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Purpose: To report a case of extensive syphilitic punctate inner retinitis (SPIR) triggering bilateral macular ischemia after intravitreal triamcinolone injections, and the multimodal retinal imaging findings.Case summary: A 69-year-old male patient with nonproliferative diabetic retinopathy was transferred to our hospital because of bilateral visual deterioration (to counting fingers) after the first intravitreal triamcinolone injection. Fundus examination revealed numerous yellow punctate precipitates in the superficial retinae, retinal arteriolitis, and vitritis. The punctate lesions and surrounding retinal regions showed decreased vascular density on optical coherence tomography angiography, and focal hypofluorescence on fluorescein angiography. The patient was positive for all of the Venereal Disease Research Laboratory test, the fluorescent treponemal antibody-absorption test, and Treponema pallidum hemagglutination; we diagnosed bilateral SPIR. After treatment with aqueous crystalline penicillin solutions (24 million units per day for 14 days), the punctate lesions reduced but arteriolitis progressed to obliterative vasculitis. After 6 months, the bilateral SPIR and vitritis resolved, and the bilateral visual acuity improved to 20/100. However, inner retinal and macular ischemia persisted because of capillary nonperfusion attributable to obliterative vasculitis.Conclusions: Extensive SPIR can develop after an initial intravitreal steroid injection; the inner retinal ischemia and visual loss may persist after treatment because obliterative vasculitis develops. Therefore, patients scheduled for intravitreal steroid injections should be screened for syphilis infection.

Intestinal organoids are emerging tools in intestinal disease modeling and regeneration. Matrigel, a basement membrane matrix extracted from mouse sarcoma, is the gold standard material for intestinal organoid culture. Yet, the tumor origin of this matrix does not effectively provide organoids with native intestine-like microenvironments. To overcome this limitation, we demonstrate a decellularized small intestine-derived hydrogel reinforced with three extracellular matrix (ECM) proteins that are essential for intestinal development. To identify optimal conditions for intestinal organoid culture, we optimized the concentrations of the ECM hydrogel derived from decellularized intestine and three ECM proteins. The intestinal organoids grown in the established ECM hydrogels have shown similarity to those grown in Matrigel in terms of organoid forming efficiency, size, and gene expression patterns of intestine-specific markers. Our intestine-mimetic hydrogel could increase the feasibility of intestinal organoids for more clinically relevant applications in disease modeling and regenerative medicine.

Butyrate-producing bacteria play a key role in human health, and recent studies have triggered interest in their development as next-generation probiotics. However, there remains limited knowledge not only on the identification of high-butyrate-producing bacteria in the human gut but also in the metabolic capacities for prebiotic carbohydrates and their interaction with the host. Herein, we discovered that Roseburia intestinalis produces higher levels of butyrate and digests a wider variety of prebiotic polysaccharide structures compared with other human major butyrate-producing bacteria. Moreover, R. intestinalis extracts upregulated the mRNA expression of tight junction proteins (i.e., TJP1, OCLN, and CLDN3) in human intestinal epithelial cells. We cultured R. intestinalis with human intestinal epithelial cells in the mimetic intestinal host–microbe interaction coculture system to explore the health-promoting effects using multiomics approaches. Consequently, we discovered that live R. intestinalis enhances purine metabolism and the oxidative pathway, increasing adenosine triphosphate levels in human intestinal epithelial cells, but that heat-killed bacteria had no effect. Therefore, this study proposes that R. intestinalis has potentially high value as a next-generation probiotic to promote host intestinal health.

Direct cardiac reprogramming has emerged as a promising therapeutic approach for cardiac regeneration. Full chemical reprogramming with small molecules to generate cardiomyocytes may be more amenable than genetic reprogramming for clinical applications as it avoids safety concerns associated with genetic manipulations. However, challenges remain regarding low conversion efficiency and incomplete cardiomyocyte maturation. Furthermore, the therapeutic potential of chemically induced cardiomyocytes (CiCMs) has not been investigated. Here, we report that a three-dimensional microenvironment reconstituted with decellularized heart extracellular matrix can enhance chemical reprogramming and cardiac maturation of fibroblasts to cardiomyocytes. The resultant CiCMs exhibit elevated cardiac marker expression, sarcomeric organization, and improved electrophysiological features and drug responses. We investigated the therapeutic potential of CiCMs reprogrammed in three-dimensional heart extracellular matrix in a rat model of myocardial infarction. Our platform can facilitate the use of CiCMs for regenerative medicine, disease modeling, and drug screening.

Immunomodulation in the local tissue microenvironment is pivotal for the determination of macrophage phenotypes and regulation of functions necessary for pro-healing effects. Herein, we demonstrate that a lymph node extracellular matrix (LNEM) prepared by the decellularization of lymph node tissues can mimic lymph node microenvironments for immunomodulation in two-dimensional (2D) and three-dimensional (3D) formats. The LNEM exhibits strengthened immunomodulatory effects in comparison to conventional collagen-based platforms. A 3D LNEM hydrogel is more effective than the 2D LNEM coating in inducing M2 macrophage polarization. The 3D LNEM induces macrophage elongation and enhances the M2-type marker expression and the secretion of anti-inflammatory cytokines. Additionally, the phagocytic function of macrophages is improved upon exposure to the intricate 3D LNEM environment. We demonstrate the reduced susceptibility of liver organoids to a hepatotoxic drug when co-cultured with macrophages in a 3D LNEM. This effect could be attributed to the enhanced anti-inflammatory functions and indicates its potential as a drug-testing platform that enables drug responses similar to those observed in vivo. Finally, the implantation of an LNEM hydrogel in a mouse volumetric muscle loss model facilitates the recruitment of host macrophages to the site of injury and enhances macrophage polarization toward the M2 phenotype for tissue healing in vivo. Therefore, 3D immune system-mimicking biomaterials could serve as useful platforms for tissue modeling and regenerative medicine development.

Clostridium difficile is a spore-forming obligate anaerobe that most commonly causes nosocomial disease, such as diarrhea and colitis. Although antibiotic treatment has been used for Clostridium difficile infection (CDI), its use can also lethally cause antibiotic-associated CDI with the risk of antibiotic resistance. Recently, to avoid these problems, probiotics therapies for CDI have been introduced and studied. However, the molecular mechanisms of C. difficile induced by probiotics, such as Lactobacillus rhamnosus GG (LGG), and associated pathways, have rarely been studied. Here, we co-cultured C. difficile and LGG, which is a promising candidate for treating CDI, in a transwell platform to profile metabolic and proteomic changes of C. difficile with mass spectrometric methods. In the co-cultured condition with LGG, energy generation pathways related to C. difficile growth, such as Stickland reactions and butyrate metabolism, were significantly inhibited, resulting in the decrease of growth rate. In particular, the inhibition of Stickland reactions had a negative effect on the toxin production of C. difficile. In addition, metabolic changes in purine biosynthesis that is known to play an important role in the life of bacteria were observed. Finally, we briefly discussed proteins involved in major iron uptake and electron transfer, as well as the chaperone proteins in bacteria that showed changes by LGG. These results demonstrate that metabolic alterations in C. difficile by LGG caused growth inhibition. Our in vitro co-culture model and multi-omics approach will not only provide better understanding of pathogen-probiotics interaction, but will also contribute to functional study, such as probiotics screening or probiotics engineering, for the therapy of disease caused by pathogenic bacteria.

Short chain fatty acids (SCFAs) are end products of fermentation by anaerobic gut microbiota. They can be used as beneficial metabolites to regulate the host’s physiological processes. Despite their importance, SCFAs are difficult to analyze with mass spectrometric technologies due to their poor ionization efficiency and susceptibility to water loss during ionization of low molecular weight organic acids. Here, we developed a sensitive and reliable method to quantify SCFAs by liquid chromatography tandem mass spectrometry (LC–MS/MS) in multiple reaction monitoring (MRM) mode. SCFAs were chemically derivatized by Girard’s reagent T (GT), providing a permanent cationic charge. This technique demonstrated an excellent quantitative capacity, showing good linearity (R2 > 0.99) and limit of quantification (femtomole levels) for five SCFAs (i.e., acetate, propionate, butyrate, valerate, and caproate). Next, we applied this derivatization method to quantitate SCFAs from a small volume of total extracellular metabolites produced by Eubacterium rectale (E. rectale), one of main butyrate-producing gut bacteria. GT-labeled SCFAs were quantitated well in small volumes of culture medium (5, 10, 15, and 20 μL), with the amount of SCFA measured being proportional to the volume of culture medium, as expected. We also investigated plant-derived polysaccharides as prebiotics that could enhance the production of butyrate by E. rectale. Finally, the production of butyrate was successfully monitored in a co-culture system for E. rectale and Bifidobacterium longum (B. longum) by analyzing GT-labeled butyrate. Taken together, our results suggest that this highly sensitive method would be useful for quantifying SCFAs extracted from stool in an aqueous solution to monitor gut health.

The halophilic bacterium Pseudoalteromonas phenolica is well known as a promising candidate that enables the recycling of organic wastes at high salinity. However, for industrial applications of P. phenolica further research is required to explore the biological mechanism for maximizing the activities and productivities of this bacterium. In this study, we investigated the osmotic stress resistance and specific protease activities of P. phenolica in a normal-salt medium (0.3 M NaCl) and high-salt medium (1 M NaCl) based on intra- and extracellular multi-omics approaches. Proteins related to betaine and proline biosynthesis were increased under high salt stress. The targeted metabolite analysis found that proline was overproduced and accumulated outside the cell at high salinity, and betaine was accumulated in the cell by activation of biosynthesis as well as uptake. In addition, extracellular serine proteases were shown to be upregulated in response to salt stress by the extracellular proteomic analysis. The specific proteolytic activity assay indicated that the activities of serine proteases, useful enzymes for the recycling of organic wastes, were increased remarkably under high salt stress. Our results suggest that betaine and proline are key osmoprotectant metabolites of P. phenolica, and they can be used for the improvement of protease production and P. phenolica activities for the recycling of high-salt organic wastes in the future.

As demands for new antibiotics and strategies to control methicillin-resistant Staphylococcus aureus (MRSA) increase, there have been efforts to obtain more accurate and abundant information about the mechanism of the bacterial responses to antibiotics. However, most of the previous studies have investigated responses to antibiotics without considering the genetic differences between MRSA and methicillin-susceptible S. aureus (MSSA). Here, we initially applied a multi-omics approach into the clinical isolates (i.e., S. aureus WKZ-1 (MSSA) and S. aureus WKZ-2 (MRSA)) that are isogenic except for the mobile genetic element called staphylococcal cassette chromosome mec (SCCmec) type IV to explore the response to β-lactam antibiotics (oxacillin). First, the isogenic pair showed a similar metabolism without oxacillin treatment. The quantitative proteomics demonstrated that proteins involved in peptidoglycan biosynthesis (MurZ, PBP2, SgtB, PrsA), two-component systems (VrsSR, WalR, SaeSR, AgrA), oxidative stress (MsrA1, MsrB), and stringent response (RelQ) were differentially regulated after the oxacillin treatment of the isogenic isolates. In addition, targeted metabolic profiling showed that metabolites belonging to the building blocks (lysine, glutamine, acetyl-CoA, UTP) of peptidoglycan biosynthesis machinery were specifically decreased in the oxacillin-treated MRSA. These results indicate that the difference in metabolism of this isogenic pair with oxacillin treatment could be caused only by SCCmec type IV. Understanding and investigating the antibiotic response at the molecular level can, therefore, provide insight into drug resistance mechanisms and new opportunities for antibiotics development.

A complete enumeration study was conducted to evaluate trends related to reperfusion therapies (intravenous thrombolysis (IVT) and endovascular treatment (EVT)) in acute ischemic stroke (AIS) in South Korea, according to sex, economic status, and age, over a 10-year period retrospectively, using the National Health Information Database (NHIS-2020-1-481). This study included AIS patients aged ≥20 years who were hospitalized in a general hospital or tertiary hospital for ≥4 days and underwent brain imaging during the same period. Study participants were classified by sex, economic status (Medical Aid beneficiaries and National Health Insurance beneficiaries) and age (20–44, 45–64, 65–79, and ≥80 years). Women showed a significantly lower OR (Odds ratio) than men in IVT (OR: 0.75; 95% CI: 0.73–0.77), EVT (OR: 0.96; 95% CI: 0.93–0.99), and any therapy (OR: 0.82; 95% CI: 0.80–0.84). The Medical Aid beneficiaries showed significantly lower OR in IVT (OR 0.91, 95% CI 0.88–0.95), EVT (OR 0.93, 95% CI 0.89–0.98), and either therapy (OR 0.92, 95% CI 0.90–0.95) than the National Health Insurance beneficiaries. This study showed sex and economic disparity related to reperfusion therapies in patients with AIS in Korea.

Brain organoids derived from human pluripotent stem cells provide a highly valuable in vitro model to recapitulate human brain development and neurological diseases. However, the current systems for brain organoid culture require further improvement for the reliable production of high-quality organoids. Here, we demonstrate two engineering elements to improve human brain organoid culture, (1) a human brain extracellular matrix to provide brain-specific cues and (2) a microfluidic device with periodic flow to improve the survival and reduce the variability of organoids. A three-dimensional culture modified with brain extracellular matrix significantly enhanced neurogenesis in developing brain organoids from human induced pluripotent stem cells. Cortical layer development, volumetric augmentation, and electrophysiological function of human brain organoids were further improved in a reproducible manner by dynamic culture in microfluidic chamber devices. Our engineering concept of reconstituting brain-mimetic microenvironments facilitates the development of a reliable culture platform for brain organoids, enabling effective modeling and drug development for human brain diseases., Brain organoids derived from human pluripotent stem cells can model human brain development and disease, though current culture systems fail to ensure reliable production of high-quality organoids. Here the authors combine human brain extracellular matrix and culture in a microfluidic device to promote structural and functional maturation of human brain organoids.

Gut microbiota, a complex microbial community inhabiting human or animal intestines recently regarded as an endocrine organ, has a significant impact on human health. Probiotics can modulate gut microbiota and the gut environment by releasing a range of bioactive compounds. Escherichia coli (E. coli) strain Nissle 1917 (EcN), a Gram-negative bacterial strain, has been used to treat gastrointestinal (GI) disorders (i.e., inflammatory bowel disease, diarrhea, ulcerative colitis, and so on). However, endotoxicity of lipopolysaccharide (LPS), a major component of the cell wall of Gram-negative bacteria in the gut, is known to have a strong influence on gut inflammation and maintenance of gut homeostasis. Therefore, characterizing the chemical structure of lipid A which determines the toxicity of LPS is needed to understand nonpathogenic colonization and commensalism properties of EcN in the gut more precisely. In the present study, MALDI multiple-stage mass spectrometry analysis of lipid A extracted from EcN demonstrates that hexaacylated lipid A (m/z 1919.19) contains a glucosamine disaccharide backbone, a myristate, a laurate, four 3-hydroxylmyristates, two phosphates, and phosphoethanolamine (PEA). PEA modification of lipid A is known to contribute to cationic antimicrobial peptide (CAMP) resistance of Gram-negative bacteria. To confirm the role of PEA in CAMP resistance of EcN, minimum inhibitory concentrations (MICs) of polymyxin B and colistin were determined using a wild-type strain and a mutant strain with deletion of eptA gene encoding PEA transferase. Our results confirmed that MICs of polymyxin B and colistin for the wild-type were twice as high as those for the mutant. These results indicate that EcN can more efficiently colonize the intestine through PEA-mediated tolerance despite the presence of CAMPs in human gut such as human defensins. Thus, EcN can be used to help treat and prevent many GI disorders.

Matrigel, a mouse tumor extracellular matrix protein mixture, is an indispensable component of most organoid tissue culture. However, it has limited the utility of organoids for drug development and regenerative medicine due to its tumor-derived origin, batch-to-batch variation, high cost, and safety issues. Here, we demonstrate that gastrointestinal tissue-derived extracellular matrix hydrogels are suitable substitutes for Matrigel in gastrointestinal organoid culture. We found that the development and function of gastric or intestinal organoids grown in tissue extracellular matrix hydrogels are comparable or often superior to those in Matrigel. In addition, gastrointestinal extracellular matrix hydrogels enabled long-term subculture and transplantation of organoids by providing gastrointestinal tissue-mimetic microenvironments. Tissue-specific and age-related extracellular matrix profiles that affect organoid development were also elucidated through proteomic analysis. Together, our results suggest that extracellular matrix hydrogels derived from decellularized gastrointestinal tissues are effective alternatives to the current gold standard, Matrigel, and produce organoids suitable for gastrointestinal disease modeling, drug development, and tissue regeneration.

The commensal gut bacterium Akkermansia muciniphila is well known as a promising probiotic candidate that improves host health and prevents diseases. However, the biological interaction of A. muciniphila with human gut epithelial cells has rarely been explored for use in biotherapeutics. Here, we developed an in vitro device that simulates the gut epithelium to elucidate the biological effects of living A. muciniphila via multiomics analysis: the Mimetic Intestinal Host-Microbe Interaction Coculture System (MIMICS). We demonstrated that both human intestinal epithelial cells (Caco-2) and the anaerobic bacterium A. muciniphila can remain viable for 12 h after coculture in the MIMICS. The transcriptomic and proteomic changes (cell-cell junctions, immune responses, and mucin secretion) in gut epithelial cells treated with A. muciniphila closely correspond with those reported in previous in vivo studies. In addition, our proteomic and metabolomic results revealed that A. muciniphila activates glucose and lipid metabolism in gut epithelial cells, leading to an increase in ATP production. This study suggests that A. muciniphila improves metabolism for ATP production in gut epithelial cells and that the MIMICS may be an effective general tool for evaluating the effects of anaerobic bacteria on gut epithelial cells.

As demands for new antibiotics and strategies to control methicillin-resistant

The cellular components of Akkermansia muciniphila are considered potential biotherapeutics for the improvement of obesity, diabetes, and metabolic diseases. However, the molecular-based mechanism of A. muciniphila for treatment of obesity, which can provide important evidence for human research, has rarely been explored. Here, we applied integrative multiomics approaches to investigate the underlying molecular mechanism involved in obesity treatment by A. muciniphila. First, the treatment with a cell lysate of A. muciniphila reduced lipid accumulation in 3T3-L1 cells and downregulated the mRNA expression of proteins involved in adipogenesis and lipogenesis. Our proteomic results revealed that A. muciniphila decreased the expression of proteins involved in fat cell differentiation, fatty acid metabolism, and energy metabolism in adipocytes. Moreover, A. muciniphila significantly reduced the level of metabolites related to glycolysis, the TCA cycle, and ATP in adipocytes. Interestingly, serine protease inhibitor A3 (SERPINA3) homologs were overexpressed in the 3T3-L1 cells treated with A. muciniphila. Small interfering RNA (siRNA) transfection demonstrated that A. muciniphila upregulates SERPINA3G expression and inhibits lipogenesis in adipocytes. Taken together, our multiomics-based approaches enabled to uncover the molecular mechanism of A. muciniphila for treatment of obesity and provide potent anti-lipogenic agents.

Gut microbiota, a complex microbial community inhabiting human or animal intestines recently regarded as an endocrine organ, has a significant impact on human health. Probiotics can modulate gut microbiota and the gut environment by releasing a range of bioactive compounds.

In this paper, we have investigated the characteristics of the differential-mode high electron mobility transistor (HEMT)-based biosensor. An Au-gate HEMT is the sensing device that reacts with biomolecules, whereas the Pt-gate HEMT is the dummy device used in the differential-mode detection circuit. Both the biosensing HEMT (Bio-HEMT) and reference HEMT (Ref-HEMT) were biased by a Pt quasi-reference electrode (QRE). The Pt QRE was used to replace the bulky conventional reference electrode. The binding of 11-mercaptoundecanoic acid, CRP-antibody, and CRP caused a variation in Bio-HEMT gate surface potential, which was confirmed by X-ray photoelectron spectroscopy. Moreover, we measured the variation of output voltage with light intensity and temperature, which was eliminated as a common-mode signal by the differential-mode measurement technique. Therefore, this technique can improve the detection limit in low CRP concentration. The output voltage of the sensor system is nonlinearly proportional to the CRP concentration from 0.01 ng/mL to 1000 ng/mL. These results indicated that the Bio-HEMT/Ref-HEMT/QRE could be applied to a portable biomolecule detection system.

A new pixel structure is proposed for wide dynamic range CMOS image sensors. A pixel based on a three-transistor active pixel sensor has two linear responses and a logarithmic response using additional circuits. The photogate surrounding the n+/p-sub photodiode exists for the second linear response. The logarithmic response is due to the biased MOS cascode. The proposed pixel was designed and fabricated using a 0.35- $\mu \text{m}$ 2-poly 4-metal standard CMOS process. The dynamic range of the pixel is higher than 106 dB. A test chip with a pixel pitch of $10 \times 10~\mu \text{m}^{2}$ and a $160 \times 120$ pixel array is evaluated.

We report a 3-D-stackable 1S1R passive cross-point resistive random access memory (RRAM). The sneak (leakage) current challenge in the cross-point RRAM integration has been overcome utilizing a field-assisted superlinear threshold selector. The selector offers high selectivity of $>10^{7}$ , sharp switching slope of $ mV/decade, ability to tune the threshold voltage, stable operation at 125 °C, and endurance of $>10^{11}$ . Furthermore, we demonstrate 1S1R integration in which the selector-subthreshold current is $ pA while offering $>10^{2}$ memory ON/OFF ratio and $>10^{6}$ selectivity during cycling. Combined with self-current-controlled RRAM, the 1S1R enables high-density and high-performance memory applications.

A new SPICE-compatible model for a gate/body-tied PMOSFET photodetector (GBT PD) with an overlapping control gate is pre-sented. The proposed SPICE-compatible model of a GBT PD with an overlapping control gate makes it possible to control the photo-current. Research into GBT PD modeling was proposed previously. However, the analysis and simulation of GBT PDs is not lacking.This SPICE model concurs with the measurement results, and it is simpler than previous models. The general GBT PD model is a hy briddevice composed of a MOSFET, a lateral bipolar junction transistor (BJT), and a vertical BJT. Conventional SPICE models are basedon complete depletion approximation, which is more applicable to reverse-biased p-n junctions; therefore, they are not appropriate forsimulating circuits that are implemented with a GBT PD with an overlapping control gate. The GBT PD with an overlapping controlgate can control the sensitivity of the photodetector. The proposed sensor is fabricated using a 0.35µm two-poly, four-metal standardcomplementary MOS (CMOS) process, and its characteristics are evaluated.Keywords: High-sensitivity, Gate/body-tied photodetector, SPICE model

This paper presents a wide dynamic range complementary metal oxide semiconductor (CMOS) image sensor with column capacitorand feedback structure. The designed circuit has been fabricated by using 0.18im 1-poly 6-metal standard CMOS technology. This sen-sor has dual mode operation using combination of active pixel sensor (APS) and passive pixel sensor (PPS) structure. The proposedpixel operates in the APS mode for high-sensitivity in normal light intensity, while it operates in the PPS mode for low-sensitivity inhigh light intensity. The proposed PPS structure is consisted of a conventional PPS with column capacitor and feedback structure. Thecapacitance of column capacitor is changed by controlling the reference voltage using feedback structure. By using the proposed struc-ture, it is possible to store more electric charge, which results in a wider dynamic range. The simulation and measurement results dem-onstrate wide dynamic range feature of the proposed PPS.Keywords: CMOS image sensor, Column capacitor, Feedback structure, Dual mode