The Hengduan Mountains (HDM) biodiversity hotspot exhibits exceptional alpine plant diversity. Here, we investigate factors driving intraspecific divergence within a HDM alpine species Salix ...brachista (Cushion willow), a common component of subnival assemblages. We produce a high-quality genome assembly for this species and characterize its genetic diversity, population structure and pattern of evolution by resequencing individuals collected across its distribution. We detect population divergence that has been shaped by a landscape of isolated sky island-like habitats displaying strong environmental heterogeneity across elevational gradients, combined with population size fluctuations that have occurred since approximately the late Miocene. These factors are likely important drivers of intraspecific divergence within Cushion willow and possibly other alpine plants with a similar distribution. Since intraspecific divergence is often the first step toward speciation, the same factors can be important contributors to the high alpine species diversity in the HDM.
The diverse biological effects of nanomaterials form the basis for their applications in biomedicine but also cause safety issues. Induction of autophagy is a cellular response after nanoparticles ...exposure. It may be beneficial in some circumstances, yet autophagy‐mediated toxicity raises an alarming concern. Previously, it has been reported that upconversion nanoparticles (UCNs) elicit liver damage, with autophagy contributing most of this toxicity. However, the detailed mechanism is unclear. This study reveals persistent presence of enlarged autolysosomes in hepatocytes after exposure to UCNs and SiO2 nanoparticles both in vitro and in vivo. This phenomenon is due to anomaly in the autophagy termination process named autophagic lysosome reformation (ALR). Phosphatidylinositol 4‐phosphate (PI(4)P) relocates onto autolysosome membrane, which is a key event of ALR. PI(4)P is then converted into phosphatidylinositol 4,5‐bisphosphate (PI(4,5)P2) by phosphatidylinositol‐4‐phosphate 5‐kinase. Clathrin is subsequently recruited by PI(4,5)P2 and leads to tubule budding of ALR. Yet it is observed that PI(4)P cannot be converted in nanoparticle‐treated hepatocytes cells. Exogenous supplement of PI(4,5)P2 suppresses the enlarged autolysosomes in vitro. Abolishment of these enlarged autolysosomes by autophagy inhibitor relieves the hepatotoxicity of UCNs in vivo. The results provide evidence for disrupted ALR in nanoparticle‐treated hepatocytes, suggesting that the termination of nanoparticle‐induced autophagy is of equal importance as the initiation.
In hepatocytes treated with upconversion nanoparticles (UCN) or nano‐SiO2, loss of phosphatidylinositol‐4‐phosphate 5‐kinase causes the disrupted phospholipid transition from phosphatidylinositol 4‐phosphate to phosphatidylinositol 4,5‐bisphosphate on enlarged autolysosomal membrane and clathrin fails to be recruited to autolysosomes; autophagic lysosome reformation is blocked, leading to enlarged autolysosomes. In the UCN‐treated mice liver, manipulation of autophagy by 3‐methyladenine or trehalose affects liver damage.
Summary
ETHYLENE INSENSITIVE 3 (EIN3) is a key regulator of ethylene signaling, and EIN3‐BINDING F‐BOX1 (EBF1) and EBF2 are responsible for EIN3 degradation. Previous reports have shown that the ebf1 ...ebf2 double homozygous mutant cannot be identified. In this study, the genetic analysis revealed that the ebf1 ebf2 female gametophyte is defective. The pollination experiment showed that ebf1 ebf2 ovules failed to attract pollen tubes. In female gametophyte/ovule, the synergid cell is responsible for pollen tube attraction. Observation of the pEIN3::EIN3‐GFP transgenic lines showed that EIN3 signal was over‐accumulated at the micropylar end of ebf1 ebf2 female gametophyte. The overexpression of stabilized EIN3 in synergid cell led to the defect of pollen tube guidance. These results suggested that the over‐accumulated EIN3 in ebf1 ebf2 synergid cell blocks its pollen tube attraction which leads to the failure of ebf1 ebf2 homozygous plant. We identified that EIN3 directly activated the expression of a sugar transporter, SENESCENCE‐ASSOCIATED GENE29 (SAG29/SWEET15). Overexpression of SAG29 in synergid cells blocked pollen tube attraction, suggesting that SAG29 might play a role in ethylene signaling to repel pollen tube entry. Taken together, our study reveals that strict control of ethylene signaling is critical for the synergid cell function during plant reproduction.
Significance Statement
Our study reveals the mechanism of ethylene signaling in synergid functioning for pollen tube attraction and facilitates the understanding of ethylene signaling in plant reproduction.
Summary
Understanding processes that generate and maintain large disjunctions within plant species can provide valuable insights into plant diversity and speciation. The butterfly bush Buddleja ...alternifolia has an unusual disjunct distribution, occurring in the Himalaya, Hengduan Mountains (HDM) and the Loess Plateau (LP) in China.
We generated a high‐quality, chromosome‐level genome assembly of B. alternifolia, the first within the family Scrophulariaceae. Whole‐genome re‐sequencing data from 48 populations plus morphological and petal colour reflectance data covering its full distribution range were collected.
Three distinct genetic lineages of B. alternifolia were uncovered, corresponding to Himalayan, HDM and LP populations, with the last also differentiated morphologically and phenologically, indicating occurrence of allopatric speciation likely to be facilitated by geographic isolation and divergent adaptation to distinct ecological niches. Moreover, speciation with gene flow between populations from either side of a mountain barrier could be under way within LP. The current disjunctions within B. alternifolia might result from vicariance of a once widespread distribution, followed by several past contraction and expansion events, possibly linked to climate fluctuations promoted by the Kunlun–Yellow river tectonic movement. Several adaptive genes are likely to be either uniformly or diversely selected among regions, providing a footprint of local adaptations.
These findings provide new insights into plant biogeography, adaptation and different processes of allopatric speciation.
Abstract
Azaleas (Ericaceae) comprise one of the most diverse ornamental plants, renowned for their cultural and economic importance. We present a chromosome-scale genome assembly for
Rhododendron ...simsii
, the primary ancestor of azalea cultivars. Genome analyses unveil the remnants of an ancient whole-genome duplication preceding the radiation of most Ericaceae, likely contributing to the genomic architecture of flowering time. Small-scale gene duplications contribute to the expansion of gene families involved in azalea pigment biosynthesis. We reconstruct entire metabolic pathways for anthocyanins and carotenoids and their potential regulatory networks by detailed analysis of time-ordered gene co-expression networks. MYB, bHLH, and WD40 transcription factors may collectively regulate anthocyanin accumulation in
R. simsii
, particularly at the initial stages of flower coloration, and with WRKY transcription factors controlling progressive flower coloring at later stages. This work provides a cornerstone for understanding the underlying genetics governing flower timing and coloration and could accelerate selective breeding in azalea.
Mesenchymal stem cells (MSCs) are promising candidates for cell-based therapies. Human platelet lysate represents an efficient alternative to fetal bovine serum for clinical-scale expansion of MSCs. ...Different media used in culture processes should maintain the biological characteristics of MSCs during multiple passages. However, bone marrow-derived MSCs and adipose tissue-derived MSCs have not yet been directly compared with each other under human platelet lysate conditions. This study aims to conduct a direct head-to-head comparison of the biological characteristics of the two types of MSCs under human platelet lysate-supplemented culture conditions for their ability to be used in regenerative medicine applications.
The bone marrow- and adipose tissue-derived MSCs were cultured under human platelet lysate conditions and their biological characteristics evaluated for cell therapy (morphology, immunophenotype, colony-forming unit-fibroblast efficiency, proliferation capacity, potential for mesodermal differentiation, secreted proteins, and immunomodulatory effects).
Under human platelet lysate-supplemented culture conditions, bone marrow- and adipose tissue-derived MSCs exhibited similar fibroblast-like morphology and expression patterns of surface markers. Adipose tissue-derived MSCs had greater proliferative potential than bone marrow-derived MSCs, while no significantly difference in colony efficiency were observed between the two types of cells. However, bone marrow-derived MSCs possessed higher capacity toward osteogenic and chondrogenic differentiation compared with adipose tissue-derived MSCs, while similar adipogenic differentiation potential wase observed between the two types of cells. There were some differences between bone marrow- and adipose tissue-derived MSCs for several secreted proteins, such as cytokine (interferon-γ), growth factors (basic fibroblast growth factor, hepatocyte growth factor, and insulin-like growth factor-1), and chemokine (stem cell-derived factor-1). Adipose tissue-derived MSCs had more potent immunomodulatory effects than bone marrow-derived MSCs.
Adipose tissue-derived MSCs have biological advantages in the proliferative capacity, secreted proteins (basic fibroblast growth factor, interferon-γ, and insulin-like growth factor-1), and immunomodulatory effects, but bone marrow-derived MSCs have advantages in osteogenic and chondrogenic differentiation potential and secreted proteins (stem cell-derived factor-1 and hepatocyte growth factor); these biological advantages should be considered systematically when choosing the MSC source for specific clinical application.
Cancer metastasis leading to the dysfunction of invaded organs is the main cause of the reduced survival rates in lung cancer patients. However, the molecular mechanism for lung cancer metastasis ...remains unclear. Recently, the increased activity of inflammasome appeared to correlate with the metastatic progression and immunosuppressive ability of various cancer types. Our results showed that the mRNA levels of absence in melanoma 2 (AIM2), one of the inflammasome members, are extensively upregulated in primary tumors compared with normal tissues derived from the TCGA lung adenocarcinoma (LUAD) database. Moreover, Kaplan‐Meier analysis demonstrated that a higher mRNA level of AIM2 refers to a poor prognosis in LUAD patients. Particularly, AIM2 upregulation is closely correlated with smoking history and the absence of EGFR/KRAS/ALK mutations in LUAD. We further showed that the endogenous mRNA levels of AIM2 are causally associated with the metastatic potentials of the tested LUAD cell lines. AIM2 knockdown suppressed but overexpression promoted the migration ability and lung colony–forming ability of tested LUAD cells. In addition, we found that AIM2 upregulation is closely associated with an increased level of immune checkpoint gene set, as well as programmed cell death‐ligand 1 (PD‐L1) transcript, in TCGA LUAD samples. AIM2 knockdown predominantly repressed but overexpression enhanced PD‐L1 expression via altering the activity of PD‐L1 transcriptional regulators NF‐κB/STAT1 in LUAD cells. Our results not only provide a possible mechanism underlying the AIM2‐promoted metastatic progression and immune evasion of LUAD but also offer a new strategy for combating metastatic/immunosuppressive LUAD via targeting AIM2 activity.
The illustration of a possible mechanism for the AIM2‐fostered EMT progression and PD‐L1 expression in the metastatic/immunosuppressive lung adenocarcinoma. AIM2 increases PD‐L1 expression via activating its transcriptional regulators NF‐kB/STAT1.
This population-based retrospective cohort study investigated the prevalence of myopia among patients with Type 1 and Type 2 diabetes mellitus (DM) and evaluate risk factors for myopia in these ...groups. Records from 2000 to 2012 with at least one year of follow-up from the Taiwan National Health Insurance Research Database were included. This study included 35,538 patients with DM and 71,076 patients without DM. Patients with DM had a significantly higher adjusted hazard ratio for myopia in all age groups and both sexes compared with patients without DM. The subgroup analysis results revealed that the rates of myopia and astigmatism were significantly higher among patients with DM compared with patients without DM aged < 60 years. However, the rates of high myopia or myopia progression to high myopia did not differ significantly between the two groups. These findings indicate that DM is a critical risk factor for myopia and astigmatism among patients aged < 60 years. Therefore, active surveillance and earlier treatment of myopia are critical for patients with DM.
It has rarely been studied whether the presence and severity of diabetic retinopathy (DR) could influence the renal disease progression among all chronic kidney disease (CKD) diabetic patients. This ...study investigates the characteristics of diabetic patients, with different stages of chronic kidney disease (CKD), according to the occurrence of diabetic retinopathy and determines the influence of retinopathy in the deterioration of renal function. We conduct a multicenter, longitudinal cohort study based on the Epidemiology and Risk Factors Surveillance of the CKD project (2008⁻2013) and the National Health Insurance Research Database (NHIRD) (2001⁻2013). A total of 4050 diabetic patients with CKD, 20⁻85 years of age, from 14 hospitals and the community are included in this study. As compared to CKD patients without DR, CKD patients with DR have a lower baseline estimated glomerular filtration rate (eGFR) (39.17 ± 30.36 mL/min per 1.73 m² vs. 54.38 ± 33.67 mL/min per 1.73 m² ); poorer glycemic control (higher glycated hemoglobin (HbA1c) 7.85 ± 4.97 vs. 7.29 ± 4.02,
< 0.01); higher proteinuria (urine protein-to-creatinine ratio (UPCR )1.94 ± 2.96 g/dL vs. 0.91 ± 2.11 g/dL,
< 0.01); more anemia (Hb 11.22 ± 2.43 g/dL vs. 12.39 ± 3.85 g/dL,
< 0.01), and more hypoalbuminemia (3.88 ± 0.95 g/dL vs. 4.16 ± 1.74 g/dL,
< 0.01). Later stage (stage 3b⁻5) CKD patients with DR had significantly higher CKD progression compared with patients without DR (OR (odds ratio) 1.66 (1.36⁻2.02)). Patients with proliferative DR had significantly higher CKD progression events compared to patients with non-proliferative DR (OR 2.18 (1.71⁻2.78)). The presence and severity of DR is a risk factor for CKD progression among our Taiwanese CKD patients with diabetes. Prevention and early detection of DR are important and DR should be routinely screened as early as possible among diabetic CKD patients.
Sodium salicylate, one of the non‐steroidal anti‐inflammatory drugs, is widely prescribed in the clinic, but a high dose of usage can cause hyperactivity in the central nervous system, including the ...hippocampus. At present, the neural mechanism underlying the induced hyperactivity is not fully understood, in particular, in the hippocampus under an in vivo condition. In this study, we found that systemic administration of sodium salicylate increased the field excitatory postsynaptic potential slope and the population spike amplitude in a dose‐dependent manner in the hippocampal dentate gyrus area of rats with in vivo field potential extracellular recordings, which indicates that sodium salicylate enhances basal synaptic transmission and neural excitation. In the presence of picrotoxin, a GABA‐A receptor antagonist, sodium salicylate failed to increase the initial slope of the field excitatory postsynaptic potential and the amplitude of the population spike in vivo. To further explore how sodium salicylate enhances the neural excitation, we made whole‐cell patch‐clamp recordings from hippocampal slices. We found that perfusion of the slice with sodium salicylate decreased electrically evoked GABA receptor‐mediated currents, increased paired‐pulse ratio, and lowered frequency and amplitude of miniature inhibitory postsynaptic currents. Together, these results demonstrate that sodium salicylate enhances the neural excitation through suppressing GABAergic synaptic transmission in presynaptic and postsynaptic mechanisms in the hippocampal dentate gyrus area. Our findings may help understand the side effects caused by sodium salicylate in the central nervous system.
PDF
