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Zhang, H.

Publications and source records attributed to Zhang, H..

At least 109 records · Page 6Linked to original sources

Hippocampal CA2 modulates trace fear conditioning through circuit-specific control of CA1

Forming associations between temporally separated events depends on pathways linking the CA1, the subiculum (SUB), and the entorhinal cortex. The degree to which this process requires the CA2, which shares extensive connectivity with these regions, remains unknown. Using trace fear conditioning (TFC), where mice learn to associate a tone and shock separated by a temporal gap, we showed that the dCA2 contributes to TFC. Interestingly, whereas chronic dCA2 inhibition decreased cue-associated freezing, acute dCA2[->]dCA1 projection inhibition increased freezing. Combined with differential effects on cFos expression, this suggests that global and projection-specific perturbations of the dCA2 have distinct effects on TFC and hippocampal activity states. Fiber photometry revealed that dCA2[->]dCA1 activity shifted from tone responsiveness during conditioning to expected shock activation during recall, consistent with learning-associated activity remodeling. Together, these findings identify the dCA2 as a contributor to TFC and implicate dCA2[->]dCA1 signaling in shaping fear expression across learning and recall.

neuroscience↗

Spinal cord Ca2+ imaging reveals glial-driven central sensitization in post-traumatic osteoarthritis

Central sensitization may be defined behaviourally, cellularly, or molecularly; yet these can all vary depending on the model and duration. Current electrophysiological approaches are time and labour intensive. Here, we developed a Ca2+ imaging and analysis pipeline (CuMIN) that implements semi-automated detection and analysis of cellular Ca2+ activity in rodent spinal cord slices, from which distinct signatures were defined for various acute and chronic pain models. Spinal cord slices from male mice were isolated after inducing pathological pain in a variety of well-established surgical or pharmacological approaches, incubated in a cell-permeant Ca2+ indicator, and imaged with epifluorescence microscopy. Intensity and temporal features of spontaneous and glutamate-evoked Ca2+ events were processed by linear discriminant analysis to map unique clusters of activity for each pain model. The resulting activity map of spinal dorsal horn activity is substantially different in the surgical model of chronic pain induced by post-traumatic osteoarthritis (PTOA), which lacks clear mechanistic evidence of central sensitization. Specifically, the PTOA Ca2+ activity signature overlapped with chemotherapy-induced neuropathy and neuropathic pain models, both of which are associated with gliosis-induced central sensitization. We confirmed gliosis in the PTOA model by immunostaining IBA1 and GFAP and observed analgesic effects of intrathecal carbenoxolone, Gap27, and minocycline that targeted glial activity. These findings validate CuMIN as a sensitive and specific approach for defining the basic cellular signatures of spinal central sensitization, with the utility of identifying potential therapeutic targets and serving as a translational platform for novel drug discovery across various acute and chronic pain models.

neuroscience↗

Inhibition of Soluble Epoxide Hydrolase Rescues Cognitive Deficits by Preserving Neurovascular Integrity and Attenuating Glial- and Neuropathology in Diabetic-Related Dementia

Diabetes mellitus (DM) is a major risk factor contributing to the development of Alzheimers disease-related dementias (ADRD). While one of the early symptoms of both Alzheimers disease (AD) and DM-related ADRD is a reduction in cerebral blood flow, the underlying biological mechanisms driving this decline remain to be fully elucidated. Genome-wide association studies have linked AD/ADRD to single-nucleotide polymorphisms in the gene encoding soluble epoxide hydrolase (sEH), an enzyme we previously reported to be upregulated in the brains of an AD rat model. Our previous work also demonstrated that chronic inhibition of sEH with 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea (TPPU) preserves hippocampal-dependent spatial learning and memory and improves cerebral hemodynamics in both AD and DM-ADRD models. In the present study, we found that chronic TPPU treatment (1 mg/kg/day for 9 weeks) reduced brain sEH expression, improved cortical-based long-term non-spatial recognition memory involving both cortical and hippocampal networks, and reduced anxiety in DM-ADRD rats. TPPU improved brain perfusion and normalized impaired whisker-evoked functional hyperemia, an effect linked to upregulation of Kir2.1 expression in cerebral capillaries. Furthermore, TPPU restored tight junction proteins (ZO-1 and OCLN), mitigated capillary rarefaction, and suppressed astrocyte and microglial activation. At the cellular level, TPPU attenuated hippocampal neurodegeneration, restored the expression of synaptic proteins (PSD95 and SY38), and reduced levels of key pro-inflammatory chemokines, including MCP-1, RANTES, and MIP-1, in DM-ADRD. In conclusion, TPPU preserves cognitive function in DM-ADRD by mitigating cerebrovascular dysfunction, neuroinflammation, and gliosis while protecting synaptic integrity and neuronal survival, representing a promising therapeutic strategy for DM-ADRD.

neuroscience↗

Primary cilia promote cardiac fibrosis and limit heart function after myocardial infarction

Cardiomyocytes die and do not regenerate after an injury such as a myocardial infarction (MI), a leading cause of mortality worldwide. Following MI, cardiac fibroblasts (CFs) proliferate and differentiate into myofibroblasts, which then produce increased collagen and extracellular matrix (ECM) leading to fibrosis. Fibrosis can weaken cardiac output via excessive stiffening and interference with electric signal transmission, but can also prevent wall rupture under load (reviewed in (1)). Thus, dampening fibrosis has been investigated as a potential therapeutic intervention. Most mammalian cells possess a single primary cilium involved in intercellular communication. We investigated the role of CF primary cilia in sensing injury signals and initiating fibrotic remodeling. We found that deleting CF cilia reduced fibrosis and improved cardiac output after MI, demonstrating that cilia act as a signaling hub that amplifies the fibrotic response in the injured heart.

physiology↗

Spatiotemporal Cascade of AP1/CCA1-TOC1 Module Gates Stem Development

Stem development is crucial in plant vertical architecture and overall crop improvement. The molecular mechanisms underlying the initiation and circadian growth of stem remain still enigmatic. Here, we demonstrate that APETALA1 (AP1) spatially initiates circadian stem growth through a noncell-autonomous role of TIMING OF CAB EXPRESSION1 (TOC1) emanating from the floral meristem to inflorescence meristem in Arabidopsis thaliana. Mechanistically, AP1 interacts with and recruits CIRCADIAN CLOCK-ASSOCIATED1 (CCA1) to associate TOC1. Dynamic formation of the AP1-CCA1 complex is crucial for maintaining the circadian rhythmicity and expression of TOC1. Tissue-specific expression of TOC1 in floral meristems rescues the developmental defects of toc1 mutants at both functional and transcriptional levels. Furthermore, TOC1 directly activates the circadian expression of pectin methylesterase gene family, which is critical for its role in stem development. AP1 homologs regulate circadian stem elongation and plant height in wheat and rice, underscoring the conserved mechanism across flowering plants. Our findings uncovered a spatiotemporal regulatory cascade gating stem development and identified candidate genes for crop improvement.

plant biology↗

(2R,6R)-Hydroxynorketamine elicits rapid antidepressant effects by promoting astrocytic μ-δ opioid receptor heterodimerization

Ketamine produces rapid antidepressant effects but is constrained by psychotomimetic properties and abuse potential. The ketamine metabolite (2R,6R)-hydroxynorketamine (HNK) shows antidepressant-like efficacy without N-methyl-D-aspartate receptor (NMDAR) blockade, yet its upstream targets remain unclear. Here we show that HNK potentiates hippocampal excitatory transmission and reverses stress-induced behavioural deficits through opioid receptor signaling. Pharmacological and genetic analyses reveal a requirement for both {micro}- and {delta}-opioid receptors in astrocytes. Chronic stress reduces {micro}-{delta} receptor heterodimers in the hippocampus, and a single dose of HNK restores their abundance. PAINT-MINFLUX nanoscopy quantifies increased {micro}-{delta} heterodimerization, and molecular dynamics simulations indicate selective binding of HNK to the {micro}-receptor protomer via Asp147 and Tyr148. Mutating these residues abolishes HNK-driven heterodimer formation, downstream signaling and rapid antidepressant-like effects in vivo. Astrocytic {micro}-{delta} opioid receptor heterodimers thus represent a targetable mechanism for next-generation rapid-acting antidepressants.

neuroscience↗

Integrating Histology with Spatial Molecular Programs Using a Multimodal Foundation Model

Histopathological assessment remains central to cancer diagnosis and stratification, yet its mechanistic interpretation remains limited without molecular context. To address this, we developed SQUALL, a multimodal foundation model integrating histology with spatial molecular programs. For pretraining, we assembled histMol, a large-scale corpus of 1.76 billion paired histology-spatial transcriptomics spots/bins across 33 tissues and 12 platforms from 3,446 tissue sections. Following pretraining, SQUALL enables transcriptome-wide virtual biomarker profiling, prognostically relevant spatial niches discovery, and integrative disease progression modeling. Leveraging its multimodal embeddings, SQUALL identifies niches associated with tertiary lymphoid structure (TLS) maturation and ovarian cancer relapse, reconstructs molecular trajectories of breast cancer invasion across 325,112 spots, and uncovers underlying transcriptional programs. Applied to whole-slide images from 898 patients, SQUALL outperforms existing pathology foundation models in outcome prediction while enabling interpretable risk stratification. Together, these results establish spatially aligned multimodal pretraining as a new paradigm for extending molecular insights into pathology images.

bioinformatics↗

Synthetic Fibrous Hydrogels as Minimal Systems to Modulate Cell Migration Modes in 3D

Cell migration in three-dimensional (3D) environments is highly plastic and regulated by extracellular matrix (ECM) cues. Engineered biomaterials provide controllable platforms to investigate how specific matrix signals regulate cell behavior in 3D, yet how defined biochemical signals control migration modes remain unclear. Here, we present tunable fibrous polyisocyanide (PIC) hydrogels functionalized with integrin-binding RGD peptides, cadherin-mimetic HAVDI peptides, or no ligands to direct mesenchymal, hybrid, or amoeboid-like migration of human adipose-derived stem cells without altering matrix mechanics. Using live-cell tracking, 3D displacement microscopy, matrix remodeling analysis, and YAP nuclear localization, we show that ligand identity governs adhesion organization, force transmission, and mechanotransduction. RGD-functionalized matrices promote {beta}1-integrin clustering, extensive matrix remodeling, strong YAP activation and upregulation of migration-related genes. In contrast, non-adhesive matrices limit adhesion formation, resulting in weak force transmission and amoeboid-like behavior. HAVDI-functionalized matrices induce cadherin clustering and heterogeneous cellular responses, indicating that a hybrid migration mode arises from adhesion organization rather than a distinct transcriptional program. Together, these findings demonstrate that ligand identity alone is sufficient to program migration mode in a force-responsive 3D matrix and provide a versatile platform to dissect cell-matrix interactions in complex environments. Statement of significanceO_LICell migration in tissues is highly adaptable, yet precise control of migration modes in defined 3D biomaterials remains challenging. C_LIO_LIWe introduce fibrous PIC hydrogels presenting RGD, HAVDI, or no adhesive ligands to bias human stem cells toward mesenchymal-like, hybrid, or amoeboid-like migration states. C_LIO_LIBy linking ligand identity to adhesion organization, matrix remodeling, YAP mechanotransduction, and gene expression, this work provides a minimal platform to dissect and engineer 3D cell-matrix interactions C_LI

biophysics↗

Efficient neural encoding of time intervals in speech and complex sound sequences

Encoding time intervals in complex sound faces dual challenges: it must be precise and cover a broad dynamic range. In speech, for example, a ten millisecond lengthening of a syllable can signal stress or phrasal boundaries, yet the syllable duration distribution is long tailed beyond 500 ms and has variable statistics across speakers. Here, we propose that the auditory cortex employs efficient coding to represent time intervals. When listeners heard syllable sequences drawn from different duration distributions, the magnetoencephalographic (MEG) response from the temporal cortex scaled with syllable duration, which is characterized using the interval-response function. Crucially, this interval-response function met predictions of efficient coding. Its intercept and slope adapted to the mean and variance of syllable duration, respectively, and it consistently exhibited a compressive nonlinearity that reduced response skewness, consistent with a maximum-entropy code. A computational model that constantly updates the inference of duration distribution provided an algorithmic account of this efficient coding, and intracranial electroencephalogram (iEEG) data confirmed the same principles during natural speech comprehension. Together, our findings reveal an efficient neural mechanism that supports precise encoding of highly variable time intervals in complex sound sequences.

neuroscience↗

GeneKnow: AI-powered literature synthesis for gene-context analysis

Biological function is context dependent, yet synthesizing evidence for a genes function in a defined cell type, disease, or perturbation remains labor-intensive. Here we present GeneKnow, an auditable artificial intelligence (AI) framework for source-grounded biological evidence synthesis. GeneKnow separates evidence-critical operations, including literature retrieval, passage selection, provenance tracking, and bibliography construction, from generative steps that are constrained to semantic analysis and literature synthesis. GeneKnow supports multi-paper discovery and single-paper inspection while preserving links from synthesized claims to source passages, generating trustworthy syntheses without fabricated citations and minimizing hallucinations. Systematic benchmarking showed that GeneKnow achieved higher claim support and citation fidelity than leading general-purpose and scientific AI systems. These results demonstrate that an AI system with controlled division of labor between deterministic and generative components can substantially improve the fidelity and auditability of biomedical literature synthesis.

bioinformatics↗

An SE(3)-equivariant Crystal Structure Prediction Framework for Prospective Identification and Development of Bioactive Nucleoside Self-Assembling Materials

Flexible organic small molecules can assemble into supramolecular biomaterials whose properties are intrinsically governed by their crystal structures, yet experimental structure determination remains difficult to scale during molecular modification and materials optimization. Crystal structure prediction (CSP) provides a potential solution, but its prospective power is limited for flexible molecules owing to incomplete conformational sampling and the difficulty of identifying experimentally realized structures from large candidate sets. Here, an SE(3)-equivariant deep-learning workflow, SE3CSP, is developed for organic crystal structure prediction. By learning molecular conformations, unit-cell parameters and packing patterns from experimentally resolved crystal structures and integrating these predictions with MACE-based structure optimization, SE3CSP establishes an end-to-end pipeline from two-dimensional molecular representations to three-dimensional crystal structures. Using nucleosides as representative flexible self-assembling building blocks, SE3CSP achieves an overall prediction accuracy of [~]57%, substantially outperforming the benchmark MACE-based Genarris 3.0 workflow ([~]14%). Furthermore, a prospective prediction strategy is developed in which an SE3CSP-predicted density window ({+/-} 0.15 g/cm3) is applied prior to energy ranking and structural deduplication, enabling all experimentally realized structure to be consistently ranked within the top 1-2% of all generated candidates. Beyond structure prediction, SE3CSP-derived energy landscapes provide insight into potential single-crystal-to-single-crystal transformations and enable the identification of a nucleoside supramolecular material with dynamic breathing porosity, which is further developed as an adsorptive platform for inflammatory mediator removal with excellent anti-inflammatory performance and biocompatibility. These results establish SE3CSP as a practical framework for prospective CSP and highlight its utility in guiding the discovery and design of bioactive self-assembled materials.

bioengineering↗

Fully Modified SpyCas9 Guide RNAs Enable Robust Genome Editing In Cells and In Vivo

Precision engineering of CRISPR/Cas9 components has advanced genome editing toward therapeutic applications. Completely chemically stabilized guide RNAs (gRNAs) have the potential to improve in vivo editing efficacy while enabling greater flexibility in delivery strategies. However, previous generations of fully modified guides have been associated with reduced Cas9 activity. Here, we employed an iterative, structure-guided optimization strategy to systematically introduce chemical modifications at each position of SpyCas9 gRNAs. Extending beyond commonly used nucleotide modifications, we incorporated 2-amino-RNA, 4-thio-RNA, and extended nucleic acid (exNA) to generate gRNA designs in which 90-100% of the nucleotides are sugar- or backbone-modified. Although certain modification patterns exhibit sequence-dependent variability, we have established a growing repertoire of guides that consistently maintain or enhance editing efficacy when applied both in vitro and in vivo. Collectively, our heavily and fully modified gRNAs hold potential for applications in nuclease editing, base editing, and other genome editing tools. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=132 SRC="FIGDIR/small/725424v1_ufig1.gif" ALT="Figure 1"> View larger version (23K): org.highwire.dtl.DTLVardef@1118f08org.highwire.dtl.DTLVardef@1c57069org.highwire.dtl.DTLVardef@1572148org.highwire.dtl.DTLVardef@14a111e_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

Cycle-consistent deep generative modeling unifies cellular states across unpaired spatial and single-cell modalities

Current spatial and single-cell technologies capture complementary but incomplete views of cellular state, with transcriptomic, proteomic, and spatial information distributed across distinct platforms. Integration is challenged by unpaired measurements, mismatched feature spaces, and modality-specific biases. We present MultiTME, a multimodal framework that integrates heterogeneous spatial and single-cell data using a spatially-regularized, cycle-consistent deep generative model. By enforcing consistency of bidirectional mappings, MultiTME learns a shared latent representation that enables translation between modalities without requiring paired observations or shared features. Across benchmarks, MultiTME outperforms existing methods, produces accurate cross-modal cell typing, improves spatial transcriptomic panel completion, and transfers whole-transcriptome information to generate spatially resolved maps at cellular resolution. Applied to a multimodal colorectal cancer dataset, we demonstrate that MultiTME integration reveals a spatially coherent proliferative-invasive tumor axis not directly observable within single modalities. Across five multimodal spatial datasets, we show MultiTME can correct for platform-specific biases between Xenium and CosMx, thereby facilitating cross-dataset harmonization and enabling pan-cancer spatial studies. Code for MultiTME is available at https://github.com/tansey-lab/multitme.

bioinformatics↗

An oncolytic adenovirus armed with anticancer prodrug-activating enzyme offers enhanced tumor killing and antitumor immunity.

Oncolytic viruses are most commonly administered via intratumoral injection; however, their clinical efficacy in achieving tumor eradication remains limited by several challenges, including insufficient penetration into all tumor cells and the inability to elicit robust systemic antitumor immune responses capable of eliminating metastatic microtumors. Here, we report an oncolytic adenovirus, OAd-2B6, with an engineered adenoviral E1 region for tumor selectivity and carrying the prodrug- activating enzyme cytochrome P450 2B6 (CYP2B6) to activate the anticancer prodrug cyclophosphamide (Cytoxan, CTX). OAd-2B6 alone induced dose-dependent tumor cell killing across multiple human tumor cell lines and exhibited strong synergistic antitumor effects when combined with CTX. Importantly, OAd-2B6-mediated local activation of CTX resulted in a potent bystander killing effect that eliminated tumor cells not directly infected by the virus. In a H1299 lung cancer xenograft nude mouse model, intratumoral injection of OAd-2B6 combined with CTX significantly inhibited tumor growth and even achieved complete tumor regression, with markedly superior efficacy compared with monotherapy. In immunocompetent mice bearing 4T1 breast cancer xenografts, OAd-2B6 alone inhibited tumor growth and was accompanied by upregulation of IFN-{gamma} and GzmB expression in the tumor-infiltrated T cells. CTX combination therapy further enhances this anti-tumor immune response, promoting the activation of T cells to suppress non-injected tumors at a distal site. Collectively, this study demonstrates that OAd-2B6 exerts potent antitumor effects through multiple mechanisms, including direct oncolysis, intratumoral prodrug activation leading to bystander killing, and enhancement of systemic antitumor immunity. These findings provide a promising strategy for improving the therapeutic efficacy of oncolytic therapy.

cancer biology↗

Structure and function of human NXPE1, a sialic acid O-acetyltransferase

Human genetic studies have identified defects in multiple mechanisms that predispose the risk of developing inflammatory bowel diseases (IBD), which include alterations in adaptive and innate immune responses, epithelial integrity and regulation of the intestinal mucus layer. Despite the importance of intestinal barrier integrity in the pathogenesis of IBD, essentially all current therapies modulate the immune responses. In this study, we determined the high resolution cryo-EM structure of human NXPE1, a IBD associated protein. Based on the structural homology, we identified NXPE1 as an O-acetyltransferase. Since NXPE1 is a pseudo gene in mouse, we generated knockout mouse model that lacked two of the mouse NXPE1 homologs, Nxpe2 and Nxpe4. The O-acetylation of sialic acid on red blood cells was abolished in the double knockout mice, confirming the sialic acid O-acetyltransferase function of NXPE1 family members. These findings underscore the potential of NXPE1 as a novel therapeutic target of the intestinal barrier functions for the treatment of IBD.

immunology↗

Comprehensive Complete-Genome Analysis of Lactobacillaceae and Bifidobacteriaceae Reveals Strain-Specific Metabolic Interactions in Chinese Gut Microbiota

Bifidobacteriaceae and Lactobacillaceae are key probiotic families and widely used in food production, yet a comprehensive understanding of strain functions and their gut microbial interactions based on complete genomes remain understudied. Here we constructed a complete-genome dataset of 3,300 strains from these two families, including 1,151 newly isolated from China. Compared with draft assemblies, complete genomes substantially recovered a gene functional landscape encompassing stress tolerance, surface exopolysaccharide synthesis, nutrient utilization, and mobile genetic elements. Major species from both families exhibited a prevalence >60% in the Chinese population, far higher than that in US/Dutch cohorts. Notably, as a core probiotic species with remarkable genomic plasticity and gut-adaptive potential, Lactiplantibacillus plantarum stood out in our dataset for its enriched functional profile and was particularly abundant in the Chinese population. Moreover, compared with non-Chinese genomes, our isolates of key species displayed less metabolic complementarity and stronger competition with potentially pathogenic keystone species in the gut, thereby linking strain origin to enhanced probiotic potential and ecological fitness to benefit human gut health.

microbiology↗

Wheat MYB transcription factor TaMYB83-7B regulates seed dormancy by influencing the balance between abscisic acid and gibberellin

In wheat, weak seed dormancy (SD) is related to an increased tendency for pre-harvest sprouting (PHS), which reduces yield and quality. However, the molecular mechanism underlying SD remains elusive. Here, we identified a wheat R2R3-MYB transcription factor (TaMYB83-7B) related to SD. Expression analysis showed that TaMYB83-7B was highly expressed in wheat seeds, and was more highly expressed in strong-dormancy varieties than in weak-dormancy varieties. Sequence and association analysis indicated that T/C mutations at -907 bp and -1133 bp in the TaMYB83-7B promoter were significantly associated with wheat SD, with C at both sites related to strong dormancy. Dual-luciferase reporter assays demonstrated that the transcriptional activity of the TaMYB83-7B promoter was significantly higher in strong-dormancy varieties than in weak-dormancy varieties. Further analyses indicated that TaMYB83-7B functions as a transcriptional inhibitor. Germination experiments revealed that overexpression of TaMYB83-7B significantly enhanced SD, while its loss-of-function reduced SD. Finally, TaMYB83-7B was found to regulate SD by influencing the balance between abscisic acid (ABA) and gibberellin (GA) in wheat seeds. Overall, the results of this study enhance our understanding of the complex regulatory mechanism underlying SD, and provide gene targets and molecular markers for the genetic improvement of PHS resistance in wheat.

molecular biology↗

Targeting THOC2-Mediated mRNA Export Induces PARP Inhibitor Vulnerability in DNA Repair-Competent Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) remains a lethal malignancy with limited therapeutic options. While Poly (ADP-ribose) polymerase inhibitors (PARPi) exploit synthetic lethality in tumors with DNA repair defects, their clinical utility in HCC is hindered by the low prevalence of canonical repair gene mutations and the enhancing DNA repair capacity. Through proteomic analysis of two independent cohorts (n=260), we identified the THO complex component THOC2 as a master regulator of DNA damage response (DDR) via mRNA nuclear export control. Clinically, THOC2 overexpression predicted poor survival (HR=2.68-6.84, P<0.001) and correlated with enhanced DDR gene expression. Mechanistically, THOC2 chaperones mRNA nuclear export of DDR effectors (MDC1, PRKDC, MSH6) and proliferation drivers (TOP2A), thereby establishing a dual pro-repair/pro-growth program. Targeting this vulnerability, THOC2 knockdown induced synthetic lethality with PARPi, reducing Olaparib IC50 by up to 61% and suppressing tumor growth by 76% (P<0.001). Our study illuminates mRNA transport as a druggable DDR modulator and establishes THOC2 as both a prognostic biomarker and a therapeutic target to overcome PARPi resistance in HCC. This work pioneers a strategy to expand synthetic lethality beyond genetic defects by targeting post-transcriptional regulation.

cancer biology↗