Effects of hormone replacement therapy on glucose and lipid metabolism in peri- and postmenopausal women with a history of menstrual disorders.

BACKGROUND: Previous studies have indicated that women with a history of menstrual disorders have an increased risk of metabolic and cardiovascular diseases. This has been attributed to the high proportion of polycystic ovary syndrome (PCOS) among this group. The favorable effects of hormone replacement therapy (HRT) on serum lipid profiles and glucose homeostasis in postmenopausal women is widely accepted. Whether HRT can also show positive effects on metabolic homeostasis in menopausal women with prior menstrual disorders (a putative PCOS phenotype) has not been reported yet. The aim of the study was to compare the effects of HRT on glucose and lipid metabolism in peri- and postmenopausal women with prior menstrual disorders and controls who did not have prior menstrual disorders. METHODS: A retrospective multicenter study was conducted including 595 peri- and postmenopausal women who received HRT at four hospitals in the Zhejiang Province from May 31, 2010 to March 8, 2021. Participants were divided into the Normal menstruation group and the Menstrual disorders group according to their prior usual menstrual cycle pattern. Glucose and lipid metabolism indicators were assessed at baseline and after HRT. The results were compared between and within the groups, and data from peri- and postmenopausal women were analyzed separately. RESULTS: HRT significantly decreased fasting insulin and homeostasis model assessment of insulin resistance in perimenopausal users, and fasting plasma glucose levels in postmenopausal users with prior menstrual disorders, compared with baseline. Furthermore, HRT decreased low-density lipoprotein cholesterol, total cholesterol, fasting insulin, fasting plasma glucose and homeostasis model assessment of insulin resistance in both peri- and postmenopausal controls, compared with baseline. Nevertheless, no significant differences were observed in any of the glucose or lipid metabolism indicators at baseline and follow-up, as well as changes from baseline levels between menopausal women with and without prior menstrual disorders. CONCLUSIONS: HRT shows more obvious within-group improvements in glucose and lipid metabolism in controls, but there is no significant between-group difference. Further prospective studies are required for confirmation.

Transcription Factor 4 Safeguards Hippocampal Dentate Gyrus Development by Regulating Neural Progenitor Migration.

The dentate gyrus (DG) of the hippocampal formation plays essential roles in learning and memory. Defective DG development is associated with neurological disorders. Here, we show that transcription factor 4 (Tcf4) is essential for DG development. Tcf4 expression is elevated in neural progenitors of the dentate neuroepithelium in the developing mouse brain. We demonstrate that conditional disruption of Tcf4 in the dentate neuroepithelium leads to abnormal neural progenitor migration guided by disorganized radial glial fibers, which further leads to hypoplasia in the DG. Moreover, we reveal that Wnt7b is a key downstream effector of Tcf4 in regulating neural progenitor migration. Behavioral analysis shows that disruption of integrity of the DG impairs the social memory highlighting the importance of proper development of the DG. These results reveal a critical role for Tcf4 in regulating DG development. As mutations in TCF4 cause Pitt-Hopkins syndrome (PTHS) characterized by severe intellectual disability, our data also potentially provide insights into the basis of neurological defects linked to TCF4 mutations.

Allosteric auto-inhibition and activation of the Nedd4 family E3 ligase Itch.

The Nedd4 family E3 ligases are key regulators of cell growth and proliferation and are often misregulated in human cancers and other diseases. The ligase activities of Nedd4 E3s are tightly controlled via auto-inhibition. However, the molecular mechanism underlying Nedd4 E3 auto-inhibition and activation is poorly understood. Here, we show that the WW domains proceeding the catalytic HECT domain play an inhibitory role by binding directly to HECT in the Nedd4 E3 family member Itch. Our structural and biochemical analyses of Itch reveal that the WW2 domain and a following linker allosterically lock HECT in an inactive state inhibiting E2-E3 transthiolation. Binding of the Ndfip1 adaptor or JNK1-mediated phosphorylation relieves the auto-inhibition of Itch in a WW2-dependent manner. Aberrant activation of Itch leads to migration defects of cortical neurons during development. Our study provides a new mechanism governing the regulation of Itch.

A subpopulation of individual neural progenitors in the mammalian dorsal pallium generates both projection neurons and interneurons in vitro.

There are two major classes of neurons in nervous systems: projection neurons and interneurons. During Drosophila nervous system development, a subpopulation of individual stem/progenitor cells gives rise to both motor neurons and interneurons. However, it remains unknown whether individual stem/progenitor cells in the mammalian brain also have the potential to give rise to both projection neurons and interneurons. Here we present evidence that single mouse neocortical progenitors generated both projection neurons and GABAergic interneurons based on studies using fluorescence-activated cell sorting (to obtain individual progenitors) and in vitro clonal analysis using time-lapse video microscopy and immunostaining. We determined that a subpopulation of individual dorsal pallial progenitors from E11.5 Dlx5/6-cre-IRES-EGFP and GAD67-GFP mice can generate both GFP-negative/Tbr1-positive (GFP(-) /Tbr1+)/Tuj1+ cells and GFP+/Sp8+/calretinin+/Tuj1+ cells. The GFP(-) /Tbr1+/Tuj1+ cells had morphological features of cultured projection neurons. Quantitative analysis of the reconstructed lineage trees derived from single progenitors showed that the projection neuron lineage appeared earlier than the interneuron lineage; however, more interneuron-like cells were produced than projection neuron-like cells. Thus, our results provide direct in vitro evidence that individual progenitors of the mammalian dorsal pallium can generate both projection neurons and interneurons.

Cai's herbal tea enhances mitochondrial autophagy of type 1 diabetic mellitus ß cells through the AMPK/mTOR pathway and alleviates inflammatory response.

BACKGROUND: This study investigates the therapeutic mechanisms of Cai's Herbal Tea in Type 1 Diabetes Mellitus (T1DM) mice, focusing on its effects on mitochondrial change and autophagy via the AMP-activated protein kinase (AMPK)-mammalian target of rapamycin (mTOR) pathway. METHODS: The composition of Cai's Herbal Tea was analyzed by Ultra-High Performance Liquid Chromatography-Quadrupole Time of Flight Mass Spectrometry (UHPLC-Q/TOF-MS). C57BL/6 mice and Min6 pancreatic beta cells were divided into control, diabetic mellitus (DM)/high glucose (HG), and treatment groups (low, medium, and high doses of Cai's Tea, and Metformin). Key physiological parameters, pancreatic islet health, Min6 cell morphology, viability, and insulin (INS) secretion were assessed. Small Interfering RNA-AMPK (si-AMPK) was utilized to confirm the pathway involvement. RESULTS: Cai's Herbal Tea improved body weight, pancreatic islet pathological injury, and INS secretion whereas reduced total triglycerides, fasting blood sugar, and Interferon gamma (INF-γ) in T1DM mice, particularly at higher doses. In Min6 cells, Cai's Tea mitigated HG-induced damage and proinflammatory response, enhancing cell viability and INS secretion. Notably, it reduced swelling and improved cristae structure in treated groups of mitochondria and promoted autophagy via the AMPK-mTOR pathway, evidenced by increased LC3II/LC3I and P-AMPK/AMPK ratios, and decreased P-mTOR/mTOR and P62 expressions in pancreatic islet ß-cells. Furthermore, these effects were converted by si-AMPK interference. CONCLUSION: Cai's Herbal Tea exhibits significant therapeutic efficacy in T1DM mice by improving mitochondrial health and inducing autophagy through the AMPK-mTOR pathway in pancreatic islet ß-cells. These findings highlight its potential as a therapeutic approach for T1DM management.

A cardiomyocyte-based biosensing platform for dynamic and quantitative investigation of excessive autophagy.

Autophagy is an important physiological phenomenon in eukaryotes that helps maintain the cellular homeostasis. Autophagy is involved in the development of various cardiovascular diseases, affecting the maintenance of cardiac function and disease prognosis. Physiological levels of autophagy serve as a defense mechanism for cardiomyocytes against environmental stimuli, but an overabundance of autophagy may contribute to the development of cardiovascular diseases. However, conventional biological methods are difficult to monitor the autophagy process in a dynamic and chronic manner. Here, we developed a cardiomyocyte-based biosensing platform that records electrophysiological evolutions in action potentials to reflect the degree of autophagy. Different concentrations of rapamycin-mediated autophagy were administrated in the culture environment to simulate the autophagy model. Moreover, the 3-methyladenine (3-MA)-mediated autophagy inhibition was also investigated the protection on the autophagy. The recorded action potentials can precisely reflect different degrees of autophagy. Our study confirms the possibility of visualizing and characterizing the process of cardiomyocyte autophagy using cardiomyocyte-based biosensing platform, allowing to monitor the whole autophagy process in a non-invasive, real-time, and continuous way. We believe it will pave a promising avenue to precisely study the autophagy-related cardiovascular diseases.

A subpopulation of dorsal lateral/caudal ganglionic eminence-derived neocortical interneurons expresses the transcription factor Sp8.

Cortical GABAergic interneurons in rodents originate from subpallial progenitors and tangentially migrate to the cortex. While the majority of mouse neocortical interneurons are derived from the medial and caudal ganglionic eminence (MGE and CGE, respectively), it remains unknown whether the lateral ganglionic eminence (LGE) also contributes to a subpopulation of cortical interneurons. Here, we show that the transcription factor Sp8 is expressed in one-fifth of adult cortical interneurons, which appear to be derived from both the dorsal LGE and the dorsal CGE (dLGE and dCGE, respectively). Compared with the MGE-derived cortical interneurons, dLGE/dCGE-derived Sp8-expressing (Sp8+) ones are born at later embryonic stages with peak production occurring at embryonic day 15.5. They tangentially migrate mainly along the subventricular/intermediate zone (SVZ/IZ) route; some continue to express mitotic markers (Ki67 and PH3) in the neonatal cortical SVZ/IZ. Sp8+ interneurons continue to radially migrate from the SVZ/IZ into the cortical layers at early postnatal stages. In contrast to MGE-derived interneurons, dLGE/dCGE-derived Sp8+ interneurons follow an outside-in layering pattern, preferentially occupying superficial cortical layers.

Controllable synthesis of lignin nanoparticles with antibacterial activity and analysis of its antibacterial mechanism.

As a kind of polyphenol substance, lignin is considered to have good biological activity and certain antibacterial properties. However, it is difficult to be applied because of its uneven molecular weight and difficulty in separation. In this study, by way of fractionation and antisolvent, we obtained lignin fractions with different molecular weight. Moreover, we increased the content of active functional groups and regulated microstructure of lignin, thereby increased lignin's antibacterial property. The classification of chemical components and the control of particle morphology also provided convenience for the exploration of lignin's antibacterial mechanism. The results showed that acetone with high hydrogen bonding ability could collect lignin with different molecular weights and increase the content of phenolic hydroxyl groups, up to 31.2 %. By adjusting the ratio of water/solvent (v/v) and stirring rate during the process of antisolvent, lignin nanoparticles (sphere 40-300 nm) with regular shape and uniform size can be obtained. Through observing the distribution of lignin nanoparticles in vivo and in vitro after co-incubation for different time, it could be found that lignin nanoparticles firstly damage structural integrity of bacterial cells externally, and then are swallowed into cells to affect their protein synthesis, which constitutes a dynamic antibacterial process.

Ccdc85c-Par3 condensates couple cell polarity with Notch to control neural progenitor proliferation.

Polarity proteins regulate the proliferation and differentiation of neural progenitors to generate neurons during brain development through multiple signaling pathways. However, how cell polarity couples the signaling pathways remains unclear. Here, we show that coiled-coil domain-containing protein 85c (Ccdc85c) interacts with the polarity protein Par3 to regulate the proliferation of radial glial cells (RGCs) via phase separation coupled to percolation (PSCP). We find that the interaction with Ccdc85c relieves the intramolecular auto-inhibition of Par3, which leads to PSCP of Par3. Downregulation of Ccdc85c causes RGC differentiation. Importantly, the open conformation of Par3 facilitates the recruitment of the Notch regulator Numb to the Par3 condensates, which might prevent the attenuation of Notch activity to maintain RGC proliferation. Furthermore, ectopic activation of Notch signaling rescues RGC proliferation defects caused by the downregulation of Ccdc85c. These results suggest that Ccdc85c-mediated PSCP of Par3 regulates Notch signaling to control RGC proliferation during brain development.

Emx1-expressing neural stem cells in the subventricular zone give rise to new interneurons in the ischemic injured striatum.

Neural stem cells from different regions within the subventricular zone (SVZ) are able to produce several different subtypes of interneurons in the olfactory bulb throughout life. Previous studies have shown that ischemic stroke induces the production of new neurons in the damaged striatum from the SVZ. However, the origins and genetic profiles of these newborn neurons remain largely unknown as SVZ neural stem cells are heterogeneous. In the present study, using a mouse model of perinatal hypoxic-ischemic (H/I) brain injury combined with BrdU labeling methods, we found that, as in rat brains, virtually all newborn neuroblasts that migrate from the SVZ into the ischemic injured striatum exclusively express the transcription factor Sp8. Furthermore, although newborn neuroblasts are plentiful in the damaged striatum, only a few can differentiate into calretinin-expressing (CR+) interneurons that continuously express Sp8. Genetic fate mapping reveals that newly born CR+ interneurons are generated from Emx1-expressing neural stem cells in the dorsal-lateral SVZ. These results suggest that the fate of the Emx1-expressing lineage in the ischemic damaged striatum is restricted. However, when Sp8 was conditionally inactivated in the Emx1-lineage cells, Pax6 was ectopically expressed by a subpopulation of Emx1-derived CR+ cells in the normal and damaged striatum. Interestingly, these cells possessed large cell bodies and long processes. This work identifies the origin of the newly born CR+ interneurons in the damaged striatum after ischemic brain injury.

Survival control of oligodendrocyte progenitor cells requires the transcription factor 4 during olfactory bulb development.

A proper number of oligodendrocytes in the nerve system is essential for neuronal functions. In the olfactory bulb (OB), enriched oligodendrocytes are crucial for olfactory information processing. However, how the precise number of oligodendrocytes in the OB is regulated remains elusive. Here we identified that the transcription factor 4 (Tcf4)-mediated cell death is essential for generating an appropriate number of oligodendrocyte progenitor cells (OPCs) and thereby oligodendrocytes in the OB. We showed that Nkx2.1-positive progenitors in the medial ganglionic eminence (MGE) and anterior entopeduncular area (AEP) provide the first source of OPCs in the OB. Conditional depletion of Tcf4 leads to an increase of OPCs in the OB, which is mediated by the suppression of programmed cell death. Furthermore, we showed that Tcf4 mediated OPC survival is cell-autonomous by transplantation assay. Mechanistically, we identified Bax/Bak as a potential key pathway to promote OPC elimination during OB development. Depletion of Bax/Bak in Nkx2.1 lineage results in an increase of OPCs in the OB. Mutations in TCF4 causes Pitt-Hopkins syndrome, a severe neurodevelopmental disorder. Thus, our findings reveal an important intrinsic mechanism underlying the survival control of OPCs in the OB and provide new insights into the pathogenesis of Pitt-Hopkins syndrome.

Decoding Cortical Glial Cell Development.

Mouse cortical radial glial cells (RGCs) are primary neural stem cells that give rise to cortical oligodendrocytes, astrocytes, and olfactory bulb (OB) GABAergic interneurons in late embryogenesis. There are fundamental gaps in understanding how these diverse cell subtypes are generated. Here, by combining single-cell RNA-Seq with intersectional lineage analyses, we show that beginning at around E16.5, neocortical RGCs start to generate ASCL1+EGFR+ apical multipotent intermediate progenitors (MIPCs), which then differentiate into basal MIPCs that express ASCL1, EGFR, OLIG2, and MKI67. These basal MIPCs undergo several rounds of divisions to generate most of the cortical oligodendrocytes and astrocytes and a subpopulation of OB interneurons. Finally, single-cell ATAC-Seq supported our model for the genetic logic underlying the specification and differentiation of cortical glial cells and OB interneurons. Taken together, this work reveals the process of cortical radial glial cell lineage progression and the developmental origins of cortical astrocytes and oligodendrocytes.

Prevalence, severity, and associated factors of menopausal symptoms in middle-aged Chinese women: a community-based cross-sectional study in southeast China.

OBJECTIVE: The aim of the study was to specify the prevalence and severity of menopausal symptoms, and to investigate associated factors in Chinese middle-aged women. METHODS: A cross-sectional, community-based study was carried out involving 1,054 participants aged 40 to 60 years in Gongshu District, Hangzhou, Zhejiang, PR China. The presence and severity of symptoms were evaluated by having the participants complete a modified Kupperman Menopausal Index questionnaire. Serum levels of follicle-stimulating hormone and estradiol were measured. Physical and sociodemographic characteristics including height, weight, education, occupation, and income were collected. Statistical analysis was performed to identify factors associated with the occurrence of the menopausal syndrome according to the modified Kupperman Menopausal Index score rank. RESULTS: The mean (SD) age of all participants was 50.85 (5.55) years. Overall, 32.6% of the participants were premenopausal, 20.2% were perimenopausal, and 47.1% were postmenopausal. The three most prevalent symptoms suffered by all participants were muscle/joint pain (54.5%), sexual problems (48.7%), and fatigue (46.1%). The prevalence of sexual problems and muscle/joint pain increased from the premenopausal stage to the postmenopausal stage (P < 0.001 for both). Compared with premenopausal women, perimenopausal and postmenopausal women have a significantly increased risk of menopausal syndrome (P < 0.001 for both). The logistic regression model revealed that the place of residence and level of education were significantly associated with the occurrence of menopausal syndrome (P < 0.05). CONCLUSIONS: Perimenopausal women are prone to the highest prevalence and severity of menopausal symptoms. Sexual problems and muscle/joint pain are noticeable symptoms in postmenopausal women. Further studies are required to verify the influences of level of education, place of residence, and other factors on menopausal symptoms in Chinese women.

Transient Sp8+ handlebar-like interneuron structure traversing the corpus callosum during the second postnatal week.

Although previous studies have implied that interneurons continue to migrate into the corpus callosum (CC) during the postnatal period, little is known about the details of the migration pattern. In this study, we analyzed the entire postnatal CC every other day and showed the presence of a transient handlebar-like structure traversing the CC during the second postnatal week. Using immunostaining and two strains of transgenic mice, we showed that this handlebar-like structure consisted of GABAergic interneurons derived from the caudal ganglionic eminence, which expressed the transcription factor Sp8. Data obtained from in-utero electroporation experiments showed that these high-density interneurons were adjacent to callosal axons. Thus, we provide the first direct evidence that a transient Sp8+ interneuron handlebar-like structure exists in the CC during a brief postnatal critical period.

Nuclear receptor COUP-TFII-expressing neocortical interneurons are derived from the medial and lateral/caudal ganglionic eminence and define specific subsets of mature interneurons.

Neocortical GABAergic interneurons in rodents originate from subpallial progenitor zones. The majority of mouse neocortical interneurons are derived from the medial and caudal ganglionic eminences (MGE and CGE, respectively) and the preoptic area (POA). It is controversial whether the lateral ganglionic eminence (LGE) also generates neocortical interneurons. Previously it was shown that the transcription factor COUP-TFII is expressed in the CGE; here we show that COUP-TFII is also expressed in the dorsal MGE, dorsal LGE (dMGE and dLGE, respectively), and POA. In the adult neocortex, COUP-TFII+/somatostatin (SOM)+ interneurons are mainly located in layer V. Using a genetic fate-mapping approach (Shh-Cre and Nkx2.1-Cre), we demonstrate that the POA and ventral MGE do not give rise to COUP-TFII+ neocortical interneurons, suggesting that the dMGE is the source of COUP-TFII+/SOM+ neocortical interneurons. We also observed a migratory stream of COUP-TFII+/Sp8+ cells emanating from the dLGE and CGE to the neocortex mainly through the subventricular zone at later embryonic stages. Slice culture experiments in which dLGE progenitors were labeled with BrdU provided additional evidence that the dLGE generates neocortical interneurons. While earlier-born dMGE-derived COUP-TFII+ interneurons occupy cortical layer V, later-born dLGE- and CGE-derived COUP-TFII+ ones preferentially occupy superficial cortical layers. A similar laminar distribution was observed following neonatal transplantation of embryonic day (E)14.5 dMGE and E15.5 dLGE. These results provide novel information about interneuron fate and position from spatially and temporally distinct origins in the ganglionic eminences.

Subcortical origins of human and monkey neocortical interneurons.

Cortical GABAergic inhibitory interneurons have crucial roles in the development and function of the cerebral cortex. In rodents, nearly all neocortical interneurons are generated from the subcortical ganglionic eminences. In humans and nonhuman primates, however, the developmental origin of neocortical GABAergic interneurons remains unclear. Here we show that the expression patterns of several key transcription factors in the developing primate telencephalon are very similar to those in rodents, delineating the three main subcortical progenitor domains (the medial, lateral and caudal ganglionic eminences) and the interneurons tangentially migrating from them. On the basis of the continuity of Sox6, COUP-TFII and Sp8 transcription factor expression and evidence from cell migration and cell fate analyses, we propose that the majority of primate neocortical GABAergic interneurons originate from ganglionic eminences of the ventral telencephalon. Our findings reveal that the mammalian neocortex shares basic rules for interneuron development, substantially reshaping our understanding of the origin and classification of primate neocortical interneurons.

Sustained increase in adult neurogenesis in the rat hippocampal dentate gyrus after transient brain ischemia.

It is known that the number of newly generated neurons is increased in the young and adult rodent subventricular zone (SVZ) and dentate gyrus (DG) after transient brain ischemia. However, it remains unclear whether increase in neurogenesis in the adult DG induced by ischemic stroke is transient or sustained. We here reported that from 2 weeks to 6 months after transient middle cerebral artery occlusion (MCAO), there were more doublecortin positive (DCX+) cells in the ipsilateral compared to the sham-control and contralateral DG of the adult rat. After the S-phase marker 5-bromo-2'-deoxyuridine (BrdU) was injected 2 days after MCAO to label newly generated cells, a large number of BrdU-labeled neuroblasts differentiated into mature granular neurons. These BrdU-labeled neurons survived for at least 6 months. When BrdU was injected 6 weeks after injury, there were still more newly generated neuroblasts differentiated into mature neurons in the ipsilateral DG. Altogether, our data indicate that transient brain ischemia initiates a prolonged increase in neurogenesis and promotes the normal development of the newly generated neurons in the adult DG.