Direct quantification of optic nerve blood flow by 3D pseudo-continuous arterial spin labeling.

BACKGROUND: Blood perfusion of the optic nerve (ON) plays a key role in many optic neuropathies. Microvascular changes precede or accompany neuronal changes, and detecting these changes at an early stage may facilitate early treatment to avoid blindness. However, the quantification of ON blood perfusion remains a challenge. This study aimed to evaluate the viability of three-dimensional pseudocontinuous arterial spin labelling (3D-pCASL) MRI for the quantification of ON blood flow (BF). NEW METHOD: The ON segmentation was performed using nnFormer on a cohort of ten participants (4 males, 6 females, 25-59 years old). Subsequently, the mean BF of each ON segment was calculated using whole brain 3D-pCASL image data. RESULTS: The average ON-BF values of the left and right intraorbital segments, left and right intracanalicular segments, left and right intracranial segments, optic chiasma, and left and right optic tract were 41.308 mL/100 g/min, 43.281 mL/100 g/min, 53.188 mL/100 g/min, 57.202 mL/100 g/min, 45.089 mL/100 g/min, 49.554 mL/100 g/min, 42. 326 mL/100 g/min, 43.831 mL/100 g/min and 45.176 mL/100 g/min, respectively. The ON-BF correlated with cerebral BF (r = 0.503, p = 0.024). COMPARISON WITH EXISTING METHOD(S): The 3D-pCASL can measure tissue microvascular blood perfusion in absolute quantitative units with good test-retest repeatability over a wide field of view and without restrictions on depth. The use of the nnFormer makes the measurement easy, objective and reproducible. CONCLUSIONS: The study showed that, 3D-pCASL may be a promising tool for detecting abnormal ON-BF. In particular, 3D-pCASL coupled with the nnFormer provides an objective, reproducible, and reliable method to quantify BF in ON.

Identification of miRNAs and Target Genes at Key Stages of Sexual Differentiation in Androdioecious Osmanthus fragrans.

Androdioecy is the crucial transition state in the evolutionary direction of hermaphroditism to dioecy, however, the molecular mechanisms underlying the formation of this sex system remain unclear. While popular in China for its ornamental and cultural value, Osmanthus fragrans has an extremely rare androdioecy breeding system, meaning that there are both male and hermaphroditic plants in a population. To unravel the mechanisms underlying the formation of androdioecy, we performed small RNA sequencing studies on male and hermaphroditic O. fragrans. A total of 334 miRNAs were identified, of which 59 were differentially expressed. Functional categorization revealed that the target genes of differentially expressed miRNAs were mainly involved in the biological processes of reproductive development and the hormone signal transduction pathway. We speculated that the miRNA160, miRNA167, miRNA393 and miRNA396 families may influence the sex differentiation in O. fragrans. Overall, our study is the first exploration of miRNAs in the growth and development process of O. fragrans, and is also the first study of androdioecious plants from the miRNA sequencing perspective. The analysis of miRNAs and target genes that may be involved in the sex differentiation process lay a foundation for the ultimate discovery of the androdioecious molecular mechanism in O. fragrans.

A complete chloroplast genome of Keteleeria davidiana (Pinaceae) and its phylogenetic implications.

Keteleeria davidiana (Bertrand) Beissner 1891 (Pinaceae) is a rare tertiary relict plant endemic to China. However, since the main morphological characteristics used for identifying K. davidiana are variable, some taxonomic treatments within the species are still controversial. Here a complete chloroplast genome of K. davidiana representing a special genotype was assembled, which could provide more information for the taxonomic study of this species. The assembled genome was 117,642 bp in length with a large single-copy (LSC) region (74,825 bp), a small single-copy (SSC) region (40,247 bp), and two incomplete inverted repeats (IRs) regions (1285 bp each). In total, 118 genes were predicted, including 4 rRNAs, 34 tRNAs, and 80 protein-coding genes. The overall GC content of the assembled genome was 38.5%. Phylogenetic analysis showed that different accessions of K. davidiana formed a clade with relatively low support (bootstrap value = 71), which indicated a high level of sequences variation within the species.

Complete chloroplast genome of a wild-type Gardenia jasminoides ellis (rubiaceae) adapted to island climate.

Gardenia jasminoides Ellis is a traditional aromatic and medicinal plant in China. Here, the complete chloroplast genome of a wild-type gardenia adapted to island climate was assembled. The assembled genome was 155,247 bp in length, with four typical regions, i.e., a large single-copy (LSC) region (85,414 bp), a small single-copy (SSC) region (18,235 bp) and two inverted repeats (IRs) regions (25,799 bp each). In total, 138 genes were predicted, including 90 protein-coding genes, 40 tRNA genes and eight rRNA genes. The overall GC content of the chloroplast genome was 37.5%. The chloroplast genome would provide more information for the phylogeography and phylogeny study of G. jasminoides.

Sulfated glycosaminoglycans in decellularized placenta matrix as critical regulators for cutaneous wound healing.

Perinatal-related tissues, such as the placenta, umbilical cord, and amniotic membrane, are generally discarded after delivery and are increasingly attracting attention as alternative sources for decellularized extracellular matrix (dECM) isolation. Recent studies indicate that glycosaminoglycans (GAGs) in the dECM play key roles during tissue regeneration. However, the dECM is organ specific, and the glycosaminoglycanomics of dECMs from perinatal tissues and the regulatory function of GAGs have been poorly investigated. In this study, we explored the glycosaminoglycanomics of dECMs from the placenta, umbilical cord and amniotic membrane. We hypothesized that the therapeutic effects of dECMs are related to the detailed composition of GAGs. Hydrogels of dECM derived from perinatal tissues were generated, and glycosaminoglycanomics analysis was employed to identify the cues that promote tissue repair and regeneration in a murine cutaneous wound-healing model. We utilized highly sensitive liquid chromatography-tandem mass spectrometry for glycosaminoglycanomics analysis. Our results revealed that placenta-derived dECM (PL-dECM) hydrogel has higher contents of chondroitin sulfate (CS) and heparan sulfate (HS). In addition, molecular imaging showed that the PL-dECM hydrogel exerted the best anti-inflammatory and proangiogenic effects in the skin wound healing model. Further in vitro analyses demonstrated that CS with 6-O-sulfo group (CS-6S) has an anti-inflammatory effect, while HS with 6-O-sulfo group (HS-6S) plays a crucial role in angiogenesis. In conclusion, this study highlights the critical roles of GAGs in perinatal tissue-derived dECMs by promoting angiogenesis and inhibiting inflammation and indicates that it is feasible to utilize 6-sulfated GAG-enriched placental dECM hydrogel as an attractive candidate for tissue engineering and drug delivery.