Background: MiR-34a is identified as a tumor suppressor gene and involved in acute myeloid leukemia (AML) development. However, the regulatory mechanism of miR-34a in AML is unclear. Methods: The expression of miR-34a and HMGB1 in HL-60, THP-1 and HS-5 cells were detected by qRT-PCR and western blot. Lipofectamine 2000 was used to transfect with miR-34a mimics, miR-34a inhibitor, si-HMGB1, pcDNA 3.1-HMGB1, and corresponding controls. The apoptosis and autophagy of transfected AML cells were assessed by flow cytometry and western blot, respectively. Bioinformatics software and dual luciferase reporter assay were applied to predict and verify the target of miR-34a. The effects of miR-34a mimics or si-HMGB1 on chemotherapy-induced autophagy were further explored in HL-60 cells treated with all-trans retinoic acid (ATRA) along with lysosomal protease inhibitors E64d and pepstatin A. Results: MiR-34a was lower expressed and HMGB1 mRNA and proteins were both higher expressed in HL-60 and THP-1 cells compared with that in HS-5 cells. Higher expression levels of MiR-34 and lower expression levels of HMGB1 both significantly promoted apoptosis and inhibited autophagy in HL-60 and THP-1 cells. Dual luciferase reporter system confirmed that HMGB1 was a potential target of miR-34a. Moreover, overexpression of HMGB1 dramatically reversed the promotion of apoptosis and inhibition of autophagy mediated by higher expression level of miR-34a. Higher expression level of miR-34a and lower expression level of HMGB1 both inhibited chemotherapy-induced autophagy by stimulating the LC3 conversion. Conclusion: MiR-34a promoted cell apoptosis and inhibited autophagy by targeting HMGB1. Therefore, miR-34a may be a potential promising molecular target for AML therapy.

Cerebral palsy is the most prevalent physical disability in children; however, its inherent molecular mechanisms remain unclear. In the present study, we performed in-depth clinical and molecular analysis on 120 idiopathic cerebral palsy families, and identified underlying detrimental genetic variants in 45% of these patients. In addition to germline variants, we found disease-related postzygotic mutations in approximately 6.7% of cerebral palsy patients. We found that patients with more severe motor impairments or a comorbidity of intellectual disability had a significantly higher chance of harboring disease-related variants. By a compilation of 114 known cerebral-palsy-related genes, we identified characteristic features in terms of inheritance and function, from which we proposed a dichotomous classification system according to the expression patterns of these genes and associated cognitive impairments. In two patients with both cerebral palsy and intellectual disability, we revealed that the defective TYW1, a tRNA hypermodification enzyme, caused primary microcephaly and problems in motion and cognition by hindering neuronal proliferation and migration. Furthermore, we developed an algorithm and demonstrated in mouse brains that this malfunctioning hypermodification specifically perturbed the translation of a subset of proteins involved in cell cycling. This finding provided a novel and interesting mechanism for congenital microcephaly. In another cerebral palsy patient with normal intelligence, we identified a mitochondrial enzyme GPAM, the hypomorphic form of which led to hypomyelination of the corticospinal tract in both human and mouse models. In addition, we confirmed that the aberrant Gpam in mice perturbed the lipid metabolism in astrocytes, resulting in suppressed astrocytic proliferation and a shortage of lipid contents supplied for oligodendrocytic myelination. Taken together, our findings elucidate novel aspects of the etiology of cerebral palsy and provide insights for future therapeutic strategies.

Constraint-induced movement therapy (CIMT) combined with repetitive transcranial magnetic stimulation (rTMS) have shown great potential in improving function in schoolchildren with unilateral cerebral palsy attributed to perinatal stroke. However, the prospect of application in preschool children with unilateral cerebral palsy (UCP) attributed to various brain disorders remains unclear. In this prospective, assessor-blinded, randomized controlled study, 40 preschool children with UCP (aged 2.5–6 years) were randomized to receive 10 days of CIMT combined with active or sham rTMS. Assessments were performed at baseline, 2 weeks, and 6 months post-intervention to investigate upper limb extremity, social life ability, and perceived changes by parents and motor-evoked potentials. Overall, 35 participants completed the trial. The CIMT plus active stimulation group had greater gains in the affected hand function (range of motion, accuracy, and fluency) than the CIMT plus sham stimulation group (P < 0.05), but there was no significant difference in muscular tone, social life ability, and perceived changes by parents between the two groups (P > 0.05). In addition, there was no significant difference in hand function between children with and without motor-evoked potential (P > 0.05). No participants reported severe adverse events during the study session. In short, the treatment of CIMT combined with rTMS is safe and feasible for preschool children with UCP attributed to various brain disorders. Randomized controlled studies with large samples and long-term effects are warranted.

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