}n (1) and {[Co2(pdpa)(CH3CN)(H2O)3]}n (2) and {[Co5(pdpa)2(µ3-OH)2(H2O)6]·2H2O}n (3) [H4pdpa = 5,5'-(pentane-1,2-diyl)-bis(oxy)diisophthalic acid] were synthesized under the same solvothermal conditions except with different concentrations of cyclic ethers (1,4-dioxane or tetrahydrofuran) as structure-directing agents. Structural transformations from a three-dimensional (3D) framework of 1 containing channels with dimensions of ∼6 Å × 6 Å to a two-dimensional layer structure of 2 consisting of large open channels with a size of ∼15 Å × 8 Å and then to a 3D nonporous framework of 3, resulting from the different concentrations of cyclic ethers, were observed. The anion-π interactions between electron-efficient oxygen atoms of cyclic ethers and electron-deficient dicarboxylic acid aromatic cores in H4pdpa imported into the synthetic process accounted for the conformational change of the ligand H4pdpa and the following structural variations. A systematic investigation was conducted to explore how different concentrations of structure-directing agents affected the frameworks of resultant metal-organic frameworks. Furthermore, 1-3 were shown to be available heterogeneous catalysts for the synthesis of 2-imidazoline and 1,4,5,6-tetrahydropyrimidine derivatives by the cascade cycloaddition reactions of aromatic nitriles with diamines. The results showed that the catalytic activity of 2 was much higher than that of 1 and 3, because of its unique structural features, including accessible catalytic sites and suitable channel size and shape. In addition, a plausible mechanism for these catalytic reactions was proposed, and the reactivity-structure relationship was further clarified.

Clinical characteristics and outcomes in critical patients with hemorrhagic fever with renal syndrome.

BACKGROUND: Hemorrhagic fever with renal syndrome (HFRS) has become an important public health concern because of the high incidence and mortality rates, and limited treatment and vaccination. Until now, clinical studies on characteristics and outcomes in critical patients with HFRS have been limited. The aim of this study was to observe the clinical characteristics and cumulative proportions surviving and explore the predictive effects and risk factors for prognosis. METHODS: A detailed retrospective analysis of clinical records for critical HFRS patients was conducted. The patients enrolled were treated in the centre for infectious diseases, Tangdu Hospital, between January 2008 and August 2012. The clinical characteristics between the survivors and non-survivors were compared by Student's t-test or Chi-square test. The risk clinical factors for prognosis were explored by logistic regression analysis. The predictive effects of prognosis in clinical and laboratory parameters were analyzed by receiver operating characteristic (ROC) curves. The cumulative proportions surviving at certain intervals in the critical patients were observed by Kaplan-Meier survival analysis. RESULTS: Of the 75 patients enrolled, the cumulative proportion surviving was 70.7% at the second week interval, with a 28-day mortality rate of 36.3%. The non-survivors tended to have higher frequencies of agitation, dyspnea, conjunctival hemorrhage, coma, cardiac failure, acute respiratory distress syndrome (ARDS) and encephalopathy (P < .05). ARDS, conjunctival hemorrhage and coma were risk factors for death in the critical patients with HFRS. The non-survivors were found to have lower serum creatinine (Scr) levels (P < .001) and higher incidences of prolonged prothrombin time (PT) (P = .006), activated partial thromboplastin time (APTT) (P = .003) and elevated white blood cells (WBC) levels (P = .005), and the laboratory parameters mentioned above reached statistical significance for predicting prognosis (P < .05). CONCLUSION: The high fatality in critical patients with HFRS underscores the importance of clinicians' alertness to the occurrence of potentially fatal complications and changes in biochemical status to ensure that timely and systematically supportive treatment can be initiated when necessary.

Early indicators of severity and construction of a risk model for prognosis based upon laboratory parameters in patients with hemorrhagic fever with renal syndrome.

BACKGROUND: The objective of this study was to explore the role of laboratory parameters as early indicators of severity and as effective predictors of prognosis in patients with hemorrhagic fever with renal syndrome (HFRS). METHODS: A total of 356 patients were enrolled in this study and were divided into mild, moderate, severe and critical types according to the clinical classification of HFRS. The levels of 12 routinely tested laboratory parameters during the acute stage among the four types were compared. The predictive values of the laboratory parameters for prognosis were analyzed, and a risk model for prognosis based upon the parameters was constructed. RESULTS: The levels of white blood counts (WBC), platelets (PLT), aspartate aminotransferase (AST), albumin (ALB), blood urea nitrogen (BUN), serum creatinine (Scr), prothrombin time (PT) and activated partial thromboplastin time (APTT) demonstrated significant differences among the four types (p<0.001); WBC, AST, PT and fibrinogen (Fib) were major independent risk factors for death; WBC, AST, PT and Fib used in combination were better for predicting prognosis than single parameters used alone (p<0.001). CONCLUSIONS: Some routinely tested laboratory parameters can be beneficial as early indicators of severity of HFRS. Using a combination of WBC, AST, PT and Fib to predict the outcome in patients with HFRS exhibited acceptable diagnostic capability.

Efficient Removal of Greenhouse Gases: Machine Learning-Assisted Exploration of Metal-Organic Framework Space.

Global warming is a crisis that humanity must face together. With greenhouse gases (GHGs) as the main factor causing global warming, the adoption of relevant processes to eliminate them is essential. With the advantages of high specific surface area, large pore volume, and tunable synthesis, metal-organic frameworks (MOFs) have attracted much attention in GHG storage, adsorption, separation, and catalysis. However, as the pool of MOFs expands rapidly with new syntheses and discoveries, finding a suitable MOF for a particular application is highly challenging. In this regard, high-throughput computational screening is considered the most effective research method for screening a large number of materials to discover high-performance target MOFs. Typically, high-throughput computational screening generates voluminous and multidimensional data, which is well suited for machine learning (ML) training to improve the screening efficiency and explore the relationships between the multidimensional data in depth. This Review summarizes the general process and common methods for using ML to screen MOFs in the field of GHG removal. It also addresses the challenges faced by ML in exploring the MOF space and potential directions for the future development of ML for MOF screening. This aims to enhance the understanding of the integration of ML and MOFs in various fields and broaden the application and development ideas of MOFs.

Induction of jasmonate signalling regulators MaMYC2s and their physical interactions with MaICE1 in methyl jasmonate-induced chilling tolerance in banana fruit.

MYC2, a basic helix-loop-helix (bHLH) transcription factor, is a key regulator in the activation of jasmonate (JA) response. However, the molecular details of MYC2 involving in methyl jasmonate (MeJA)-induced chilling tolerance of fruit remain largely unclear. In the present work, two MYC2 genes, MaMYC2a and MaMYC2b, and one homolog of the inducer of the C-repeat-binding factor (CBF) gene, MaICE1 were isolated and characterized from banana fruit. MaMYC2s and MaICE1 were found to be all localized in the nucleus. In addition, the proline-rich domain (PRD) and the acidic domain (AD) in the N-terminus were important for the transcriptional activation of MaMYC2 in yeast cells. Unlike MaICE1's constitutive expression, MaMYC2a and MaMYC2b were induced rapidly following MeJA treatment during cold storage. Moreover, protein-protein interaction analysis confirmed that MaMYC2s interacted with MaICE1. The expression of ICE-CBF cold-responsive pathway genes including MaCBF1, MaCBF2, MaCOR1, MaKIN2, MaRD2 and MaRD5 was also significantly induced by MeJA. Taken together, our work provides strong evidence that MaMYC2 is involved in MeJA-induced chilling tolerance in banana fruit through physically interacting and likely functionally coordinating with MaICE1, revealing a novel mechanism for ICE1 in response to cold stress as well as during development of induced chilling tolerance.

Changes in Type II NRG-1 Expression during Regeneration Following Autologous Nerve Transplantation in Rats.

AIM: To investigate the changes in type II neuregulin-1 (NRG-1) during the regeneration process following autologous sciatic nerve transplantation in rats. MATERIAL AND METHODS: In total, 40 healthy male Sprague-Dawley (SD) rats of clean grade with body weights between 250 g and 300 g were randomly divided into an experimental and control group, with 20 rats per group. Five time points were set, including the 3 < sup > rd < /sup > , 7 < sup > th < /sup > , 14 < sup > th < /sup > , 21 < sup > st < /sup > and 28 < sup > th < /sup > days after surgery. In the experimental group, reversed autologous transplantation of the sciatic nerve was performed, while in the control group, the sciatic nerve was simply exposed without autologous transplantation. At the different time points, changes in the rat footprints were observed, the sciatic functional index (SFI) was calculated, changes in the regeneration of the myelin sheath at the nerve end after transplantation were observed by transmission electron microscopy, changes in type II NRG-1 protein expression were detected by a western blot analysis, and changes in type II NRG-1 mRNA expression were detected by real-time PCR. RESULTS: The SFI in the experimental group was lower than that in the control group at all time points after surgery, and the SFI in the experimental group gradually increased; these differences were statistically significant (p < 0.05). The expression of type II NRG-1 protein in the experimental group was significantly increased on the 3rd day after nerve transplantation and peaked on the 7 < sup > th < /sup > day, which continued until the 28 < sup > th < /sup > day after surgery, indicating a significant difference from the control group (p < 0.01). NRG-1 mRNA expression was markedly increased on the 7th day after nerve transplantation, further increased, and peaked on the 14 < sup > th < /sup > day (p < 0.01). The area of medullated nerve fibers (?m2) in the experimental group significantly differed from that in the control group on the 7 < sup > th < /sup > , 14 < sup > th < /sup > , 21 < sup > st < /sup > and 28 < sup > th < /sup > days (p < 0.01), and the diameters of the axons in the experimental group notably differed from those in the control group on the 7 < sup > th < /sup > , 14 < sup > th < /sup > and 21 < sup > st < /sup > days (p < 0.01). CONCLUSION: Type II NRG-1 expression peaked between the 3 < sup > rd < /sup > day and 14 < sup > th < /sup > day after autologous nerve transplantation and is likely involved in the regulation of myelin sheath regeneration during this period.

Type III NRG-1 plays a regulatory role in the regeneration process of nerves from the beginning of transplantation.

The present study investigated the effect of type III Neuregulin-1 (NRG-1) on changes in the myelin sheath and the recovery of nerve function during the regeneration process following autologous nerve transplantation. Seventy-two Sprague-Dawley rats were divided into a Blank, Model and (antisense oligonucleotide, ASON) group. The Model and ASON groups of SD rats were subjected to autologous nerve transplantation, and the Blank group only had the sciatic nerve exposed. The Model and ASON groups were given local injections of 2 ml PBS buffer solution and 2 ml ASON of Type III NRG-1, respectively, the NRG-1 type III was inhibited by ASON. Changes in the sciatic nerve functional index (SFI) and conduction velocities were observed at different 6 time points. Regeneration of the myelin sheath was observed using transmission electron microscopy. Type III NRG-1 protein was detected using Western blotting and immunohistochemistry, and NRG-1 mRNA was detected using PCR. The SFI of the ASON group was lower than the Model group after transplantation. The conduction velocities of the ASON group on the 14th and 21st days after autologous nerve transplantation were lower than the Model group (P < 0.01). The protein and mRNA expression of type III NRG-1 in the ASON group was lower than the Model group at all 6 time points. The area of medullated nerve fibres was significantly different between the ASON group and the Model group on the 3rd day (P < 0.05), as was the number of medullated nerve fibres per unit area (P < 0.01). The diameter of axons was obviously different between the two groups (P < 0.01). Type III NRG-1 played an important regulatory role in the regeneration process of the nerve from the beginning of transplantation to the 28th day.

A Phase I Expansion Cohort Study Evaluating the Safety and Efficacy of the CHK1 Inhibitor LY2880070 with Low-dose Gemcitabine in Patients with Metastatic Pancreatic Adenocarcinoma.

PURPOSE: Combining gemcitabine with CHK1 inhibition has shown promise in preclinical models of pancreatic ductal adenocarcinoma (PDAC). Here, we report the findings from a phase I expansion cohort study (NCT02632448) investigating low-dose gemcitabine combined with the CHK1 inhibitor LY2880070 in patients with previously treated advanced PDAC. PATIENTS AND METHODS: Patients with metastatic PDAC were treated with gemcitabine intravenously at 100 mg/m2 on days 1, 8, and 15, and LY2880070 50 mg orally twice daily on days 2-6, 9-13, and 16-20 of each 21-day cycle. Pretreatment tumor biopsies were obtained from each patient for correlative studies and generation of organoid cultures for drug sensitivity testing and biomarker analyses. RESULTS: Eleven patients with PDAC were enrolled in the expansion cohort between August 27, 2020 and July 30, 2021. Four patients (36%) experienced drug-related grade 3 adverse events. No objective radiologic responses were observed, and all patients discontinued the trial by 3.2 months. In contrast to the lack of efficacy observed in patients, organoid cultures derived from biopsies procured from two patients demonstrated strong sensitivity to the gemcitabine/LY2880070 combination and showed treatment-induced upregulation of replication stress and DNA damage biomarkers, including pKAP1, pRPA32, and γH2AX, as well as induction of replication fork instability. CONCLUSIONS: No evidence of clinical activity was observed for combined low-dose gemcitabine and LY2880070 in this treatment-refractory PDAC cohort. However, the gemcitabine/LY2880070 combination showed in vitro efficacy, suggesting that drug sensitivity for this combination in organoid cultures may not predict clinical benefit in patients.