Genomic insights into local adaptation and vulnerability of Quercus longinux to climate change

BACKGROUND

Climate change is expected to alter the factors that drive changes in adaptive variation. This is especially true for species with long life spans and limited dispersal capabilities. Rapid climate changes may disrupt the migration of beneficial genetic variations, making it challenging for them to keep up with changing environments. Understanding adaptive genetic variations in tree species is crucial for conservation and effective forest management. Our study used landscape genomic analyses and phenotypic traits from a thorough sampling across the entire range of Quercus longinux, an oak species native to Taiwan, to investigate the signals of adaptation within this species.

RESULTS

Using ecological data, phenotypic traits, and 1,933 single-nucleotide polymorphisms (SNPs) from 205 individuals, we classified three genetic groups, which were also phenotypically and ecologically divergent. Thirty-five genes related to drought and freeze resistance displayed signatures of natural selection. The adaptive variation was driven by diverse environmental pressures such as low spring precipitation, low annual temperature, and soil grid sizes. Using linear-regression-based methods, we identified isolation by environment (IBE) as the optimal model for adaptive SNPs. Redundancy analysis (RDA) further revealed a substantial joint influence of demography, geology, and environments, suggesting a covariation between environmental gradients and colonization history. Lastly, we utilized adaptive signals to estimate the genetic offset for each individual under diverse climate change scenarios. The required genetic changes and migration distance are larger in severe climates. Our prediction also reveals potential threats to edge populations in northern and southeastern Taiwan due to escalating temperatures and precipitation reallocation.

CONCLUSIONS

We demonstrate the intricate influence of ecological heterogeneity on genetic and phenotypic adaptation of an oak species. The adaptation is also driven by some rarely studied environmental factors, including wind speed and soil features. Furthermore, the genetic offset analysis predicted that the edge populations of Q. longinux in lower elevations might face higher risks of local extinctions under climate change.

Ibrutinib facilitates the sensitivity of colorectal cancer cells to ferroptosis through BTK/NRF2 pathway

Ibrutinib is a drug that inhibits the protein Burton's tyrosine kinase and thereby the nuclear translocation of Nrf2, which played a key role in mediating the activation of antioxidants during stress conditions and ferroptosis resistance. This study aimed to identify the effect of Ibrutinib and ferroptosis inducer on colorectal cancer (CRC) treatment and its underlying mechanism. In our study, we found the upregulation of Nrf2 was correlated with CRC progression and antioxidant proteins. Ibrutinib sensitized CRC to ferroptosis inducers, suggested by further reduced CRC cell viability, proliferation and decreased antioxidant protein levels in CRC cells after combination treatment of Ibrutinib and RSL3 or Ibrutinib and Erastin both in vivo and in vitro. Knockout of Nrf2 diminished the regulatory effect of Ibrutinib on CRC sensitivity to ferroptosis inducers. Altogether, this study demonstrated that Ibrutinib increases the sensitivity of CRC cell to ferroptosis inducers by inhibiting Nrf2.

A preoperative nomogram predicts prognosis of up front resectable patients with pancreatic head cancer and suspected venous invasion

BACKGROUND

Pancreatic head adenocarcinoma is commonly diagnosed at an advanced stage when adjacent vascular invasion is present. This study aimed to establish a preoperative prognostic nomogram for patients who underwent attempted curative resectional surgery for pancreatic head cancer with suspected peripancreatic venous invasion.

METHODS

Data on all consecutive patients were retrospectively collected from 2012 to 2016 at four academic institutions. The demographic and radiological parameters were analyzed using univariate and multivariate Cox regression analyses. The final nomogram was established using the concordance Harrell's C-indices and calibration curves from data obtained in three institutions and validated in the cohort of patients coming from the fourth institution.

RESULTS

The nomogram was constructed using data from 178 patients while the validation cohort consisted of 61 patients. Age, length of tumor contact, peripancreatic venous abnormalities and lymph node staging were independent factors of overall survival. The nomogram showed good probabilities of survival on calibration curves. The C-index of the model in predicting overall survival (OS) was 0.824 for the validation cohort.

CONCLUSIONS

The nomogram accurately predicted OS in patients with pancreatic head cancer with suspected peripancreatic venous invasion after attempted curative pancreatic resectional surgery.

Modified-FOLFIRINOX in metastatic pancreatic cancer: A prospective study in Chinese population

FOLFIRINOX chemotherapy has shown remarkable responses in patients with metastatic pancreatic cancer (MPC), and has significantly improved prognosis. However, FOLFIRINOX is currently not frequently applied in China because of its high incidence of adverse events, and there is no recognized optimization for this therapy in Chinese population. Modification of FOLFIRINOX may be better for its acceptance in China. In this study, we evaluated the efficacy and safety of modified-FOLFIRINOX in patients with MPC. A total of 62 MPC patients were treated with modified-FOLFIRINOX (no Fluorouracil bolus, 85% Oxaliplatin and 75% Irinotecan) between April 2014 and April 2017 in our institute. 40 of them were evaluated, with a response rate of 32.5% (13/40). The frequent grade 3/4 adverse events are neutropenia (29%) and alanine aminotransferase elevation (14.5%). No treatment-related death was observed. The median overall survival and median progression-free survival are 10.3 months and 7.0 months, respectively. In conclusion, modified-FOLFIRINOX had significantly improved tolerance with similar efficacy to FOLFIRINOX. These findings may provide evidence for the use of FOLFIRINOX in Chinese patients with MPC.

Superiority of mitral valve replacement with preservation of subvalvular structure to conventional replacement in severe rheumatic mitral valve disease: a modified technique and results of one-year follow up

BACKGROUND AND AIM OF THE STUDY

Mitral valve replacement with preservation of the subvalvular apparatus (MRVP) has been proven superior to conventional mitral valve replacement (MVR). We devised a simple modified MVRP method in this prospective, randomized study to investigate the clinical effects and one-year follow up echocardiographic results of MVRP compared with MVR in patients with severe rheumatic mitral insufficiency (MI).

METHODS

Sixty-eight patients with severe rheumatic MI with or without stenosis were randomized to MVRP (n = 35) and MVR (n = 33) groups. In MVRP patients, the preserved tissue was pulled back posteriorly to the posterior wall of the left ventricle, then plicated and reaffixed to one-fourth of the annular circumference in the posterior annulus, in order to prevent left ventricular outflow tract (LVOT) obstruction. Clinical data including cumulative ventricular arrhythmias and use of inotropes were collected. Echocardiography examination was performed before surgery, and at five days, three months and one year thereafter.

RESULTS

There were no preoperative differences patient data. The cross-clamp time was 2.2 min longer in MVRP patients. The one-month mortality rate after surgery was lower in MVRP patients (2.9% versus 15.2%, p = 0.074). Mechanical ventilation and ICU times were shorter in the MVRP group (17.6 versus 24.8 and 52.5 versus 70.6 h, p = 0.001 and 0.1, respectively). There were fewer ventricular arrhythmias and less need for inotropic support in this group. One year follow up echocardiography data showed better preserved left ventricular ejection fraction (LVEF) and better recovery of heart size after MRVP. There was no indication that preserved valvular tissue interfered with mechanical valve function, or caused LVOT obstruction.

CONCLUSION

This modified MVRP technique is simple, effective and without risk of LVOT obstruction. In severe rheumatic MI patients the outcome of MVRP is superior to that of conventional MVR in term's of mortality, postoperative care needs, left ventricular function and heart dimensions.

Cyanide-induced neurotoxicity involves nitric oxide and reactive oxygen species generation after N-methyl-D-aspartate receptor activation

To study oxidative mechanisms in cyanide toxicity, cyanide-induced generation of intracellular oxidant species was determined by microfluorescence in cerebellar granule cells loaded with the oxidant-sensitive fluorescence dye 2,7-dichlorofluorescin. KCN produced a concentration-dependent (25-200 microM) generation of intracellular oxidant species that was blocked by N-methyl-D-aspartate receptor antagonists (MK-801 or AP5) or by removal of extracellular Ca++ from the incubation medium. To determine the relative contribution of NO and reactive oxygen species (ROS) to the increase of cellular fluorescence after KCN, a selective inhibitor of nitric oxide synthase, a NO scavenger and enzymes that metabolize ROS were added to the incubation medium. Interference with the nitric oxide system (reduced hemoglobin as a NO scavenger or [N(G)-nitro-L-arginine methyl ester [L-NAME] reduced fluorescence by 50%). Addition of enzymes that metabolize peroxide (catalase or superoxide dismutase [SOD]) also reduced fluorescence by nearly 50%. Combination of SOD with hemoglobin or L-NAME provided additional attenuation of the fluorescence and it was concluded that both NO and ROS are generated concurrently after KCN. Furthermore a correlation was observed between NO and ROS formation and levels of malonaldehyde (MDA), a marker of lipid peroxidation. Pretreatment with MK-801 blocked KCN-induced MDA formation, whereas L-NAME partially diminished MDA production. Treatment with a combination of SOD/catalase and L-NAME blocked the KCN-induced lipid peroxidation. In cytotoxicity studies cyanide-induced cell death was blocked by MK-801, whereas partial attenuation was produced by L-NAME; SOD/catalase treatments did not protect the cells. However, significant protection from cyanide-induced cytotoxicity was observed when L-NAME was combined with SOD/catalase. It is concluded that cyanide activates N-methyl-D-aspartate receptors to simultaneously generate both NO and ROS, which may lead to formation of the cytotoxic peroxynitrite anion.