Biology subjects

Zhang, Q.-L.

Publications and source records attributed to Zhang, Q.-L..

3 recordsLinked to original sources

bioRxiv2025

Putative long-range mossy fiber sprouting and regional hypermetabolic capacity in the hippocampus of patients with mesial temporal lobe epilepsy

Mesial temporal lobe epilepsy (MTLE) is pathologically characterized by neuronal loss in the dentate hilus, CA3 and CA1 regions, and mossy fiber (MF) sprouting into the inner molecular layer (iML). The latter forms aberrant excitatory circuities that are considered to facilitate recurrent seizures, with the subiculum also being related to epileptogenic activation. We recently identified a distinct expression of -smooth muscle actin (SMA) at the MF terminals in human hippocampus. This prompted us to explore MF sprouting in resected hippocampi (n=20) from patients with MTLE relative to postmortem control (n=20) using SMA along with reference markers for pathological cross-validation. Compared to control, neuronal loss assessed with neuron-specific nuclear antigen and sortilin immunolabeling reached CA1 in all resected hippocampi. SMA, zinc transporter 3 and {beta}-secretase 1 immunolabeling in the iML tended to be increased. The MF-related markers also revealed a preserved fibrous band extending across CA1 to subiculum. Cytochrome c oxidase immunolabeling also increased in iML and subiculum in the MTLE group. Taking together, the current findings point to the existence of long-range MF sprouting and a regional hypermetabolic compacity in the hippocampal formation of patients with drug resistant MTLE.

neuroscience↗

bioRxiv2024

Sortilin C-terminal fragment deposition depicts tangle-related nonamyloid neuritic plaque growth in Alzheimers disease

Sortilin C-terminal fragments (sorfra) can co-deposit in {beta}-amyloid (A{beta}) plaques in human brain. However, sorfra plaques develop in the cerebrum with a spatiotemporal trajectory as of tauopathy. Here we examined sorfra pathogenesis relative to neuritic plaque evolution in the human brains with amyloid and tau pathologies converged in the neocortex and hippocampus. Sorfra plaques occurred in correlation with pTau/tangle, but not A{beta}, pathologies across cerebral regions, neighboring cortical/hippocampal areas, and along the sulcal valley to gyral hilltop transition. Sorfra plaques and neuritic plaques were matchable in location, shape and size between consecutive sections, and were colocalized in double-labeling preparations. Microscopical study and tissue clearance three-dimensional imaging revealed sorfra/A{beta} colocalized as well as independent plaques. Among the former, sorfra labeling correlated negatively to A{beta}/amyloid labeling and {beta}-secretase-1 labeling in dystrophic neurites. Sorfra plaques were depleted of microtubule-associated protein 2 (MAP2) labeled neuronal somata and dendrites, whereas normal looking MAP2/sortilin co-labeled profiles occurred nearby. Sorfra deposits were seen in astrocytes but not microglia around the plaques. Taken together, sorfra plaques are anatomically matchable to silver stained neuritic plaques. They develop with tangle-related somatodendritic degeneration, presenting as nonamyloid growth of the A{beta} plaques and formation of A{beta}-independent neuritic plaques during Alzheimers disease pathogenesis.

neuroscience↗

bioRxiv2023

Mitochondrial phylogeography of grassland caterpillars (Lepidoptera: Lymantriinae: Gynaephora) endemic to the Qinghai-Tibetan Plateau

Grassland caterpillars (Lepidoptera: Lymantriinae: Gynaephora) are the most damaging pests to alpine meadows in the Qinghai-Tibetan Plateau (QTP). Here, we conducted extensive sampling from 39 geographic populations covering almost the entire distribution of the eight Gynaephora species in the QTP to investigate phylogeographic patterns and speciation based on two mitochondrial genes (cox1 and nad5). A total of 40 haplotypes were detected in the 39 populations, with >70% of haplotypes specific to single population. The monophyletic QTP Gynaephora migrated from non-QTP regions during the Pliocene, corresponding to the uplift of the QTP, suggesting a mode of transport into the QTP. Among the eight QTP Gynaephora species described by morphological characteristics, two species (G. alpherakii and G. menyuanensis) were recovered as monophyletic groups (Clades B and C), while the remaining six species formed two monophyletic clades: Clade A (G. qinghaiensis, G. jiuzhiensis, and G. qumalaiensis) and Clade D (G. aureate, G. rouergensis, and G. minora). These results suggested that the number of the QTP Gynaephora species may be overestimated and further studies based on both morphological and nuclear gene data are needed. Genetic differentiation and speciation were driven by intensive uplifts of the QTP and associated climate fluctuations during the Pleistocene, suggesting that isolation and subsequent divergence was the dominant mode of speciation. The Sanjiangyuan region (i.e., Clade A, characterized by high genetic diversity) may have been a glacial refugium of the QTP Gynaephora, as supported by analyses of gene flow and biogeography. High levels of genetic diversity were found in QTP Gynaephora, without population expansion, which may explain the high-altitude adaptation and outbreaks of grassland caterpillars in alpine meadows of the QTP. This study provides the largest phylogeographic analysis of QTP Gynaephora and improves our understanding of the diversity and speciation of QTP insects.

zoology↗