Lucas Zellmer

Mr. Lucas Zellmer


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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16 January 2018 in Genes
Verified
Journal Article
Open access
PDF file
YHYan He
Yan He
CYChengfu Yuan
Chengfu Yuan
LCLichan Chen
Lichan Chen
MLMingjuan Lei
Mingjuan Lei
LZLucas Zellmer
Lucas Zellmer
DLDezhong Liao
Dezhong Liao
Tens of thousands of chimeric RNAs, i.e., RNAs with sequences of two genes, have been identified in human cells. Most of them are formed by two neighboring genes on the same chromosome and are considered to be derived via transcriptional readthrough, but a true readthrough event still awaits more evidence and trans-splicing that joins two transcripts together remains as a possible mechanism. We regard those genomic loci that are transcriptionally read through as unannotated genes, because their transcriptional and posttranscriptional regulations are the same as those of already-annotated genes, including fusion genes formed due to genetic alterations. Therefore, readthrough RNAs and fusion-gene-derived RNAs are not chimeras. Only those two-gene RNAs formed at the RNA level, likely via trans-splicing, without corresponding genes as genomic parents, should be regarded as authentic chimeric RNAs. However, since in human cells, procedural and mechanistic details of trans-splicing have never been disclosed, we doubt the existence of trans-splicing. Therefore, there are probably no authentic chimeras in humans, after readthrough and fusion-gene derived RNAs are all put back into the group of ordinary RNAs. Therefore, it should be further determined whether in human cells all two-neighboring-gene RNAs are derived from transcriptional readthrough and whether trans-splicing truly exists.

29 April 2021 in Experimental Biology and Medicine
Verified
Journal Article
Closed access
PDF file
YCYu-Ting Cheng
Yu-Ting Cheng
JLJian Liao
Jian Liao
QZQian Zhou
Qian Zhou
HHHua Huo
Hua Huo
LZLucas Zellmer
Lucas Zellmer
DLDezhong Joshua Liao
Dezhong Joshua Liao
Bone mass loss (osteoporosis) seen in postmenopausal women is an adverse factor for implant denture. Using an ovariectomized rat model, we studied the mechanism of estrogen-deficiency-caused bone loss and the therapeutic effect of Zoledronic acid. We observed that ovariectomized-caused resorption of bone tissue in the mandible was evident at four weeks and had not fully recovered by 12 weeks post-ovariectomized compared with the sham-operated controls. Further evaluation with a TUNEL assay showed ovariectomized enhanced apoptosis of osteoblasts but inhibited apoptosis of osteoclasts in the mandible. Zoledronic acid given subcutaneously as a single low dose was shown to counteract both of these ovariectomized effects. Immunohistochemical staining showed that ovariectomized induced the protein levels of RANKL and the 65-kD subunit of the NF-κB complex mainly in osteoclasts, as confirmed by staining for TRAP, a marker for osteoclasts, whereas zoledronic acid inhibited these inductions. Western blotting showed that the levels of RANKL, p65, as well as the phosphorylated form of p65, and IκB-α were all higher in the ovariectomized group than in the sham and ovariectomized + zoledronic acid groups at both the 4th- and 12th-week time points in the mandible. These data collectively suggest that ovariectomized causes bone mass loss by enhancing apoptosis of osteoblasts and inhibiting apoptosis of osteoclasts. In osteoclasts, these cellular effects may be achieved by activating RANKL-NF-κB signalling. Moreover, zoledronic acid elicits its therapeutic effects in the mandible by counteracting these cellular and molecular consequences of ovariectomized.

30 July 2021 in Journal of General Internal Medicine
Verified
Journal Article
Open access
PDF file
LZLucas Zellmer
Lucas Zellmer
BJBryan Johnson
Bryan Johnson
AIAhmed Idris
Ahmed Idris
CMChristopher J. Mehus
Christopher J. Mehus
IBIris W. Borowsky
Iris W. Borowsky
Background Social determinants of health play a fundamental role in a patient’s health status. In recent years, health systems across the nation have implemented numerous strategies aimed at identifying and addressing the health-related social needs of the patients they serve. Despite the influx of peer-reviewed research highlighting outcomes of specific health-related social needs interventions, the spectrum of practices utilized by primary care clinics has not been established. Objective To determine the range of ways primary care clinics address health-related social needs after identification and initial contact with a frontline staff person is completed. Design We conducted 12 semi-structured, in-person interviews with staff from purposively sampled clinics. If the interview included more than one staff person, all participants were interviewed together. Participants Twenty-one administrative staff and frontline clinic personnel with experience in 24 separate primary care clinics in the Minneapolis-St. Paul, Minnesota metropolitan area. Approach Interviews focused on the range of health-related social needs processes utilized by clinics, including staff titles, referral procedures, and barriers to addressing needs. Interview recordings were transcribed and coded using thematic analysis. Key Results Thematic analysis identified variation in four key areas involving how clinics address patients’ health-related social needs after identification and initial contact by frontline staff: clinic personnel involved in addressing needs, clinic referral processes, “resource” and “success” definitions, and barriers to accessing community-based supports. Conclusions This study describes the large variation in primary care clinic practices to address health-related social needs after they are identified. The results suggest challenges to standardization and real-world application of previously published studies. Our findings also highlight the opportunity for improved relationships between health systems and community-based agencies.

5 March 2020 in bioRxiv
Verified
Preprint
Open access
PDF file
YHYan He
Yan He
JZJu Zhang
Ju Zhang
JQJiayuan Qu
Jiayuan Qu
LZLucas Zellmer
Lucas Zellmer
YZYan Zhao
Yan Zhao
DLDezhong Liao
Dezhong Liao
Most human genes can produce multiple protein isoforms that should appear at multiple positions of polyacrylamide gel electrophoresis (PAGE) with sodium dodecyl sulfate (SDS), but most published results of Western blotting show only one protein. We performed SDS-PAGE of proteins from several human cell lines, isolated the proteins at the 72-, 55-, 48-, 40-, and 26-kD positions, and used liquid chromatography and tandem mass spectrometry (LC-MS/MS) to determine the protein identities. Although ACTB and GAPDH are 41.7-kD and 36-kD proteins, respectively, LC-MS/MS identified peptides of ACTB and GAPDH at all of these SDS-PAGE positions, making us wonder whether they produce some unknown protein isoforms. The NCBI (National Center for Biotechnology Information, USA) database lists only one ACTB mRNA but five GAPDH mRNAs and one non-coding RNA. The five GAPDH mRNAs encode three protein isoforms, while our bioinformatic analysis identified a 17.6-kD isoform encoded by the non-coding RNA. All LC-MS/MS-identified GAPDH peptides at all positions studied are unique, but some of the identified ACTB peptides are shared by ACTC1, ACTBL2, POTEF, POTEE, POTEI, and POTEJ. ACTC1 and ACTBL2 belong to the ACT family with great similarities to ACTB in protein sequence, whereas the four POTEs are ACTB-containing chimeric genes with the C-terminus of their proteins highly similar to ACTB. These data collectively disqualify GAPDH and ACTB from serving as the reference genes for determination of the protein level in such techniques as Western blotting, a leading role these two genes have been playing for decades in the biomedical research.