Physiological and Transcriptional Analyses Provide Insight into Maintaining Ion Homeostasis of Sweet Sorghum under Salt Stress

Sweet sorghum is an important bioenergy grass and valuable forage with a strong adaptability to saline environments. However, little is known about the mechanisms of sweet sorghum coping with ion toxicity under salt stresses. Here, we first evaluated the salt tolerance of a sweet sorghum cultivar "Lvjuren" and determined its ion accumulation traits under NaCl treatments; then, we explored key genes involved in Na⁺, Cl^-, K⁺ and NO₃^- transport using transcriptome profiling and the qRT-PCR method. The results showed that growth and photosynthesis of sweet sorghum were unaffected by 50 and 100 mM NaCl treatments, indicative of a strong salt tolerance of this species. Under NaCl treatments, sweet sorghum could efficiently exclude Na⁺ from shoots and accumulate Cl^- in leaf sheaths to avoid their overaccumulation in leaf blades; meanwhile, it possessed a prominent ability to sustain NO₃^- homeostasis in leaf blades. Transcriptome profiling identified several differentially expressed genes associated with Na⁺, Cl^-, K⁺ and NO₃^- transport in roots, leaf sheaths and leaf blades after 200 mM NaCl treatment for 6 and 48 h. Moreover, transcriptome data and qRT-PCR results indicated that HKT1;5, CLCc and NPF7.3-1 should be key genes involved in Na⁺ retention in roots, Cl^- accumulation in leaf sheaths and maintenance of NO₃^- homeostasis in leaf blades, respectively. Many TFs were also identified after NaCl treatment, which should play important regulatory roles in salt tolerance of sweet sorghum. In addition, GO analysis identified candidate genes involved in maintaining membrane stability and photosynthetic capacity under salt stresses. This work lays a preliminary foundation for clarifying the molecular basis underlying the adaptation of sweet sorghum to adverse environments.

[Reliability and validity of the Chinese version of the test of the adherence to inhalers (TAI)]

Objectives: To evaluate the reliability and validity of the Chinese version of the test of the adherence to inhalers (TAI) in Chinese patients with chronic airway disease. Methods: Based on the English version of TAI, the items of the Chinese version of TAI were determined after forward-backward translation and cultural adaption. Totally, 165 patients with chronic obstructive pulmonary disease (COPD) and asthma were enrolled from Respiratory Clinic of the Second Xiangya Hospital of Central South University from July to November 2021, and a questionnaire survey was conducted using the Chinese version of TAI and the Morisky medication adherence scale 8-item version (MMAS-8). The content validity of the scale was expressed by content validity index (CVI) and the construct validity was analyzed by exploratory factor analysis (EFA). The convergence validity was evaluated by Pearson correlation analysis. The reliability of the scale was expressed by Cronbach's α coefficient, the split-half reliability and test-retest reliability. Results: The CVI was 0.966. There were 10 items in total. Two factors were extracted from the Chinese version of TAI and the cumulative variance contribution rate was 57.236%. The load value of each item was more than 0.400 and the factor attribution of the item was consistent with the original scale. The total score of the Chinese version of TAI was positively correlated with the total score of the MMAS-8(r=0.835,P<0.001). The Cronbach's α of the overall scale was 0.843, the Guttman's half-reliability coefficient was 0.796 and the test-retest reliability was 0.884 (P<0.001), respectively. Conclusions: The Chinese version of TAI has good reliability and validity, which may be a reliable tool for evaluating the adherence to inhalers of patients with chronic airway disease in China.

[Effect of FBXW7 gene mutation on the prognosis of immunotherapy in patients with non-small cell lung cancer]

Objective: To explore the effect of F-box and WD-40 domain protein 7 (FBXW7) gene mutation on the prognosis of immunotherapy in patients with non-small cell lung cancer (NSCLC). Methods: (1) The clinical data of 125 patients with advanced NSCLC in the First Affiliated Hospital of Nanjing Medical University from January 2019 to June 2021 were collected. There were 70 males and 55 females, with a median age [M (Q₁, Q₃)] of 64(57, 70) years. The correlation of FBXW7 mutation with immunotherapy efficacy and prognosis was analyzed. (2) The Data set of NSCLC patients treated with immunotherapy from cBioPortal database was downloaded. A total of 261 patients were included as immunotherapy group. There were 120 males and 141 females, with a median age of 66(57, 73) years. The association of FBXW7 mutation with clinical characteristics and prognosis of NSCLC patients was investigated. (3) The data of patients with NSCLC from the cancer genome atlas (TCGA) database were downloaded. A total of 1 030 patients were included as TCGA group. There were 633 males and 397 females, with a median age of 67(60, 73) years. The effect of FBXW7 mutation on the efficacy of immunotherapy was analyzed. The key molecules and their biological functions were also determined Results: Among the 125 NSCLC patients, the FBXW7 mutation rate was 5.6% (7/125). All FBXW7 mutation types was truncating mutation. In these FBXW7 mutation patients who received immunotherapy, 4 had partial response, 2 had stable disease, and 1 had progressive disease. The objective response rate (ORR) and disease control rate (DCR) were 4/7 and 6/7, respectively. The median progression-free survival (PFS) was 13.0 months (95%CI: 7.0-22.0 months) for patients with FBXW7 mutation and 4.0 months (95%CI: 2.0-11.5 months) for patients with FBXW7 wild type, with a statistically significant difference (P=0.046). The bioinformatics analysis indicated that patients with FBXW7 mutation have higher clinical benefits from immunotherapy. Moreover, patients with FBXW7 mutation in immunotherapy group had higher tumor mutational burden (TMB) [M (Q₁, Q₃): 17.8 (11.5, 29.3)/Mb] than those with FBXW7 wild type [5.7 (3.0, 10.4)/Mb, P=0.001]. The TMB of patients with FBXW7 mutation in TCGA group was 15.9 (4.2, 28.1)/Mb, insertion-deletion (Indel) neoantigen was 192.5 (70.8, 535.0) and single nucleotide variant (SNV) neoantigen was 363.0 (194.8, 534.8), which were significantly higher than those of patients with FBXW7 wild type [5.6 (3.2, 8.9)/Mb, 53.0 (12.0, 131.0), 83.5 (34.0, 178.0), respectively] (P=0.002, P=0.008, P<0.001). The results indicated that FBXW7 mutated tumors had stronger immunogenicity, which might generate anti-tumor immunity. FBXW7 mutation was also related to the activation of T cells (T lymphocyte receptor complexes and signaling). In addition, FBXW7 mutation was correlated with increased infiltration of CD8⁺T cells and M1 macrophages. CD8⁺T cells and M1 macrophages infiltration level was significantly up-regulated in FBXW7 mutation group than wild-type group [10% (8%, 14%) vs 7%(4%, 12%), P=0.049; 8%(4%, 11%) vs 4%(1%, 8%), P=0.046]. Conclusions: NSCLC patients with FBXW7 mutant have higher clinical benefits from immunotherapy. FBXW7 mutation has the potential as a predictive marker for the efficacy of immunotherapy in NSCLC patients.

[Application and prospect of multiomics techniques in susceptibility to occupational noise hearing loss]

With the continuous innovation of technology, genomics and other omics techniques, such as transcriptomics, proteomics, and metabolomics, are increasingly becoming an important basis for precision medicine. Current research on susceptibility to occupational noise hearing loss (ONHL) has focused on genomics. Building the future of precision medicine is the focus of current ONHL research. Compared to single-omics studies, the use of multi-omics analysis can provide an integrated flow of information on ONHL susceptibility. This paper outlines the advantages and limitations of different histological techniques and the application of each histology in the disease, and focuses on the feasibility of applying multi-omics techniques in ONHL susceptibility research. The analysis of multi-omics techniques can better guide the comprehensive understanding of the disease in clinical research.

[Effect of serum lipid level on prognosis of patients with small cell lung cancer at the initial treatment]

Objective: To investigate the effect of serum lipid level on prognosis of patients with small cell lung cancer (SCLC) at the initial treatment. Methods: The clinical data of patients with SCLC from 2012 to 2017 in our hospital were retrospectively analyzed. According to the standard of appropriate level and abnormal stratification of blood lipid in Chinese population, the lipids included total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDLC) and low-density lipoprotein cholesterol (LDLC) at the time of initial treatment were grouped. Then the relationship between different lipid levels and clinicopathological characteristics was analyzed. Finally, Cox proportional hazard model was used to analyze the independent prognostic factors of patients. Results: A total of 129 patients with SCLC were included in this study. At the time of initial treatment, there were 90 (69.8%) cases whose TC < 5.2 mmol/L, while 39 (30.2%) cases ≥5.2 mmol/L; 95 (73.6%) cases whose TG <1.7 mmol/L, while 34 (26.4%) cases ≥1.7 mmol/L; 27 (20.9%) cases whose HDLC <1.0 mmol/L while 102 cases (79.1%) ≥1.0 mmol/L; 90 (69.8%) cases whose LDLC <3.4 mmol/L while 39 cases (30.2%) ≥3.4 mmol/L. The patients' triglyceride initial treatment was associated with their body mass index (P<0.05). The median disease-free survival (PFS) of SCLC patients was related with their serum TC level and clinical stage (P<0.05) and the overall survival (OS) was related with clinical stage of SCLC patients (P<0.05). The median PFS of SCLC patients in the TC <1.7 mmol/L group at the initial treatment was 10.5 months, significantly longer than 8.8 months of the TC ≥1.7 mmol/L group (P=0.024). The median OS of SCLC patients in the TG <1.7 mmol/L group at the initial treatment was 20.2 months, marginally longer than 15.6 months of the TG ≥1.7 mmol/L group (P=0.097). Multivariate analysis result showed that, the TG level was an independent risk factor of SCLC progression at the time of initial treatment (P=0.024). There was no significant correlation of TC, HDLC, LDLC and SCLC prognosis (P>0.05). Conclusion: TG level is an independent risk factor for the progression of SCLC at the time of initial treatment, and the increase of TG level indicates rapid disease progression and poor prognosis.

Chloride is beneficial for growth of the xerophyte Pugionium cornutum by enhancing osmotic adjustment capacity under salt and drought stresses

Chloride (Cl-) is pervasive in saline soils, and research on its influence on plants has mainly focused on its role as an essential nutrient and its toxicity when excessive accumulation occurs. However, the possible functions of Cl- in plants adapting to abiotic stresses have not been well documented. Previous studies have shown that the salt tolerance of the xerophytic species Pugionium cornutum might be related to high Cl- accumulation. In this study, we investigated the Cl--tolerant characteristics and possible physiological functions of Cl- in the salt tolerance and drought resistance of P. cornutum. We found that P. cornutum can accumulate a large amount of Cl- in its shoots, facilitating osmotic adjustment and turgor generation under saline conditions. Application of DIDS (4,4´-diisothiocyanostilbene-2,2´-disulfonic acid), a blocker of anion channels, significantly inhibited Cl- uptake, and decreased both the Cl- content and its contribution to leaf osmotic adjustment, resulting in the exacerbation of growth inhibition in response to NaCl. Unlike glycophytes, P. cornutum was able to maintain NO3- homeostasis in its shoots when large amounts of Cl- were absorbed and accumulated. The addition of NaCl mitigated the deleterious effects of osmotic stress on P. cornutum because Cl- accumulation elicited a strong osmotic adjustment capacity. These findings suggest that P. cornutum is a Cl--tolerant species that can absorb and accumulate Cl- to improve growth under salt and drought stresses.

Sodium chloride facilitates the secretohalophyte Atriplex canescens adaptation to drought stress

Atriplex canescens is a C₄ shrub with excellent adaptation to saline and arid environments. Our previous study showed that the secretion of excessive Na⁺ into leaf salt bladders is a primary strategy in salt tolerance of A. canescens and external 100 mM NaCl can substantially stimulate its growth. To investigate whether NaCl could facilitate Atriplex canescens response to drought stress, five-week-old seedlings were subjected to drought stress (30% of field water capacity) in the presence or absence of additional 100 mM NaCl. The results showed that, under drought stress, the addition of NaCl could substantially improve the growth of A. canescens by increasing leaf relative water content, enhancing photosynthetic activity and inducing a significant declined leaf osmotic potential (Ψs). The addition of NaCl significantly increased Na⁺ concentration in leaf salt bladders and the Na⁺ contribution to leaf Ψs, while had no adverse effects on K⁺ accumulation in leaf laminae. Therefore, the large accumulation of Na⁺ in salt bladders for enhancing osmotic adjustment (OA) ability is a vital strategy in A. canescens responding to drought stress. In addition, the concentration of free proline, bataine and soluble sugars exhibited a significant increase in the presence of NaCl under drought stress, and the betaine contribution to leaf Ψs was significantly increased by additional NaCl compared with that under drought treatment alone, suggesting that compatible solutes are also involved in OA in addition to functioning as protectants to alleviate water deficit injury.

Transcriptomic Profiling Identifies Candidate Genes Involved in the Salt Tolerance of the Xerophyte Pugionium cornutum

The xerophyte Pugionium cornutum adapts to salt stress by accumulating inorganic ions (e.g., Cl⁻) for osmotic adjustment and enhancing the activity of antioxidant enzymes, but the associated molecular basis remains unclear. In this study, we first found that P. cornutum could also maintain cell membrane stability due to its prominent ROS-scavenging ability and exhibits efficient carbon assimilation capacity under salt stress. Then, the candidate genes associated with the important physiological traits of the salt tolerance of P. cornutum were identified through transcriptomic analysis. The results showed that after 50 mM NaCl treatment for 6 or 24 h, multiple genes encoding proteins facilitating Cl⁻ accumulation and NO₃⁻ homeostasis, as well as the transport of other major inorganic osmoticums, were significantly upregulated in roots and shoots, which should be favorable for enhancing osmotic adjustment capacity and maintaining the uptake and transport of nutrient elements; a large number of genes related to ROS-scavenging pathways were also significantly upregulated, which might be beneficial for mitigating salt-induced oxidative damage to the cells. Meanwhile, many genes encoding components of the photosynthetic electron transport pathway and carbon fixation enzymes were significantly upregulated in shoots, possibly resulting in high carbon assimilation efficiency in P. cornutum. Additionally, numerous salt-inducible transcription factor genes that probably regulate the abovementioned processes were found. This work lays a preliminary foundation for clarifying the molecular mechanism underlying the adaptation of xerophytes to harsh environments.

[Spectrometric analyses of larotaxel and larotaxel liposomes quantification by high performance liquid chromatography]

OBJECTIVE

Larotaxel is a new chemical structure drug, which has not been marketed worldwide. Accordingly, the standard identification and quantification methods for larotaxel remain unclear. The spectrometric analyses were performed for verifying weight molecular formula, molecular weight and chemical structure of larotaxel. Besides, a quantification method was developed for measuring larotaxel in the liposomes.

METHODS

The molecular formula, molecular weight and chemical structure of larotaxel were studied by using mass spectrometry (MS), infra-red (IR), nuclear magnetic resonance (NMR) and ultraviolet-visible (UV-vis) spectrometric techniques. The absorption wavelength of larotaxel was investigated by UV-vis spectrophotometry full-wavelength scanning. Besides, a quantification method was developed by high performance liquid chromatography (HPLC), and then validated by measuring the encapsulation efficacy of larotaxel liposomes.

RESULTS

The four spectral characteristics of larotaxel were revealed and the corresponding standard spectra were defined. It was confirmed that larotaxel had the structure of tricyclic diterpenoids, with the molecular formula of C45H53NO14, the molecular weight of 831.900 1, and the maximum absorption wavelength of 230 nm. The quantitative method of larotaxel was established by using HPLC with a reversed phase C18 column (5 μm, 250 mm×4.6 mm), a mobile phase of acetonitrile-water (75:25, volume/volume), and a detection wavelength of 230 nm. The validation study exhibited that the established HPLC method was stable, and had a high recovery and precision in the quantitative measurement of larotaxel in liposomes. In addition, a new kind of larotaxel liposomes was also successfully prepared. The particle size of the liposomes was about 105 nm, with an even size distribution. And the encapsulation efficiency of larotaxel in the liposomes was above 80%.

CONCLUSION

The present study offers reference standard spectra of larotaxel, including MS, IR, NMR, and UV-vis, and confirms the molecular formula, molecular weight and chemical structure of larotaxel. Besides, the study develops a rapid HPLC method for quality control of larotaxel liposomes.

Identification of candidate genes related to salt tolerance of the secretohalophyte Atriplex canescens by transcriptomic analysis

BACKGROUND

Atriplex canescens is a typical C₄ secretohalophyte with salt bladders on the leaves. Accumulating excessive Na⁺ in tissues and salt bladders, maintaining intracellular K⁺ homeostasis and increasing leaf organic solutes are crucial for A. canescens survival in harsh saline environments, and enhanced photosynthetic activity and water balance promote its adaptation to salt. However, the molecular basis for these physiological mechanisms is poorly understood. Four-week-old A. canescens seedlings were treated with 100 mM NaCl for 6 and 24 h, and differentially expressed genes in leaves and roots were identified, respectively, with Illumina sequencing.

RESULTS

In A. canescens treated with 100 mM NaCl, the transcripts of genes encoding transporters/channels for important nutrient elements, which affect growth under salinity, significantly increased, and genes involved in exclusion, uptake and vacuolar compartmentalization of Na⁺ in leaves might play vital roles in Na⁺ accumulation in salt bladders. Moreover, NaCl treatment upregulated the transcripts of key genes related to leaf organic osmolytes synthesis, which are conducive to osmotic adjustment. Correspondingly, aquaporin-encoding genes in leaves showed increased transcripts under NaCl treatment, which might facilitate water balance maintenance of A. canescens seedlings in a low water potential condition. Additionally, the transcripts of many genes involved in photosynthetic electron transport and the C₄ pathway was rapidly induced, while other genes related to chlorophyll biosynthesis, electron transport and C₃ carbon fixation were later upregulated by 100 mM NaCl.

CONCLUSIONS

We identified many important candidate genes involved in the primary physiological mechanisms of A. canescens salt tolerance. This study provides excellent gene resources for genetic improvement of salt tolerance of important crops and forages.

The synergistic effects of sodium and potassium on the xerophyte Apocynum venetum in response to drought stress

Apocynum venetum is an eco-economic plant species with high adaptability to saline and arid environments. Our previous work has found that A. venetum could absorb large amount of Na⁺ and maintain high K⁺ level under saline conditions. To investigate whether K⁺ and Na⁺ could simultaneously enhance drought resistance in A. venetum, seedlings were exposed to osmotic stress (-0.2 MPa) in the presence or absence of additional 25 mM NaCl under low (0.01 mM) and normal (2.5 mM) K⁺ supplying conditions, respectively. The results showed that A. venetum should be considered as a typical K⁺-efficient species since its growth was unimpaired and possessed a strong K⁺ uptake and prominent K⁺ utilization efficiency under K⁺ deficiency condition. Leaf K⁺ concentration remained stable or was even significantly increased under osmotic stress in the presence or absence of NaCl, compared with that under control condition, regardless of whether the K⁺ supply was sufficient or not, and the contribution of K⁺ to leaf osmotic potential consistently exceeded 37%, indicating K⁺ is the uppermost contributor to osmotic adjustment of A. venetum. Under osmotic stress, the addition of 25 mM NaCl significantly increase Na⁺ accumulation in leaves and the contribution of Na⁺ to osmotic adjustment, thus improving the relative water content, concomitantly, promoting the photosynthetic activity resulting in an enhancement of overall plant growth. These findings suggested that, K⁺ and Na⁺ simultaneously play crucial roles in the osmotic adjustment and the maintenance of water status and photosynthetic activity, which is beneficial for A. venetum to cope with drought stress.

Growth retardation in senescent arterial smooth muscle cells and its reversal following brain stimulation: implications for atherogenesis

Advancing age and psychosocial stress are each associated with a rising incidence of atherosclerosis. In this investigation we attempted to answer the question of whether they are independent of each other or not. Since a key feature of atherosclerosis is the proliferation of arterial smooth muscle cells (ASMC), we transplanted aortic tissue from aged rats, half of which had received hypothalamic stimulation, as a model for stress, to growth supporting medium, immediately after stimulation and observed their growth behavior for a period of 4 months. Similar observations were carried out on young animals for comparison. Although there was little difference in outgrowth frequency of explants from young animals between stimulated and non-stimulated subjects, in the case of the older rats, explants from animals which were not stimulated were considerably retarded in their growth, whereas those from subjects which had received HS, grew as well as those of the younger ones. These results show that HS can reverse the growth decline in aortic tissues explanted from senescent rats. They also suggest that age per se is not atherogenic in terms of proliferative behavior of ASMC, whereas when interacted with a stressful condition, this may be the case. Since in the elderly there is a decreased tolerance to stress, the 'atherogenic' effects of age in these individuals may be mediated through the stress response.

Age differences in the proliferative response of cultured arterial smooth muscle cells induced by sera of hypothalamically-stimulated rats

In an earlier report, it was shown that arterial smooth muscle cells (ASMC) cultured from normal rat aorta, proliferated in response to homologous sera from young rats which had received hypothalamic stimulation (HS), in contrast to the effect of sera from non-stimulated age-matched controls (sham-operated). In the present study, this proliferative response was compared in young and old rats. Isolated target cells were subcultured from primary explants of aortic tissue obtained from young, male, Fischer 344 rats, which were electrode-implanted in the hypothalamus but not stimulated. After an initial quiescence period (growth arrest), target cells were exposed to plasma derived serum (PDS) from 4 experimental groups: young stimulated rats; young sham-operated controls; aged stimulated rats and aged sham-operated controls, at PDS concentrations of 2.5% and 5.0% and counted at days 2 and 5. Proliferative responses of ASMC were found to be influenced by concentration of the PDS, age of the donor animal contributing the serum and the presence of HS. The greatest responses were observed in relation to sera derived from aged stimulated rats, especially at the higher concentration, suggesting an interaction of HS with advanced age. These results are discussed in reference to their possible bearing on the pathogenesis of atherosclerosis.