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Biomedical subjects

Qianqian Li

Publications and source records attributed to Qianqian Li.

4 recordsLinked to original sources

Strigolactones constrain rice drought acclimation by suppressing ROS scavenging through the D53-OsWRKY31-ZFP36 module.

Strigolactones (SLs) are a class of plant hormones essential for tiller development and yield under diverse environmental conditions. Drought is a major limiting factor for rice yields. Although SLs contribute to drought resistance, mechanisms and practical applications of SL pathway in drought acclimation of rice remain poorly understood. Our study shows that short-term dehydration represses SL biosynthesis in rice roots. Genetic assays indicate that disruption of SL biosynthesis or signaling elevates rice drought resistance, whereas SL signaling activation or supplementation with the SL analog GR244DO impairs drought resistance. SLs negatively regulate drought acclimation by promoting degradation of the repressor protein DWARF53 (D53). D53 interacts with the transcription factor OsWRKY31 via its N-terminal domain and suppresses the protein level of OsWRKY31, which binds to and represses transcription of the ZFP36 promoter. ZFP36 encodes a zinc-finger transcription factor that promotes H2O2 scavenging to sustain reactive oxygen species (ROS) homeostasis during drought stress. Notably, the drought-resistant upland rice variety IRAT109 exhibits lower SL levels in root exudates than the lowland rice variety Nipponbare (NP). Genome editing of key components in SL pathway enhances drought resistance in NP, Huazhan (HZ), and IRAT109. The agronomic potential of tuning SL biosynthesis is further supported by the elite D17/HTD1 allele, which weakens SL biosynthesis and improves drought resistance and grain yield in Nekken 2 (NK2) under field conditions. These findings uncover a key mechanism underlying SL-repressed drought acclimation in rice and provide an effective strategy to improve drought resistance in diverse rice varieties amid ongoing climate change.

D53

Oro-esophageal feeding for tracheostomized patients with severe traumatic brain injury: a randomized controlled trial.

BACKGROUND: This study reports the clinical effects of intermittent oro-esophageal tube feeding (IOE) versus nasogastric tube feeding (NGT) on nutritional status, aspiration pneumonia, decannulation, and level of consciousness in tracheostomized patients with severe traumatic brain injury (sTBI). METHODS: A randomized controlled trial was conducted between March 2024 and October 2025 in China and included tracheostomized patients with sTBI. Participants were randomized 1:1 to the intervention and control groups for 28-day interventions. IOE or NGT was used for nutritional supports, respectively. The primary outcome was nutritional status, including hemoglobin, albumin, prealbumin and body mass index. The secondary outcomes included aspiration pneumonia, decannulation, and level of consciousness assessed using the Glasgow Coma Scale (GCS). Generalized linear mixed-effects models, generalized estimating equations, and Cox regression were used for data analyze. RESULTS: A total of 104 participants were included in the analysis. After intervention, significant interaction effects were observed in hemoglobin (&#x3b2;&#x2009;=&#x2009;5.272, 95% CI: 2.707, 7.837), albumin (&#x3b2;&#x2009;=&#x2009;3.675, 95% CI: 1.854, 5.496), prealbumin (&#x3b2;&#x2009;=&#x2009;11.835, 95% CI: 6.623, 17.047), body mass index (&#x3b2;&#x2009;=&#x2009;1.719, 95% CI: 0.868, 2.569), the GCS (&#x3b2;&#x2009;=&#x2009;0.981, 95% CI: 0.572, 1.390), and aspiration pneumonia (OR= 0.304, 95% CI: 0.133, 0.693). The Cox model revealed that group significantly influenced the decannulation outcomes [HR (95% CI) =5.556 (3.197, 9.657), p&#x2009;<&#x2009;0.001]. CONCLUSIONS: In tracheostomized patients with sTBI who received routine treatment, IOE is more conducive to decannulation and the improvement in nutritional status, aspiration pneumonia, and level of consciousness than NGT. CLINICAL TRIAL REGISTRATION: Prospectively registered at ClinicalTrials.gov (NCT06328985, 03/18/2024, clinicaltrials.gov/study/NCT06328985).

Humans

Deciphering acquired resistance mechanisms to sustained auxin-inducible protein degradation in cells and mice.

Targeted protein degradation is a favorable strategy for studying the immediate downstream effects of protein loss-of-function. An appealing platform among these technologies is the auxin-inducible degron (AID) system. Although this system has been applied extensively to cell and animal models, degradation resistance to long-term auxin treatment has not been studied. With the advent of the new AID2 system, cellular toxicity due to the high concentrations of auxin required in the original AID1 system is no longer a concern, making it possible to study protein degradation over extended periods. In this study, we derived multiple miniAID-tagged knock-in human cell lines and a Ctcf-miniAID knock-in mouse strain to investigate mechanisms of degradation resistance. We revealed four independent resistance mechanisms, including a nonsense mutation in the CTCF coding sequence that removed the miniAID peptide, a missense point mutation in the miniAID coding region that disrupted ubiquitin complex targeting, and silencing of the OsTIR1 adaptor protein. Resistance to auxin degradation was also acquired in mouse primary CtcfminiAID/miniAID knock-in B-ALL cells through missense mutations of the OsTIR1(F74G) protein in vivo and ex vivo. In summary, our innovative study expands our understanding of the AID system and cautions careful consideration of design for future applications in mammalian system.

CTCF

Genetic analysis of three patients from two unrelated Chinese families with autosomal recessive spastic ataxia of Charlevoix-Saguenay.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a rare early-onset neurodegenerative disorder characterized by progressive cerebellar ataxia, spasticity, and sensorimotor peripheral neuropathy. This disorder is caused by homozygous or compound heterozygous variants in the sacsin (SACS) gene on chromosome 13q12.12. Three patients with ARSACS from two unrelated Chinese families were recruited for this study. Patient #1 was an 18-year-old male who had been walking unstably for 12 years. Patient #2, the younger sister of Patient #1, was a 5-year-old girl who had been walking unstably for 2 years. Patient #3 was a 19-year-old female who had been walking unstably and a tendency to fall for 17 years. For Patient #1, whole-exome sequencing (WES) identified a hemizygous variant c.8310_8313delAGAT (p.Asp2771fs4*) in SACS (NM_014363.6), with the father being heterozygous, the mother wild-type, and Patient #2 hemizygous, as verified by Sanger sequencing. Additional copy number variant analysis of the WES data indicated that Patient #1 had a heterozygous gross deletion of chr13q12.12 (chr13:23,808,732&#x2009;-&#x2009;24,890,322). Low-coverage whole-genome sequencing results revealed that Patient #2 carried a chr13q12.12 deletion (chr13:23,520,000-24,940,000). Together with Sanger sequencing results, this gross deletion was speculated to have been inherited from the mother, further explaining the hemizygous state of c.8310_8313delAGAT (p.Asp2771fs4*) in Patients #1 and #2. Through WES, Patient #3 was identified as having suspected compound heterozygous variants of c.2881&#xa0;C&#x2009;>&#x2009;T (p.Arg961*) and c.6409&#xa0;C&#x2009;>&#x2009;T (p.Gln2137*), inherited from the father and mother, respectively, as confirmed by Sanger sequencing. This study identified three variants in SACS. The c.8310_8313delAGAT (p.Asp2771fs4*) is novel, whereas c.2881&#xa0;C&#x2009;>&#x2009;T (p.Arg961*) and c.6409&#xa0;C&#x2009;>&#x2009;T (p.Gln2137*) have been reported previously. Moreover, this study highlights the growing trend that ARSACS has become increasingly prevalent worldwide rather than being localized to a specific region or race. As an increasing number of patients with ARSACS are diagnosed, the genetic spectrum of ARSACS will gradually broaden, providing an accurate genetic basis for prenatal diagnosis of mothers in the years ahead, if possible.

Adolescent